Waste Management of New York (Towpath) - Decision, February 10, 2003
Decision, February 10, 2003
STATE OF NEW YORK
DEPARTMENT OF ENVIRONMENTAL CONSERVATION
Albany, New York 12233-1010
In the Matter
- of -
the Application of WASTE MANAGEMENT OF NEW YORK, LLC
for permits to construct and operate a solid waste management facility,
the Towpath Environmental and Recycling Center, in the Town of
Albion, Orleans County
DEC No. 8-3420-00019/00005
DECISION OF THE COMMISSIONER
SEQRA FINDINGS STATEMENT
February 10, 2003
DECISION OF THE COMMISSIONER
SEQRA FINDINGS STATEMENT
The attached Hearing Report by Administrative Law Judge ("ALJ") Edward Buhrmaster in the Matter of the Application of Waste Management of New York, LLC for permits to construct and operate a solid waste management facility, the Towpath Environmental and Recycling Center, in the Town of Albion, Orleans County, is hereby adopted as my Decision on the issues that were adjudicated in this matter, except as noted below. The Hearing Report, along with the other documents referenced at the end of the report, are also accepted as the Final Environmental Impact Statement ("FEIS") for this action, in which the Department is the lead agency pursuant to ECL Article 8, the State Environmental Quality Review Act ("SEQRA").
Issues certified for adjudication in this matter concerned hydrogeology and noise. As indicated in the ALJ's report, the noise issue was resolved by agreement of the parties in the form of a written stipulation. The hydrogeology issues concerned the hydrogeologic investigation conducted as part of the application, the reliability of the conclusions in the Applicant's hydrogeologic report, the effectiveness of the environmental monitoring plan, and the ability to monitor and remediate any escape of leachate from the Towpath site. I adopt the conclusions of the ALJ's report with regard to these issues, except as noted below.
The FEIS, which includes the record of this hearing, affords an adequate basis for rendering the SEQRA findings statement pursuant to 6 NYCRR § 617.11. Accordingly, I certify that:
- The requirements of 6 NYCRR Part 617 have been met;
- Consistent with social, economic and other essential considerations from among the reasonable alternatives available, the action hereby approved is one that avoids or minimizes adverse environmental impacts to the maximum extent practicable, including the effects disclosed in the FEIS; and
- Consistent with social, economic and other essential considerations, to the maximum extent practicable, adverse environmental effects revealed in the environmental impact statement process will be avoided or minimized by incorporating as conditions to this approval those mitigative measures identified in the draft permit prepared by DEC Staff, as amended by the conditions recommended by ALJ Buhrmaster with respect to the hydrogeology issues and the conditions agreed to by all parties to the adjudicatory hearing with regard to resolution of the noise issue.
Since the requirements of SEQRA have been satisfied and the proposed project has been shown to comply with all applicable laws and regulations, Department Staff is hereby directed to issue the requisite permits to construct and operate the Towpath facility consistent with this Decision and all other associated documents constituting the FEIS, as soon as feasible after the completion of the SEQRA notice procedures required by 6 NYCRR Part 617.
Insofar as the permit conditions relating to environmental monitors are concerned, DEC staff in its initial closing brief proposed some revisions to special condition No. 12. The ALJ concurred with these "minor, non-substantive revisions". See Hearing Report at 61, 62. Upon my review, I propose additional non-substantive revisions and direct DEC staff to revise special condition No. 12 in a manner consistent with the following instructions. Special condition No. 12 should be revised to provide that the Applicant procure a suitable entity (e.g., an environmental consulting firm, or environmental engineering firm) (hereinafter "third party firm") to arrange for or perform the environmental monitoring services.
The selection of the third party firm shall be approved by DEC staff, and the environmental monitoring services arrangement between the Applicant and the third party firm, which should also be approved by DEC staff, must ensure that DEC staff retain appropriate oversight of the monitoring services provided by the third party firm. All reports on environmental compliance activities should be submitted through the third party firm to DEC staff as required, and DEC staff should retain the right to seek information pertaining to environmental compliance activities from the third party firm as needed.
Additionally, as for the location of the environmental monitors, the portion of the language in special condition No. 12(a) placing environmental monitoring services at the Towpath Landfill is acceptable. However, the determination of a suitable location for the remaining environmental monitoring services described in that condition (e.g. work on other Applicant owned/operated solid waste management facilities in the Region) should be left to the discretion of the Applicant and the third party firm, subject to DEC staff approval.
Finally, it bears mention that revising this portion of the permit to allow for the Applicant to secure a third party firm to arrange for or perform the environmental monitoring services may nullify other portions of special condition No. 12. Accordingly, DEC staff should ensure the monitor language in this condition, or elsewhere in the permit, is revised in a manner consistent with this decision.
To provide other agencies and the public with an opportunity to consider the FEIS, this Decision will be effective ten (10) days from the date of publication of the notice of completion of the FEIS, consistent with 6 NYCRR 617.11(a).
For the New York State Department of
By: Erin M. Crotty, Commissioner
Albany, New York
February 10, 2003
STATE OF NEW YORK
DEPARTMENT OF ENVIRONMENTAL CONSERVATION
Albany, New York 12233-1550
In the Matter
- of -
the Application of WASTE MANAGEMENT OF NEW YORK, LLC
for permits to construct and operate a solid waste management facility,
the Towpath Environmental and Recycling Center, in the Town of
Albion, Orleans County
DEC No. 8-3420-00019/00005
HEARING REPORT AND
FINAL ENVIRONMENTAL IMPACT STATEMENT
- by -
Administrative Law Judge
WASTE MANAGEMENT OF NEW YORK, LLC
Table of Contents
Background and Brief Project Description
Legislative Public Hearing
Rulings on Issues and Party Status
Commissioner's Interim Decision
Resolution of Noise Issue
The Adjudicatory Hearing
The Responsiveness Summary
POSITIONS OF THE PARTIES
Position of WMNY and Department Staff
Position of the Towns of Albion and Murray
FINDINGS OF FACT
Orleans Sanitary Landfill
Towpath Liner Design
Leakage Prevention and Monitoring
Part 360 Consistency
Relevant Permit Conditions
Site Investigation Plan
Scope of Investigation
"Top of Rock" and "Deep Rock" Water-Bearing Zones
Contaminant Transport Processes
Groundwater Flow Modeling
Operational Monitoring Program
Establishing Existing Water Quality
Sub-zone Analysis of Water Quality
Intra-well Analysis of Water Quality
Monitoring Well Network
Fixing Monitoring Well Locations
Consideration of Background Ion Levels
Operational Water Quality Monitoring
Detection of Leachate Impacts
McKenna's Impact on Towpath Monitorability
The Case for Monitorability
Groundwater Flow Directions
Monitoring Well Network
Graphical Methods (Chemical Fingerprinting)
Appropriateness of MODFLOW Model
Siting Restriction (Bedrock Subject to Rapid or Unpredictable Groundwater Flow)
Adequacy of Groundwater Monitoring Network
Proposed Permit Conditions
Towns' Proposed Conditions
WMNY's Proposed Conditions
DEC Staff's Proposed Conditions
FINAL ENVIRONMENTAL IMPACT STATEMENT
APPENDIX "A" - - MAP OF TOWPATH SITE AND ADJACENT AREA
APPENDIX "B" - - SITE PLAN MAP
APPENDIX "C" - - NOISE ISSUE STIPULATION
APPENDIX "D" - - DEC STAFF DRAFT PERMIT
APPENDIX "E" - - LINER SYSTEM PROFILE
APPENDIX "F" - - MAP OF LANDFILL CELLS, WATER QUALITY SUB-ZONES, AND
MONITORING WELL LOCATIONS
APPENDIX "G" - - SUMMARY OF MONITORING WELLS
APPENDIX "H" - - SUMMARY OF MONITORING WELL LOCATIONS
APPENDIX "I" - - DEC STAFF'S PROPOSED PERMIT AMENDMENTS
Background and Brief Project Description
Waste Management of New York, LLC ("WMNY," or "the Applicant") proposes to expand the closed Orleans Sanitary Landfill ("OSL") at 3511 Densmore Road in the Town of Albion, Orleans County, creating a new facility that would be known as the Towpath Environmental & Recycling Center. This facility ("Towpath") would be located south of the New York State Erie Canal, east of Densmore Road, west of Transit Road, and north of the Conrail tracks. [See Appendix "A" of this report, a map of the site and adjacent area, and Appendix "B", a site plan map, both of which are part of the application documents.] Apart from the landfill, the facility would include an administration building, scale house, maintenance building, leachate storage tanks, surface water collection and storm water management facilities, and a recycling center with a drop-off area for source-separated recyclables.
The approximately 204-acre parcel upon which Towpath would be developed includes the 40-acre OSL site, where landfilling occurred between 1983 and 1991. Another landfill, the McKenna Landfill, operated between 1968 and 1983 on an adjacent parcel north of the proposed expansion area. The proposed expansion includes an overfill of about four acres on the eastern slope of the closed OSL and an approximately 73-acre eastward expansion towards Transit Road.
WMNY leases the land for the Towpath facility from the Estate of the Orleans Sanitary Landfill, Inc. and Irene M. Smith. Under terms of its 48-year lease agreement, WMNY is obligated to obtain all required permits to construct and operate the landfill expansion and thereby create a revenue stream, a portion of which would be distributed to creditors of the Estate.
WMNY has also entered into a consent order with the New York State Department of Environmental Conservation ("the Department," or "DEC") for the development of a closure remedial program for the McKenna landfill, which is a Class 2 site on the New York Registry of Inactive Hazardous Disposal Sites. This program includes installation of a low-permeability landfill cap, construction of a perimeter leachate and groundwater collection system, off-site leachate and groundwater treatment, and an improved gas-venting system.
As proposed, the Towpath landfill would have a design capacity of 1,800 tons of solid waste per day. According to an activity schedule timeline provided by WMNY, the project would last about 18 years, 16 of which would involve the placement of waste. At full capacity, the landfill would be about 200 feet above the surrounding ground level and about 90 feet higher than the existing OSL. All construction for the Towpath landfill would include a double-composite bottom liner, collection and treatment of gas and leachate, storm water management, and groundwater, leachate, gas, surface water and sediment monitoring.
To move ahead with this project, WMNY requests a permit to construct and operate a solid waste management facility, issuance of which is controlled by the Department pursuant to Title 7 of Article 27 of the Environmental Conservation Law ("ECL") and Part 360 of Title 6 of the Official Compilation of Codes, Rules and Regulations of the State of New York ("6 NYCRR Part 360"). Also, WMNY requests a dam safety permit under Title 5 of Article 15 of the ECL (for the construction of a sedimentation basin), an air pollution control permit under Article 19 of the ECL (addressing the release of landfill gases), and a water quality certification under Section 401 of the Clean Water Act (related to wetland impacts).
In conjunction with the solid waste management facility permit, WMNY is seeking two variances. One is from the requirement of 6 NYCRR 360-2.7(b)(9)(iv) that two separately functioning subcells be maintained so that a non-functioning subcell can be made inoperable to allow for investigation and remediation while another subcell continues to receive solid waste. WMNY intends to operate the first landfill cell before the second is constructed, and in the event the first cell must become inoperable prior to the second one's availability, WMNY would divert the inbound solid waste stream to alternate authorized transfer and/or disposal facilities.
The second variance sought is from the requirements of 6 NYCRR 360-2.12(a)(1)(v) and (vi) that unconsolidated deposits underlying the proposed landfill either exist or be constructed to be 20 feet or greater in thickness as measured from the base of the constructed liner system. WMNY intends to provide a subgrade that would be no less than 10 feet thick, exhibiting performance at least equivalent to that contemplated by the 20-foot layer prescribed by the regulations. Because of this, WMNY concludes that filling with an additional 10 feet of soil would unduly increase construction costs and raise the liner elevation, thereby eliminating air space and its associated revenue.
As lead agency under the State Environmental Quality Review Act ("SEQRA," ECL Article 8), DEC determined that the proposed Towpath project is a Type I action and issued a Positive Declaration on May 6, 1994. The Applicant prepared a three-volume Draft Environmental Impact Statement ("DEIS"), which DEC Staff accepted for review on March 24, 1999.
Legislative Public Hearing
A legislative hearing to receive comments on the permit application was held during the evening of July 1, 1999, at the Sheret Post #35 of the American Legion, 131 S. Main Street, Albion. More than 200 people attended, and 46 spoke. Oral and written comments made in response to the Department's notices were overwhelmingly negative about the project and its impact on the surrounding community.
Public officials speaking against the project included State Senator George D. Maziarz (61st District), Marcia Tuohey, chairperson of the Orleans County Legislature, Orleans County Legislator George Bower, and Barre Town Board member Shirley A. Walter. Also speaking against the project were the New York State Parks and Conservation Association, which said the landfill would be incompatible with the development of recreation and tourism along the Erie Canal, and the statewide Citizens' Environmental Coalition, which voiced concerns about impacts to public health and safety, as well as the environmental compliance record of WMNY's parent company, Waste Management Inc., which it said warranted permit denial or, at the least, heightened monitoring if the project goes forward.
At the time of the legislative hearing, community opposition to the landfill centered on the following concerns:
- Noise, odor, visual, vector and other environmental impacts along the Erie Canal corridor, which is used for boating, hiking and biking;
- Diminished property values and lost canal-related tourism opportunities;
- Visual impacts affecting local landmarks like the observation tower at the Mount Albion Cemetery;
- The impact of landfill-related traffic on public safety, particularly at the intersection of Routes 31 and 98 and along Route 31 near public schools;
- Monitorability of the Towpath facility given its proximity to OSL and the McKenna landfill;
- The potential for escaped leachate to contaminate groundwater and drinking water wells, and to escape detection in bedrock fractures; and
- Potential waste mass instability, given the possibility of earthquakes along a nearby fault.
Opponents questioned the need for the landfill, some also arguing that landfills are archaic ways to dispose of waste and a disincentive to recycling. Citing OSL and the McKenna facility, local residents said Albion had "had its turn" with landfills, and any new ones should be sited elsewhere. Some commenters questioned whether WMNY could be trusted to obey all relevant environmental laws, given its past compliance history. Others doubted whether DEC has sufficient staff to provide adequate surveillance.
Though expressed public opinion was mostly against the project, there were some letters of support from local residents. Project proponents applauded WMNY's efforts to remediate OSL and the McKenna landfill, one calling the Applicant a good company that had been attentive to neighbors' concerns, and another saying an open, monitored landfill like Towpath would be better than a closed, abandoned one like OSL. Proponents said an expected package of host community benefits could keep property taxes down while providing valuable local services.
On July 20, 1999, I started an issues conference at the Albion Town Hall, the purpose of which was to determine what proposed issues bearing on DEC's permitting decisions would require adjudication, and who, among the petitioners for party status, would participate in an adjudicatory hearing, should one be required. The conference continued on July 21 and 22, and August 17, 18, 19 and 20.
Participating at the conference were WMNY and DEC Staff, as well as the following petitioners for full party status: the Towns of Albion and Murray, the New York State Canal Corporation, citizens' groups Stop Polluting Orleans County ("SPOC") and the Albion Coalition, and Edward R. (Ted) Scharping, a real estate agent. Another individual, Alan J. McKenna Sr., made a late filing for amicus status.
At the start of the conference, Staff said that it had identified no issues of its own for adjudication, adding that a few matters remained under negotiation with WMNY and that additional permit conditions were contemplated. WMNY proposed various changes to Staff's draft permits, and these permits were in fact revised by Staff between the July and August conference dates. Also during this time WMNY negotiated an agreement resolving all of the issues proposed by the Canal Corporation, which pertained to impacts the project might have upon the Erie Canal corridor. When the issues conference resumed on August 17, a copy of that agreement (addressing visual impacts as well as impacts from landfill-derived gas, vectors and litter) was taken into the record, and the Canal Corporation's request for party status was withdrawn.
Because of new information provided by WMNY after the issues conference commenced, coupled with changes to Staff's draft permits, all petitioners for party status were given an opportunity to supplement their filings before the conference resumed in August. When the conference resumed DEC Staff said it had no issues to propose, and WMNY said it had no objection to the revised permit terms. Therefore, as between WMNY and DEC Staff, there was nothing to litigate, and the only issues remaining to consider were those proposed by the prospective intervenors, whose offers of proof were entertained at the conference and in subsequent rounds of written submissions.
Rulings on Issues And Party Status
On December 31, 1999, I identified three issues for adjudication. One concerned whether the Applicant is suitably fit to receive the permits requested from the Department. A second concerned the anticipated noise impact of Towpath operations. A third concerned the hydrogeologic investigation conducted as part of the application, the reliability of the conclusions in WMNY's hydrogeologic report, the effectiveness of the environmental monitoring plan, and the ability to monitor and remediate any escape of leachate from the Towpath site.
I found that all other issues proposed by the prospective intervenors did not require adjudication.
Among those filing petitions, I granted full party status to the Towns of Albion and Murray and to SPOC. Each of them, I found, had raised substantive and significant issues: the Town of Albion with regard to hydrogeology and noise, the Town of Murray with regard to hydrogeology, and SPOC with regard to the fitness of WMNY.
I also found that the remaining petitioners, the Albion Coalition and Mr. Scharping, had not raised any issues for adjudication and had not shown that they could meaningfully contribute to the record on the issues that I said should be pursued. Therefore, their petitions for party status were denied.
Commissioner's Interim Decision
On May 15, 2000, Department Commissioner John P. Cahill issued an interim decision addressing appeals of my rulings. He concurred with my issues rulings except with regard to WMNY's fitness, which he decided did not require further consideration. Because the fitness issue was the only one proposed by SPOC, SPOC's party status was rescinded and the remaining issues of noise and hydrogeology were remanded to me for further proceedings. Scheduling of the adjudicatory hearing was subsequently delayed at WMNY's request due to discussions among the parties concerning WMNY's lease with the bankruptcy trustee and the status that the trustee would have at the hearing. The bankruptcy trustee indicated at one point that he would intervene and participate at the hearing as a co-applicant with WMNY; however, in the end, he agreed to a more limited role in which, by counsel, he would appear only as a "second chair" or assistant to WMNY, being part of the service list but not making submissions of his own. This role was acceptable to me and the designated parties.
Addressing to DEC Staff's satisfaction its concerns about WMNY's lease arrangement, the trustee represented in a letter of October 16, 2000 that although he and WMNY had discussed certain provisions of the lease, the lease had not been terminated. The trustee also assured me and the parties that WMNY "will prosecute, is contractually obligated to prosecute, and will continue to be responsible for prosecuting, with due diligence, the permit application to final adjudication/determination."
Resolution of Noise Issue
In the months leading up to the adjudicatory hearing, WMNY, DEC Staff, and the Towns of Albion and Murray reached an agreement resolving the noise issue, eliminating the need for its adjudication. The agreement was confirmed in the form of a stipulation, which is attached to this hearing report as Appendix "C". The stipulation provides for various amendments to WMNY's Towpath operations and maintenance manual as well as the permits DEC would issue if this project is approved. Because the parties settled the noise issue, I have no remaining role in its consideration, except to ensure that the stipulation becomes part of the hearing record so that the Commissioner, upon review of my report, becomes aware of its terms. [See DEC Organization and Delegation Memorandum 94-13 (May 5, 1994).]
The Adjudicatory Hearing
Adjudication of the hydrogeology issues occurred on April 3, 4, 24, 25, 26 and 27, as well as May 1, 2, 3, 22, 23 and 24, 2001. The hearing was held at the Albion Town Hall except on May 22, when it was held at the Albion Village Hall.
The permit applicant, Waste Management of New York, was represented at the adjudicatory hearing by Kevin M. Bernstein and Robert R. Tyson, Esqs., of Bond, Schoeneck & King, LLP, in Syracuse.
DEC Staff was represented by Paul J. D'Amato, Esq., of the Department's Region 8 office in Avon.
The Town of Albion was represented by Daniel A. Spitzer and Michael Kotin, Esqs., of Hodgson, Russ, Andrews, Woods & Goodyear, LLP, in Buffalo.
The Town of Murray was represented by Mindy L. Zoghlin, Esq., of Bansbach, Zoghlin, Wicks & Wahl, P.C., in Rochester.
The following witnesses testified as each party presented its direct case on the hydrogeology issues:
- For the Applicant, Dr. Jonathan D. Howland, a civil engineer chiefly responsible for the landfill design; Timothy R. Roeper, a hydrogeologist who managed the site hydrogeologic investigation; and Dr. William M. Goodman, a hydrogeologist who assisted in the implementation of the site investigation plan and preparation of the hydrogeologic report.
- For DEC Staff, Edward D. Kieda, a DEC environmental engineer who reviewed the engineering portion of the landfill application for regulatory compliance; and Vincent K. Fay, a DEC engineering geologist who reviewed the Applicant's hydrogeologic report and environmental monitoring plan for regulatory compliance.
- For the Towns of Albion and Murray, Dr. Matthew Becker, an assistant professor of geology at the State University of New York at Buffalo, and Dr. Mark R. Noll, an assistant professor of earth sciences at the State University of New York College at Brockport, both of whom reviewed the application documents on issues of hydrogeology and site monitorability.
Each witness was cross-examined on the basis of pre-filed direct testimony that is part of the hearing exhibits. The Applicant presented its witnesses first, followed by DEC Staff and then the Towns. In addition, the Applicant, which was directed to pre-file its testimony before the other parties, presented a rebuttal case addressing the Towns' arguments. That case involved re-calling Mr. Roeper and Dr. Goodman, and presenting a new witness, Kenneth E. Kasparek, technical director of Severn Trent Laboratories in Buffalo, which analyzes groundwater samples for WMNY.
There were 100 numbered hearing exhibits, and 1796 pages of hearing transcript. DEC Staff's draft permit was received as an attachment to Mr. Kieda's pre-filed testimony, and a copy of that permit is attached as Appendix "D" to this report.
The parties provided lists of proposed transcript corrections, none of which met any objection. I have written these corrections into my copy of the transcript, as well as corrections of my own that were circulated to the parties on August 22, 2001.
Before the start of the adjudicatory hearing, I made written rulings addressing various motions to strike pre-filed testimony. On March 7, 2001, I granted the Towns' motion to strike portions of Dr. Howland's testimony, finding that those portions were not relevant to the issues to be adjudicated. On March 29, 2001, I struck portions of Mr. Kieda's testimony, also upon a motion by the Towns, and again after finding the testimony irrelevant.
During the hearing, in a ruling read into the record on April 4, 2001, I struck an additional portion of Dr. Howland's pre-filed testimony because it was not relevant to the hearing issues. This was done on my own initiative, in the absence of a motion by one of the parties. I also determined that the cross-examination related to that portion of the testimony would be struck from the transcript, a ruling to which the Towns took exception on the record.
I have marked in the transcript and pre-filed testimony those portions that have been struck. I have not considered those portions in relation to this report's findings and conclusions. The report's "Discussion" section includes a delineation of the hydrogeology issues and an explanation for my rulings striking testimony not related to those issues.
The parties waived the opportunity to make opening statements, and submitted written closing statements according to a schedule they negotiated among themselves. There were two rounds of closing briefs: a first round so the parties could summarize their arguments, and a second round so they could respond to each other. The first round of briefs was received on July 18, 2001, and the second round on August 1, 2001.
With regard to the issues that were adjudicated, the record closed on August 22, 2001, at which point this hearing report was prepared. With regard to the issues that were not adjudicated, the record remained open for the receipt of a responsiveness summary addressing public comments on the project application and DEIS.
The Responsiveness Summary
Pursuant to 6 NYCRR 624.12(b), the hearing record must include comments on the DEIS and the Department's responses thereto, in what is known as a responsiveness summary. A draft of the responsiveness summary was prepared by the Applicant's consultants and provided to Department Staff on February 20, 2002. A final responsiveness summary, developed from the draft by Department Staff, was sent to me on June 27, 2002.
By a memorandum dated July 26, 2002, I requested a certain revision of the responsiveness summary's discussion of the hydrogeology issue. That revision - - providing a substantive response to public comments not within the scope of the adjudicatory hearing - - was provided by Department Staff under a cover letter of August 19, 2002.
With my permission, the Towns submitted letters dated August 26, 2002, addressing perceived flaws in the responsiveness summary. The Applicant responded to these letters in a letter dated September 13, 2002, and Department Staff, by a letter dated October 7, 2002, explained why it would not be further modifying the text of the document in relation to the Town's concerns. While this recent exchange of letters has not changed the language of the responsiveness summary, all the letters, taken together, have been deemed an appendix or supplement to the responsiveness summary, which also makes them part of the Final Environmental Impact Statement for this project.
Department Staff's letter of October 7 was received by my office on October 10, 2002, on which date the record in this matter closed. By a memorandum dated October 15, 2002, I informed the parties of this fact, indicating also that there should now be an adequate record for the Commissioner's SEQRA decision-making with regard to the permit application.
POSITIONS OF THE PARTIES
Position of WMNY and Department Staff
The pending application should be approved because WMNY's hydrogeologic investigation and report complies with the relevant Part 360 provisions. The investigation confirms that groundwater monitoring and remediation can be conducted at the Towpath site, despite its proximity to OSL and the McKenna landfill. The computerized groundwater flow model used by WMNY was appropriate and confirmed the conceptual model developed by its consultants. The Towpath facility is not sited in an area where bedrock would be subject to rapid or unpredictable groundwater flows. The proposed monitoring well array is adequate to detect leachate releases.
Position of the Towns of Albion and Murray
The pending application should be denied because WMNY has failed to demonstrate compliance with various key Part 360 requirements concerning groundwater monitorability. In part because of inadequate well spacing, WMNY has failed to establish that it could detect and monitor leachate releases before they move off-site. It has failed to establish that it could differentiate Towpath leachate impacts from impacts due to alleged leachate releases from the existing OSL and the McKenna landfill. In addition, WMNY could not differentiate between leachate and naturally occurring groundwater at the proposed Towpath site. WMNY has not shown that the bedrock underlying the site is not subject to rapid or unpredictable groundwater flow. If the application is not denied, the Department should require certain project modifications before approval. These include closer monitoring well spacing, installation of additional wells at certain key locations, and more frequent well sampling than is now proposed. WMNY should be required to do transport modeling that would help establish new well locations. The northern boundary of the Towpath landfill should be moved 250 feet to the south to ensure that monitoring wells are placed in an area that is not likely to remain contaminated with McKenna landfill leachate. Also, the landfill footprint should be resized to eliminate the OSL overlap area.
FINDINGS OF FACT
- Waste Management of New York ("WMNY," or "the Applicant") proposes to expand the closed Orleans Sanitary Landfill ("OSL") at 3511 Densmore Road in the Town of Albion, Orleans County, creating a new facility that would be known as the Towpath Environmental & Recycling Center. This facility ("Towpath") would be located south of the Erie Canal, east of Densmore Road, west of Transit Road, and north of the Conrail tracks.
- The proposed expansion includes an overfill of about four acres on the eastern slope of OSL and an approximately 73-acre eastward expansion towards Transit Road. Receiving up to 1,800 tons of solid waste per day, the landfill is expected to last 16 years. At completion it would be about 200 feet above the existing ground level and about 90 feet higher than the existing OSL.
- The 204-acre parcel on which the landfill would be built and adjacent parcels have been used for waste disposal for more than 40 years. The Village of Albion operated a waste disposal site (about one acre in size) in the northwest portion of the site during the 1950's. From 1968 to 1983, the McKenna Landfill operated on an adjacent property, and from 1983 to 1993 waste was accepted at OSL.
Orleans Sanitary Landfill
- OSL is a 40-acre closed solid waste landfill within the southwest corner of the 204-acre project site. OSL was privately owned and operated from 1983 to 1991. During OSL's operation, violation of its operating permits resulted in a 1987 consent order between its owner and operator, Orleans Sanitary Landfill, Inc. ("OSLI") and DEC, which included, among other things, payment of a civil penalty for the violation.
- In August 1991, OSLI, its parent and subsidiaries filed for relief under Chapter 11 of the U.S. Bankruptcy Code. In December 1991, the federal bankruptcy court appointed a non-operating trustee. On October 26, 1992, that trustee executed a lease with WMNY that was amended and restated in August 1993. Among other things, the lease conveys certain rights and obligations to WMNY, including the right to develop and operate the premises as a landfill for a term of 48 years. As a condition of the lease, WMNY is obligated to obtain all required permits to construct and operate a landfill on the site for purposes of creating a revenue stream to be distributed to creditors of the debtor corporation.
- Before filing for bankruptcy, OSLI performed initial landfill closure activities. As a result of the 1991 bankruptcy filing, OSLI was unable to meet its regulatory obligations to provide ongoing closure and post-closure monitoring and maintenance. Since the 1991 filing, closure and post-closure activities have been managed by the bankruptcy trustee.
- In 1991, DEC approved a modified OSL closure plan that included regrading of the landfill by accepting 100,000 tons of municipal solid waste, final capping of the regraded landfill, and installation of a new and expanded environmental monitoring network. WMNY provided these services and implemented the modified closure plan from 1991 to 1993 as a contractor to the trustee. OSL is now capped in accordance with the plan's specifications, and WMNY is providing comprehensive post-closure monitoring and maintenance activities under contract to the trustee.
- Because the construction of Towpath is considered an expansion of OSL, and the western part of the expansion would be atop OSL, DEC views OSL and Towpath as a single site with regard to long-term monitoring and care. Pursuant to special conditions 58 and 59 in DEC Staff's draft permit, WMNY, as operator of Towpath, would become obligated to care for the existing OSL as well as the expansion area, such care to include but not be limited to collection of leachate on an as-needed basis; groundwater, surface water, and leachate monitoring; and repair of damage to the final cover and other structures at the site. The responsibility for both facilities would last at least through the operation, closure and post-closure periods of the Towpath facility.
- Immediately adjacent to the northeast portion of the Towpath site is the 18-acre McKenna landfill. Privately owned, the McKenna landfill was operated from 1968 to 1983, its closure coinciding with the opening of OSL. The McKenna landfill is a Class 2 site on the New York State Registry of Inactive Hazardous Disposal Sites.
- In March 1998, WMNY entered into a consent order with DEC for the development and implementation of a remedial closure program for the McKenna landfill and the payment of the state's oversight costs related to the closure activities. The program includes installation of a soil/bentonite slurry cut-off wall keyed into the bedrock surface, followed by placement of a leachate collection system (at or just below groundwater level) within the wall's perimeter. Other features include placement of a low-permeability landfill cap, regrading to promote proper site drainage, off-site treatment of leachate and groundwater, and installation of a passive gas venting system.
- On January 10, 2000, the Department approved WMNY's final design report for the closure remedial program, and remedial construction was to be completed during the summer of 2001.
Towpath Liner Design
- The Towpath landfill is designed to ensure that waste placed into it, and any leachate generated from the mixing of the waste with precipitation, are isolated from the surrounding soils and groundwater. The primary design feature in this regard is a double composite liner and leachate collection system.
- The Towpath liner system would collect leachate so that it does not penetrate the landfill bottom and thereby reach the surrounding environment. This would be accomplished by a redundant system of leachate collection and barrier layers, as illustrated in Figure 3.4-2 of the DEIS (Hearing Exhibit No. 4-3, a copy of which is attached as Appendix "E" to this report).
- At the top of this system, the primary leachate collection layer is designed to gather virtually all of the leachate generated by the waste and move it to the leachate removal system. This collection layer would consist of 24 inches of sand and gravel with a permeability greater than 0.3 centimeters per second (cm/sec).
- Immediately below the primary leachate collection layer, the primary composite liner would prevent downward migration of leachate, forcing it instead through the overlying sand and gravel. The primary composite liner would consist of a very-low-permeability high-density polyethylene (HDPE) geomembrane underlain by a low-permeability geosynthetic clay liner. The clay liner would be designed to retard seepage through any minor manufacturing or construction defects in the geomembrane.
- One foot of structural fill would separate the primary and secondary liner systems so that potential damage to the primary system would not likely carry through to the secondary system. Immediately below the fill, a secondary leachate collection layer, consisting of geosynthetic drainage material, would collect any leachate that penetrated the primary composite liner.
- Below that, a secondary composite liner would stop the downward migration of whatever leachate might get through the primary liner, directing that leachate instead through the secondary collection layer. The secondary composite liner would consist of a very low permeability HDPE geomembrane underlain by two feet of low-permeability compacted clay.
- The leachate removal system would collect leachate from the primary and secondary leachate collection layers and move it via a system of pipes to separate sumps at the lowest point in each landfill cell. The leachate would then be pumped from the sumps to storage tanks with secondary containment for subsequent off-site treatment and disposal.
Leakage Prevention and Monitoring
- The liner system would work to prevent the release of leachate from the landfill by controlling the two factors necessary for leakage: (1) holes or permeable material to leak through, and (2) liquid pressure (or "head") to drive leachate downwards. Rapid leachate removal through the primary collection layer is intended so that less than one foot of head can build up on the primary liner.
- The secondary liner system would operate in a similar manner to the primary liner system. However, in the secondary system, the hydraulic load would be only the leakage from the primary liner. The small amount of flow in the secondary leachate collection system during operations when the primary liner is intact (operating below the leakage rate allowed by DEC regulation) would be rapidly pulled from the top of the secondary liner to on-site storage tanks, thus minimizing the potential for leakage.
- The Department's regulations restrict the maximum amount of leakage from the primary liner, as observed in the secondary leachate collection system, to 20 gallons per acre per day. For a typical landfill cell of 10 acres in area, this allowable leakage rate equates to a flow of about 0.14 gallons per minute into the secondary leachate collection sump.
- By monitoring the flow in the secondary leachate collection system, one can effectively monitor the performance of the overlying primary liner.
- The Department's regulations require the Applicant to monitor the flow in the secondary leachate collection system on a daily basis to determine the presence, quantity, nature and significance of any liquid that is detected. If flows in the secondary collection system exceed 20 gallons per acre-day based on a 30-day average, the operator must notify the Department, determine the cause of the exceedance, and propose a method of resolving the problem.
- The daily monitoring of leachate flow would allow one to determine the leachate chemistry for comparison with leachates that have been generated at OSL and the McKenna landfills.
- In all areas except the four acres overlying the existing OSL landfill, an engineered subgrade (beneath the liners and leachate collection layers) would provide structural support for the Towpath liner system and waste that is placed in the landfill. This subgrade also would provide separation between the liner system and the bedrock underneath the Towpath site.
- Because of the site's thin natural soils, WMNY is seeking a variance from the requirement of 6 NYCRR 360-2.12(a)(1)(v) that unconsolidated deposits below the landfill either exist or be constructed to be 20 feet or greater in thickness as measured from the base of the liner system. WMNY would provide a subgrade consisting of at least 10 feet of compacted soils exhibiting a maximum in-place permeability of 2.5 x 10-6 cm/sec.
- WMNY's low-permeability subgrade would be at least equivalent in performance to the unconsolidated deposits otherwise required by the regulations. In fact, it would take a year and a half for any leachate exiting the secondary composite liner system to pass through the subgrade and reach the underlying bedrock. Also, the flux, or quantity of leachate, that could permeate the engineered subgrade would be less than half of that which could flow through the natural subgrade otherwise required by Part 360.
- The engineered subgrade would be constructed in controlled lifts with construction quality assurance control and frequent testing to assure that performance standards are met. The layering of the subgrade would protect against the development of vertical cracks through which leachate might move quickly.
- The Towpath expansion would consist of eight separate cells, with filling proceeding from west to east across the site. The four-acre overlay on top of OSL would be part of Towpath Cell No. 1, the first to be constructed.
- As each cell reaches its final operating grade, a final cover system would provide a physical barrier minimizing the infiltration of precipitation into the waste mass. This cover system would minimize the generation of leachate after a cell is closed. Also, a storm water management system would control clean storm water and direct it away from operating landfill cells, further minimizing the production of leachate.
- The portion of OSL on top of which Towpath would be built is in OSL's Phase IV area, which was constructed during the summer of 1988. Phase IV has a double liner system: a 60-mil synthetic primary liner and a secondary soil liner which consists of 3 feet of low-permeability compacted clay. It has two independent leachate collection systems: a primary system above the synthetic liner consisting of 12 inches of coarse sand, and a secondary system, also 12 inches of coarse sand, that is located between the synthetic liner and the clay liner. These collection systems direct leachate to manholes. The leachate is then removed from the site for disposal.
- The OSL liner system would be useful in the monitorability of Towpath because, in a manner similar to the Towpath system, it would protect against the flow of leachate into the surrounding environment, allow access to the leachate for chemical analysis, and indicate leachate volume, which would be helpful in assessing the performance of the primary OSL liner.
- The existence of OSL under a portion of the proposed Towpath landfill does not affect the ability to monitor the two landfills separately, at least from a design standpoint. The primary and secondary leachate collection systems for the Towpath landfill would be separate and distinct from the collection systems for OSL. Any leakage through Towpath's primary liner system would appear in that landfill's secondary collection system before it could pass through into OSL. In addition, the fairly steep side slope for OSL (greater than 25 percent) would preclude the possibility of leachate ponding on top of the Towpath liner, thereby reinforcing the tendency of the leachate to travel downslope, parallel to the liner rather than through the liner and into OSL.
Part 360 Consistency
- Towpath's design is typical of that employed for other municipal solid waste landfills constructed pursuant to New York's Part 360 regulations. Safety enhancements beyond the requirements of Part 360 include the engineered subgrade layer, the use of a geosynthetic drainage layer in the secondary leachate collection system, and a sideslope leachate riser design that allows engineered penetrations of the primary geomembrane liner only at the perimeter berm, not in the sump.
- The geosynthetic drainage layer in the secondary leachate collection system provides a leak detection rate about 50 times greater than that afforded by a sand drainage layer that would otherwise be required under Part 360. This means that leakage from the primary composite liner would be seen 50 times faster in the secondary sump, allowing WMNY to respond much faster to identify and correct the source of any leakage.
- The design of the proposed Towpath facility meets and, for some components, exceeds Part 360 requirements. For instance, the minimum permeability of the primary leachate collection layer (0.3 cm/sec) is 30 times greater than the minimum required by Part 360. Also, the permeability of the primary composite liner (1 x 10-9 cm/sec) is about 100 times less than the maximum permeability allowed by Part 360 for this layer. Finally, the engineered stability of the landfill (as measured by the factor of safety, defined as the ratio of resisting forces to driving forces) exceeds the requirements of Part 360 for both the period of waste placement and the post-closure period, which diminishes any chance of waste slippage opening up a large tear in the liner system.
Relevant Permit Conditions
- The monitorability of the Towpath expansion is further enhanced by several conditions of the draft permit prepared by Department Staff (Appendix "D" to this report).
- Special condition 42 requires that the primary and secondary leachate collection and removal systems be inspected on a bi-weekly basis and the pump stations on a weekly basis. In addition, if the action leakage rate in the secondary collection system is exceeded, the Department is to be notified verbally within 48 hours (and in writing within seven days) and WMNY is to immediately initiate appropriate actions as defined in its contingency plan (discussed below).
- Special condition 43 requires that the primary leachate collection and removal system be flushed along its entire length with a high pressure hose at least annually to keep it clean, unobstructed and free-draining. Should the system's efficiency become impaired, remedial cleaning operations are required.
- Special condition 47(c) requires that WMNY report to the Department on a quarterly basis information on flow rates in both the primary and secondary leachate collection systems and action leakage rates for each cell.
- Special condition 49(f) requires that WMNY provide an annual report noting the quantity of leachate collected in the secondary leachate collection/leak detection and removal system for each cell. This information must be compiled on a monthly basis to assess primary liner system performance.
- Special condition 61 requires financial surety to ensure that monitoring and maintenance can take place should WMNY default on its obligations.
- The monitorability of the Towpath site depends on an understanding of site hydrogeology, which involves the interaction between water and geologic materials.
- The Applicant's hydrogeologic investigation is detailed in a nine-volume report that is part of the Part 360 application. Many investigative techniques were used, and the collected information was evaluated for various criteria including speed and direction of groundwater flow, which are key to the location of appropriate monitoring points.
Site Investigation Plan
- The hydrogeologic investigation of the Towpath site went forward on the basis of a site investigation plan (SIP) that was developed in coordination with DEC Staff and updated as the application process progressed.
- The objectives of the SIP were to document the technical basis, data needs, and methods of investigation that would be employed to characterize the site hydrogeology and define the critical stratigraphic section. [As defined at 6 NYCRR 360-1.2(b)(47), the critical stratigraphic section means "all stratigraphic units, both unconsolidated deposits and bedrock including but not limited to the unsaturated zone, uppermost aquifer and first water-bearing unit into which facility-derived contaminants that escape from a solid waste management facility might reasonably be expected to enter and cause contamination during the active life or within 30 years following closure of the facility."]
- The SIP was developed according to a conceptual model of the site hydrogeology obtained from existing regional and site-specific data. On the basis of this preliminary understanding of site geology, groundwater flow and groundwater geochemistry, a technical approach and scope of work was developed which described the proposed investigation in terms of the number and location of monitoring wells to be installed, the screened intervals, the testing methods and procedures to be employed, groundwater sampling locations and parameters, methods of analysis and the data to be collected and reported.
- A draft SIP was submitted to DEC Staff in October 1992 and revised in response to Staff's input in June 1994. An addendum to the SIP was submitted to DEC in March 1995. The June 1994 document and the March 1995 addendum have been consolidated and presented as Section 4.0 of the hydrogeologic report.
Scope of Investigation
- The hydrogeologic investigation began in June 1994, and a draft of the hydrogeologic report was completed in February 1996 and finalized in May 1996. Various investigative tools were used as part of the investigation:
- Fracture and joint orientations were determined from geologic mapping, aerial photo interpretation, and azimuthal resistivity.
- Forty-seven exploratory test pits were dug to locate the top of bedrock.
- Twenty locations were chosen for the installation of monitoring wells or piezometers.
- Two locations were chosen for the advancement of angle boring sets.
- Surface geophysical techniques were employed to evaluate potential groundwater quality impacts associated with OSL and the McKenna landfill.
- A borehole geophysical program was designed to assess the presence of horizontal bedding plane fractures, potential water-bearing zones, and stratigraphic correlations from borehole to borehole.
- Using slug tests, packer testing within open bedrock coreholes, and pump tests, hydraulic conductivities were measured to determine the pathways and volumetric rates of groundwater flow beneath the site.
- Water levels were monitored to determine representative seasonal fluctuations within each identified geologic unit.
- Groundwater was sampled to establish existing water quality conditions and to understand the site's hydrogeochemistry.
- Ongoing field work, completed since submittal of the final hydrogeologic report in May 1996, has included the collection of monthly water level readings through February 1997, and additional rounds of groundwater sampling completed in March, April, August and December of 1999 and in March, June, October and December of 2000.
- The Towpath site is located on an outcrop belt of the Medina Group, which is underlain by the Queenston formation. The Medina Group has been divided into six formations, three of which (the Kodak, Cambria and Thorold formations) underlie the proposed facility. The Medina group is comprised primarily of fine-grained sandstone with occasional interbeds of siltstone and shale.
- The bedrock units dip (or slope) to the south and the ground surface slopes to the north (towards the Erie Canal). Therefore, the depth below ground surface to each formation decreases as you move north across the site. For example, the depth of the Queenston shale at the south side of the study area is about 90 feet below ground surface, but at the north end of the study area near the Erie Canal it is only about 45 feet below the ground surface.
"Top of Rock" and "Deep Rock" Water-Bearing Zones
- Generally speaking, there are two water-bearing zones below the site surface, and they function as pathways for the movement of groundwater. These zones are separated by an aquitard, a unit that restricts or impedes groundwater movement.
- The uppermost water-bearing zone is contained within discontinuous glacial till deposits (which range up to 10 feet deep across the site) and the underlying "top of rock" zone that exists within the upper 15 to 30 feet of the Medina Group. The till and "top of rock" behave at least seasonally as a single water-bearing zone, with groundwater flowing generally to the north with an overall hydraulic conductivity of 6 x 10-4 cm/sec.
- A localized groundwater flow reversal occurs immediately south of the McKenna landfill within the "top of rock" water-bearing zone, so that groundwater there flows to the south. The flow reversal is due to the mounding of leachate within the McKenna landfill, and extends about 150 feet south of McKenna to an area about 50 feet north of the Towpath footprint, significantly impairing water quality in this area.
- The "top of rock" zone is underlain by 20 to 60 feet of relatively unfractured sandstone known as the intermediate Medina aquitard. The aquitard has a low vertical hydraulic conductivity in the range of 6 x 10-9 to 5 x 10-7 cm/sec, which makes it difficult for water to pass through it. The aquitard extends across the project site, but thins to the north and is absent in the vicinity of the Erie Canal.
- Below the intermediate Medina aquitard is another water-bearing area called the Medina/Queenston zone (commonly referred to in the application and hearing record as the "deep rock" zone). This zone is laterally extensive due to bedding plane fractures at or near the Medina/Queenston geologic contact.
- Groundwater flow within the "deep rock" zone is controlled by a series of localized vertical fractures. Flow is primarily to the north-northwest, but there are localized changes in flow direction in response to the fracturing.
- A groundwater divide causes flow in the "deep rock" zone under the southeastern part of the Towpath footprint to move toward the south and east. Consequently, the "deep rock" monitoring well 2EDR, just outside the southeast corner of the Towpath footprint, is considered a downgradient well, while the "top of rock" well monitoring well at the same location, 2ETR, is considered an upgradient well. (Monitoring well locations are shown in Figure 3-1 of WMNY's environmental monitoring plan. A copy of that figure is attached as Appendix "F" to this report.)
- Finally, below the Medina/Queenston (or "deep rock") zone is the Queenston formation aquitard, which has a low vertical hydraulic conductivity estimated at 6 x 10-8 cm/sec.
- According to a principle of physics called the Tangent Law, if two geologic units differ in hydraulic conductivity by two orders of magnitude or more, the groundwater flow paths in the unit of higher hydraulic conductivity (the more permeable unit) will be essentially horizontal, while the groundwater flow paths in the unit of lower hydraulic conductivity (the less permeable unit) will be essentially vertical.
- Because the intermediate Medina aquitard is about two orders of magnitude lower in permeability than the overlying "top of rock" and underlying "deep rock" water-bearing zones, operation of the Tangent Law assures that groundwater flow is predominantly horizontal in the "top of rock" and "deep rock" water-bearing zones, and predominantly vertical in the intermediate Medina aquitard.
- The "top of rock" water-bearing zone is the primary focus of WMNY's environmental monitoring plan because a potential release would move with the groundwater - - away from the landfill footprint - - in that unit. Should leachate somehow penetrate the intermediate Medina aquitard, it would again move horizontally within the "deep rock" water-bearing zone, so the "deep rock" unit would be monitored too.
- As groundwater flows generally to the north in the "top of rock" water-bearing zone, it must cut across the various geologic formations of the Medina group, since the bedrock units dip to the south across the site while the topography slopes to the north. Because of this, bedding planes that separate each successive rock layer (and which are typically identified by a change in grain size or rock type) do not play a significant role in groundwater movement.
- Bedding plane fractures could be preferred pathways for horizontal groundwater flow. However, no such fractures can be traced across the site, with the exception of one that is associated with the "deep rock" water-bearing zone. Instead, the predominant fracturing within the rock is associated with vertical or near-vertical joints.
Contaminant Transport Processes
- The process by which contaminants are transported by the bulk motion of flowing groundwater is known as advection. Groundwater flows from higher to lower points of hydraulic head, as measured by piezometers that determine water level elevations. Advection would tend to control the movement of contaminants except in areas where groundwater is stagnant or very slow-moving.
- Apart from advection, processes such as dispersion and diffusion affect contaminant movement. Dispersion involves a tendency for solutes to spread out from the path they would be expected to follow according to the advective hydraulics of the flow system. This spreading occurs laterally and vertically, so that leachate forms an expanding plume. The dispersion of contaminants is also associated with their dilution in the groundwater.
- Diffusion involves the movement of contaminants from areas of high to low concentration. Unlike advection, diffusion does not depend on, and can occur in the absence of, flowing groundwater.
- Diffusion tends to retard the movement of leachate as contaminants become bound up in the rock matrix. The rate of retardation depends upon the type of soil or rock, its porosity (which affects the volume of material it can hold), the time of travel, and the concentration gradient.
Groundwater Flow Modeling
- In addition to collecting data as part of its hydrogeologic investigation, WMNY developed a groundwater flow model for the project area using MODFLOW, a modular three-dimensional flow model originally developed by the United States Geological Survey.
- The MODFLOW model was used both as an interpretive tool to test the reproducibility of WMNY's conceptual model of the site's groundwater flow system, and as a predictive tool in that it could simulate the hydrologic impacts of future changes in site conditions such as placement of the low-permeability engineered subgrade and the landfill's subsequent construction. While these changes would cut off rainwater recharge in the footprint area, thereby somewhat depressing groundwater elevations, WMNY's modeling suggests that they would not upset the generally northerly groundwater flow patterns in the "top of rock" and "deep rock" water-bearing zones.
- WMNY's use of MODFLOW to interpret and predict groundwater flow was appropriate in light of the site's fracture pattern. The rationale for using MODFLOW - - a porous media flow model - - to simulate groundwater flow in fractured bedrock is based on the concept of "porous media equivalency." In other words, at the scale at which the model is applied (i.e., the project area and its surroundings), the density of fractures within the bedrock is sufficient to allow groundwater flow to behave as if it were in truly porous media.
- As observed in on-site outcrops, fractures at the site are generally less than 10 feet apart, and can be less than one foot apart. At depth, fracture spacing ranges from 2.5 to 7.75 feet, with the fractures forming an interconnected network. From a site-wide perspective, individual fractures are insignificant as discrete, preferred flow paths. The cone of depression (zone of lowered water levels) generated by WMNY's pump test supports the idea of porous media equivalency in that the degree of fracture anisotropy reflected in the cone is not extreme.
- MODFLOW is the most widely used groundwater flow program in the world and has been accepted as a legitimate approach to the analysis of groundwater flow systems. The model has been successfully used in other settings to simulate groundwater flow in fractured rock. MODFLOW met the modeling objectives of WMNY's hydrogeologic investigation, which required an evaluation of the hydrogeologic system as a whole and thus did not warrant the detail needed for simulation of discrete flow paths.
- The bedrock beneath the Towpath site does not contain individual fractures or open channels capable of transmitting large quantities of groundwater. Therefore, a fracture flow model, accounting for such fractures, is not required for this site.
- The bedrock under Towpath is not subject to rapid or unpredictable groundwater flow. Such flow is normally associated with carbonate rocks such as limestone and dolomite, in which groundwater can dissolve the rock to form open subterranean drainage and sink holes. The bedrock under Towpath is generally sandstones and shales, neither of which are susceptible to this kind of dissolution.
- The bedrock under Towpath contains vertical fractures, but these fractures are not significant pathways of contaminant movement in the "top of rock" water-bearing zone, because of sufficient variations in fracture orientation.
- In the "deep rock" zone, fracture orientation provides a preferential direction of groundwater flow (to the north-northwest, consistent with one of the primary joint orientations). Because of this, large portions of the site can be monitored with a single well.
- Vertical fractures at depth can become filled with clay or squeezed shut by the weight of the overlying rock, thereby restricting the flow of water. By itself, Towpath's siting in a fractured rock environment does not suggest a need to augment the monitoring well network.
- Consistent with 6 NYCRR 360-2.11(c), WMNY's landfill permit application includes an environmental monitoring plan (EMP) that is designed to determine whether leachate has been released to the environment and, if it has, to ascertain what impact the release is having on groundwater quality.
- The EMP defines the site's existing water quality as a baseline against which one may compare water quality data collected during the facility's operation or after its closure. The EMP also defines the criteria to determine if a leachate release may have occurred, and includes evaluative methods to determine the source of groundwater impacts.
- The basic elements of the EMP include:
- A discussion of the critical stratigraphic section and the technical basis behind monitoring well placement as it relates to groundwater flow;
- A statistical evaluation of existing groundwater quality;
- The components of the operational monitoring program, including a monitoring schedule, well locations, and analytical parameters; and
- The procedures to follow if there is a significant adverse change in groundwater quality.
- An additional component of the EMP is the site analytical plan (SAP) which identifies the data quality objectives, quality assurance and control procedures, field sampling methodology and laboratory procedures.
Operational Monitoring Program
- WMNY's operational monitoring program is a series of routine activities and measurements which would be performed to verify that the facility is functioning as designed and that a leachate release has not occurred.
- As part of this program, the flow of liquid in the primary and secondary liner systems would be monitored daily, and a leak within the primary liner system would be identified by an increase in the volume of liquid within the secondary liner system.
- In addition, samples of the leachate within both the primary and secondary liner systems would be collected semi-annually for laboratory analysis. This analysis would establish a database of leachate chemistry which could be used for comparison to water quality data collected routinely from monitoring wells surrounding the landfill footprint.
- Groundwater in the monitoring wells would be sampled and analyzed quarterly and the results compared to the existing water quality database established prior to the deposition of waste at the facility. This comparison would be conducted using trigger levels for analytical parameters that are set out in Part 360.
- A trigger level is a statistically derived maximum concentration for each parameter based upon the existing water quality. The trigger level is defined by Part 360 as the arithmetic mean, per parameter, of the existing water quality data, plus three standard deviations, or a concentration that is above both the arithmetic mean of the existing water quality and the water quality standard for the parameter as defined by 6 NYCRR Parts 701, 702 or 703.
- If the quarterly groundwater monitoring indicates that a trigger level has been exceeded, a leachate release is presumed and the EMP dictates the required action to define the release and address its impacts.
Establishing Existing Water Quality
- In many cases, existing (or background) water quality is established with data collected from hydraulically upgradient wells in the same rock formation. Such an approach is not appropriate here due to the extent that water quality varies in both the "top of rock" and "deep rock" water-bearing zones.
- The most effective manner of addressing spatial variability is to compare data collected from one location in what is described as an intra-well analysis. However, this method requires a minimum of 8 independent background data sets, and the database employed during the preparation of the EMP contained fewer sets. Therefore, this method could not be employed when the EMP was developed.
- Also, establishing the existing water quality based on the mean and standard deviation of all the wells within a given water-bearing zone would not in all cases yield values that are protective of the environment.
- For example, leachate from the McKenna landfill has impacted both a "top of rock" and "deep rock" well at the MW-2 well cluster between McKenna and the proposed Towpath footprint; therefore, data from that cluster cannot be used to establish existing water quality. However, removing MW-2 from the data base used to establish zonal water quality would falsely suggest that there is no statistically significant impact at that cluster. Therefore, that method too would not be acceptable.
Sub-zone Analysis of Water Quality
- Accordingly, the method chosen to determine existing water quality was to subdivide the facility into six sub-zones (three in each of the two water-bearing zones) representing similar water quality characteristics. These sub-zones are illustrated in Figure 3-1 of the EMP (Appendix "F" to this report) and were based upon an assessment of water quality that suggested the highest concentrations of particular parameters were in the southeast corner of the site (at the 2E cluster, encompassing 2ETR and 2EDR) and the lowest concentrations were in the northwest corner of the site (at the 34 cluster, encompassing 34ETR and 34DR).
- As shown in Figure 3-1, sub-zone 1 encompasses the southeast corner of the landfill site, sub-zone 2 the middle of the site, and sub-zone 3 the site's northwest corner as well as the northernmost part of each of the planned eight cells.
- After the sub-zones were identified, existing water quality was determined by apportioning the well data to particular sub-zones as shown in Table 3-1 of the EMP (a copy of which is attached as Appendix "G" to this report) and pooling the data by sub-zone for the statistical calculation of trigger levels. This approach showed that concentrations detected at the MW-2 cluster (assigned to sub-zone 3) would indicate a statistically significant increase, which tended to validate use of the approach when the EMP was submitted to DEC Staff in 1999.
- WMNY has continued to monitor water quality since the EMP was submitted, with the specific intention of increasing the size of the existing water quality database. To ensure a statistically valid database, the EMP requires that monitoring wells be installed and sampled at Towpath about two years prior to the deposition of waste in adjacent cells so that seven or eight quarters of data will be available prior to waste deposition. This would ensure the availability of sufficient fresh data so that new trigger levels can be established on an intra-well basis.
Intra-well Analysis of Water Quality
- An intra-well approach would eliminate concerns about spatial variability in water quality that are inherent to a zone (or sub-zone) approach, and therefore is the preferred method for comparing pre- and post-operation water quality.
- Spatial variability increases the standard deviation of the data, leading to higher trigger values. Therefore, one can expect that trigger values calculated on an intra-well basis would be more conservative than the ones now set for the sub-zones.
Monitoring Well Network
- WMNY's monitoring well network is summarized in Table 1-1 of the EMP, a copy of which is attached to this report as Appendix "H". This network is designed to detect leachate that escapes from the landfill, penetrates the engineered subgrade, and enters either the "top of rock" (TR) or "deep rock" (DR) water-bearing zones. Well locations are based on the location of the facility in relation to groundwater flow directions determined as a result of the hydrogeologic investigation.
- For the overburden, the monitoring wells currently include E-1S located cross-gradient to the easternmost proposed cell (Cell No. 8) and monitoring wells 2S and B-27S located upgradient of the proposed facility. There are no downgradient overburden wells because there is little or no overburden downgradient of the proposed facility.
- Additional overburden wells would be installed at proposed cluster locations if there is a minimum of 10 feet of overburden present. A minimum of ten feet of overburden is necessary to properly install a monitoring well with five feet of screen, a sand pack, filter sand, and cement/bentonite grout with a protective casing.
- For the "top of rock" water-bearing zone, monitoring wells E-43TR, 34ETR, E-41TR, MW-2ETR, PL-16TR and E-42TR are all located downgradient of the facility and are spaced in accordance with Part 360 requirements.
- Groundwater flow within the "top of rock" water-bearing zone is generally directly north towards the Erie Canal with variation only in the vicinity of the southeastern corner of the McKenna landfill. This variation, however, is expected to diminish or disappear completely following remediation of the McKenna landfill and redirection of the small drainage channel in this vicinity. Monitoring of the downgradient perimeter of the facility within the "top of rock" water-bearing zone is thus simply a matter of distributing the monitoring points along this downgradient perimeter.
- Given the relatively consistent groundwater flow direction in the "top of rock" water-bearing zone, E-1TR represents a cross-gradient monitoring location for the full footprint and 2ETR, B27ETR, and E-3TR represent upgradient locations. E-21TR and E-22TR would serve as interim cross-gradient locations during development of the facility.
- The potentiometric surface for the "deep rock" water-bearing zone is more complex than that of the "top of rock" water-bearing zone and illustrates more variation in the groundwater flow direction within the Towpath footprint. One result of these variations is that there is only one distinctly upgradient location (E-3DR) within the "deep rock" zone. Fortunately, the variations in the "deep rock" zone illustrate the location of preferred flow paths, which may then form the focal point for monitoring locations.
- Wells 34DR, E-41DR, E-4DR, 2EDR and E-43DR are all located within preferred flow paths as established by potentiometric surface contours. The remaining wells (MW-2DR, PL-16DR, E-42DR, and E-1DR) are positioned to monitor both sides of the groundwater high located near the northeast corner of the proposed footprint. Interim monitoring locations similar to those in the "top of rock" water-bearing zone have not been proposed because the configuration of the potentiometric surface contours indicates that groundwater flow would be toward the permanent monitoring well locations throughout various stages of development.
- Although the configuration of the "deep rock" potentiometric surface is more complex than that of the "top of rock" zone, the groundwater divides and associated preferential groundwater flow paths allow for monitoring of large portions of the site with a single monitoring well. Also, while possible, it is unlikely that a contaminant release would reach the "deep rock" water-bearing zone, given the thickness of the "top of rock" zone, the tendency for contaminants to be carried horizontally through that zone (rather than downward), and the presence beneath that zone of the low-permeability intermediate Medina aquitard.
- No monitoring wells are located in the intermediate Medina aquitard. Installing monitoring wells within this unit of the critical stratigraphic section would serve no purpose because if leachate constituents were to enter it, they would tend to move straight down until reaching the "deep rock" water-bearing zone. Because of the vertical flow of water within the aquitard, monitoring wells are ill-suited to detect contaminants as they pass through it.
Fixing Monitoring Well Locations
- Monitoring well locations were fixed on the basis of groundwater flow directions established by field measurements of potentiometric head at wells and/or piezometers. Potentiometric (or hydraulic) head is the elevation of groundwater at a particular location. Groundwater flows from areas of high head to low head according to potentiometric gradients. These gradients are the measure of the change in head between two locations divided by the lateral distance between them.
- The potentiometric gradient indicates the direction in which groundwater movement occurs. Horizontal gradients are typically determined by analyzing a potentiometric surface map that consists of contour lines representing locations of uniform head. By drawing flow vectors perpendicular to the equipotential lines on the maps, one can locate wells that would be expected to detect leachate releases outside the footprint perimeter.
- If a landfill is located upgradient of a monitoring well, a leachate release from the landfill will flow towards the monitoring well and will be detected at that location. Conversely, if a landfill is located downgradient of a monitoring well, a detected impact to water quality in the well generally cannot be attributed to the landfill. This is because the leachate from the landfill cannot flow against the potentiometric gradient.
- The relative positions of OSL, the McKenna landfill and the proposed Towpath landfill, both with respect to monitoring wells and each other, can be used to determine the source of a potential impact to groundwater, so that an evaluation of heads and gradients is useful to establish monitorability.
- Graphical methods (also known as chemical fingerprinting) contribute to monitorability because they can be used to determine the source of any potential groundwater impacts. For example, such methods may involve plotting the major ion data of groundwater and leachate samples to produce a visual representation of their chemistry.
- Major cations include sodium, potassium, calcium and magnesium. Major anions include chloride, alkalinity (expressed as carbonate and bicarbonate) and sulfate.
- When plotted on Stiff and Piper diagrams, data for these cations and anions provide a visual or chemical fingerprint of different water quality and leachate types that can be used to distinguish background water quality from contaminated groundwater.
- Stiff diagrams allow for a qualitative comparison of groundwater data using three parallel horizontal axes extending on each side of a vertical axis representing a concentration of zero. This representation of cation and anion concentrations in milliequivalents per liter presents the water quality of a given sample as a shape.
- The shapes shown on Stiff diagrams allow an easy visual comparison to determine similarities and differences among different samples, with chemically similar samples having similar shapes and water quality differences evidenced by different shapes.
- In the event that natural groundwater is contaminated by leachate, the shape of the Stiff diagram representing the natural groundwater will change to become more similar to the shape representing the leachate. Naturally occurring groundwater and leachate will have different shapes depending on their origin and chemical composition.
- Examples of the use of Stiff and Piper diagrams for the Towpath facility are discussed in Section 3.5.4 of the EMP (Exhibit 59) on pages 3-24 through 3-26. In the EMP, Stiff and Piper diagrams are presented for undiluted leachate samples collected from both the OSL and the McKenna landfill, a water quality sample from MW-2ETR which is known to be impacted by McKenna leachate (referenced in the diagrams as 2 ETR), and a water quality sample from 34ETR representing the natural water quality. (Figure 3-4, the Piper diagram, is also part of the record as Exhibit 35, and Figure 3-5, the Stiff diagram, is Exhibit 36.)
- As illustrated in Exhibit No. 36, the unaffected groundwater plot for well 34ETR is very different from those of the McKenna and OSL leachates. The leachate samples from OSL and McKenna illustrate certain similarities; however, distinctive differences between the two leachates are noted in the dominance of magnesium over calcium and iron in the OSL leachate, the relative differences between the various anions and cations between the two samples, and the much larger shape of the OSL graph representing a significantly higher concentration of total dissolved solids (TDS).
- The plot for the impacted groundwater represented by MW-2ETR illustrates a much larger shape (higher TDS) than the plot of the unimpacted groundwater represented by 34ETR. Furthermore, the impacted sample illustrates a groundwater that is more consistent with the leachate samples than with 34ETR, and most closely approximates the size and shape of the McKenna leachate. This is most apparent in the consistent decline in concentration of the cations as one moves down the left-hand margin of the 2 ETR diagram.
- As illustrated, the size and shape of the impacted groundwater approaches the shape of the leachate which has likely resulted in the change in groundwater chemistry. The Stiff diagrams thus provide a quick and simple method to help determine the source of a leachate impact.
- Piper diagrams are a combination of anion and cation triangles that lie on a common baseline. Adjacent sides of the triangles are 60 degrees apart, and a diamond shape between them is used to re-plot the data as circles whose areas are proportionate to their TDS content.
- In contrast to Stiff diagrams, Piper plots permit the cation and anion compositions of many samples to be represented on a single graph in which major groupings or trends in the data can be discerned visually. The location of the plots within the central diamond illustrates the dominant and subordinate cations and anions as well any similarity between the plots.
- Like Stiff diagrams, Piper diagrams would assist in determining which landfill is contaminating water at a particular monitoring location.
Consideration of Background Ion Levels
- The use of graphical methods, such as Stiff and Piper diagrams, is not affected by the fact that major ions are present across the Towpath site at naturally elevated levels. This is because the EMP is based upon the establishment of an existing water quality database that accounts for these elevated levels, to which future groundwater samples can be compared. In other words, a leachate release would be detected because of a change in the concentration of one or more individual constituents or the relative concentrations of several constituents.
Operational Water Quality Monitoring
- According to the EMP, operational water quality monitoring would commence in a phased manner as cell construction proceeds across the site. Wells would be installed about two years prior to the deposition of waste in adjacent cells, and sampled at various intervals for baseline, routine and expanded parameters established by Part 360, so that there is an understanding of the water chemistry prior to waste deposition. Also, groundwater level measurements would be obtained quarterly from each well, so that groundwater flow patterns can be evaluated.
- The EMP provides that, as the facility operates and during its closure and post-closure periods, monitoring wells would be sampled quarterly: once a year for baseline parameters and three times a year for routine parameters, with the baseline parameters rotated to a different quarter each year. The collected groundwater quality data would be screened for any parameter that exceeds the established trigger level. In the event a trigger level is exceeded, the data would be further evaluated to determine if the exceedance resulted from an error in sampling or analysis, or from natural variation in water quality.
Detection of Leachate Impacts
- To see if the exceedance is landfill-related, particular attention would be paid to a subset of parameters that are present in measurable concentrations in both the groundwater and leachate and for which there is a relatively large data base. Target parameters would include leachate parameters that are significantly elevated as compared to groundwater concentrations, those that may be uniquely associated with solid waste, and those that are considered relatively mobile in groundwater.
- For example, the concentration of chloride in leachate is typically significantly higher than groundwater concentrations, and chloride migration is not retarded, meaning that chloride will be detectable at a downgradient location before other parameters that may have been released at the same time. Stiff and Piper diagrams (described above) could be used to establish the prevalent chemical character of sampled groundwater for comparison to nearby leachate sources. For verification purposes, wells would be re-sampled for specific parameters for which an apparent exceedance is indicated; if the exceedance is confirmed, monitoring for a broader range of parameters would occur during the next quarterly sampling event.
- If WMNY could demonstrate to DEC Staff that a trigger value exceedance is not related to a landfill release, or if follow-up sampling found no further exceedances, quarterly operational monitoring, as discussed above, would continue. Otherwise, contingency water quality monitoring would be initiated upon the determination that a verified significant increase has occurred for one or more of the Part 360 baseline parameters.
- Contingency monitoring would involve sampling of all monitoring wells for expanded parameters. If the concentration of any expanded parameter were to exceed established groundwater protection standards set in accordance with 6 NYCRR 360-2.11(c)(5)(iii)(f), WMNY would notify DEC Staff as well as local officials. Also, in accordance with 6 NYCRR 360-2.11(c)(5)(iii)(e), efforts would be undertaken to either (1) characterize the nature and extent of the release and initiate a corrective measures assessment; or (2) submit documentation that a source other than the landfill caused the contamination, or that the significant increase resulted from an error in sampling or analysis, or from natural variation in water quality.
- Determining the source and extent of a release might involve drilling additional monitoring wells or increasing the amount of sampling at wells already identified in the EMP. Even if the measures identified in the EMP were not adequate to determine the source of any contamination, DEC could insist on others, and it would remain WMNY's burden to show it is not responsible for the problem.
McKenna's Impact on Towpath Monitorability
- The Towpath landfill is located in an area where monitoring and remediation can be conducted, despite its proximity to the McKenna landfill.
- Although leachate mounding within the McKenna landfill has caused a flow reversal in the "top of rock" layer, spreading contaminants southward to about 50 feet north of the Towpath footprint, the remediation of the McKenna landfill is expected to eliminate the mound and erase the groundwater divide between McKenna and Towpath. This is because the McKenna leachate collection system would be set at or slightly below the "top of rock" groundwater levels. Construction of the system, in conjunction with the soil/bentonite slurry cut-off wall, is intended to create an inward gradient, so that groundwater no longer flows south in the direction of Towpath.
- Existing well cluster MW-2 has been included in WMNY's operational monitoring program to verify the anticipated improvement in water quality at that location after completion of the McKenna remediation. In the event that water quality does not improve, new monitoring wells can be installed in the Towpath berm, which is beyond the most southern extent of the groundwater impacts associated with McKenna.
The issues in this case concern WMNY's hydrogeologic investigation, the reliability of the conclusions in the hydrogeologic report, the effectiveness of the EMP, and the ability to monitor and remediate any escape of leachate from the Towpath landfill. Whether the Towpath landfill can be monitored separately from the existing OSL (as an expansion of that facility) and from the McKenna landfill (an adjacent inactive hazardous waste disposal site) is a key question to be answered.
- - Legal Background
The monitorability of the Towpath Landfill must be considered in relation to the mandate of 6 NYCRR 360-2.12(c)(5) that new landfills "not be located in areas where environmental monitoring and site remediation cannot be conducted. Identification of these areas must be based upon ability to sufficiently characterize groundwater and surface water flow to locate upgradient and downgradient directions; ability to place environmental monitoring points which will detect releases from the landfill; ability to characterize and define a release from the landfill and determine what corrective actions may be necessary; and the ability to carry out those corrective actions."
Section 360-2.12(c)(5) allows for lateral expansions adjacent to existing landfills which are already contaminating groundwater, provided that the proposed expansion area can be constructed in a way that demonstrates compliance with the regulations. According to the regulation, this may be demonstrated using remedial actions at the existing site resulting in a demonstrated improvement in groundwater quality, and any additional monitoring requirements that the Department needs to ensure the integrity of the expansion area, such as leakage detection lysimeters installed beneath the new liner, statistical triggers of groundwater monitoring, tracers, additional monitoring wells surrounding the entire site, and any other monitoring methods required by the Department.
The allowance for lateral expansions next to leaking landfills "hardly suggests that [Section 360-2.12(c)(5)] should be interpreted as discouraging the construction of landfills adjacent to each other on monitorability grounds," said former Deputy Commissioner David Sterman on page 7 of his second interim decision, dated October 3, 1995, in Matter of Saratoga County Landfill. "It simply requires that a reasonable and prudent system be engineered to be able to detect and identify releases, and to provide for such remedial action as may be warranted in the event of leakage."
The Deputy Commissioner said his interpretation of Section 360-2.12(c)(5) was that "so long as a prudently designed monitoring system is provided for, siting adjacent landfill facilities is not to be disfavored simply because cross contamination might possibly occur. In fact, there may be overriding sound reasons for siting facilities (including multi-celled landfills) adjacent to one another, such as land use, roads, geologic and hydrologic factors. The regulation should be interpreted in light of the environmental purpose that it serves, and not rigidly or narrowly." Id. at 7.
Monitorability was identified as an issue in the Saratoga County matter and adjudicated in relation to the requirements of 6 NYCRR 360-2.12(c)(5). In my hearing report's discussion of the issue, which was adopted by the Deputy Commissioner in his September 3, 1996 decision, I found that the County's landfill site was monitorable even though it would be next to a previously permitted paper sludge landfill belonging to Scott Paper Company and Finch, Pruyn & Company, Inc.
One factor supporting this conclusion was the ability to monitor the secondary leachate collection and removal system of the County's landfill for a containment failure (or breakdown) of the primary liner, so that leakage could be detected in advance of any groundwater contamination. (Finding of Fact 30, page 85 of hearing report.) A second factor was knowledge of groundwater flow directions, which would help trace contaminants back to their source. (Finding of Fact 32, page 85 of hearing report.) A third factor was the adequacy of the monitoring well network to detect spreading contaminants, and the ability to supplement the network if necessary. (Finding of Fact 36, page 86 of hearing report; see also discussion on page 108 of the report.) These three factors, I concluded, provided the "main assurance" in the Saratoga County matter that "leakage would be detected, identified and remediated in a timely fashion." (Report, page 110.)
Groundwater flow considerations were also relevant in another case, Matter of Monroe County (Mill Seat Landfill - Town of Riga), in which project opponents were rebuffed in their attempt to raise monitorability as a hearing issue. In that case, the opponents suggested that the landfill site represented a recharge area with generalized multidirectional flow to and through the till margins and then down to bedrock. Addressing this point, the Commissioner found that even if this were true, "it does not follow that the site is unmonitorable. In fact, the Environmental Monitoring Plan accounts for all possible groundwater flow directions in the overburden, fractured bedrock and bedrock zones." [Interim Decision of the Commissioner, July 2, 1991, page 7.]
- - The Case for Monitorability
In this case, witnesses for both WMNY and DEC Staff testified convincingly that the Towpath expansion can be monitored as required by Part 360. Two of the witnesses - - Jonathan Howland for the Applicant and Edward Kieda for DEC Staff - - addressed monitorability primarily in terms of the landfill's engineered design. Three other witnesses - - Timothy Roeper and William Goodman for the Applicant, and Vincent Fay for DEC Staff - - addressed monitorability primarily in terms of the hydrogeologic setting in which the landfill would be placed.
The witnesses for WMNY and DEC Staff all demonstrated a strong background in the development and review, respectively, of landfill applications, as well as a thorough knowledge of the Part 360 requirements and how they help assure monitorability. Their testimony, which was basically unshaken during rigorous and extensive cross-examination, is the basis for the fact findings outlined above.
Dr. Howland is a civil engineer with extensive experience designing municipal solid waste landfills; since 1985, he has worked on Part 360 permit applications for eight sites, including four that involved liner systems extending over an existing waste mass, similar to the Towpath project. Mr. Roeper is a hydrogeologist with 19 years of experience in the investigation and characterization of proposed and existing landfill sites, including many in upstate New York that required an evaluation of groundwater and contaminant movement in fractured rock. Likewise, Dr. Goodman is a hydrogeologist with 16 years of experience evaluating the geologic and hydrogeologic conditions of western New York, including groundwater flow at landfills proposed for or actually built at fractured bedrock sites.
The opinions of DEC Staff, as impartial project reviewers, were particularly important in this case given the sharp conflict between experts for WMNY and the Towns. That conflict was especially intense on the issues of hydrogeology addressed by Mr. Fay. According to his pre-filed testimony, Mr. Fay is an engineering geologist who has spent 11 years with DEC reviewing geologic and hydrogeologic investigations and site characterizations for new landfills, lateral expansions and landfill closures. Mr. Kieda also has an extensive Department history that involves 17 years of work as an environmental engineer reviewing landfill applications for technical feasibility and Part 360 compliance.
The testimony of WMNY's and DEC Staff's witnesses adequately demonstrates that the Towpath site is independently monitorable, despite contrary testimony from the Towns' two experts, Mark Noll and Matthew Becker, which is discussed below. In fact, the monitorability of the Towpath site can be established in much the same way as it was in the Saratoga County matter: in relation to landfill design, knowledge of groundwater flow directions, and adequacy of the monitoring well network.
-- Landfill Design
The assurance of Towpath's monitorability is based in part on the landfill's engineered design, which involves a double composite liner and leachate collection system. As Dr. Howland explained, the secondary leachate collection system provides a means to evaluate the performance of the primary composite liner system, in that it is the first line of detection for excessive leakage from that system. The quantity and quality of the liquids in the secondary leachate collection system would be measured at eight distinct liner areas (or cells) beneath the facility, which would help identify the source of any liner break or tear. This data would be regularly collected for review in the event of a significant adverse change in existing water quality at one of the downgradient monitoring wells.
As Dr. Goodman explained, if the volume of liquids in the secondary leachate collection system is less than 20 gallons per acre per day and the parameter of interest is below the concentration found in the monitoring well groundwater sample, one can conclude that the source of the groundwater contaminant is not the Towpath facility. Conversely, if there is excessive flow into the secondary leachate collection system, and the flow exhibits one or more of the constituents that are elevated in the groundwater sample, then Towpath can be considered the likely contamination source, so that, in this sense, the leachate collection system becomes the facility's primary monitoring point.
The relevance of landfill design to the issue of monitorability was also emphasized by Mr. Kieda for DEC Staff, who testified that in discussing whether a "reasonable and prudent design" capable of detecting releases has been built, one should not ignore the ability of the physical design of the liners and leak detection systems to add critical information to the deliberative and investigative process as to the origin of a release which might reach the environment. Because, in the OSL overlay area, both OSL and Towpath would have secondary leachate collection systems capable of monitoring performance of the overlying liners, monitoring of these systems would help determine which facility is the source of any off-site leachate-related impacts. Also, WMNY's assumption of responsibility for the post-closure monitoring and maintenance of OSL removes any incentive WMNY might have to attribute Towpath's environmental impacts to the OSL facility.
Of course, landfill design is intended not only to detect leaks, but to prevent them in the first instance. However, that function is not relevant to the monitorability issue, as I ruled in striking portions of Dr. Howland's testimony concerning the safety record of landfills designed in accordance with Part 360 requirements. In a written ruling dated March 7, 2001, I said:
"The issues we are adjudicating concern the ability to detect, monitor and remediate releases that might occur from the landfill, not the likelihood of a release actually occurring. Whatever the safety record of landfills constructed under the new Part 360 regulations, those regulations still require that these landfills not be located in areas where environmental monitoring and site remediation cannot be conducted. . . The ability to monitor and remediate depends upon a proper understanding of the subsurface environment in which the landfill is located, working from the legal presumption that a release may occur, because if no release were possible, there would be no reason for the monitorability requirement in the first place." (Ruling, page 2.)
This reasoning was repeated in my oral ruling of April 4 striking another part of Dr. Howland's testimony, which concerned the adequacy of the Towpath liner system to protect against leachate leakage into the underlying OSL waste mass. This testimony, I said, had to be disregarded since it turned the hearing back to the issue of the likelihood of a release actually occurring, which I had said previously would not be considered. Landfill design, I said, is relevant to the extent it can assist in detecting and identifying releases, but not relevant to the extent it is meant to prevent them.
The Towns failed to address landfill design in their pre-filed testimony; in fact, neither of their witnesses is an engineer. The Applicant's explanation of how landfill design assists in monitorability was essentially unchallenged. In their questioning of the other parties' witnesses, the Towns' attorneys raised the possibility of a failure of the leachate collection system. However, there was no evidence, or even a suggestion, as to how this failure might occur. In this context, it bears noting that the Town of Murray unsuccessfully attempted during the issues conference to raise structural integrity issues, both in relation to earthquakes and the overlaying of waste on top of the existing OSL. [See issues rulings, pages 44-46.]
- - Groundwater Flow Directions
Apart from landfill design, a second factor that assists in site monitorability is knowledge of groundwater flow directions. As noted above, there are two water-bearing zones (or aquifers) through which contaminants could move off-site: one in the "top of rock" bedrock zone and the other in the "deep rock" zone. These zones were identified on the basis of packer tests in boreholes. Packer testing determines the hydraulic conductivity of isolated bedrock intervals prior to the construction of wells or piezometers, as explained in Mr. Roeper's testimony. This testing not only identified the two water-bearing zones, it also established the presence of the intermediate Medina aquitard, a low-permeability formation that separates them. The continuous presence of this aquitard across the site, and the fact that it impedes the flow of groundwater, were confirmed by water level measurements, aquifer test data, isotope data, and geochemistry data collected during the hydrogeologic investigation.
Water levels collected from wells meeting Part 360 standards were plotted and mapped to determine the directions of groundwater flow and the hydraulic gradient (or slope) of the water surface. This effort indicated that groundwater flow in both the "top of rock" and "deep rock" zones is generally to the north, except in the "deep rock" under the southeastern portion of the Towpath footprint, where flow is to the southeast. After determining existing groundwater flow directions, WMNY employed groundwater modeling to depict the impact of landfill construction in cutting off rainwater infiltration over the footprint area. As Mr. Roeper testified, the modeling indicated that the elimination of recharge would cause a small lowering of groundwater elevations beneath the site, but would not upset the prevailing directions of groundwater flow.
The potential for Towpath's construction to upset the groundwater flow regime was the main reason modeling was required by DEC Staff during its review of the project application. Although a computer model is not required in all cases for a landfill application, modeling acceptable to DEC is required in the case of a landfill proposed to be located next to a Class 2 inactive hazardous waste disposal site like the McKenna landfill [See 6 NYCRR 360-1.9(g)(1)(iv).] Such modeling is necessary to assess what hydrogeologic and environmental effects the landfill would have on the remediation of the inactive hazardous waste disposal site.
In this case, Staff reviewers were particularly concerned that if the recharge to the groundwater were sufficiently reduced by the Towpath liner construction, it would be possible that the contaminated groundwater beneath the McKenna landfill could migrate south and, eventually, underneath the Towpath footprint. As explained by Mr. Fay, this concern was alleviated by WMNY's modeling showing that Towpath's construction would not result in a major groundwater flow reversal. Whatever impact there is, Mr. Fay testified, would be verified by observing actual field conditions as they develop, and the groundwater monitoring array (in particular, MW2ETR, between Towpath and McKenna) would be checked quarterly to confirm that groundwater beneath McKenna is not moving to the south.
Knowledge of groundwater flow paths, now and as projected after the landfill is built, would be helpful in tracing leachate-derived impacts back from monitoring wells to their source, thereby assuring Towpath's monitorability as a separate entity. As Mr. Roeper explained, the groundwater flow direction within the "top of rock" and "deep rock" water-bearing zones is generally perpendicular to the equipotential lines (lines of equal hydraulic elevation or head) presented on the potentiometric surface map for these zones. If, for instance, a groundwater impact were detected at cluster E-43 (north of the OSL overlap), groundwater flow paths would eliminate McKenna as a potential source. Similarly, groundwater impacts at any cluster east of E-34 (near Towpath's northwest corner) would eliminate OSL as a potential source. Finally, with the exception of MW-2, all of the monitoring well clusters would be upgradient of the McKenna landfill, irrespective of the changes in flow direction that are expected from McKenna's remediation. Therefore, as Mr. Roeper argues, it is unlikely that any given monitoring well could be impacted by both McKenna and Towpath, which further helps to identify the source of a potential release.
-- Monitoring Well Network
Finally, the placement of monitoring wells in relation to groundwater flow paths is also important to assuring the monitorability of the Towpath facility. The Department's regulations require that monitoring wells be capable of detecting landfill-derived groundwater contamination within the critical stratigraphic section. Horizontal spacing of wells must be based upon site-specific conditions including groundwater flow rates and estimated rates of longitudinal and transverse dispersivity. In the first water-bearing unit of the critical stratigraphic section (which in this case is the "top of rock" zone) well spacing must not exceed 500 feet along the downgradient perimeter of the facility. [See 6 NYCRR 360-2.11(c)(1)(i)(a) and (b).]
WMNY's monitoring array would be developed in a phased approach as landfill cells are constructed, consistent with 6 NYCRR 360-2.11(c)(5)(ii)(b). A total of 22 wells (12 in the "top of rock" and 10 in the "deep rock" ) are planned, some of which have been used previously to monitor OSL. Of these 22 wells, nine (six in the "top of rock" and three in the "deep rock") would monitor the initial stage of development. Well MW2ETR, which has been impacted by McKenna leachate, is not expected to become part of the operational monitoring array until four to six years after the landfill begins operating (when cells 4 and 5 and reached). However, it would be monitored from the start to check the effectiveness of McKenna's remediation in cleaning up the groundwater south of that landfill.
The sampling of monitoring wells and the comparison of pre- and post-operation water quality would be useful in determining where any escape of Towpath leachate is having impacts outside the footprint area. During the hearing, WMNY committed to eight rounds of pre-operation water sampling (double the four rounds required by Part 360) to assure an accurate gauge of pre-operation water quality and to afford the opportunity to compare pre- and post-operation water quality on an intra-well basis. Analysis of water quality on an intra-well basis would eliminate problems associated with spatial variability when one pools data by sub-zone, as had been discussed previously in the EMP due to the limited rounds of testing available when the EMP was written and submitted.
As Mr. Fay testified, DEC Staff expressed a particular concern about the use of MW2ETR and MW2DR as monitoring wells, because they both have been polluted by McKenna leachate. Theoretically, he said, one can monitor from a well whether or not it has been previously contaminated; one simply needs to establish the existing water quality, and then monitor for significant contaminant increases. However, Mr. Fay said he was not comfortable with this approach, so WMNY has addressed Staff's concern by agreeing that if the McKenna remediation does not result in improved water quality at the MW-2 cluster, it will replace these wells with two additional ones to be installed within the Towpath berm, south of the area affected by McKenna. These wells would have to go in at least two years before the operation of the adjacent landfill cells, to acquire the eight rounds of data necessary for intra-well analysis.
According to Mr. Fay, his review of the Towpath EMP resulted in the addition of well cluster E43 (north of the OSL overlay) to enhance monitorability in that vicinity, the westward relocation of well cluster E42 (outside the northeast corner of the footprint) so that it can better monitor both cells 7 and 8, and the commitment to replace the MW2 cluster if the McKenna remediation does not cause a reasonable drop in contaminant levels there. With these adjustments, he was satisfied that the well array is properly designed to detect landfill-derived impacts, noting that contaminants do not move in straight-arrow paths, but in spreading plumes due to dispersion associated with advective transport in groundwater.
As further discussed below in relation to their own case, the Towns sought to establish that contaminants moving along certain flow paths could travel off-site while escaping detection in the monitoring well array. While this is theoretically possible (and Mr. Fay conceded the possibility for at least one scenario) the Towns' exercises generally misrepresented how contaminants would actually travel. Leachate releases do not occur instantaneously at points in the water-bearing landfill subsurface and then move off-site in line fashion. Rather, they begin in the liner system, where in all likelihood they are detected in the leachate collection system even before they reach the water-bearing zones. Also, should it penetrate both landfill liners, a leachate release must next move through the engineered subgrade, which is designed to retard its advance such that it would take one and a half years for the subgrade to be penetrated. Only after penetrating the subgrade and any overburden, which is discontinuous across the site, would any release reach the bedrock and, eventually, its water-bearing layers. All this movement would tend to broaden even the smallest leachate break-out, and in the water-bearing layers one would expect further dispersion of contaminants, thereby enhancing the possibility of monitoring well detection. Finally, to reach the "deep rock" layer beneath the landfill, contaminants would have to penetrate downward through the low-permeability intermediate Medina aquitard, a difficult task when advective flow in the "top of rock" would tend to pull contaminants off-site in a horizontal fashion.
Monitoring, the Towns claimed, could be improved by increasing the number of wells, moving the downgradient wells further away from the footprint, or (as a preferred solution) moving the Towpath footprint further away from the wells, in effect decreasing the size of the project. However, as WMNY pointed out in its reply brief, DEC's regulations require that downgradient monitoring wells must be located as close as practical, but not more than 50 feet from the waste boundary. [6 NYCRR 360-2.11(c)(1)(i)(e).] According to Mr. Fay, one wants to locate monitoring wells as close to the landfill as possible, since the closer the location, the higher the concentration of leachate that can be detected. Should the liner system detect any leakage, Mr. Fay said additional wells could then be added downgradient of the leaking landfill cell. Given the low permeability of the subgrade, the costs of well construction and maintenance, and the speed with which new wells can be installed and sampled if needed, deferring a decision to add wells until a liner leak is detected is preferable to expanding the monitoring well network at this time.
- - Graphical Methods (Chemical Fingerprinting)
While the leak detection capacity of the landfill design, knowledge of groundwater flow paths, and establishment of an adequate well array are key to establishing the monitorability of the Towpath facility, they are not the only considerations relied on by the Applicant. WMNY also relies on graphical methods (otherwise known as chemical fingerprinting) to determine if groundwater has been impacted by leachate and to help determine the source of that impact. Such reliance is warranted, as the evidence shows that graphical methods would contribute to monitorability even if, standing alone, they would not ensure it.
The use of chemical fingerprinting here is somewhat more complicated than it was in the Saratoga County matter. In that matter, the County proposed to site its municipal solid waste landfill next to a concurrently operating landfill for paper mill sludge, and I found that because of the landfills' different waste streams, their leachates would have different chemical characteristics, which would be helpful for monitorability purposes. That reasoning does not apply here, since there is no certainty that the waste stream entering Towpath would be markedly different from what was taken in at OSL and McKenna. On the other hand, McKenna and OSL are both closed, so they and Towpath would not be operating simultaneously. This is an important distinction, because, as Dr. Goodman testified, leachates can be distinguished not only on the basis of source, but on the basis of age.
Dr. Goodman testified on rebuttal that today's municipal solid waste stream is different from what it was in the past, meaning that Towpath's leachate could have a quite different chemistry from that of OSL and McKenna. However, he added that even if it does not, Towpath's leachate could still be distinguished on the basis of its age, as manifested by its strength. As Dr. Goodman explained, OSL's leachate is aging and McKenna's leachate has matured to the point that concentrations of major ions are approaching regulatory groundwater quality standards. According to Goodman, older leachate from either of these landfills could be distinguished from a fresh Towpath outbreak because of the varying rates at which contaminants weaken. For instance, he said under cross-examination that ammonia and total organic carbon stay elevated longer as leachate ages, meaning they are present in a mature leachate at a relatively higher abundance than other constituents.
Of course, Towpath must be monitorable not only for its operating life, but for a 30-year post-closure period, when its leachate would be aging in the same way that OSL's and McKenna's are now. By that time, as Dr. Goodman explained, these other landfills will be non-issues, given the continuing weakening of their leachates during the operating life of Towpath.
Under questioning by the Towns, Dr. Goodman conceded that one could not distinguish leachates with identical chemistries in the same well. One could only do that, he said, with an understanding of groundwater flow directions, so that the leachate can be traced from the well back to its source. It is important to remember that WMNY's plan for monitorability is not based exclusively on chemical fingerprinting, and that the explanations of chemical fingerprinting in the EMP are merely examples of how that process could be employed at the Towpath site, in conjunction with other things such as monitoring the liner system.
In the Saratoga County matter, I concluded that chemical fingerprinting appeared to be useful in determining which landfill was causing a particular problem, but that, by itself, chemical fingerprinting did not ensure monitorability. I draw the same conclusion here. Even if Towpath's leachate closely mirrors that of OSL or McKenna, age-related changes to its chemical composition, coupled with an understanding of groundwater flow patterns, should be helpful in tracking contaminants to their source.
- - Towns' Case
The Towns presented two witnesses, Dr. Mark Noll and Dr. Matthew Becker, on monitorability and the others issues bearing on site hydrogeology. Dr. Noll has a Ph.D. in soil physical chemistry and is an assistant professor in SUNY-Brockport's Department of Earth Sciences. Dr. Becker has a Ph.D. in water resources engineering and is an assistant professor of geology at SUNY-Buffalo.
Both witnesses are well-qualified in their fields, and their competence to give expert opinions was not challenged by the other parties. However, I have not adopted their conclusions as my own because of apparent flaws in their analysis that were revealed both during their cross-examination by WMNY counsel, and by WMNY's rebuttal case involving the return of Dr. Goodman and Mr. Roeper to the stand.
WMNY was able to show that many of the Towns' conclusions were based on incomplete information, inaccurate or unreasonable assumptions, and misunderstandings of the permit application or the Part 360 regulations. Some of this may have been attributable to the Towns' witnesses' relative lack of experience in landfill permitting matters, when compared to the experience of the other witnesses, as discussed above. For instance, under cross-examination, both Dr. Noll and Dr. Becker admitted that they had never conducted a hydrogeologic investigation - - or prepared an environmental monitoring plan - - for a solid waste management facility seeking a Part 360 permit. Dr. Noll admitted that he has not done much hydrogeologic work at all in western New York State, and that he has never done independent research on landfill leachate, though the geochemical aspects of monitorability were the main focus of his testimony. Also, Dr. Becker admitted that the greater portion of his experience has involved igneous rock sites, not sedimentary rock sites like this one.
- - Dr. Noll
Dr. Noll became involved in this matter in July 1999, shortly before the issues conference. In preparation of his pre-filed testimony, he reviewed both the hydrogeologic report and the EMP that were submitted as part of the Part 360 application. Dr. Noll also performed various analyses using the water quality data in paper copies of laboratory reports furnished by WMNY during discovery. Dr. Noll analyzed the data in various different ways. First, he generated Piper and Schoeller diagrams to graphically represent the cation and anion information. Second, he calculated charge balance errors for the cations and anions. Third, he performed mass balance calculations using chloride, a major ion, to evaluate mixing and dilution reactions associated with groundwater flow.
According to Dr. Noll, these three methods are all commonly used to analyze groundwater chemistry and provide information on the mixing of different water sources. However, he said that WMNY had chosen not to do mass balance calculations and had unwisely restricted use of graphical methods to the chemical fingerprinting of major ions alone. In his pre-filed testimony, Dr. Noll drew several conclusions that are key to the issue of monitorability:
1. It is not possible to graphically distinguish leachate from McKenna and OSL, or to know what Towpath's leachate would be like, since Towpath has not yet been built.
According to Dr. Noll, graphical methods using major ions poorly distinguish the existing leachates from the McKenna and OSL landfills, and these leachates would be even more difficult to distinguish when mixed with background groundwater. Noll said his Schoeller diagrams show a similar pattern for both McKenna and OSL leachates, except with regard to magnesium, and that the two leachates plot in overlapping fashion on his Piper diagrams. (The use of Schoeller diagrams for chemical fingerprinting was not challenged by the other parties, though, unlike Stiff and Piper diagrams, they are not referenced in WMNY's discussion of monitorability in the EMP.)
2. It is not possible to distinguish leachate from background groundwater at the Towpath site because of the variability of the natural groundwater chemistry, the statistical basis by which background is calculated, potential future variations in groundwater chemistry due to Towpath's construction, the proximity of upgradient wells to landfill cells, and the chemical comparability of leachate and local groundwater.
According to Dr. Noll, concentrations of the major ions chloride and sodium vary by three orders of magnitude across the site, so that characterizing background water quality by a single well within a sub-zone (as would be the case for sub-zone 1 in the "deep rock" water-bearing layer) would create problems of statistical validity. Noll said that Towpath's construction and eventual capping would severely limit recharge so that groundwater with high major ion concentrations could migrate, undiluted, beneath the site from southeast to northwest, forcing trigger level exceedances that one might otherwise associate with a leachate escape. He said that if a leak occurred near the landfill's southern boundary, leachate might impact upgradient wells given their proximity to the footprint and the changed post-construction hydrogeologic conditions. Finally, citing data from well 2-DR, he said that concentrations of major ions in OSL and McKenna leachate are actually less than those found in background groundwater, and that if the same were true for Towpath leachate, major ion data alone would not be useful for monitoring purposes.
3. None of the three sub-zones identified in WMNY's EMP are monitorable in either the "top of rock" or "deep rock" aquifers.
Dr. Noll addressed each of these sub-zones separately in his testimony, but in general his conclusions were based on the variability of groundwater chemistry within the sub-zones, and the possibility that, because of this variability, trigger values for these sub-zones might be unrealistically high, resulting in possible masking of leachate impacts. Dr. Noll said that due to wide spatial variations in groundwater chemistry, trigger values more protective of the environment should be set using the mean plus one standard deviation, rather than mean plus three standard deviations, which is the Part 360 standard. Dr. Noll said that, to address concerns regarding spatial groundwater variability, intra-well comparisons and the establishment of separate trigger values for each well would be more appropriate than the establishment of these values by sub-zone.
4. Well MW2TR is unsuitable for use as a monitoring well given the past impacts of McKenna leachate at the well's location.
According to Dr. Noll, Well MW2TR and McKenna leachate show similar patterns when graphically represented in Schoeller diagrams, and the impact of McKenna leachate is apparent in both the "top of rock" and "deep rock" aquifers at this location. According to Noll, this impact suggests that either there is a natural connection between the "top of rock" and "deep rock" aquifers (contrary to WMNY's hydraulic model of the site) or the MW-2 cluster is acting as a conduit for leachate to migrate to the "deep rock" aquifer (in which case the well should be decommissioned to eliminate the impact). Because he says it is not now possible to determine which hypothesis is true, Noll said the well should be decommissioned, a new well installed, and continued monitoring completed to evaluate changes in the "deep rock" aquifer chemistry. Furthermore, Noll expressed concern that wells 34ETR and 34 EDR also show evidence of McKenna leachate impacts, which makes their use for monitoring Towpath problematic.
5. Leachate from OSL as well as McKenna may have penetrated the Towpath subsurface.
According to Noll, OSL leachate has elevated levels of boron, and boron concentrations in groundwater at the Towpath site have a geochemical gradient that proceeds from high values in the southwestern portion (near OSL), decreasing in a roughly radial pattern as one moves to the east and north, counter to both the concentrations of the major ions investigated and the site's hydraulic gradient. Noll said the spread of boron from OSL to Towpath may be due to lateral dispersion or more complex hydraulics than those described in WMNY's hydrogeologic report.
Overall, Dr. Noll concluded that one could not monitor Towpath adequately in light of background groundwater conditions and leachate impacts he attributed not only to McKenna, but to OSL as well. (WMNY and DEC Staff do not concede any leakage from OSL, and say that with the remediation of McKenna, that landfill will not be an obstacle to Towpath's monitorability by the time the cells in McKenna's vicinity are constructed.) WMNY was able to undermine Dr. Noll's conclusions through a combination of cross-examination, contrary rebuttal testimony from Dr. Goodman and Mr. Roeper, and references to application materials (including, most important, the EMP) as well as Part 360 monitoring requirements.
Important points established in relation to Dr. Noll's testimony include the following:
1. Monitorability by use of graphical methods is not limited to major ion constituents.
WMNY's EMP (Exhibit 59) discusses graphical methods in relation to the plotting of major ion data of groundwater and leachate samples to provide visual fingerprints of those samples that can be used to distinguish background water quality from contaminated groundwater. (Section 3.5.4, page 3-24.) However, as WMNY points out in its closing brief, DEC's Part 360 regulations require the quarterly analysis of 21 different water quality parameters, 14 of which are not considered major ions, and 10 of those 14 are also leachate indicators. Trigger values have been established for all of these parameters, and they would be evaluated consistent with Figure 3-2 of the EMP, a flow chart for groundwater data evaluation. Dr. Noll understandably could have read the EMP's description of graphical methods as limiting their use to major ions. But such a limitation was not the intent of WMNY, nor was it the expectation of DEC Staff. DEC Staff requested that WMNY include in its EMP examples of the types of chemical fingerprinting analyses it would use to identify a leachate outbreak, but there are a number of different methods, both graphical and numerical, that can be used not only with regard to major ions, but other measured parameters as well. As Mr. Roeper explained, the EMP was not intended to be "an exhaustive dissertation" on the various fingerprinting methods; in fact, he said, "There is a world of possibilities that could be used."
Roeper confirmed that, in the quarterly sampling of its monitoring well network, WMNY would be looking for parameters that exceed their trigger values. Should a trigger value be exceeded, that parameter in the groundwater would be compared to the same parameter in the Towpath leachate, to see if there is a possible relationship.
Dr. Noll conceded that trigger values would be established for a number of parameters other than major ions, and agreed that detection of certain volatile organic compounds (like TCE, which is not a major ion) could suggest a leachate impact. Mr. Roeper later agreed that one could detect groundwater contamination from volatile organic constituents that appear in both the Towpath leachate and wells downgradient of the landfill.
Dr. Noll also acknowledged one could use the isotopic ions "Oxygen 18" and deuterium to distinguish landfill leachate from background groundwater, noting how on a graph (received as Exhibit 60) McKenna and OSL leachate plot far from the global meteoric water line that represents groundwater quality.
2. The recalculation of trigger values on an intra-well basis would address Dr. Noll's concerns about natural variability of parameter concentrations across the Towpath site.
An intra-well approach involves groundwater samples being compared to others in that well's history. Converting to such an approach would mean the replacement of the trigger values previously set on the sub-zone basis outlined in the EMP. The EMP states that monitoring wells would be installed and sampled at Towpath approximately two years prior to deposition of waste in adjacent cells so that seven to eight quarters of data would be available before waste deposition. [Section 3.2.1, page 3-11.] It also states that trigger values would be recalculated following the collection of two years of data prior to facility operation. [Section 188.8.131.52, page 3-7.] In its closing brief, WMNY said it would agree to a permit condition that, prior to operation, trigger values would be recalculated on an intra-well basis for each of the wells that would be part of the monitoring program for which there is at least eight rounds of data. [WMNY closing brief, July 17, 2001, page 60, footnote 25.] On cross-examination, Mr. Roeper testified that there already is sufficient data to calculate intra-well statistics for the wells that would initially be part of the monitoring network.
As WMNY argues, going over to an intra-well approach is more protective of the environment because it eliminates spatial variability that is inherent to a sub-zone approach. When spatial variability is eliminated, a lower standard deviation results, which lowers trigger values because those values are calculated on the basis of mean plus three standard deviations. Dr. Noll agreed that setting trigger values on an intra-well basis is more appropriate than setting them on a sub-zone basis. The permit condition proposed by WMNY should become part of any final permit, since there is no apparent dispute among the parties that the intra-well approach is more conservative and environmentally protective than the sub-zone approach outlined in the EMP. However, it would not be appropriate to re-set trigger values at this time, since they should be set on the most recent data available before landfilling operations actually begin.
3. There is no persuasive evidence that OSL is spreading contamination across the Towpath site.
Dr. Noll's concern about OSL leaking is based on his review of boron data in "deep rock" monitoring wells. Dr. Goodman agreed with Dr. Noll that boron is a significant constituent of OSL leachate, but added that, in the "top of rock" water-bearing zone east of OSL, there is no evidence of other leachate indicators suggestive of spreading OSL contamination. Goodman adds that if OSL leachate were spreading eastward from that landfill, it would appear in the "top of rock" zone before entering the "deep rock" zone, and there is nothing to suggest this has happened. Goodman also says it is hard to understand leachate spreading eastward from OSL to Towpath when groundwater flow in the "deep rock" of the western part of the Towpath site is generally from south to north, and the geochemical gradient there is from north to south. According to Goodman, leachate breaking out of OSL would tend to move north through the "top of rock" water-bearing layer before it could penetrate the "deep rock" layer, so one would not expect it to be detected first in the deep rock at E-3DR, in the southwest corner of the Towpath site.
Dr. Goodman offered credible evidence that the background boron concentrations at the Towpath monitoring wells are attributable to borate salts that came out of sea water when the underlying rock strata were formed. WMNY produced textbook documentation that the Medina formation and the Queenston shale both have naturally elevated boron concentrations. Also, WMNY was able to show that these concentrations have little variability across the site.
4. Even if leachates from both McKenna and OSL have spread under the Towpath footprint, these two leachates are distinguishable from each other, and both would be distinguishable from any leachate generated by Towpath.
In his pre-filed testimony, Dr. Noll himself acknowledged that McKenna and OSL leachates can be distinguished by comparing their concentrations of magnesium. However, as Mr. Roeper pointed out, and Dr. Noll conceded on cross-examination, they may to a lesser extent also be distinguished by comparing their concentrations of chloride and alkalinity. Concentrations of all three constituents are markedly higher for OSL leachate, as is apparent by looking at Noll's own Schoeller diagram, Exhibit 11-C, based on four samplings of the two leachates encompassing the years 1999 and 2000. (Dr. Goodman points out correctly that Noll's use of a log scale for the readings in milliequivalents per liter on this exhibit suggests a greater similarity between the two leachates than actually exists.)
Exhibit 41 (WMNY's Piper diagram for OSL and McKenna leachates) also highlights the difference between the two leachates based on their total dissolved solid concentrations, which are much higher for OSL, as evidenced by the comparison of circle sizes in the diagram's central diamond (a larger circle for the OSL leachate, a smaller one for the McKenna leachate).
In his rebuttal testimony, Dr. Goodman presented a series of graphs and diagrams (Exhibits 80 to 93) showing how McKenna and OSL leachate plot differently from each other and background groundwater in the various monitoring sub-zones that WMNY established. Through cross-examination, the Towns then sought to show how it would be difficult to identify leachate impacts when leachate is limited to concentrations of 1 percent and 5 percent in background groundwater. Dr. Goodman acknowledged this difficulty, especially if one had a very limited number of groundwater samples and looked at only certain parameters, as assumed in the Town's questions. However, that would not be a real-world scenario, because WMNY would be monitoring for a wide assortment of parameters, and doing so on a regular basis, potentially with increased frequency if a trigger level is exceeded. Goodman also pointed out that water quality monitoring does not occur in a vacuum, and that other factors (including an assessment of groundwater flow patterns) also are important to tracing leachate impacts back to their source. Goodman noted that all leachates have certain indicators - - elevated alkalinity, elevated ammonia, and elevated total organic carbon - - that would tend to signal their appearance in monitoring wells.
As for future Towpath leachate, Dr. Goodman emphasized that even if its chemistry were identical to OSL's or McKenna's, its distinguishing trait would be its strength, given the maturation and associated weakening of leachates from the other two landfills.
5. There is no natural connection between the "top of rock" and "deep rock" at the MW-2 cluster, nor is that cluster transmitting leachate from the "top of rock" water-bearing layer to the "deep rock" water-bearing layer.
At the time WMNY prepared its hydrogeology report, it considered the idea that drawdown during drilling of MW-2DR resulted in elevated concentrations of total dissolved solids in that well. But as noted by Mr. Roeper, if that were the case, one would see a reduction in these concentrations over time, and that has not occurred. The idea that MW-2DR is a conduit for leachate migration from the top of rock to the deep rock may also be ruled out, because of the significant difference in the potentiometric heads in the two water-bearing zones at that location.
In its closing brief, WMNY lays out the various lines of evidence that there is no possibility of a connection between the two water-bearing zones, and that the intermediate Medina aquitard exists at the MW-2 cluster. That evidence, overlooked by Dr. Noll, includes the hydraulic gradient between the two zones throughout the site, the isotopic data which show different plots for MW-2ETR and MW-2DR, the VLF geophysical survey which located no vertical conduits for groundwater flow, the aquifer test in the "deep rock" zone (which resulted in a drop of water levels there, but no response in the "top of rock" zone, suggesting poor hydraulic communication between the two zones), packer test data indicating the presence of the aquitard at the MW-2 cluster, and the surface geophysical investigation.
WMNY's witnesses convincingly explained that the high level of total dissolved solids in well MW-2DR is likely related to the identified stagnation area in the "top of rock" water-bearing zone south of McKenna. The stagnation of water at this location (where the prevailing northerly flow of groundwater encounters the southerly flow from McKenna) means that advection is not controlling there; instead, McKenna contaminants are diffusing through the aquitard from areas of higher concentration in the "top of rock" zone to areas of lower concentration in the "deep rock" zone.
As noted in the findings of fact, McKenna's remediation should eliminate the stagnation zone and restore the overall northerly flow of groundwater in the area of the MW-2 cluster before Towpath begins operating in that vicinity. Should water quality not improve, the potential remains for establishing a new Towpath monitoring location further to the south, as noted in the findings of fact.
6. Dr. Noll used the wrong well data in raising his concerns about variability of background groundwater chemistry.
Dr. Noll questioned the validity of using the mean plus three standard deviations (as required by Part 360) to calculate trigger values because of high variability in the groundwater chemistry, citing in particular sub-zone 1 in both the "top of rock" and "deep rock" aquifers. He said that while well B27TR (also known as B27ETR) showed a reasonable comparison of the mean and median values for major ions, well 2-TR (also known as 2-ETR) showed substantial variation between the mean and median for sodium, potassium, magnesium, chloride and sulfate, which might indicate that sample variation for well 2-TR does not follow a normal distribution. According to Noll, well 2-DR (also known as 2-EDR, the only "deep rock" well sampled in sub-zone 1) showed a similar problem: major ion constituents varied by over one-half to one order of magnitude, and a comparison of mean and median values showed discrepancies in all major ion constituents except alkalinity, again suggesting that the data were not normally distributed.
Dr. Noll's analysis was based on WMNY data, but as it turned out, he used data for the wrong wells. As was brought out during his cross-examination, Dr. Noll erroneously used data for wells C-2TR and C-2DR (wells that are off the Towpath site and not part of the monitoring well network) for his assertions regarding wells 2-ETR and 2-EDR. Noll used data for C-2TR and C-2DR from December 1999, March 2000 and October 2000; data for these dates from wells 2-ETR and 2-EDR do not exist. This error affected many of Noll's exhibits (11-E, 11-F, 11-H, 11-K and 11-N) and effectively destroyed his mean and median analysis.
In his redirect examination, Dr. Noll admitted his confusion of the wells, but said that using the correct data for 2-ETR and 2-EDR, there was still evidence of non-normal distribution for at least a few constituents, namely sulfate in well 2-EDR and chloride in well 2-ETR. However, as WMNY points out, Dr. Noll offered his new conclusions without supporting analysis or calculations. Also, Mr. Roeper examined these two parameters using what he called the Shapiro-Wilks test, an EPA-recommended statistical method for determining whether groundwater is normally distributed, and found that the data were normally distributed. Mr. Roeper explained that EPA does not recognize mean and median comparisons to determine the normal distribution of data, and that Noll's textbook reference to a mean and median approach does not apply in this context because that approach depends on determining a particle size, which groundwater does not have.
7. Dr. Noll's charge balance calculations were based on an improper assumption.
Dr. Noll performed charge balance calculations for the ion data plotted in his Schoeller diagrams, and found large charge balance errors, which would reflect apparent discrepancies in the number of milliequivalents per liter of anions and cations that are required to maintain the electrical neutrality of a solution. These large errors suggested to Noll that the ion data were not well distributed and fed his concern about using that data to set trigger values.
In performing his calculations, Dr. Noll assumed the data as reported in WMNY's lab reports represented dissolved ion constituents, which requires the filtering of samples. However, as WMNY pointed out, Part 360 mandates that groundwater samples not be filtered, unless otherwise approved by the Department [see 6 NYCRR 360-2.11(d)(3)(vi)(f)], and not filtering, which was the case for data Dr. Noll reviewed, leaves one with total ion concentrations, not dissolved ion concentrations. Dr. Noll conceded that not filtering samples can create large charge balance errors. In fact, WMNY's hydrogeology report notes that the cation/anion balances for OSL monitoring wells were typically higher than is generally acceptable, which it points out is likely due to the lack of sample filtering.
8. Dr. Noll's mass balance calculations were flawed and assumed an unrealistic scenario.
As noted above, Dr. Noll performed mass balance calculations using chloride, a major ion, to evaluate mixing and dilution reactions associated with groundwater flow. Noll says these calculations are useful because they show links between geochemistry and hydrogeology, though Dr. Goodman, testifying for WMNY, said that they are not required by Part 360, that he had never done them as part of a Part 360 investigation, and that there are no textbooks that describe the methodology one would use to do them.
Dr. Noll performed his calculations using chloride because he said it is a conservative tracer. He is concerned that once Towpath is built and recharge is curbed under its footprint, high total dissolved solids will move, undiluted, across the footprint in the "top of rock" zone. However, once Towpath is constructed, groundwater in the "top of rock" zone would continue to move generally from south to north. Dr. Noll did his calculations employing high concentrations of total dissolved solids (and chloride in particular) as recorded at 2ETR, at the footprint's southeast corner, in March 1999. But he omitted reference to the simultaneous readings at B27ETR (midway across the footprint's southern perimeter) and E-3TR (in the southwest corner) which are roughly comparable to those at 34 ETR (in the northwest corner). The effect of this was to overstate the concentration of chloride along the southern edge of the footprint, in comparison to the concentration along the northern edge.
Dr. Noll further suggested that high concentrations of chloride at 2 ETR could reach 34 ETR by spreading under the footprint from southeast to northwest in the "top of rock" zone. However, this would be at odds with the south-to-north advective groundwater flow, which prevails against movement dictated by concentration gradients. Also, it suggests a level of constituent dispersion, or spreading with groundwater movement, that is not realistic. Testifying on rebuttal, Mr. Roeper said there is no mechanism for groundwater flow from southeast to northwest in the "top of rock" zone. He said that the amount of recharge lost due to Towpath's construction would be minor compared to the large volume of water flowing across the site from south to north, so he would not expect the concentration of total dissolved solids to rise once the liner system is put in. In fact, he twice compared the size of the liner to that of a "postage stamp" in relation to the regional groundwater system.
9. Dr. Noll failed to use the entire WMNY water quality data base, even though this data base was furnished by WMNY on computer disc to counsel for the Towns (and from Town counsel to Dr. Noll) more than two weeks before the Towns' pre-filed testimony was due.
Rather than use entire data base, Dr. Noll performed his analyses on the basis of paper copies of laboratory reports provided to the Towns by WMNY during pre-hearing discovery. For his Schoeller diagram comparison of McKenna and OSL leachates, he used four data sets, though these leachates had been sampled on eight different occasions. Likewise, he did not use all the available data sets for the monitoring wells depicted in his exhibits.
Dr. Noll testified that he used sampling data for April 1999, December 1999, March 2000 and October 2000, representing the four most recent samplings for which he had complete data. Noll said he omitted data from an August 1999 sampling because data were missing for some wells, though he could not recall if there was August 1999 data available for all the wells he referenced in his exhibits. Noll's failure to use summertime data was cited unfavorably by Dr. Goodman, who said it is important that the data reflect all seasonal variations, including the summertime low water table condition. Goodman pointed out that data from a June 2000 sampling were as complete as any of the data sets that Dr. Noll used, and that incorporating that data would have addressed the issue of seasonal geochemical variations.
Witnesses for WMNY and DEC Staff emphasized that one should use all existing data to reach the best conclusions, and that selective use of data must be viewed with some suspicion. Even so, it was not generally demonstrated that Dr. Noll selected data sets so as to skew his results in a manner favorable to the Towns' position.
10. Dr. Noll misunderstood how alkalinity data were reported in WMNY's laboratory reports.
In Dr. Noll's Schoeller diagrams, he identified alkalinity as carbonate on the understanding that the lab reports he reviewed reported the carbonate ion as the dominant species. He said his conversion of the lab data from milligrams per liter to milliequivalents per liter (a conversion necessary to develop his Schoeller diagrams) used both the molecular weight and charge of carbonate, and that his calculations would have been different had he considered the bicarbonate ion to be the dominant species.
In fact, Kenneth Kasparek, technical director for Severn Trent Laboratories, the certified lab that analyzes and reports the Towpath sampling data, testified on rebuttal that total alkalinity is expressed in the lab reports in milligrams per liter of calcium carbonate, as required by EPA, without differentiating between carbonate and bicarbonate concentrations. Kasparek said that the lab reports do not report alkalinity as carbonate because, based on the pH of the samples, carbonate is not the dominant species; the predominant species is bicarbonate, and the carbonate concentration is insignificant. Dr. Noll agreed that for the leachate and groundwater samples he evaluated, the pH values would indicate bicarbonate as the dominant species, which was also confirmed by textbook references (Exhibit 64, Fetter; and Exhibit 66, Freeze and Cherry) indicating that carbonate is the dominant species only for very alkaline water with a pH of 9 or higher.
Dr. Noll's misreading of the lab information affected his Piper diagrams (Exhibits 11-D and 11-R) as well as his Schoeller diagrams (11-C, 11-J, 11-S, 11-T and 11-U) with regard to their identification of alkalinity values. Noll said that had he considered bicarbonate to be the dominant species, his values would have been about half of what he actually reported, due to the different charges on carbonate and bicarbonate ions. Mr. Kasparek agreed that Noll's assuming carbonate (rather than bicarbonate) to be the dominant ion species affected the conversion of milligrams to milliequivalents by a factor of almost two.
All this being said, if Dr. Noll's mistake affected each of his alkalinity determinations in the same way, it is unclear what impact the mistake has on his conclusions, to the extent these conclusions are based on a comparison of values from different sources, rather than an assessment of the absolute values themselves.
11. Dr. Noll's Piper diagrams omit important information, and are somewhat deceptive.
The Piper diagrams attached to Dr. Noll's pre-filed testimony are not fully completed since the trilinear diagrams for cations and anions are not filled out. Dr. Noll testified that he prefers to plot information in the central diamond only, because that diamond represents the complete water chemistry. However, as Dr. Goodman explained, the trilinear diagrams provide valuable information to the degree that similarities in cations and anions influence how data plot in the central diamond.
Furthermore, Dr. Noll's Piper diagrams do not contain data points sized in proportion to differences in total dissolved solids concentrations, which is important because, as even Dr. Noll noted, that is how one could distinguish a very dilute solution from a very concentrated solution having the same ion chemistry. This sizing is apparent in WMNY's own Piper diagrams, which illustrate, for instance, the relative strengths of McKenna and OSL leachate. Piper diagrams prepared by WMNY as part of its rebuttal case (Exhibits 81, 83, 85, 87, 89, 91 and 93) show clear distinctions in amounts of total dissolved solids in leachate and groundwater samples, which would be helpful in identifying the source of a release.
Finally, as WMNY argues in its closing brief, Dr. Noll's Piper diagrams are deceptive to the extent they suggest overlaps between leachate and groundwater. For instance, in Exhibit 11-R, Noll plotted four data points for McKenna leachate and four data points for well 34ETR. Of the four data points he showed for well 34ETR, only one overlapped with the data points for McKenna, and that was because of an obvious outlier value for sodium. (This high reading for sodium at well 34ETR, recorded in March 2000, suggests a possible "hit" of McKenna leachate at that location which has since subsided, as evidenced by much lower readings, in line with the well's previous history, that have been recorded subsequently.)
While, for the reasons stated above, I do not credit Dr. Noll's conclusions about monitorability, it is also worth noting two points on which he and the other parties' experts seem to agree: (1) One should not limit graphical methods to major ions, but extend them to a wide range of parameters; and (2) Trigger levels that are established on an intra-well basis are preferable to those that are set on a sub-zone basis. As noted above, groundwater monitoring for a wide array of parameters, many of which are non-ion leachate indicators, would provide the data necessary to do chemical fingerprinting on a broad scale. Also, WMNY's proposed permit condition - - which met no objection from the other parties - - would assure that intra-well trigger values are set where sufficient data exist to fix such values on a reliable basis.
- - Dr. Becker
The Towns' other witness, Dr. Becker, became involved in this matter in November 2000, after being contacted by Dr. Noll. According to his pre-filed testimony, Dr. Becker reviewed WMNY's hydrogeologic report and associated MODFLOW computer modeling, then performed particle tracking analysis and transport simulations using WMNY's model but adding a value of dispersivity derived from literature sources. To facilitate his review, Dr. Becker said he imported the input and output files for WMNY's model into a software known as Visual MODFLOW, a graphical user interface that allows for the review of output in graphical form.
Dr. Becker's particle tracking was performed using the program MODPATH, which estimates the path that a theoretical particle might take if it were placed in the flow field calculated by MODFLOW and allowed to "float" along with the groundwater in the "top of rock" or "deep rock" water-bearing zones. Particle tracking was done in two modes: (1) steady-state (in which the particle is afforded an infinite amount of time to travel to its destination); and (2) transient (in which the time of travel is calculated based upon specific discharge vectors and an assumed effective porosity).
Becker's steady-state particle tracking analysis determined that leachate leaking from Towpath in the "top of rock" zone would migrate generally to the north, and that leachate entering the "deep rock" zone would likewise migrate northward except in the southeastern end of the footprint, where it would travel to the south and east. Becker's transient particle tracking analysis determined that any leak from the landfill liner into the "top of rock" zone would be expected to move to the northeast of the facility and across the Erie Canal so rapidly that it would be very difficult, if not impossible, to respond in a timely manner once groundwater contamination was detected at the monitoring wells. Becker said this same scenario could play out in the "deep rock" zone as well, depending on the value one accepts for that layer's hydraulic conductivity.
According to Dr. Becker, transport simulations are important to establish whether potential contamination can be detected in a timely manner and remediated before the spreading plume migrates off-site. Becker performed two types of simulations, area-release and point-release, assuming values for dispersion and effective porosity, and modeling the "top of rock" and "deep rock" layers separately. In an area-release simulation, a known mass is added uniformly under the landfill footprint to highlight transport over the entire area. In a point-release simulation, meant to simulate a pin-hole leak in the liner, contaminants are depicted as entering one of the water-bearing layers at a particular point, and one then determines the ability of the monitoring wells to detect the spreading leakage.
Dr. Becker's area-release simulations suggested that a contaminant plume released into the "top of rock" unit could be past the Erie Canal in only 30 days, and a contaminant plume released into highly conductive vertical fractures in the "deep rock" unit could be past the Erie Canal in 180 days. In such cases, the Towns argue, a leachate plume could pass undetected by monitoring wells even if these wells were in the plume's direct path. And even if the plume were detected, they argue, the time frames for follow-up as established in the EMP are not sufficient to assure remediation before there are widespread off-site impacts. The Towns are especially concerned about contaminants moving under the McKenna landfill, since any extraction wells drilled through that footprint could have further potential for contaminating groundwater. (In fact, no extraction wells are planned, and WMNY agrees they would not be a good idea.)
Finally, Dr. Becker's point-release simulations suggest that it is possible for plumes to migrate between downgradient monitoring wells in WMNY's proposed array, a problem that is most pronounced in the "top of rock" unit. The Towns argue that the primary flaw here may be the close proximity of the monitoring wells to the Towpath footprint. Were the monitoring wells located farther downgradient, the Towns argue, dispersion would make it more likely that a plume would be detected. The Towns say monitorability could be improved by increasing the number of monitoring wells, moving the wells downgradient, or moving the Towpath landfill footprint upgradient. The Towns are especially concerned about the ability to conduct contingency monitoring in the limited space between McKenna and the proposed Towpath footprint, and the potential for confusing the two landfills' groundwater impacts.
In conjunction with its hydrogeologic investigation, WMNY constructed its own groundwater flow model, both to test its conceptual model for the site and to predict the impacts that Towpath would have on existing groundwater flow processes. Like Dr. Becker, WMNY used the MODFLOW program, but its modeling was strictly numerical, so that no graphics were developed. Also, as Dr. Becker conceded, WMNY's intent was not to create a transport model; in fact, transport or particle tracking models are not required by the Part 360 regulations, and WMNY's modeling concerns were restricted to the site itself, so impacts at and beyond the Erie Canal were not addressed.
After Dr. Becker testified, Mr. Roeper was recalled as a rebuttal witness. To answer Dr. Becker's claims, Mr. Roeper produced transport simulations he generated by running Dr. Becker's model but changing the input values for effective porosity and longitudinal dispersivity. The modeling was done for Dr. Becker's scenario of a release appearing in the "top of rock" zone under the footprint and moving with the groundwater for periods of 90 days, 180 days, 1 year and 3 years, with separate depictions for each of these time periods. (See Exhibit 95, which represents the results of Mr. Roeper's modeling.)
Dr. Becker's conclusions were effectively discredited during his cross-examination by WMNY counsel, and by Mr. Roeper's subsequent rebuttal testimony. Because the accuracy of modeling results depends on the reliability of assumptions employed in the modeling, WMNY's challenge focused on Dr. Becker's values for porosity and dispersivity, coupled with an understanding of the path contaminants would actually follow in exiting the landfill. Important points established in relation to Dr. Becker's testimony include the following:
1. Contaminants exiting the landfill (except in the overlap area) would have to penetrate the engineered subgrade before entering the "top of rock" water-bearing zone, so it is unrealistic to characterize a release as beginning in that zone and then moving off-site with the groundwater flow.
During his cross-examination, Dr. Becker admitted that he had not reviewed Towpath's design plans and that his modeling did not account for Towpath's engineered subgrade. This is an important error because the subgrade is designed to slow the movement of contaminants escaping the liner system, thereby affording more time for monitoring and remediation. As noted in my findings of fact, the subgrade would consist of at least 10 feet of compacted soils exhibiting a maximum in-place permeability of 2.5 x 10-6 cm/sec. With this depth and permeability, it would take a year and a half for any leachate exiting the secondary composite liner system to pass through the subgrade and reach the underlying bedrock. Because the liner system has leak detection capacity, the low permeability of the engineered subgrade affords WMNY and DEC Staff plenty of advance notice of a problem in a particular cell, so that, if it is deemed necessary, increased monitoring can be ordered at downgradient wells, or new wells can be added.
Even if a tear developed in the liner system, little leachate would likely escape, as Mr. Roeper explained, because of the high permeability of the leachate collection systems and the tendency for leachate to be pulled along through those systems, rather than migrate downward through holes or breaks. Mr. Roeper pointed out that, once in the subgrade, any leachate that did escape would tend to move vertically until it reached the "top of rock" water-bearing zone. But along the way, it would be weakened by retardation processes, so that it would not emerge from the subgrade at full strength.
Dr. Becker's failure to account for the engineered subgrade is especially significant because the subgrade adds 18 months to the travel time for leaking contaminants to move off-site. Even if one accepts the results of his modeling, Dr. Becker's scenarios only account for flow in one of the water-bearing zones, as if the subgrade did not exist. In other words, they tell only part of the story.
2. Dr. Becker's simulations do not account for sorption, chemical reactivity, or biodegradation of contaminants, even though it was within his model's capacity to address these factors.
Dr. Becker admitted that he did not account for these factors both because they are extremely difficult to quantify on a site-specific basis, and because there was no geochemical data to analyze. Even so, he acknowledged that these behaviors would occur to some degree during transport in the water-bearing layers.
During cross-examination, Dr. Becker agreed that sorption, chemical reactivity, biodegradation and diffusion into the fractured rock would generally slow down and attenuate contaminants, so that a contaminant front would not move as fast or as far as his simulations suggest. In fact, he was presented with a paper he recently co-wrote (Exhibit No. 70) stating that diffusion of chemical constituents from fractures to the less permeable void space of a rock matrix acts to attenuate and store dissolved constituents migrating with groundwater in bedrock terrain, and that this matrix diffusion often is looked upon positively in scenarios of waste isolation. Despite the effect matrix diffusion would have in retarding plume movement, Dr. Becker did not account for it in his modeling, as Mr. Roeper explained on rebuttal.
3. Dr. Becker's value of effective porosity was unrealistically low, thereby exaggerating the rate of contaminant travel.
In its hydrogeologic report, WMNY used an estimated fracture porosity value of 0.0025 to calculate flow velocities for the intermediate Medina and Queenston aquitards, and a value of 0.02 (2 percent) for flow velocities in the "top of rock" and "deep rock" water-bearing units, reasoning that the higher value for these units is warranted in light of their greater degree of fracturing. [See report, page 5-48.] In his pre-filed testimony, Dr. Becker said that 0.02 is a reasonable value, but not a conservative one, and that it could underestimate the potential for transport away from the facility. Therefore, for his transport simulations, Dr. Becker assumed a value of 0.002 (0.2 percent), which had the effect of speeding the rate of contaminant transport by one full order of magnitude.
In challenging this value, WMNY compared it to effective porosity values for fractured rock strata identified in one of Mr. Becker's own exhibits. These values are highlighted in orange pen on Table 1 of Exhibit No. 10-G, an article by Gelhar and others on field-scale dispersion in aquifers. This table's effective porosity values for fractured rock aquifers range from 0.5 to 60 percent, suggesting that Dr. Becker's value is unreasonably low.
The Towns respond that Dr. Becker's porosity estimate is within the typical range of values for sedimentary rock as determined by WMNY's own literature review conducted as part of its hydrogeolgic investigation. However, Mr. Roeper points out that this range is related to deep rock formations associated with petroleum reservoirs, and therefore would not apply in the more highly fractured "top of rock" zone at Towpath.
As Mr. Roeper explained, there is an inverse relationship between effective porosity and the rate of contaminant transport, in that as one decreases the effective porosity, one increases the rate of travel. This played itself out in Dr. Becker's analysis where he concludes that a contaminant plume released from Towpath into the "top of rock" unit would be well past the Erie Canal in only 30 days. Using WMNY's suggested effective porosity value instead of his own, the contaminant plume would be well past the Erie Canal in about one year. (Of course, these scenarios do not account for the 18 months it would take contaminants to penetrate the engineered subgrade.)
4. Dr. Becker's value of longitudinal dispersivity was at the low end of possible values, thereby tending to understate the spreading of contaminants as they move along in the groundwater.
In his pre-filed testimony, Dr. Becker explained that in his transport simulations longitudinal dispersion was set at 10 feet, which he assumed to be a reasonable value based upon values determined at other sites where transport distances were on the order of 1 kilometer. Dr. Becker indicated that he was relying on the Gelhar article (Exhibit 10-G), so during cross-examination counsel for WMNY asked him to look at Figure 2 of that article, a graph plotting longitudinal dispersivity against scale, and to verify his assumption from that. In this plot, Dr. Becker calculated a value at about 1 kilometer of about 50 meters or 150 feet. WMNY also highlighted a statement in the Gelhar article that at a given scale, longitudinal dispersivity ranges over 2 to 3 orders of magnitude, suggesting that at 1 kilometer the value could actually be as high as 500 or 5,000 meters.
WMNY's cross-examination did not demonstrate that Dr. Becker's dispersivity value was inaccurate, only that it was at the low end of values he might have selected. In rebuttal, Mr. Roeper testified that upon his own review of Gelhar, an appropriate value of longitudinal dispersivity would have been between 100 and 150 feet, and that Dr. Becker's 10-foot value results in too narrow a plume, one apparently designed to support his argument that monitoring wells are spread too far apart.
Mr. Roeper's "top of rock" transport simulations, presented as part of WMNY's rebuttal case, were meant to respond to Dr. Becker's, using values that WMNY considered reasonably conservative. These simulations changed the value for effective porosity from 0.002 to 0.02, and the value for longitudinal dispersivity from 10 feet to 100 feet, at the low end of Mr. Roeper's suggested range. The simulations indicate that, using values Mr. Roeper considers to be consistent with the Gelhar article, the monitoring wells have been spaced close enough to detect Dr. Becker's hypothetical releases.
Of course, neither the simulations prepared by Dr. Becker, nor the ones prepared by Mr. Roeper, account for the various processes outlined above that would slow and weaken a contaminant plume. Nor do they account for the engineered subgrade, which is perhaps their biggest flaw. WMNY did not intend that its simulations be relied upon, and prepared them only so one could see how varying certain assumptions would affect the result.
5. Whereas WMNY's modeling was validated in relation to its aquifer test, there is no comparable basis to validate Dr. Becker's modeling.
In his pre-filed testimony, Dr. Becker conceded that there is no way to know whether a model represents an accurate depiction of hydrogeology, as a model is ultimately a product of the hydrogeologist's interpretation. He also said that the uniqueness of a model is increased if it can respond to a variety of hydraulic stresses such as those applied in an aquifer test.
This last point bears emphasis, because WMNY's MODFLOW modeling, calibrated for steady-state conditions, was able to simulate the response of its aquifer test, thereby demonstrating its reliability. However, Dr. Becker's modeling could not be reconciled with real-life conditions, as evidenced, for example, by the model's projection that there would be measurable impacts north of the canal from a Towpath leachate break-out.
Mr. Roeper emphasizes that the unlined McKenna landfill, between Towpath and the canal, has already produced what would be described as a wide area release, but there are no detectable levels of contaminants in the remedial investigation wells that are north of the canal. Mr. Roeper reasons that "it's hard to imagine that you would have detectable levels in groundwater north of the canal associated with a leak from Towpath when, in fact, we have site-specific data from McKenna, which is closer to the canal, and we don't have impacts in groundwater north of the canal. So the predictions of [Becker's] model don't match what we would anticipate based upon site-specific field data." (Transcript, page 1649.)
6. Although it is part of the identified critical stratigraphic section, there is very little likelihood of contaminant migration to the "deep rock" zone, so Dr. Becker's scenarios of a release entering this zone have little probative value.
To reach the "deep rock" zone, contaminants leaving the landfill would have to penetrate the subgrade, "top of rock" water-bearing zone, and intermediate Medina aquitard. By operation of the Tangent Law, contaminants would likely be swept along by advection in the "top of rock" water-bearing zone without penetrating the aquitard. The aquitard's actual parameters, including those for thickness and permeability, are not part of Dr. Becker's model, so the model cannot evaluate the aquitard's impact on contaminant flow.
7. WMNY has accounted for the flow of water to the south and east in the southeast section of the "deep rock" zone beneath the Towpath footprint.
In his pre-filed testimony, Dr. Becker said that WMNY makes no mention in its hydrogeologic report of a southeasterly flow of water from the site in the "deep rock" unit, and has not proposed a probable geologic feature that might explain such flow, such as a laterally extensive fault transecting the Medina/Queenston contact south of the site.
Actually, as Mr. Roeper points out, a southeasterly component of flow can be identified in WMNY's "deep rock" potentiometric surface mapping. The hydraulic boundary associated with this flow is discussed in the hydrogeologic report, and the EMP accounts for the flow in its designation of 2EDR, E-1DR and E-4DR as downgradient monitoring wells. The southeasterly flow component is associated with a hydraulic low to the south of Towpath that is represented by an L-shaped channel in WMNY's modeling. As Mr. Roeper explained, this channel does not represent an actual geologic feature, but merely a condition of lower heads south of Towpath, which could have been simulated just as well in the model by other techniques such as extraction wells. Because the channel does not imply the existence of a feature, one cannot conclude, as Dr. Becker does, that the failure to identify it represents a failure to sufficiently characterize the site's hydrogeology.
8. WMNY's model predicts the groundwater mound beneath McKenna, contrary to Dr. Becker's testimony.
Dr. Becker says that WMNY's model is inconsistent with its hydrogeologic report because the model is unable to correctly predict the groundwater mound beneath the McKenna landfill. However, as Mr. Roeper points out, the mound is detected in Figure 4-4 of the hydrogeologic report (received separately as Exhibit No. 99) based upon the northward bulge of the computed 520 and 530 potentiometric surface contours for the "top of rock" zone. Roeper adds that the actual groundwater divide associated with the mound is not shown because the hydraulic gradient (or change in water level over distance) associated with the divide is very similar to the natural gradient of the site, so the two cannot be distinguished. Water levels north and south of the divide show little difference, suggesting that the divide is weak, as WMNY claims, not strong, as Dr. Becker implies in his testimony.
Overall, Dr. Becker was unable to discredit WMNY's modeling, while WMNY was able to show serious flaws in Dr. Becker's modeling. In terms of the monitorability issue, the most serious flaw of Dr. Becker's modeling is its disregard of the engineered subgrade. That, coupled with his questionable values for porosity and dispersivity, and failure to account for well-known processes that would slow contaminant movement, suggest that his conclusions about how fast contaminants would move off-site - - and whether they could be detected in a timely fashion - - are not credible.
Apart from monitorability, there were other issues bearing on hydrogeology that were identified in my issues rulings. This section discusses those remaining issues.
- - Appropriateness of MODFLOW Model
At the issues conference, the Towns challenged WMNY's use of the MODFLOW porous media groundwater flow model, claiming that a fracture flow model should have been used instead. In its hydrogeologic report, WMNY explains the use of MODFLOW to simulate groundwater flow in fractured bedrock in relation to the concept of "porous media equivalency." (See report, pages 4-33 and 4-34.) In other words, at the scale at which the model is applied, the density of the fractures within the bedrock is sufficient to allow groundwater flow to behave as it would in truly porous media.
The Towns maintained during the issues conference that MODFLOW should not have been used at this site because it would not necessarily produce a valid representation of site hydrogeology. This, they said, is because the model generates a weighted average of flow through high-conductivity, high-flow-velocity fractures and lower-conductivity, lower-flow-velocity pores. This alleged pitfall, the Towns claimed, could be avoided with a grid that is sufficiently scaled to separate highly and poorly fractured zones, so these zones may be assigned their own values for hydraulic parameters.
As noted in my findings, the MODFLOW model was used both as an interpretive tool to test the reproducibility of WMNY's conceptual model of the site's groundwater flow system, and as a predictive tool to simulate the hydrologic impacts associated with Towpath's construction.
I find that WMNY's use of MODFLOW to interpret and predict groundwater flow patterns was appropriate for the following reasons:
- MODFLOW met WMNY's stated large-scale modeling objective which called for an assessment of the complete groundwater flow system as opposed to individual paths.
As Mr. Roeper explained in his pre-filed testimony, WMNY's modeling objectives were large-scale ones requiring an evaluation of the hydrogeologic system as a whole and thus did not require or warrant the detail needed for simulation of discrete flow paths. MODFLOW and other porous media equivalency models are most useful for well-connected fracture systems such as those under the Towpath site, and where information is needed on average behavior rather than the details of individual flow paths. Mr. Roeper explained that, compared to porous equivalency models, discrete fracture models have three distinct disadvantages:
- They require statistical information that may be difficult to obtain (for instance, about fracture size);
- They are complex and computationally intensive for realistic fracture densities; and
- There is no guarantee that a model reproducing the apparent geometric properties of a fracture network will capture its essential flow or transport features.
For DEC Staff, the primary purpose of computer modeling was to anticipate generalized changes in groundwater flow direction that would be associated with Towpath's construction. As Mr. Fay explained, Staff was particularly concerned that the reduction in groundwater recharge attributable to the Towpath liner system might cause groundwater beneath the McKenna landfill to migrate south underneath the Towpath footprint. The modeling completed by WMNY indicated that Towpath's construction would not result in a major flow reversal. Because the modeling objectives required an assessment of the complete groundwater flow system, the use of MODFLOW was an appropriate choice.
- WMNY's data demonstrated that the fractured rock behaves as a porous media equivalent.
WMNY's hydrogeologic investigation demonstrated that the rock fractures are spaced rather close together and form an interconnected network, and that from a site-wide perspective individual fractures are insignificant as discrete, preferred flow paths. As my findings of fact point out, the concept of porous media equivalency for this site is supported by WMNY's pump test in that the degree of fracture anisotropy reflected in the cone of depression was not extreme.
As Mr. Fay explained, a fracture flow model is used when one wishes to model a relatively high-velocity zone within a zone of relatively low velocity. The information compiled by WMNY does not identify any specific high-velocity zone that might be interpreted as a fracture zone, Mr. Fay said. This conclusion is supported by the surface outcrop analysis, subsurface rock core analysis, surface geophysical investigation, borehole geophysical analysis and the analysis of hydraulic conductivity values.
- MODFLOW is a widely used "industry standard" for groundwater flow modeling.
In his pre-filed testimony, Mr. Fay said he was comfortable with WMNY's choice of MODFLOW in part because it is the acknowledged industry standard and is perhaps the most widely used groundwater flow model for both the public and private sectors. It was developed for porous media, though it is appropriate for large-scale modeling in fractured media as well, as Mr. Roeper, Dr. Goodman and Mr. Fay all explained in their pre-filed testimony. Mr. Roeper said that WMNY selected MODFLOW because it is "the most widely used groundwater flow program in the world" and because it met the objectives of the modeling exercise as documented in the hydrogeologic report. Similarly, Dr. Goodman said that MODFLOW is frequently considered to be the most reliable, verified and utilized groundwater flow model available.
Even Dr. Becker, the Town's modeling expert, testified that he has used MODFLOW to simulate groundwater movement through the Mirror Lake watershed in New Hampshire, a fractured rock site. Dr. Becker was brought into this hearing after the issues conference, so he was not responsible for the Towns' offer of proof (made during the conference) that MODFLOW should not have been used. Nevertheless, by presenting Dr. Becker as their expert, the Towns backed off this key earlier claim. Dr. Becker said a porous media equivalency model, handled appropriately, would be sufficient for characterization of the Towpath site, and that while it would not have been inappropriate to have used a fracture flow model instead, he was not sure that such a model would have offered significant advantages over a porous media model.
- - Siting Restriction (Bedrock Subject to Rapid or Unpredictable Groundwater Flow)
My issues rulings identified as a separate sub-issue whether the application complies with a siting restriction at 6 NYCRR 360-2.12(a)(1)(iii) prohibiting the location of landfills in areas where bedrock is subject to rapid or unpredictable groundwater flow, unless it can be demonstrated that a containment failure would not result in contamination entering the bedrock system.
WMNY and DEC Staff both contend that the bedrock underneath the Towpath site is not subject to rapid or unpredictable flow, and I agree with their analysis. As Mr. Roeper explained in his pre-filed testimony, rapid or unpredictable flow is generally caused by large voids or fractures in the rock that form open pathways for groundwater flow. It is typically associated with carbonate rocks such as limestone and dolomite where groundwater can dissolve the rock to form open subterranean drainage and sink holes.
Both regional and site-specific investigations by WMNY have identified the rock beneath the site as sandstones and shales, neither of which is susceptible to dissolution by groundwater. Furthermore, open channels, or even fractures, which have the capability to transmit large quantities of water would have been identified by the surface geophysical techniques employed during the site investigation. Similarly, there is no evidence of rapid or unpredictable groundwater flow provided by the slug test data, the aquifer test results, or the potentiometric surface mapping.
Despite all this evidence that groundwater flow is predictable, Dr. Becker testified that the difficulty in predicting flow behavior means that transport modeling (not performed by WMNY) is necessary at this site. The source of this difficulty is not apparent. As Mr. Roeper pointed out on rebuttal, WMNY's model, which is a predictive tool, adequately reproduced the flow field in both the "top of rock" and "deep rock" water-bearing zones.
Under cross-examination, Dr. Becker was unable to point out hydraulic conductivity results or any other data from the hydrogeologic report that would support the contention in his pre-filed testimony that there are vertical fractures in the intermediate Medina aquitard. Also, he admitted that the hydrogeologic report presents several independent lines of evidence, based on test results and field data, to support the conclusion that the aquitard is present beneath the Towpath footprint.
Mr. Roeper stressed that WMNY used many different methods to look for open vertical fractures in the aquitard that would result in hydraulic communication between the "top of rock" and "deep rock" units:
"We did the VLF survey, which specifically is designed to look for conductive vertical fractures, and that did not indicate that any were present. We looked at tritium results, both with respect to differences between the Top of Rock and Deep Rock, as well as the modeling associated with the tritium values, which indicated that the Intermediate Medina Aquitard was, in fact, continuous and of low hydraulic conductivity throughout the site. We did the aquifer tests, which again illustrated that - - the same fact, we didn't see any drawdown in the Top of Rock, none whatsoever. We did the Neuman-Witherspoon Method of Analysis, which is specifically developed to evaluate the vertical conductivity of a confining unit between two water-bearing zones. There's the differences in hydraulic head between the Top of Rock and the Deep Rock. There's differences in water quality between the Top of Rock and Deep Rock. There's just multiple lines of evidence that indicate that increasing vertical recharge or vertical leakance through the aquitard is not applicable. And as I noted before, during our calibration efforts of the [MODFLOW] model, when we tried to do that, we couldn't reproduce the results of the aquifer test, which, again, supports the fact that the Intermediate Medina Aquitard is, in fact, of low vertical hydraulic conductivity and is continuous throughout the site." (Transcript, pages 1665-1666.)
Dr. Becker's release simulations suggest that, even if the intermediate Medina aquitard effectively separates the "top of rock" and "deep rock" water-bearing zones, contaminants entering either of these zones could move rapidly off-site. However, as discussed above, these simulations assume an unrealistically low value of effective porosity, thereby exaggerating the rate of contaminant travel.
Speaking as the reviewer for DEC Staff, Mr. Fay confirmed that nothing he had seen in the hydrogeologic report suggested there were areas underlying the Towpath site where flow might be characterized as rapid or unpredictable. Dr. Goodman also testified that, even where fractures have varied flow directions in the "deep rock" zone, that zone's flow system remains predictable and monitorable.
- - Adequacy of Groundwater Monitoring Network
Section 360-2.11(c)(1) requires that groundwater monitoring wells must be capable of detecting landfill-derived groundwater contamination within the critical stratigraphic section. Generally speaking, downgradient monitoring wells in the first water-bearing unit of the critical stratigraphic section must not be more than 500 feet apart. Even though WMNY's wells meet this requirement, the Town of Albion said during the issues conference that it would be prudent to insist that the wells be no more than 150 feet apart, to best ensure that contaminant plumes are detected. The Town's arguments are discussed below in relation to its proposed permit conditions.
Proposed Permit Conditions
In a memorandum of May 31, 2001, I requested that the parties include in their initial briefs any permit condition amendments they think are necessary, allowing an opportunity for the other parties to respond to any proposals in their reply briefs. Parties were offered the opportunity to argue in the alternative: for instance, that the landfill surroundings are unmonitorable by any means and therefore a permit should be denied, but if a permit is issued it should contain certain specified conditions.
Permit amendments were proposed by all sides in their initial briefs. In their reply brief, the Towns' list of proposed amendments was expanded. My discussion of the Towns' proposals is limited to the amendments proposed in their initial brief because, by adding to their list in their reply brief, they foreclosed the opportunity for the other parties to respond to the additions.
I recommend that the amendments proposed by WMNY and DEC Staff be adopted, and that the amendments proposed by the Towns not be made.
- - Towns' Proposed Conditions
The Towns contend that this permit application should be denied because, in their view, WMNY has fallen far short of meeting its burden of proof that Towpath would comply with all applicable provisions of Part 360. However, if a permit is granted, the Towns contend that it must be supplemented with the following conditions.
1. "WMNY shall install additional monitoring wells capable of detecting releases from (a) the deep rock on the east side of the Towpath site in the vicinity of potentiometric line 507; (b) subzone 2DR, as identified in the EMP; and (c) "Point 4" on Exhibit 38 (in the northeast corner of cell 8, as shown on WMNY's monitoring well locator map)."
In their initial closing brief, the Towns write that WMNY admitted that the monitoring well array proposed in the EMP would not necessarily detect all releases from the "deep rock" on the east side of the Towpath site or from the "deep rock" water-bearing unit in subzone 2. The Towns draw particular attention to statements by Mr. Roeper and Dr. Goodman.
Cross-examined as to whether the possibility of an east-flowing leak in the "deep rock" zone in the vicinity of Transit Road between the approximate location of a groundwater divide and the 507 potentiometric contour surface had been mentioned anywhere in the hydrogeologic report, Mr. Roeper replied, "No, It's extremely unlikely, so it's not mentioned at all." (Transcript, pages 291-292.) Cross-examined as to whether it is conceivable that E-1DR, the only downgradient monitoring well for sub-zone 2DR, would not pick up a release of Towpath leachate into that sub-zone, Dr. Goodman replied, "Yes." (Transcript, pages 617-618.)
Section 360-2.11(c)(1) requires that groundwater monitoring wells must be capable of detecting landfill-derived groundwater contamination within the critical stratigraphic section, which in this case includes both the "top of rock" and "deep rock" water-bearing layers. However, that requirement must be read in conjunction with Section 360-2.11(c)(1)(i)(b), which provides that water-bearing units subsequent to the first must be monitored, as required by the Department, "based upon the potential for contaminant migration to that unit." For these units, unlike the first, there are no maximum well separation standards, so the Department has more discretion about how rigorously they are monitored.
The "deep rock" unit under Towpath is the second water-bearing unit into which contaminants would escape. As Mr. Roeper explained, there is little potential for contamination migration to that unit. To reach that unit, a release would first have to pass through the "top of rock" water-bearing unit, where, due to operation of the Tangent Law, it in all likelihood would be pulled along horizontally with the groundwater rather than penetrate down through the low-permeability aquitard separating the "top of rock" and "deep rock" units. This is not to say that it is impossible for leachate to enter the "deep rock" unit, but the chances are slim. It is much more likely that the leachate would move with the groundwater in the "top of rock" zone and be detected at a downgradient "top of rock" well.
The concern about "Point 4" as shown on Exhibit 38 relates to the DEC-requested relocation of well cluster E-42 to the west so it can monitor Towpath cells 7 and 8, rather than cell 8 only. Point "4" (in cell 8) is labeled with pink highlighter on Exhibit 38 and pink lines have been drawn by DEC Staff witness Mr. Fay indicating likely directions of groundwater flow from that point in both the "top of rock" (TR) and "deep rock" (DR) units. Mr. Fay agreed that it was possible for releases entering the "top of rock" and "deep rock" zones at point "4" to leave the site without being detected by E-42TR or E-42DR. The ability to detect such releases would depend in large part on the amount of plume dispersion, which is hard to know in advance.
As the Towns argue, the possibility that a plume might go undetected could warrant the addition of monitoring wells, and Mr. Fay, in his redirect testimony, did not disagree. However, the issue is whether such wells should be added now, as the Towns request, or later, in the event of an actual liner leak, if deemed necessary at that time. Mr. Fay stressed that he would expect any release to be detected in the liner system before it could reach the "top of rock" zone. Monitoring of the leachate collection system would provide ample advance notice of any problem in a particular cell, especially since it would take an estimated 18 months before a leak could penetrate the subgrade. Wells can be added to the monitoring array rather quickly (in a matter of days, according to Mr. Fay) compared to the time it would take for leachate exiting the landfill to reach the water-bearing layers. Also, as Mr. Fay pointed out, it is very unlikely for any release to reach the "deep rock" zone because of the low-permeability aquitard above it, echoing a point made by WMNY's experts.
Because DEC has the regulatory authority to require the addition of monitoring wells even after a permit is issued, it makes sense that any addition to the proposed array be made at some future point when (1) monitoring of the leachate collection system indicates that a particular cell has leaked, and (2) the area downgradient of that cell can be identified with current information.
2. "WMNY shall sample its monitoring wells every 30 days at a minimum."
The EMP provides for quarterly sampling of monitoring wells during the landfill's operation as well as its closure and post-closure periods: once a year for baseline parameters and three times a year for routine parameters, with the baseline sampling event rotated to a different quarter each year. This sampling frequency is the minimum required by Section 360-2.11(c)(5)(ii)(a); more frequent sampling of baseline parameters would not be required unless warranted by a pattern of contamination.
The Towns want more frequent well sampling on the theory that contaminants entering the water-bearing zones would migrate quickly off-site, so early detection at the monitoring wells is necessary to assure timely remediation. The Towns' travel time estimates are based on Dr. Becker's modeling; however, as I find that modeling flawed, as explained above, I do not consider those estimates to be reliable. Even if one accepted the modeling, it tells only part of the story, since the contaminants would have to travel through the low-permeability subgrade before reaching the water-bearing zones. (Also, contaminants reaching the "deep rock" zone would have to penetrate the intermediate Medina aquifer.) The Towns argue as if leak detection begins at the monitoring wells, when in fact it begins in the liner system. Should leachate flows in the liner system suggest a leak, the Department retains the authority to require modification of the operational water quality monitoring plan. Increasing the frequency of monitoring at the outset of operations, without evidence of actual leakage, would impose costs on WMNY out of proportion to any environmental protection benefit that would be gained.
3. "WMNY shall assure closer monitoring well spacing, the locations of wells to be established after WMNY performs transport modeling pursuant to 6 NYCRR 360-2.11(c)(1)(i)(c)."
The requirements governing monitoring well spacing are set out in Section 360-2.11(c)(1)(i). Generally speaking, in the first water-bearing unit of the critical stratigraphic section, monitoring well spacing must not exceed 500 feet along the downgradient perimeter of the facility, and upgradient or crossgradient well spacing must not exceed 1,500 feet. Closer well spacing may be required in sensitive or geologically complex environments, or, in the case of upgradient or crossgradient wells, where upgradient sources of contamination are known to exist. Well spacing in subsequent water-bearing units is not governed by maximum separation distances; instead, monitoring is based upon the potential for contaminant migration to those units.
The Towns acknowledge that Towpath's downgradient wells are spaced between 300 and 500 feet apart, and therefore assert no claim that the well spacing violates the maximum separation requirements. Nonetheless, they say that leachate plumes could migrate, undetected, between well clusters, particularly in the "top of rock" water bearing unit. To provide faster, more comprehensive plume detection, the Towns offer three possible solutions: (1) moving the wells farther downgradient, so that contaminant dispersion would make detection more likely, (2) moving the Towpath landfill footprint upgradient (in effect, reducing the project's size); and (3) increasing the number of wells. According to the Towns, the first solution is not an option because of the proximity of the McKenna landfill to the north. But even if it were, yet another problem is the Part 360 regulations, which say that downgradient monitoring wells must be located as close as practical to but not less than 50 feet from the waste boundary, for the very purpose of early plume detection. [See 6 NYCRR 360-2.11(c)(1)(i)(e).]
Of the remaining two options, increasing the number of wells, in effect grouping them more closely, is physically possible but not warranted by the record of this hearing. The Towns rely on Dr. Becker's release simulations, which, for the reasons stated above, I do not deem reliable. When Mr. Roeper repeated these simulations using reasonable values for porosity and dispersivity, he found that monitoring well spacing in the "top of rock" zone is adequate to ensure leak detection, so additional computer modeling pursuant to Section 360-2.11(c)(1)(i)(c) is not necessary.
Finally, there is no evidence that Towpath would be situated in a sensitive or geologically complex environment, which might justify closer well spacing under the Part 360 regulations. No public or private wells are located directly downgradient of the proposed facility. Downgradient flow patterns are well-understood now, and potential changes in flow direction due to Towpath's construction have been modeled reliably by WMNY.
4. "WMNY shall move the northern boundary of the Towpath footprint 250 feet further to the south to ensure that the monitoring wells are placed in an area that is not likely to remain contaminated with McKenna leachate."
The Towns claim that moving the Towpath footprint further upgradient in relation to the general groundwater flow direction is warranted to open a wider space between Towpath and McKenna. Doing so, they add, would facilitate the remediation of leaks from Towpath because it would open more space for monitoring wells and better ensure that impacts of Towpath and McKenna are not confused.
With the project as proposed by WMNY, 200 feet would separate the Towpath and McKenna waste masses, and the area between the two landfills would be policed by monitoring wells. These wells would include those at the MW-2 cluster, which already has been affected by McKenna leachate, but whose water quality is expected to improve upon completion of McKenna's remediation and before the well becomes part of the active Towpath monitoring array. Even if this improvement does not occur, WMNY would be able to install new monitoring wells in the Towpath berm, which is beyond the southerly extent of McKenna's groundwater impacts, as noted in my findings of fact. Therefore, moving Towpath's northern boundary to the south is not necessary to ensure successful monitoring.
5. "WMNY shall resize the landfill footprint to eliminate the OSL overlap area."
The Towns claim that eliminating the OSL overlap area (which is part of Cell 1) is necessary because WMNY has not demonstrated how this area could be monitored successfully. The Towns point out that the engineered subgrade, which WMNY is counting on to slow a contaminant escape, is not present in the area where Towpath would be built atop OSL, and that the mixing of leachates from OSL and Towpath in this area would provide an easy case for WMNY to disclaim responsibility for problems that might develop.
It is true that, in the overlap area, there is no engineered subgrade, as readily conceded by WMNY and DEC Staff. That is not to say, however, that environmental protection would in any way be diminished there. The overlap area is designed, like the rest of Towpath, with the same double liner and leachate collection systems, separate and apart from similar features of the underlying OSL liner. As my findings make clear, any leakage through Towpath's primary liner system would appear in that landfill's secondary collection system, and would not be expected to pass through into OSL. Also, the fairly steep side slope of OSL (greater than 25 percent) precludes the possibility of any leachate ponding on top of the Towpath liner, thereby reinforcing the tendency of the leachate to travel parallel to the liner (downslope) as opposed to through the liner and into OSL.
Even if there were a mixing of Towpath and OSL leachates, or for some other reason one could not segregate impacts of the two landfills, one must still take account of the fact that Towpath is an expansion of the OSL landfill and that the two landfills would be treated as one by the Department. Special condition 59 of DEC Staff's draft permit provides that, as operator of the expanded landfill site, WMNY would become obligated to care for the existing OSL as well as the expansion area, such responsibility extending through Towpath's closure and post-closure periods.
6. "WMNY shall install additional monitoring wells in the area of a groundwater mound in the southern part of OSL, to be on line from the date waste disposal begins."
The "mound" referred to by the Towns is actually an area of relatively high potentiometric surface in the portion of the "deep rock" water-bearing zone underlying the south-central part of the existing OSL and diminishing in the direction of the planned overlap area, which is part of the first cell that would be constructed. The Towns are concerned about contaminants entering the "deep rock" zone in the area of the mound, and the impact the mound would have on contaminant movement.
As Mr. Roeper stressed, contaminants exiting the landfill could not enter the "deep rock" zone without first passing through the "top of rock" zone and the intermediate Medina aquitard. In the "top of rock" zone above the so-called mound, the potentiometric surface contours drawn on Exhibit No. 38 suggest that groundwater flow is from south to north, so contaminants entering that zone would tend to be pulled to the north, away from the area of concern. Therefore, as Mr. Roeper explained, the so-called mound has no bearing or significance with regard to the monitorability of the Towpath site.
- - WMNY's Proposed Conditions
WMNY states that it would agree to a permit condition that, prior to operation, trigger values shall be recalculated on an intra-well basis for each of the wells that will be part of the monitoring program for which eight rounds of data exist. Neither DEC Staff nor the Towns responded to this proposal in their reply briefs.
As I have stated above, calculating trigger levels on an intra-well basis makes sense in that it removes the issue of spatial groundwater quality variability that is inherent to the sub-zone approach articulated in the EMP. For that reason, the condition proposed by WMNY should be part of any final permit.
- - DEC Staff's Proposed Conditions
DEC Staff proposes minor, non-substantive revisions to special condition No. 12 of its draft permit, which requires WMNY to fund two environmental monitors, one who would work exclusively at the Towpath landfill and the other who would be assigned to DEC's Region 8 office in Avon to work on projects involving the Towpath landfill and other solid waste management facilities owned or operated by WMNY in Region 8. These monitors, employed by and reporting to DEC, would help assure that the landfill is constructed and operated in accordance with the approved application documents and the terms of any issued permit. According to Staff counsel, the reasons for the proposed changes are purely administrative, to assure that the condition is identical to others used state-wide to establish environmental monitoring positions.
DEC Staff also proposes the addition of a new special condition No. 63 requiring WMNY to notify DEC and the Town of Albion in the event it sells, transfers in any way, or relinquishes to the bankruptcy trustee its rights under the leases which give WMNY the property right to operate the Towpath landfill. Staff acknowledges that the regulatory permit transfer process would be the major avenue of control over the site's future operation by a party other than WMNY, but contends that simple notice of a proposed change in WMNY's leasehold status is warranted given the continued involvement of the bankruptcy court and the possibility of assignment of WMNY's rights to a bankruptcy trustee.
Staff's proposed amendments to the draft permit, as outlined above, were set out in an attachment to its initial closing brief. (That attachment is Appendix "I" of this report.) WMNY does not object to these amendments (or, for that matter, to any other term in Staff's draft permit). For that reason, and because the Towns took no position regarding the new language, these amendments raise no new issues for adjudication.
- The Towpath landfill would be located in an area where environmental monitoring and site remediation can be conducted, consistent with 6 NYCRR 360-2.12(c)(5). Monitorability is not compromised by Towpath's proximity to the McKenna landfill or by its being an expansion of OSL. WMNY has developed a reasonable and prudent system for detecting and identifying leachate releases.
- WMNY's MODFLOW model was appropriate for use at this site. A fracture flow model was not required instead.
- The Towpath landfill complies with the siting restriction at 6 NYCRR 360-2.12(a)(1)(iii) which prohibits the location of landfills in areas where bedrock is subject to rapid or unpredictable groundwater flow. Such areas do not exist at this site.
- WMNY's groundwater monitoring wells are capable of detecting landfill-derived groundwater contamination within the critical stratigraphic section, consistent with 6 NYCRR 360-2.11(c)(1).
Absent reconsideration of my previous ruling that fitness be adjudicated as a hearing issue, the Commissioner should grant the permit requested by WMNY. The final permit should be consistent with the draft permit prepared by DEC Staff, incorporating the changes proposed by DEC Staff and WMNY in their initial closing briefs, as discussed on pages 61 and 62 of this report. Based on the parties' agreement, the final permit should also incorporate the changes agreed to in the stipulation resolving the noise issue (Appendix "C" to this report).
FINAL ENVIRONMENTAL IMPACT STATEMENT
The Final Environmental Impact Statement ("FEIS") for this project shall include the following:
- This hearing report;
- The permit application and associated documents;
- The Draft Environmental Impact Statement ("DEIS");
- The record of the legislative hearing, including all oral and written comments from the public;
- The record of the issues conference;
- The record of the adjudicatory hearing, including the transcripts and those exhibits received in evidence;
- The ALJ's rulings on issues and party status, dated December 31, 1999;
- The Commissioner's interim decision, dated May 15, 2000, resolving appeals from those rulings; and
- The correspondence between the ALJ and the parties to this proceeding; and
- The responsiveness summary submitted to the ALJ by Department Staff.