Mirant Bowline, LLC - Hearing Report and Recommended Decision, November 30, 2001

Hearing Report and Recommended Decision, November 30, 2001

STATE OF NEW YORK : DEPARTMENT OF ENVIRONMENTAL CONSERVATION
625 Broadway
Albany, New York 12233-1550

In the Matter

- of -

Application for a State Pollutant Discharge Elimination System (SPDES) permit
pursuant to Environmental Conservation Law (ECL) Article 17 and Title 6 of
the Official Compilation of Codes, Rules and Regulations of the State of New York (6 NYCRR)
Parts 704 and 750 et seq., and Air Pollution Control permits consisting of
a Preconstruction permit and a Certificate to
Operate, pursuant to ECL Article 19 and 6 NYCRR Parts 200 et seq.,

- by -

MIRANT BOWLINE, LLC,
[formerly Southern Energy Bowline, LLC],

DEC No. 3-3922-0003/00015
SPDES No. NY0264342

HEARING REPORT and RECOMMENDED DECISION

- by -

____________/s/____________
Kevin J. Casutto
Public Service Law Article X Associate Examiner and
NYSDEC Administrative Law Judge

November 30, 2001

Table of Contents

PROCEEDINGS

DISCUSSION

RECOMMENDATIONS

FINDINGS OF FACT

CONCLUSIONS OF LAW

EXCEPTIONS AND COMMENTS ON RECOMMENDED DECISION

APPENDIX A

PROCEEDINGS

I. The Application and Project Description

In August 2000, Mirant Bowline, LLC (formerly Southern Energy Bowline, LLC; the Applicant or Mirant), applied for a Certificate of Environmental Compatibility and Public Need pursuant to Article X of the New York Public Service Law (PSL)⁽¹⁾ and Air Pollution Control and State Pollutant Discharge Elimination System (SPDES) permits pursuant to Articles 19 and 17 of the Environmental Conservation Law (ECL), to construct and operate a 750 megawatt (MW) combined cycle electric generating facility. The facility would consist of three General Electric 7-FA combustion turbine generators (CTG), three heat recovery steam generators (HRSG), one steam turbine generator (STG) with associated balance-of-plant systems and facilities. The primary fuel would be natural gas. Low sulfur (0.05%) fuel oil would be used for backup.

The Bowline Generating Station is located approximately thirty miles north of New York City in the Haverstraw Bay section of the Hudson River. The proposed new facility would be located next to two existing power facilities, Bowline Units 1 and 2, off Samsondale Avenue in the Town of Haverstraw, Rockland County, New York, on part of a 257-acre parcel owned by Mirant (the site). The entire project area is zoned Planned Industrial Office. The project site is bounded on the east by Bowline Point Park and the Hudson River, on the west by a public park (Peck's Pond), on the south by combined residential and light industry properties, and on the north by Keahon Auto Wreckers. Also to the north are approximately 97 acres of vacant land which also are part of the 257-acre Bowline Generating Station property. The cooling water intake structures (CWISs) would be located in Bowline Pond, which is connected to the Hudson River along the west bank of the Hudson River. The N.Y.S. Department of State (DOS), with the assistance of the New York State Department of Environmental Conservation (DEC or the Department), has designated Haverstraw Bay a Significant Fish and Wildlife Habitat under the Coastal Zone Management Program (CZMP or CZM). Executive Law Article 42, 19 NYCRR Part 600, et seq.

Mirant's application for an Article X Certificate also included a request for a State Pollutant Discharge Elimination System (SPDES) permit and Air Pollution Control permits (the environmental permits required pursuant to 6 NYCRR Parts 201, 231 704 and 750). Mirant's initial application proposed that the facility would withdraw process water from Bowline Pond for cooling purposes, employing mechanical draft cooling technology requiring 7.5 million gallons per day (mgd). A portion of the cooling water would evaporate into the atmosphere, the balance would be returned to the river. The proposed combined cycle generating technology allows a low intake velocity and limits intake capacity to the proposed maximum of 7.5 mgd.

The Staff of the Department (DEC Staff) reviewed Mirant's SPDES and Air permit applications, and subsequently developed draft SPDES and Air permits, dated January 16, 2001 (including a single draft permit dated January 16, 2001, captioned 'Air State Facility Permit' pursuant to 6 NYCRR Parts 201 and 231; hereinafter, the draft Air permit[s]).⁽²⁾ The draft SPDES permit authorizes the reuse of cooling water discharge from existing Bowline Units 1 and 2 as cooling water for Bowline Unit 3, annually from October through mid-February. Ex. 79.

Subsequently, on February 13, 2001, Mirant revised its water intake and cooling proposal from a mechanical draft cooling system to a hybrid cooling system. As with the initial proposal, the intake structure would include a 2.0 millimeter (mm) wedge wire screen and a Gunderboom ^TM Marine/Aquatic Life Exclusion System (Gunderboom MLES or Gunderboom) engineered geotextile porous curtain to provide a physical barrier between the CWISs and the aquatic biota of Bowline Pond for exclusion of aquatic biota (Mirant's hybrid cooling/Gunderboom proposal). The Gunderboom curtain is comprised of three layers, two permeable polyester fabric layers with a mesh net layer in the middle. The curtain is suspended at the surface of the water body by vinyl- covered floatation billets. Gunderboom, Inc., is the owner of the Gunderboom MLES proprietary fabric curtain technology. In recent years, Gunderboom, Inc., has been developing its Gunderboom product for CWISs applications, to minimize fish mortality. The Gunderboom textile curtain would be suspended from the existing intake structure pumphouse to the shoreline. Mirant has explained that the primary reason for revising the cooling/intake proposal is to reduce cooling tower steam plumes, thereby further reducing adverse visual impacts of the project. Consequently the current draft SPDES permit, issued prior to Mirant's modification of cooling tower technology, does not address the recently proposed hybrid cooling system. The proposed maximum water intake remains 7.5 mgd gallons per day. Although the draft SPDES permit does not address the revised cooling technology and intake proposal, Mirant contends that its hybrid cooling/Gunderboom proposal will comply with all terms and conditions of the draft SPDES permit. DEC Staff agrees with this assessment.

The Legislative Hearing and Issues Conference

Following a duly published public notice and public comment period, a DEC legislative hearing session was held on February 21, 2001 at 6:30 p.m., at the Haverstraw Town Hall, 1 Rosman Road, Garnerville, New York.⁽³⁾ A joint prehearing conference pursuant to PSL Article X and issues conference pursuant to 6NYCRR 624 (the joint issues conference) commenced on March 7, 2001 and continued on March 8, 2001, at the same location.

The March 30, 2001, DEC issues ruling identified several issues for adjudication. Following appeal, the Commissioner's June 20, 2001 Interim Decision found that the only issues requiring adjudication were issues related to 'best technology available' (BTA) as that term is used in 6 NYCRR 704.5 and the federal Clean Water Act Section (CWA) 316(b). The first and primary adjudicable issue is whether the draft SPDES permit requires the best technology available to minimize the potential adverse environmental impacts related to Mirant's withdrawal of process water from the Hudson River, as required by 6 NYCRR 704.5 and 33 USC §1326(b) [CWA §316(b)]. Within this issue are several sub-issues, including whether the proposed Gunderboom technology is an available technology suitable for implementation as 'best technology available' at Bowline Unit 3, or whether it remains a premature experimental technology, consequently not available for implementation at Bowline Unit 3; and lastly, whether the DEC Staff's rejection of dry cooling technology as 'best technology available' when preparing the draft SPDES permit for Bowline Unit 3 was proper.

The other adjudicable issue is whether and to what extent BTA requires that cooling water discharged from Bowline Units 1 and 2 should be reused as cooling water for proposed Unit 3. The BTA issues were identified by joint intervenors Riverkeeper and Scenic Hudson, who were granted party status in the March 30, 2001 DEC issues ruling (the Joint Intervenors).

The Adjudicatory Hearing

The BTA component of the joint adjudicatory hearing was held on September 5 through 7, 2001. A further joint adjudicatory hearing session was convened on September 20, 2001 to receive additional testimony on land use requirements and impacts for Mirant's two hybrid cooling tower location proposals and the alternatives analysis for a dry cooling tower location.

A third potential issue that remained in the DEC component of the joint hearing concerning the Draft Air permit, is review of Emission Reduction Credits (ERCs) for Oxides of Nitrogen (NOx) and Volatile Organic Compounds (VOCs) required under the federal Clean Air Act, ECL Article 19 and 6 NYCRR 231-2.10. Once Mirant submitted documentation for the ERCs on October 2, 2001, a public notice advertising a comment period regarding the proposed ERCs, and providing for supplemental petitions for party status on ERCs issues, was duly published. No petitions or comments were received regarding the ERCs.

Riverkeeper, Inc., was represented by David K. Gordon, Esq., Staff Attorney.

The DEC Staff was represented by staff attorneys Meghan A. Purvee, Esq., and Richard Williams, Esq.

Mirant was represented by the law firm of Couch White, Algird White, Esq., and Barbara Brenner, Esq., of counsel.

Scenic Hudson was represented by the Pace Energy Project, Victor Tafur-Dominguez, Esq., of counsel.

Prior to the adjudicatory hearing, pursuant to the schedule, the parties filed pre-filed expert testimony. During the DEC adjudicatory hearing component, the parties each presented their expert witnesses for examination. Mirant presented several witnesses, most in panels by topic area. Some witnesses appeared in more than one panel. Mirant presented the following witnesses: Louis F. Friscoe, Director of Environmental and External Affairs, Mirant Bowline, LLC; Donald K. Gray, Technical Support Manager, Mirant Bowline, LLC; David E. Schafer, Mirant Bowline Unit 3 Project Manager, TRC Environmental Corp.; W. Allen Marr, Ph.D., Chief Engineer, GeoTesting Express; Andrew J. McCusker, Mackworth Environmental Management; Charles Cooper, Director of Environmental Permitting and Planning, TRC Environmental Corp., James Campbell, Senior Engineer, Peratrovich, Nottingham & Drage, Inc.; Anne E. Meyer, Ph.D., Principal Research Scientist and Site Director, Research Foundation of State University of New York at Buffalo, Industry/University Center for Biosurfaces, Scott J. Heim, TRC Environmental Corp., Project Manager for Ecological Assessments; and Bruce H. Burn, Manager, Industrial Power, Simons Engineering.

DEC Staff presented the following staff witnesses: Aquatic Biologists Edward W. Radle and John M. Cianci.

Riverkeeper presented the following witnesses: Ralph E. Huddleston, Jr., Senior Vice-President, CEA Engineers, P.C., Bruce A. Bell, Ph.D., President, CEA Engineers, P.C.; and Peter A. Henderson, Ph.D., Director, PISCES Conservation, Ltd.⁽⁴⁾

Scenic Hudson presented William W. Dougherty, Ph.D., Senior Scientist, Tellus Institute.

During the September 20, 2001 proceeding, the following witnesses testified: Mr. Heim and Dr. Marr testified for Mirant and James de Wall Malefyt testified for the Department of Public Service Staff.⁽⁵⁾

The stenographic record of the adjudicatory hearing was received by October 3, 2001. Closing briefs and replies were received by October 15, 2001. The record of the DEC adjudicatory component of the joint hearing closed with the conclusion of the ERCs comment period, on November 15, 2001.⁽⁶⁾

II. The Federal Clean Water Act Section 316(b) and 6 NYCRR 704.5

Introduction

1. Statutory and Regulatory Provisions

Section 316 of the federal Water Pollution Control Act (FWPCA; 33 USCA §1251 et seq., commonly referred to as the Clean Water Act) addresses the discharge of thermal pollution, as well as the intake of cooling water.⁽⁷⁾ CWA Section 316(b), an enabling statute authorizing promulgation of regulations, establishes a mandatory requirement regarding cooling water intake structures:

Any standard established pursuant to section 1311 [CWA §301] ... or section 1316 [CWA §306] ... and applicable to a point source shall require that the location, design, construction, and capacity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impact.

No federal regulations currently are effective to implement the mandates of CWA Section 316(b), although the United States Environmental Protection Agency (USEPA) is in the process of promulgating such regulations.⁽⁸⁾ In the absence of implementing regulations, CWA Section 316(b) has been applied as a self-executing statute.

New York State requirements based upon 33 USC §1326(b) appear in the Department's regulations at 6 NYCRR 704.5. The Department's regulation does not elaborate further about what constitutes BTA. Nor has the Department's Division of Water issued any formal guidance document on this subject, such as a Division of Water, Technical and Operational Guidance Series (TOGS) document. However, on November 2, 1994 an attorney then in the Department's Office of General Counsel issued a memorandum providing his opinion of factors to be considered by Department Staff in making a BTA determination. Exhibit 144. This memorandum is discussed further below.

Recently, the Commissioner, citing USEPA, has confirmed that the federal BTA analysis will be applied to BTA determinations for projects in New York:

Pursuant to CWA §316(b), a four step analysis determines whether "best technology available" is being utilized by any particular facility: (1) whether the facility's cooling water intake structure may result in adverse environmental impact;⁽⁹⁾ (2) if so, whether the 'location, design, construction and capacity of the cooling water intake structure reflects best technology available for minimizing adverse environmental impact'; (3) whether practicable alternate technologies are available to minimize the adverse environmental effects; and (4) whether the costs of practicable technologies are wholly disproportionate to the environmental benefits conferred by such measures. In re Brunswick Steam Electric Plant, Region 4, EPA (Nov. 7, 1977).

In the Matter of Athens Generating Company, LP, Interim Decision of the Commissioner, at 9, DEC Case No. 4-1922-00055/00001 (June 2, 2000).

2. Definitions

In discussing the analysis required by CWA Section 316(b), the definition of terms is a necessary starting point. Unfortunately, these terms are not defined in the CWA or in 6NYCRR. In federal administrative decisions and case law, the USEPA administrator has applied common dictionary definitions to some terms. During the hearing, although the parties and their witnesses used many of these terms, the definition of important terminology remained ambiguous. The definition of these terms, for purposes of this Recommended Decision, is intended to refine New York's procedures for this and future BTA determinations.

'Adverse' means unfavorable, harmful, difficult or detrimental. In re Brunswick Steam Electric Plant, Initial Decision re: Permit No. NC007064, Region 4, USEPA (Nov. 7, 1977).

'Available' means present and ready for use; at hand; accessible; capable of being gotten; qualified. American Heritage College Dictionary, [Third Edition, 1993]. As applied in the BTA analysis, 'available' reasonably means a proven technology, not an experimental technology; and further, a technology that is capable of being installed at a particular project site. The central issue addressed, infra, is whether Mirant's proposed application of Gunderboom technology for the Bowline 3 CWISs is a proven technology or whether at present it remains an experimental technology.

'Best' means surpassing all others or to the highest degree. American Heritage College Dictionary, [Third Edition, 1993].

'Cooling Water Intake Structures (CWISs)': Cooling water intake structures "may consist of one or more elements including an inlet structure (the point of water entrance), closed conduits and open channels, a pump structure or a combined screen and pump structure." Development Document for Best Technology Available for the Location, Design, Construction and Capacity of Cooling Water Intake Structures for Minimizing Adverse Environmental Impact, USEPA, 1976 at 15 (the 1976 Development Document). Further, a "[cooling water] intake structure comprises the total structure used to direct cooling water from a water body into the components of the cooling system wherein the cooling function is designed to take place . . . the intake structure includes circulating and service water pumps where those pumps are located in the cooling system prior to the heat exchangers or condensers." 1976 Development Document at 2.

The definition of CWISs limits the scope of 'adverse impacts' to be considered in the BTA determination. Therefore, the CWISs component of the Bowline Unit 3 project is separate from the cooling tower component or the electric generation component. In re Brunswick Steam Electric Plant, (Brunswick I), Region IV, USEPA, Initial Decision, Permit No. NC007064,(Nov. 7, 1977). Mirant and DEC Staff contend that impacts of cooling towers, specifically visual impacts and terrestrial and wildlife impacts, must be considered in the BTA determination. Also, the CWISs definition is implicated in the issue of whether cooling water from Bowline Units 1 and 2 may be reused for cooling Unit 3. These issues are addressed further, below.

'Entrainment' is the process by which smaller organisms including larval fish and fish eggs are carried along with the intake water through any intended exclusion technology such as screens (or a Gunderboom), into the cooling system where they are damaged or killed. Athens Interim Decision, supra at 9.

'Impingement' is the process by which larger organisms, including fish, are caught against intended exclusion technology such as screens (or a Gunderboom) by the force of the intake water flows, resulting in either suffocation or injury of the organisms. Athens Interim Decision, supra at 9.

'Location' refers to both the horizontal and vertical placement of the intake structure with respect to the local above-water and under-water topography . . . [including such issues as] where is the intake to be located with respect to the shoreline, navigation channels, wetlands, discharge structures, areas of important biological activity and the depth from which the water is to be drawn. 1976 Development Document at 15.

'Minimize' means to reduce to the smallest possible amount, extent or degree. The absolute term 'minimize' is distinct from the relative term 'reduce' which means 'to diminish or lessen as in extent, amount or degree'. American Heritage College Dictionary, [Third Edition, 1993].

III. The Parties' Positions

Applicant and DEC Staff

The DEC Staff conducted a BTA analysis, concluding that Mirant's hybrid cooling/Gunderboom CWISs proposal represents BTA for the Bowline Unit 3 site. Mirant concurs. DEC Staff contends that the proposed CWISs represent BTA as required by 6NYCRR 704.5 and CWA Section 316(b), and further, that the draft SPDES permit, as conditioned, will mitigate any adverse impacts so that there will be no significant effect to the NYSDOS designated habitat. Additionally, DEC Staff concludes that the Bowline Unit 3 discharge, located in Haverstraw Bay, has been subjected to stringent effluent modeling and will meet all applicable water quality standards. No other party conducted a BTA analysis challenging the Staff's BTA analysis.

Mirant and DEC Staff contend that the Joint Intervenors have unduly focused upon the 'capacity' factor in asserting that dry cooling is BTA because it requires substantially less capacity than Mirant's Hybrid cooling/Gunderboom proposal; 0.175 mgd (dry) compared to 7.5 NYCRR (hybrid/Gunderboom).

The Joint Intervenors' Position

The Joint Intervenors contend that Mirant and DEC Staff have improperly ignored the 'capacity' factor. In the Joint Intervenors' view, dry cooling technology is BTA for this site, because it uses 97% less water and thus minimizes adverse aquatic impacts. Moreover, in their view, due to several infirmities with the proposed Gunderboom technology and the proposed location, the Gunderboom technology remains a promising experimental technology but currently is not 'available' for the Bowline Unit 3 project.

Relying upon the Commissioner's Interim Decision in Athens, the Joint Intervenors note the Commissioner's conclusion that the application of Gunderboom technology at the Athens site was premature. Since the Commissioner's pronouncement in Athens, the efficacy of the Gunderboom is supported by two additional deployment years, 1999 and 2000, involving a different site and a different application (a retrofit to a 45 year old facility consisting of five fossil fuel fired steam turbine electric generating units at Mirant's Lovett electric power generation facility). Although BTA determinations are site-specific, the application of Gunderboom technology for a facility also located on the Hudson River, some 80 miles north of the Bowline site, was deemed 'premature'. Athens Interim Decision, supra. Therefore, one component of the BTA analysis must evaluate how the Gunderboom technology has advanced since the Athens Interim Decision in June 2000. See, Bowline Issues Ruling at 20 (Ruling #7), DEC Case No.3-3922-0003/00015 (March 30, 2001).

Resolution of the Reuse Issue

The other adjudicable issue is the extent to which Mirant may reuse the cooling water discharged from Bowline Units 1 and 2 to cool Bowline Unit 3. The DEC draft SPDES permit authorizes reuse of cooling water discharged from Bowline Units 1 and 2 to provide cooling water makeup for Bowline Unit 3, annually from October 1 through mid-February. Ex. 79. The Joint Intervenors contended that reuse whenever available throughout the year is the best method of minimizing adverse aquatic impacts. Therefore, they conclude that reuse should be authorized throughout the year whenever such water is available as makeup water for Bowline Unit 3.

This issue has been resolved by DEC Staff's revised position as set forth in its closing reply brief. DEC Staff now will allow reuse of cooling water discharged from Bowline Units 1 and 2 to cool Bowline Unit 3, whenever available throughout the year, subject to Mirant's acceptance of new permit conditions. The new conditions would specify that such reuse throughout the year does not affect any subsequent BTA determination for Bowline Units 1 and 2 (or any other existing facility that uses once-through cooling technology). Since Mirant originally proposed such reuse, the issue of water reuse is resolved, irrespective of which cooling technology or capacity limitation may be authorized in a final SPDES permit for this project.

DISCUSSION

The primary issue adjudicated in the DEC component of the joint hearing was whether the Bowline Unit 3 CWISs with proposed Gunderboom technology is BTA for this site, as required by 6 NYCRR 704.5 and CWA Section 316(b). As noted above, several issues are subsumed within this overarching issue.

The federal analytical method for determining BTA has been identified by the USEPA in the Brunswick case, supra, and has been adopted in New York by the DEC Commissioner in the Athens Interim Decision, supra. That four step analysis is applied to the Bowline Unit 3 project in this Recommended Decision.

The BTA discussion begins with a brief description of the river setting and the cooling water intake structures, the scope of impacts to be considered and the effect of the Athens Generating Co., LP, case and post-Athens developments. The next section applies the Brunswick/Athens procedures to the Bowline 3 CWISs, providing an analysis of whether the capacity, location, design, and construction of the proposed CWISs will minimize adverse environmental impacts, as required. The discussion and recommended decision that follow are based upon the joint hearing record in this proceeding as well as all arguments presented by the parties in their closing briefs.

The decision recommended in this report, as set forth more fully below, is that the Gunderboom technology for CWISs fish exclusion is not a proven technology, but remains a promising experimental technology at this time. Therefore, the Gunderboom technology for CWISs fish exclusion currently is not an available technology. Instead, dry cooling technology is recommended as BTA for the Bowline Unit 3 CWISs. However, since this is a recommended decision, the full BTA analysis has been completed assuming, arguendo, that the Gunderboom is a proven technology (and assuming, arguendo, that any other infirmities with Mirant's hybrid cooling/Gunderboom proposal that are identified in this Recommended Decision were not an impediment to the BTA determination). The purpose of this additional analysis is to provide the parties and the DEC Commissioner with a complete examination of all BTA issues presented in the record, from which the parties may state their support or exception. By this process, the Commissioner will have a comprehensive record including the Associate Examiner's complete BTA analysis and the parties' exceptions from that analysis, for final agency determination.

The parties do not dispute that dry cooling technology, with a capacity limitation of 0.175 mgd will result in lower fish mortalities from the Bowline Unit 3 CWISs than Mirant's hybrid cooling/Gunderboom proposal with a capacity limitation of 7.5 mgd. However, it is the position of the DEC Staff and Mirant that reducing adverse aquatic impacts from the proposed hybrid cooling/Gunderboom CWISs by using a dry cooling technology CWISs, is not directly proportional to reduced capacity. Instead, DEC Staff concludes that the hybrid cooling/Gunderboom proposal is an 'approximately equivalent' exclusion system (as compared to dry cooling technology), and therefore should be considered BTA for the Bowline Unit 3 project. Further, DEC Staff concludes that the additional cost of a dry cooling technology CWISs is unnecessary to reduce adverse impacts of the CWISs. Consequently, the DEC Staff concludes that the cost of dry cooling technology is wholly disproportionate to the environmental benefits to be realized. Mirant concurs.

DEC Staff contends that the Joint Intervenors ignored the BTA factors other than capacity, i.e., location, design and construction. But, this view must be rejected.

I. Preliminary Considerations in the Determination of BTA

A. The Cooling Water Intake Structures: The River Setting and Description of the Cooling Water Intake Structures

The Bowline Power Generation Facility, currently the site of Bowline Units 1 and 2, is located approximately at Hudson River Mile 37 (approximately 37 miles above the Battery), in the Haverstraw Bay section of the River. Haverstraw Bay is a DOS Designated Significant Coastal Fish and Wildlife Habitat. The proposed Bowline Unit 3 facility, comprising approximately 25 acres of the 257 acre Bowline Power Generation Facility, would be located on the west bank of the Hudson River, just north of Bowline Pond. An existing pumphouse serving Bowline Units 1 and 2 is located in Bowline Pond and withdraws a maximum of 1,100 mgd of water. Bowline Pond has an approximate surface area of 54 acres and is separated from Haverstraw Bay by an intake channel that is less than 100 feet wide.

Mirant proposes to construct a new, separate intake structure for Bowline Unit 3 that would be attached to the side of the existing pumphouse. The DEC draft SPDES permit authorizes the reuse of cooling water from Units 1 and 2, annually from October through mid-February. Ex. 79. (But, in view of DEC Staff's revised position, supra, the new Unit 3 intake would function only when cooling tower makeup water is not available from reuse of Units 1 and 2 discharge.)

The majority of Bowline Unit 3 intake water from Bowline Pond (fed by the Hudson River) would be used for cooling purposes. For Mirant's hybrid cooling technology proposal, the water demand would be a maximum of 7.5 mgd, under typical gas-fired operation. Water would be withdrawn with a maximum through screen velocity of 0.5 feet per second (fps). The maximum flow through velocity for the Gunderboom curtain (at 7.5 mgd), would be approximately 1.4 feet per second (fps).

- Description of the Gunderboom

The proposed intake structures include the Gunderboom porous curtain barrier as the primary intended fish (ichthyoplankton) exclusion technology. Behind the Gunderboom, the CWISs inlet is enclosed by an engineered wedge wire screen with a screen opening of 2.0 mm. This 2.0 mm wedge wire screen is a secondary technology intended to provide exclusion of biota greater than 15 mm that (for whatever reason) may cross the primary intended exclusion technology (the Gunderboom curtain barrier).

Annually during the period from February 15 through September 30, the Bowline Unit 3 intake will be enclosed behind the Gunderboom. But, the Gunderboom will not enclose the adjacent existing intakes for Bowline Units 1 and 2. A single Gunderboom curtain panel would span approximately 137 feet in length oriented at a right angle with the existing intake structure serving Units 1 and 2, with water depths averaging 27.5 feet. The curtain surface area of the Gunderboom will be approximately 3200 square feet.

The draft SPDES permit requires that the pore size of the outside boom fabric must not exceed 0.5 mm, but the inside fabric may have a larger pore size to facilitate boom cleaning. (As discussed below, the parties disputed the relationship of outside fabric pore size to effectiveness in ichthyoplankton exclusion.)

An anchoring system will be employed using deadweight concrete blocks of approximately 15 tons each, located about 30 feet apart on either side of the deployed boom. The curtain is suspended at the surface of the water body by vinyl-covered floatation billets. A computer controlled air backwash system (the Air Burst system) will provide for automatic cleaning of the boom at fixed intervals, and the boom will be equipped with strain gauges and water level monitors to further detect and alert unit operators of the need for additional cleaning cycles. A rubberized plastic skirt along the base of the fabric curtain boom is intended to create an effective seal along the bottom of the boom. The existing multiport-high speed diffuser which serves Bowline Units 1 and 2 is adequate to accommodate the discharge of Bowline Unit 3.

In discussing the level of effectiveness or possible failure of the Gunderboom in excluding fish, the following factors were identified: overtopping (water flowing over the Gunderboom rather than through it), tunneling (water flowing under the Gunderboom rather than through it) and tearing of the fabric. As discussed, infra, the parties disputed the conditions that could cause such failures of the Gunderboom to occur.

DEC Staff has identified five fish species of concern in reviewing this project: White Perch, Bay Anchovy, River Herring, American Shad and Striped Bass. For the majority of these species, the Haverstraw Bay segment of the Hudson River is an important nursery, but not an important spawning area. Instead, DEC Staff contends that primary spawning areas of these species, producing organisms more vulnerable to entrainment mortality, are found in other sections of the Hudson River, not Haverstraw Bay or Bowline Pond.

B. The Scope of Impacts to be Considered in the BTA Analysis

- Exhibit No. 144

The scope of 6 NYCRR 704.5 and CWA Section 316(b) is limited to minimizing adverse environmental impacts of cooling water intake structures, as those terms are defined, supra. But, DEC Staff and Mirant, citing a 1994 memorandum from an attorney then in DEC Counsel's Office, assert that the BTA determination includes consideration of adverse impacts of other components of the project in addition to the CWISs component. Ex 144. Impacts that Mirant and DEC Staff assert should be considered in the BTA determination include visual impacts of the cooling towers and terrestrial, wetland and wildlife impacts of hybrid cooling tower locations (Mirant has proposed two locations) versus impacts of a dry cooling tower location (different from the two hybrid locations). Exhibit 144 is a (then) DEC staff attorney's opinion as to how a BTA analysis should be conducted. It is not a formal guidance document such as the DEC Division of Water, Technical and Operational Guidance Series (TOGS) documents. Accordingly, it is not entitled to be given as much weight as such formal agency guidance.⁽¹⁰⁾ Instead, it is analogous to DEC Staff's legal arguments and opinions as set forth in the record.

Exhibit 144 recommends consideration of technology that minimizes overall adverse environmental effects, as opposed to limiting consideration of adverse impacts to the CWISs. Mirant and DEC Staff construe this guidance to require consideration of adverse impacts of other components of the project than the CWIS, specifically, impacts of the cooling tower component. But, 6 NYCRR 704.5 and CWA Section 316(b) require minimization of adverse impacts of the cooling water intake structure only, not the project as a whole. The expansive language in Exhibit 144 is not substantiated by the plain language of 6 NYCRR 704.5 or CWA Section 316(b).

Nor is DEC Staff's interpretation of Exhibit 144 supported by the federal guidance document, the 1976 USEPA Development Document. The Development Document states that major impacts of the CWISs are those affecting the aquatic ecosystem, primarily fish populations. 1976 Development Document at 5. The Development Document does describe 'other environmental impacts', but consideration of such impacts also reasonably are limited to impacts of the CWISs, not the project as a whole. For example, regarding aesthetic impacts, the Development Document provides that where the intake structures and balance of the plant are separated by great distances, the intake structure itself may have an imposing physical presence. 1976 Development Document at 10. The relevant aesthetic adverse impact for the BTA determination is the impact of the CWISs, not the impact of the entire plant.

Instead, in New York State, impacts of the project as a whole are reviewed under ECL Article 8 (State Environmental Quality Review Act [SEQRA]) or, in electric generation siting cases, by PSL Article X which provides for a review that is the functional equivalent of SEQRA. See, 6 NYCRR 617.5(c)(35); compare, PSL Section 168(2)(c).

In sum, consideration of the project impacts as a whole in the BTA analysis is not appropriate. The BTA analysis of environmental impacts must focus exclusively upon adverse impacts of the CWISs component of the project. To the extent that Exhibit 144 varies from this principle, Exhibit 144 is rejected. The DEC Staff erroneously rejected dry cooling technology for the Bowline CWISs because dry towers did not meet the test required in Exhibit 144 (item 8), of 'minimizing overall adverse environmental impacts'.⁽¹¹⁾ Adverse impacts of other components of the project, such as the cooling technology component or the power generation component are addressed in the related PSL Article X Recommended Decision, issued this date.⁽¹²⁾

C. The Precedent of Athens Generating Co., LP

- The Athens Gunderboom Exclusion Technology

The parties dispute whether the Gunderboom technology is an available (proven) technology or an experimental technology. In the June 2000 Athens Interim Decision, supra, the Commissioner held that the application of Gunderboom technology to the Athens project site was premature. In my view, 'premature' means that the technology was, in June 2000, as yet unproven and experimental. This holding is relevant to the present BTA determination. In view of the Athens Interim Decision, the present BTA analysis must include an evaluation of advances or events relevant to the development of Gunderboom technology that have occurred since June 2000 Athens Interim Decision. These factors are discussed further below.

The parties disagree about how to evaluate the alternative option of dry cooling technology in the Bowline Unit 3 BTA analysis. As Mirant has noted in its reply brief, neither the CWA nor state law or regulation provide any specific structure for the BTA analysis. In Athens, supra, the Commissioner confirmed that the BTA determination requires a site-specific analysis; no one technology (such as dry cooling) can be considered BTA statewide. Nonetheless, at present dry cooling technology is undisputedly the available technology that presumptively minimizes fish mortality by reducing the water intake requirements (capacity) for a particular project. Therefore, logic dictates that the BTA analysis must begin with the proven technology that minimizes adverse impacts of the CWISs, absent cost considerations; at present, dry cooling technology.

This does not mean that dry cooling is necessarily BTA for any particular site, or for Bowline Unit 3, as the Applicant and DEC Staff contend. But certainly, as the currently available most effective proven technology in reducing adverse aquatic impacts, it must be pivotal in a current BTA determination process, including the BTA analysis for the present project.⁽¹³⁾ Consequently, dry cooling is the technology against which any other proposed or alternative technologies must be measured in arriving at the site-specific determination of BTA that minimizes adverse impacts of the CWISs.

But, this is only one step in the BTA analysis, and does not consider cost. Costs are addressed subsequently in the BTA analysis. This is the approach adopted by the Commissioner in the Athens case, and advocated by Joint Intervenors in this proceeding, and it is the approach that will be followed here.

D. Developments Since Athens

In identifying advances or recent events in the development of Gunderboom technology for fish exclusion at CWISs, Mirant and DEC Staff point to the report on the Lovett Gunderboom deployment for the 2000 season and impingement experiments conducted by DEC Staff Biologist Radle during the 2000 season. Additionally, during this proceeding, Riverkeeper and Mirant have conducted static panel tests of Gunderboom fabric samples. These events are discussed, infra, in evaluating whether the Gunderboom is a proven technology, 'available' for the Bowline Unit 3 project.

II. Whether the Facility's Cooling Water Intake Structure May Result in Adverse Environmental Impact

The parties do not dispute that a proposed Bowline Unit 3 CWISs located in Bowline Pond will result in adverse aquatic environmental impacts, specifically, fish mortalities. Instead, the parties dispute the extent of mitigation necessary to 'minimize' such adverse impacts and also, whether Mirant's hybrid cooling/Gunderboom proposal or a dry cooling technology alternative is the 'best technology available' for this project site.

Regarding adverse aquatic impacts, DEC Staff provided fish mortality data including estimated raw mortality numbers and Conditional Mortality Rates (CMR) for five species of concern, White Perch, Bay Anchovy, River Herring, American Shad and Striped Bass. The CMR is a percentage reflecting the ratio of estimated fish mortality for a subject species at a particular CWIS compared to the estimated population of that species in the water body (here, the Hudson River). These data are discussed further below in the 'Cost' section. The parties did not dispute that these five fish species are the species of concern in evaluating adverse aquatic impacts of the CWISs for Bowline Unit 3.

III. Whether the 'Location, Design, Construction and Capacity of the Cooling Water Intake Structure Reflects Best Technology Available for Minimizing Adverse Environmental Impact'

Mirant's hybrid cooling technology proposal for the Bowline Unit 3 project includes a CWIS inlet with 2.0 mm wedge wire screen, enclosed by a fabric curtain Gunderboom. Therefore, this section of the BTA analysis evaluates whether this proposal is BTA for minimizing adverse environmental impacts of the proposed Bowline Unit 3 CWISs; and if not, what other technology does minimize adverse impacts.

This section of the BTA analysis requires a comparison of the proposed CWISs technology with any other available technologies that may be more effective in reducing adverse impacts, to determine which technology minimizes adverse impacts without regard to cost. Consideration of costs is addressed in the third section of the BTA analysis, immediately following this section. To the extent that DEC Staff compared the proposal to other less effective technologies, as discussed above, Staff's approach is rejected.

A. Capacity

Mirant and DEC Staff dispute the Joint Intervenors' contention that capacity is the primary or most important factor in a BTA determination. But, no party disputes that, all other factors being equal, the amount of water withdrawn from a water body will be directly proportional to fish mortality of the fish population of that water body. This is why, historically, it has been reasonable to conclude that capacity is the most important factor in determining BTA. The direct relationship between fish mortality and capacity applies to dry cooling technology. Dry cooling is effective in minimizing fish mortality because it minimizes capacity (dry cooling, 0.175 mgd versus hybrid cooling technology/Gunderboom: 7.5mgd).

However, developing technologies such as the Gunderboom hold the promise of destroying this historical relationship between capacity and fish mortality. If, arguendo, the Gunderboom technology is a proven (not experimental) technology, then the capacity factor as a predictor of fish mortality is less significant in assessing BTA.

Riverkeeper contends that dry cooling would use 29 times less water than hybrid cooling.⁽¹⁴⁾ But no one substantially disagrees with the contention of Riverkeeper's Dr. Dougherty that compared to other technologies, dry cooling would significantly reduce water usage. DEC Staff responds, however, that a once-through system would use billions of gallons per day. DEC Staff contends that it is misleading to compare two very small numbers. That is, in DEC Staff's view, 7.5 mgd is a small quantity of water compared to once-through cooling technology. For example, Bowline Units 1 and 2 use a combined maximum capacity of 1,100 mgd. But this argument is unpersuasive because the regulatory standard is to minimize, not merely reduce, impacts.

Instead, DEC Staff points to the difference between entrainment of a dry cooling intake (with 2.0 mm wedge wire screen) versus a hybrid cooling intake (with 2.0 mm wedge wire screen but without the Gunderboom), contending that the additional reduction in entrainment with dry cooling technology is less than 1%. In Staff's view, the addition of Gunderboom technology to the proposed hybrid cooling intake is intended to reduce the 1% entrainment difference between dry cooling and hybrid cooling. In this light, DEC Staff concludes, the proposed 7.5mgd hybrid intake capacity is not a large capacity CWISs and therefore already substantially reduces potential CWISs adverse impacts (entrainment).

But, as the Joint Intervenors note, potential CWISs adverse impacts must not simply be reduced, but minimized. (In my view, the Joint Intervenors are mistaken, because in the cost section, technologies that 'minimize' impacts may be rejected as BTA if costs are wholly disproportionate to the incremental environmental benefits.) This is discussed further in the 'cost' section, infra.

B. Design

The CWA Section 316(b) limits consideration of adverse environmental impacts to adverse impacts of the CWISs component of the project. Consistent with the federal statute, the Commissioner has stated that the BTA 'design' requirement primarily concerns designs to reduce the fisheries impacts of the cooling water intake structure, particularly fish losses due to both entrainment and impingement. Athens Interim Decision, supra at 16. Nonetheless, Mirant and DEC Staff, relying on Exhibit 144, contend that other environmental impacts of the cooling technology should be considered as adverse environmental impacts in the BTA determination. As discussed, supra, this view is rejected.

The facility must be designed using the best technology available. As discussed above, 'available' means a proven technology, not an experimental technology (and also, a technology that is capable of being installed at a particular project site). One design issue is whether the Gunderboom proposal is a proven technology, as Mirant and DEC Staff assert, or whether it is still an experimental technology, and therefore not 'available' at this stage of its technological development.

1. The Lovett Gunderboom: 1995 through 1998

The proprietary Gunderboom technology was developed for aquatic applications other than CWISs exclusion. The first application of this technology as a component of a CWISs for a power generation station was the experimental deployment at the Lovett Generating Station, beginning in 1995. The parties dispute whether the Lovett Gunderboom deployment continues to be an experimental application of the Gunderboom technology, or whether it has advanced to the point that it is no longer experimental, but is now a proven technology.

The Gunderboom configuration proposed for Mirant's Bowline Unit 3 Gunderboom, described above, is similar to the Gunderboom configuration developed at Lovett.⁽¹⁵⁾ But, the Lovett Gunderboom is in excess of 500 feet in length. It is located in the Hudson River, subject to strong currents and estuarine tidal influences. The Lovett Gunderboom is not configured as a straight curtain, but is angled in the River. Due to its length, it is comprised of several curtain sections that have been joined together. By comparison, the proposed Bowline Unit 3 Gunderboom would be approximately 137 feet in length, one section, and would be located in a straight line configuration in Bowline Pond. The Bowline Gunderboom would not be subject to the strong currents and tidal forces of the Hudson River.

Studies of the Lovett Gunderboom's effectiveness at ichthyoplankton exclusion were conducted for the 1995 and 1998 deployment seasons (prior to Athens). In addition, as discussed below, a third season of ichthyoplankton exclusion data were obtained during the 2000 deployment season (after the Athens Interim Decision). The three years of exclusion data are discussed together, infra.

2. The Athens Project

In Athens, the Commissioner concluded that the capacity of the CWISs should be reduced beyond the proposed Athens hybrid cooling technology intake capacity, to further minimize environmental impacts. Instead, the Commissioner required dry cooling technology. Athens, Interim Decision, supra at 16.

DEC Staff has not directly addressed what advance in Gunderboom technology has occurred since the Commissioner's determination in Athens, supra. Instead, DEC Staff asserts that the Commissioner's Athens Interim Decision, supra, does not prohibit the designation of the Gunderboom technology as BTA for Bowline 3. But, this is not really in dispute and is irrelevant. The issue is whether, in view of Athens, the Gunderboom exclusion technology has advanced to the point that it is no longer experimental - - so that a Bowline 3 determination that Gunderboom technology is BTA would not be premature, as the Commissioner deemed it to be in Athens.

Next, Mirant and DEC Staff contend that the Commissioner rejected the Athens Gunderboom proposal because that Gunderboom proposal was a completely different configuration than the Gunderboom configuration deployed at the Lovett facility. They assert that whereas the Athens Gunderboom had numerous unique and previously untested design elements, the proposed Bowline Gunderboom design and configuration is similar to the Lovett design that has been under development since 1995. Also, unlike the Athens Gunderboom proposal, Mirant and DEC Staff assert that this record includes drawings and schematics of the Gunderboom configuration and the facilities and structures to be installed as part of the Gunderboom system, descriptions of how deployment of the Gunderboom would take place, descriptions of the maintenance and support systems, the biological monitoring program and a contingency plan if the Gunderboom fails.

Mirant and DEC Staff point out that the proposed Bowline Gunderboom will be smaller than Lovett (approximately 137 linear feet versus approximately 500 linear feet), and will have less flow per unit area resulting in lower loading on the fabric and overall Gunderboom system than the Lovett system. Also, the Bowline Unit 3 Air Burst system (intended to clear clogged fabric pores) will be fully integrated into plant operations and the Bowline Unit 3 project will include a formal Gunderboom system operating monitoring program. Neither a fully integrated Air Burst system nor the monitoring program are in place at Lovett.

Finally, Mirant and DEC Staff contend that the layered technological design of the Bowline Unit 3 Gunderboom proposal 'minimizes' adverse impacts within the meaning of CWA Section 316(b). By layered, Staff refers to the low velocity of intake water, the 2.0 mm wedge wire screens, the Gunderboom MLES (curtain) enclosing the CWISs inlet, and the combined cycle generating technology that allows the reduced intake velocity and reduces capacity to the proposed 7.5 mgd.

No party disagrees that the state should encourage the development of new CWISs exclusion technologies such as the Gunderboom. But, since the Gunderboom technology application for electric power generation CWISs is being developed exclusively at Lovett, that development program should be completed before the technology is applied to other CWISs. The objective milestone for completion of that development project is a Departmental determination that the Lovett CWISs, with seasonal Gunderboom deployment, is BTA for that site. Significantly, the Department has not yet determined that the Lovett Gunderboom is BTA. Therefore, it remains an experimental development project.⁽¹⁶⁾

3. Post-Athens Gunderboom Developments

In its BTA determination, the DEC Staff concludes that the Gunderboom technology is a proven, and therefore an appropriately considered, technology. But, in New York consideration of whether the Gunderboom technology is proven or experimental must consider advances or developments since the Athens Interim Decision, because in that case the Commissioner held that the Gunderboom CWIS exclusion technology was 'premature', or experimental.

The Commissioner stated in Athens that merely because a technology like the Gunderboom is relatively new, that does not render it unacceptable; the Department has an obligation to pursue new technologies. Commissioner's June 2, 2000 Interim Decision in Athens, supra, at 10. Nonetheless, in Athens, the Commissioner concluded that the application of Gunderboom technology to the Athens project site was 'premature'. Athens, supra, at 10. In the Athens case, as here, DEC Staff with direct Gunderboom experience at the Lovett project site assert that the Gunderboom technology is a proven technology, not experimental.

The DEC Staff contends that the record demonstrates that the Gunderboom is a highly effective technology that will prevent entrainment or impingement of aquatic organisms at the Bowline Unit 3 CWISs. But the record here is not substantially different than the record in Athens.

Since the Commissioner's Athens Interim Decision in June 2000, Mirant's engineering consultant for the Lovett project has issued a report on the 1999 Lovett Generating Station Gunderboom Deployment and a report on the 2000 Lovett Generating Station Gunderboom Deployment. Ex. 21 [Report on the Lovett Generating Station Gunderboom Deployment Program 1999]; Ex 115 [Report on the Lovett Generating Station Gunderboom Deployment Program 2000 (dated April 2001)]. Entrainment data was collected for the Lovett 2000 season.

Also, since Athens, in May 2001 DEC Staff Biologist Radle conducted experiments with exposure of American shad eggs and larvae to Gunderboom fabric samples at the Pennsylvania Boat and Fish Commission, Van Dyke Anadromous Fish Hatchery.⁽¹⁷⁾ Lastly since the Commissioner's Athens Interim Decision, Riverkeeper and Mirant have each conducted biofouling studies on Gunderboom fabric samples as part of this proceeding. These events are discussed in greater detail, infra.

In addition, Mirant and DEC Staff distinguish Mirant's Bowline Gunderboom proposal from the Athens Gunderboom proposal in several ways. First, the Athens inlet and Gunderboom proposal was to be located in the Hudson River, whereas the Bowline Unit 3 inlet and Gunderboom proposal would not be located in the Hudson River, but in Bowline Pond. Initially, Mirant and Gunderboom, Inc., represented that stronger currents (as occur in the Hudson River) are necessary for proper functioning of the Gunderboom. But, they now contend that Bowline Pond is an appropriate site for the Gunderboom.

The Athens Gunderboom design proposal was not a curtain suspended across the water column (as is the Lovett Gunderboom and the Bowline Unit 3 Gunderboom proposal). Instead, the Athens design proposal was for a submerged fabric panel structure enclosing the water inlet (apparently similar to the Gunderboom design proposed for the pending PSEG Bethlehem project). Relying upon this distinction and the Lovett history, Mirant and DEC Staff conclude that the Bowline Gunderboom proposal is a proven configuration of the Gunderboom technology.

Also, Mirant and DEC Staff note that the segment of the Hudson River where the Athens project was proposed, approximately 80 miles north of the Bowline site, is a different biological region of the Hudson River. Mirant and DEC Staff contend that the river area at the Athens site is a spawning area for the fish species of concern (except Bay Anchovy). In contrast, the Haverstraw Bay segment of the river at the Bowline site is a significant nursery area for these species and a DOS Significant Fish and Wildlife Habitat, but not a significant spawning area. DEC Staff contends that this is an important distinction relative to impingement and entrainment impacts at the intake structures. In the spawning phase of development, fish are smaller and therefore more susceptible to entrainment or impingement. As the organisms develop and migrate to the Haverstraw Bay (and Bowline Pond) nursery area of the River, they are larger and motile. Therefore, according to Mirant and DEC Staff, these developed organisms will be able to swim away from the intake flow of the proposed Bowline Unit 3 Gunderboom (and inlet) to avoid entrainment or impingement.

The following discussion of the post-Athens events concludes that no significant advances in Gunderboom technology have occurred since Athens, and therefore, the Gunderboom remains an experimental technology for CWISs fish exclusion.

a. The Lovett Year 2000 Deployment

Mirant and DEC Staff identified the Lovett 1999 and 2000 Reports as providing two additional years during which the Lovett Gunderboom was 'successfully' deployed. But, the Joint Intervenors challenged the characterization of the Lovett 1999 and 2000 season deployments as 'successful' in minimizing entrainment and impingement. Entrainment effectiveness data was collected only for the 2000 season. Mirant refutes the Joint Intervenors' contention that success of the Lovett Gunderboom deployments have been undermined by recurring problems such as structural failure due to biological growth, causing the curtain to lift off the bottom (breaking the bottom seal), and overtopping caused by failures of the temporary compressed air supply system for the Air Burst system, and clogging of the Gunderboom curtain due to biofouling (live aquatic biota) and sedimentation (inert matter).

- The Three Years of Ichthyoplankton Exclusion Data

Although the Lovett Gunderboom has been deployed annually for six years, from 1995 through 2000, measurements of Gunderboom effectiveness for fish (ichthyoplankton) exclusion were conducted only for three seasons: 1995, 1998 and 2000. Data was gathered by comparing an intake enclosed with the Gunderboom (Lovett Unit 3) to an intake without Gunderboom technology (Lovett Unit 4). DEC Staff contends that the Gunderboom reduced entrainment at Lovett by 75% to 90% during three entrainment monitoring years.

Based upon the three years of Lovett exclusion data, the DEC Staff predicts an effective exclusion rate of at least 80% for Bowline Unit 3, as required in the draft SPDES Permit. Moreover, DEC Staff posits that Bowline Unit 3 exclusion rates may exceed 90% due to anticipated improvements in the proposed Bowline Unit 3 Gunderboom installation.

The Joint Intervenors contend that the three years of Lovett monitoring data show that the Gunderboom is unreliable, with widely varying exclusion effectiveness. They assert that the claimed effectiveness of 75% or more never extended beyond a period of between four and six weeks for any of the three monitoring years; for each of the three years when entrainment mitigation was evaluated at Lovett, a 75% exclusion rate was never achieved for any one full deployment season. The Joint Intervenors conclude that the wide variation of effectiveness in fish exclusion indicates the continuing experimental status of the Gunderboom technology as a technology for exclusion of aquatic biota at CWISs.

DEC Staff respond that as early fish stage densities decreased in the river, measurements of Gunderboom effectiveness are not as reliable because the comparison is between small numbers. But, DEC Staff never explained why the proportional exclusion rate would not continue, even at lower densities. Nor did Staff identify a density below which the results would be predictably unreliable.

The Joint Intervenors contend that DEC Staff's interpretation of 75% to 90% effectiveness at Lovett is based upon a selective evaluation of the data. For example, they contend that in 1995, approximately 25% of the days DEC Staff included for comparison have little or no data for the non-Gunderboom intake. Thus, this results in a selectively optimistic conclusion of 75% or more exclusion effectiveness. In response, Mirant and DEC Staff contend that when comparing only those days when both plants were operating at full flow, the Gunderboom excluded 91.03% of the organisms entrained without the Gunderboom. But, the Joint Intervenors' criticism is that the selective use of data yields an invalid unreliable result. The Joint Intervenors contend that the Gunderboom has not reliably and consistently achieved such a high claimed exclusion percentage for any one full season, absent such selective interpretation of the monitoring data.

In 1998, the Gunderboom was deployed for a period of 12 weeks. The Joint Intervenors contend, however, that Mirant and DEC Staff rely only upon a 4-week period for their conclusion that the Gunderboom operated at 76% effectiveness for exclusion. Similarly, the Joint Intervenors, citing Exhibit No. 147, the 1999 Lovett Gunderboom Report, contend that from late July through the end of the deployment on August 31, the Gunderboom system functioned at substantially reduced effectiveness, with entrainment densities that did not differ from entrainment densities of the intake absent the Gunderboom.

The Joint Intervenors make a similar argument for the year 2000 deployment, contending that the 80% effectiveness claimed by Mirant and DEC Staff pertains only to the three initial weeks of the deployment season. Citing the Lovett 2000 Report, the Joint Intervenors assert that after six weeks of operation, effectiveness began to decline and by the end of July, the Gunderboom was not effective in exclusion of aquatic biota.

Mirant and DEC Staff contemplate a seven and a half month Gunderboom deployment period for Bowline Unit 3. The Joint Intervenors have created substantial doubt about the reliability and effectiveness of the Gunderboom exclusion technology. During the hearing, Mirant modified its position to voluntarily deploy a new (or cleaned) Gunderboom curtain at the beginning of the peak nursery season, to further assure effective exclusion during this critical time. In their closing briefs, the DEC Staff proposed to amend the draft SPDES permit to require that Mirant monitor and report on the effectiveness of the Gunderboom functioning during the deployment season (mid-February through March).

Further, Staff would require that Mirant replace the deployed Gunderboom with a clean or refurbished Gunderboom prior to the peak entrainment season. Staff concludes that in the unlikely event that progressive bio-fouling of the Gunderboom does occur, installation of a new or refurbished boom in anticipation of the peak entrainment season at Bowline Unit 3 will resolve this concern. But, the responses of Mirant and DEC Staff are not persuasive in overcoming the reliability and effectiveness issues that pertain to whether the Gunderboom technology remains experimental at this time.

Lastly, the Joint Intervenors point to the Bowline Unit 3 draft SPDES permit conditions that authorize two or possibly three years of Bowline Unit 3 operation before Mirant is required to achieve a fully operational Gunderboom. And even after this 'startup period', the draft SPDES permit authorizes operation of Bowline Unit 3 for up to 15 days per year with a functional failure of the Gunderboom before Mirant has violated the SPDES permit conditions (failure is defined a operating at less than 75% entrainment efficiency when the plant is operational during a 24 hour period) . Ex. 79, page 9 of 15. Such a startup period is not authorized under 6 NYCRR 704.5 or CWA Section 316(b), and is another indicator that the Gunderboom is experimental. Moreover, Riverkeeper points to Mirant's opinion, expressed prior to DEC Staff's issuance of the draft SPDES permit, that use of a Gunderboom for Bowline Unit 3 could reduce entrainment and impingement losses for Unit 3, but would increase entrainment and impingement losses for Units 1 and 2, when those Units are operational; and further, that background current velocity is low in Bowline Pond, which will limit the effectiveness of the Air Burst system and increase fouling rates by attached algae. These permit conditions would not be necessary with dry cooling technology and contradict DEC Staff's conclusion that the proposed hybrid cooling/Gunderboom technologies are approximately equivalent to the mitigation afforded by dry cooling technology.

b. The 2000 American Shad Impingement Experiments

The experiments conducted by DEC Biologist Radle included impingement of American shad eggs on Gunderboom fabric for one, two and four hours; observations of the ease of release of impinged eggs from the outside surface of the fabric (i.e., the surface of the fabric upon which impingement would occur in the deployed Bowline 3 Gunderboom); and exposure of day-old larvae in a tank to flows of 5 gpm/ft² flow through a panel of Gunderboom fabric. Testing control organisms were held for a total of 24 hours for latent mortality observation. Twelve hundred eggs were included in the experimental and control tests.

The highest mortality observed during the post-impingement mortality studies was 2%. Several treatments indicated no mortality. Biologist Radle's conclusion is that the experiments suggest that the mortalities that did occur were reflective of the natural random mortality that occurs independent of the test conditions. No party challenged the methodology of this test or Mr. Radle's conclusions. Mr. Radle's evidence and conclusions regarding these experiments is uncontroverted in the record. The Radle 2000 impingement tests provide probative information that contributes to understanding and development of the Gunderboom technology, and supports a conclusion that adverse impacts of the Gunderboom related to impingement mortality would be de minimis.

c. The Bowline Unit 3 Pisces-Riverkeeper Biofouling Studies and Mirant's Flow Test Apparatus (FTA) Studies

As a general matter, non-toxic materials placed in a rich estuarine environment will foul with aquatic organisms. In June and July, 2001 Riverkeeper conducted biofouling studies in Bowline Pond using Gunderboom fabric samples provided by Mirant and Gunderboom, Inc. The purpose of the studies was to evaluate the role of such fouling in a Bowline Unit 3 Gunderboom deployment. The results of the studies are described in the report, Gunderboom Fouling Studies in Bowline Pond, PISCES Conservation Limited (July 2001).Ex. 151 [PH-2].

Riverkeeper's studies and Applicant's FTA studies demonstrate progressive fouling of the Gunderboom with a variety of organisms. This fouling limited the Gunderboom's water filtering ability. On average, the Riverkeeper's static fabric panels retained their permeability after 11 days, but were reduced to approximately 50% permeability after 20 days. By the 29^th day (the final day of the test), the panels were 62% less permeable than they were at the beginning of the test period. By day 29, obvious colonization had increased to 70% of the available surface area. By comparison, the Lovett Gunderboom deployments of 1995, 1998 and 2000 showed effective filtering for periods of between four and six weeks, after which, for reasons not identified, effectiveness was severely compromised or in complete failure.

In the Riverkeeper's studies, quantitative analyses to assess the levels of microbes within the Gunderboom fabric all showed an increase in bacterial levels over the 29 day period of the study. The Joint Intervenors contend that as with other instances of biological growth, the increase in density of Gunderboom colonization would be expected to grow exponentially over time. They conclude that ultimately, this will result in failure of the Gunderboom's filtering capacity.

In response to Riverkeeper's proposed biofouling studies, Mirant conducted separate alternative Gunderboom fabric flow tests, but with fabric samples equipped with an air-burst feature similar to the feature proposed for the full Bowline Unit 3 Gunderboom deployment. (The Riverkeeper studies did not include an air-burst feature.) As described, supra, the air-burst feature is intended to agitate or shake the curtain, in situ, thereby loosening colonizing organisms (biofouling) from the Gunderboom curtain.

Mirant utilized a Flow Test Apparatus device (FTA) to suspend the fabric samples used in its studies (the FTA studies). However, after the studies were completed, Mirant provided raw data, but did not provide any report summarizing the FTA study results. Instead, Mirant (and DEC Staff) rejected the validity of these studies, contending that both the Riverkeeper/PISCES biofouling studies and its own FTA studies are not relevant because the studies are microcosm experiments that cannot be simply extrapolated to the larger boom to the functioning of a fully deployed Gunderboom such as the Lovett Generation Station Gunderboom or as is proposed for Bowline Unit 3.

In addition, to support the contention that the microcosm experiments do not apply to a fully deployed Gunderboom, Mirant contends that an essential effect of the Air Burst system is the billowing effect it has upon the fully deployed Gunderboom curtain, but that in the 29-day studies, this billowing effect did not occur because the fabric samples were too small and also because they were secured to a frame that precluded billowing. They also contend that Mirant's panels were in a device (the FTA) that to some extent shielded the panels from predator communities that arguably would reduce or slow the colonization of a fully deployed Gunderboom.

Mirant and DEC Staff conclude that the studies in fact demonstrate that the Gunderboom fabric samples never 'failed', because throughout the 29 days of the studies, the fabric samples provided a flow of 5 gallons/min/sq.ft., a rate more than adequate to supply the Bowline 3 intake. Nonetheless, the fact that Mirant did not challenge Riverkeeper's study design before the study was implemented, and to the contrary, participated by conducting its own simultaneous FTA study, weakens the credibility of Mirant's criticisms.

Normally, in a DEC permit hearing, intervenors are without the resources to mount such a study. Here, the PSL Article X provisions require an intervenor fund that provided funding for the study. But, Mirant and DEC Staff have presented some credible criticisms of the studies. For example, it is unlikely that the Air Burst system designed for a large, fully deployed curtain would function similarly on the small static fabric panels (and the Riverkeeper studies used no air-burst feature). Also, Mirant and DEC Staff persuasively refute the Joint Intervenors' assertion that biological growth on the Gunderboom will continue unabated until the available habitat on the fabric is substantially colonized. Mirant's witness, Mr. Schafer, testified that in the 1999 and 2000 Lovett deployments, biological growth on that Gunderboom did not result in failure of the Lovett Gunderboom.

Nonetheless, the Riverkeeper/PISCES studies and Mirant's FTA studies are relevant to an assessment of the functioning of a fully deployed Gunderboom over a period exceeding seven months, as is proposed for Bowline Unit 3. These studies do provide credible evidence suggesting that biofouling is a contributing factor limiting the Gunderboom's effective exclusion to a period not exceeding between four and six weeks.

d. Bowline Unit 3 Gunderboom Fabric Perforation Size and Riverkeeper's Motion for Adverse Inference

The Joint Intervenors contend that Mirant failed to comply with Riverkeeper's discovery request for samples of the Bowline Unit 3 Gunderboom fabric. The fabric that was provided, they claim, is different from the fabric that has been used in the Lovett Gunderboom deployments because the fabric perforation size (or pore size) is twice that of the Lovett fabric. The Joint Intervenors conclude that Mirant provided the wrong fabric.

Riverkeeper's Dr. Henderson measured the perforation size of the Bowline Unit 3 fabric as approximately 1 mm, using an electron microscope. The DEC draft SPDES permit requires that "the maximum pore size of the outside fabric shall be 0.5 mm, and the inside fabric may have larger holes to facilitate boom cleaning." Ex. 79 at 8 of 15. The Joint Intervenors contend that the 1 mm perforation size is inconsistent with Gunderboom, Inc.'s, engineering specifications for the fabric and in violation of the draft SPDES condition.

Accordingly, the Joint Intervenors argue that an adverse inference should be drawn against Mirant, that the Bowline Unit 3 Gunderboom will biofoul and will fail to adequately filter the water and aquatic organisms. Riverkeeper reasons that, if the perforation size were smaller, like the Lovett fabric perforation size, then the effects of biofouling in its 29-day studies would have been much greater.

But, Mirant asserts that the fabric sample it provided to Riverkeeper is the correct fabric intended for use in the Bowline Unit 3 Gunderboom. Further, Mirant contends that the fabric provided complies with the Bowline Unit 3 draft SPDES permit requirement that the 'maximum pore size of the outside [Gunderboom] fabric shall be 0.5 mm'. Apparently, Gunderboom, Inc., has revised its fabric with a larger perforation size, to be used for the Bowline Unit 3 project (and presumably to other similar projects).

The controversy pertains to the perforation size of the fabric proposed for the Bowline Unit 3 Gunderboom (as compared to the Lovett fabric) and whether the proposed Bowline Unit 3 fabric complies with the draft SPDES permit condition limiting perforation size to a maximum of 0.5 mm. The DEC draft SPDES permit does not specify a methodology for compliance with the requirement 'not to exceed 0.5 mm'. Ex 79, page 8.

The methodology employed to measure perforation size is critical to any evaluation of compliance with this permit condition, because by specifying a methodology, others can verify the perforation size. Dr. Marr, Mirant's rebuttal witness, testified that the appropriate methodology to measure geotextile perforation size, such as the Bowline Unit 3 fabric, is the ASTM⁽¹⁸⁾ Standard Test Method for Determining Apparent Opening Size (AOS) of a Geotextile, ASTM D-4751-99a (revised 1999). The test identifies an AOS size that indicates the approximate largest size particle that will pass through a geotextile. Briefly, the test requires placement of a fabric sample in a sieve frame. Sized glass beads are placed on the fabric surface, then the frame is shaken by a special apparatus to induce the beads to pass through the fabric. Dr. Marr testified that in his professional judgment, the ASTM D-4751-99a (AOS) methodology is generally accepted standard in the field of geotextile engineering to evaluate effective or apparent opening sizes concerning a particle or an object flowing through a fabric.

The ASTM D-4751-99a methodology requires conducting the test on a dry fabric sample, but due to the proposed use of the fabric, Dr. Marr also conducted the test on a wet fabric sample. He determined that the perforation size of the dry Bowline Unit 3 fabric sample was 0.5 mm and the perforation size of the wet sample was 0.425 mm.

But, the Joint Intervenors respond that for at least the past three years, the Lovett Gunderboom fabric has had 0.5 mm diameter perforations, with an AOS of approximately 0.212 mm. The Lovett 2000 Report describes the fabric specifications as follows: "Gunderboom Incorporated's brochure on the Gunderboom Marine/Aquatic Life Exclusion System indicates that the Apparent Opening Size (AOS) for the Gunderboom material based on a Standard Sieve Analysis methodology is 70, which equates to a mesh opening of 212 [microns] or 0.212 mm. The effective mesh opening of the boom material is effective at limiting the passage of all planktonic organisms including fish eggs and larva [sic]." Ex. 115 at 2-1. The Lovett 1999 Report states that "[t]he boom material, with a nominal mesh opening of 0.212 mm, was constructed with 0.5 mm perforations in the upstream and downstream ply and included several rows of larger perforations in the downstream ply to facilitate water passage while maintaining the filtering integrity of the material." See, Lovett 1999 Report at 3-1, in Ex. 21.

In sum, Joint Intervenors conclude that the 0.5 mm reference in the Bowline draft SPDES permit historically has referred to the diameter of the holes, not the AOS measurement, which historically has been 0.212 mm (approximately 2 microns). They conclude that it should be interpreted as such with respect to the Bowline Unit 3 draft SPDES permit condition.

The Joint Intervenors persuasively contend that the proposed Bowline Unit 3 fabric has 1.0 mm diameter holes (as measured by Dr. Henderson) and an AOS of 0.5mm, more than twice the hole size of the historically utilized Lovett Gunderboom ffabrics. Therefore Joint Intervenors contend that the Lovett Gunderboom history of exclusion effectiveness (for fabric with 0.5 mm diameter perforations and 0.212 mm AOS) does not pertain to, and is irrelevant to, the proposed Bowline Unit 3 fabric (with 1.0 mm diameter perforations and 0.425 mm AOS). Consequently, the record contains no evidence of effectiveness in exclusion of fish for the new Gunderboom fabric.

The draft SPDES permit condition requiring that the Gunderboom fabric perforation size must not exceed 0.5 mm is of limited value absent specification of methodology applicable to that standard. The historical Lovett Reports provide context defining that standard as a nominal measurement of perforation diameter. But, the record demonstrates that the ASTM D-4751-99a AOS methodology is the only generally accepted standard in the field of geotextile engineering to evaluate fabric opening sizes concerning a particle or an object flowing through a fabric. Moreover, the record is uncontroverted that the Lovett Gunderboom fabric has had an AOS of 0.212 mm and the proposed Bowline Unit 3 fabric has an AOS of 0.425 mm, an AOS more than twice the Lovett AOS.

The '0.5 mm' perforation diameter draft permit standard is imprecise and should be rejected in favor of an AOS standard. The draft SPDES permit should be revised to specify a maximum perforation size as determined by ASTM D-4751-99a. In addition, Riverkeeper's motion for adverse inference should be granted. Since the new Gunderboom fabric proposed for Bowline Unit 3 has an AOS perforation opening almost twice the size of the fabric used at Lovett, the Lovett exclusion history can not be a basis for effectiveness of the Bowline Unit 3 Gunderboom. Mirant must show how the Lovett history with AOS 0.212 fabric is predictive of the exclusion effectiveness of the new AOS 0.425 fabric.

But, Mirant has not provided any explanation relating the performance of the Lovett fabric to the performance of the new fabric (nor has DEC Staff). Consequently, the record contains no evidence of effectiveness in exclusion of fish for the new Gunderboom fabric. This is another indicator supporting a conclusion that Mirant's Bowline Unit 3 hybrid cooling/Gunderboom proposal is experimental, not proven technology.

e. Conclusion Regarding BTA Design

The DEC Staff acknowledge that it is difficult to identify a precise time when a developing technology such as the Lovett Gunderboom CWISs application no longer is experimental. In Staff's view, the technology will continue to develop even after it is past the experimental stage. Although DEC Staff argues that all the lessons learned from the Lovett test deployments, will be applicable to the Bowline 3 Gunderboom, the fact remains that the Lovett developmental Gunderboom has not yet been deemed BTA for that site. In my view, this fact alone creates a substantial presumption that Gunderboom technology for CWISs remains an experimental technology.

Nonetheless, based upon the Lovett deployment history, DEC Staff concludes that the proposed Bowline 3 Gunderboom CWISs application no longer is experimental, and in fact is far beyond the experimental stage. DEC Staff maintains that it is a fully developed technology that will provide a high degree of entrainment protection. But, the Gunderboom MLES component of the proposed CWIS is an exclusion technology still under development at Mirant's Lovett generation site. The Lovett Gunderboom technology has not yet been determined to comprise BTA for the CWISs at that site. In addition, the Bowline Unit 3 draft SPDES permit authorizes a 3-year startup period before the Gunderboom is required to operate at its required 80% exclusion rate. No CWIS Gunderboom project exists or has been designated BTA. These facts also indicate that Gunderboom technology for CWIS fish exclusion remains an experimental technology. By comparison, it is undisputed that dry cooling technology and hybrid cooling technology are proven technologies.

The DEC Staff's 2000 impingement tests provide probative information that contributes to understanding and development of the Gunderboom technology. But, these tests, and the year 1999 and year 2000 Lovett deployments, are indicative of early phases of development the Gunderboom technology for CWISs fish exclusion. These events do not advance the Gunderboom technology from its developmental experimental status in Athens, to require a determination that the technology no longer is experimental.

Moreover, Mirant has not provided any explanation relating the performance history of the Lovett Gunderboom fabric to the performance of the new Bowline Unit 3 fabric (nor has DEC Staff). Consequently, the record contains no evidence of effectiveness in exclusion of fish for the new Gunderboom fabric. This is another factor in concluding that the Bowline Unit 3 Gunderboom is experimental, not a proven technology.

In sum, Mirant and DEC Staff offer the Lovett Gunderboom history, particularly the three years of exclusion data, to show that the technology no longer is experimental. But, this is the same data that will be used in a BTA determination for Lovett, a determination that has not yet been made. Consequently, the Lovett demonstration project Gunderboom remains a premature, experimental technology for CWIS fish exclusion. The Gunderboom technology has not meaningfully advanced since the Commissioner's June 2, 2000 Athens Generating Company, LP, Interim Decision. Moreover, Mirant has not provided any explanation relating the performance history of the Lovett Gunderboom fabric to the performance of the new Bowline Unit 3 fabric (nor has DEC Staff).

Because the Bowline Unit 3 Gunderboom proposal is an experimental technology, the report recommendation is that only a dry cooling technology cooling water intake structure is best technology available for this site, as required by 6 NYCRR 704.5 and CWA Section 316(b).

Normally, my analysis of BTA for the Bowline project would conclude at this point. But, since this is a recommended decision, the BTA analysis is continued assuming, arguendo, that the Gunderboom technology is not experimental.

C. Location

The language of 6 NYCRR 704.5 and CWA Section 316(b) limit discussion of location to location of the CWISs, as defined above. The USEPA states in its 1976 Development Document that the 'location' factor can be the most important consideration in the BTA analysis. In the Development Document, USEPA recommends drawing water from main channels of large streams or from biologically deficient areas. Other recommendations in the 1976 Development Document include: (1) avoiding important spawning areas, fish migration paths, shellfish beds and other areas where aquatic life may be concentrated, (2) selecting a water depth where aquatic life is minimal, (3) selecting locations with strong currents to assist in carrying aquatic life past the intake structures, and (4) selecting locations suited to the proper technical functioning of the particular screening system to be used.⁽¹⁹⁾ Making a determination about the best location for a cooling water intake structure also includes a consideration of the cumulative impacts of other cooling water intake structures.⁽²⁰⁾ But, as discussed above, Mirant and DEC Staff go further than this and expand the scope of relevant adverse impacts beyond CWIS impacts to impacts of other project components - - particularly adverse impacts of the location of the cooling towers. As discussed, supra, in view of the definition of CWISs, I have rejected this argument.

But, impacts of project components other than the CWISs component are properly considered, and have been considered, in the Article X component of the joint hearing. As noted, Article X requires an environmental review that is the functional equivalent of SEQRA. Those impacts are addressed in the joint Article X Recommended Decision, and include the issues of relocation or culverting of Minisceongo Creek and possible loss of 0.8 acres of artificial creek (if dry cooling technology is required), visual impact of cooling tower plumes of hybrid technology towers versus dry technology cooling towers and potential U.S. Army Corps of Engineers (USACOE) wetland impacts (if dry cooling technology is required).

Under any proposal considered for Bowline Unit 3, the CWISs would be located in Bowline Pond as an addition to the existing CWISs for Units 1 and 2. In order to prevent the Gunderboom curtain from failure due to sedimentation or biofouling, the draft SPDES permit requires use of the Air Burst system. Ex 79 at 8.

1. The Coastal Zone Management Program

The DOS administers New York's Coastal Zone Management Program (CMP). See, Executive Law Article 42, 19 NYCRR Part 600, et seq. Bowline Unit 3 project will be located in Bowline Pond. The DOS, with the assistance of the DEC, has designated the adjacent Haverstraw Bay section of the Hudson River a CMP Significant Coastal Fish and Wildlife Habitat. Pursuant to the DOS Haverstraw Bay designation, if a proposed action is subject to a consistency review under the DOS CMP, the CMP habitat protection policy applies whether the proposed action is to occur within or outside the designated area. Therefore, although Bowline Pond is not within the DOS Haverstraw Bay designated area, the DOS CMP policies apply because a CMP consistency review is required for this project.

The DOS CMP includes 44 policies that are applicable to development and use proposals within or affecting New York's coastal area. A specific CMP policy regarding protection of fish and wildlife resources of statewide significance requires that, "Significant coastal fish and wildlife habitats will be protected, preserved and where practical, restored so as to maintain their viability as habitats." Other relevant CMP policies address development in the coastal zone.

NYSDOS requires an 'impairment test' for projects proposed in CMP designated areas. Although Bowline Pond is outside the mapped DOS CMP Significant Fish and Wildlife Habitat Area, the Bowline Unit 3 project requires a CMP consistency review because other components of the project are within the DOS designated area. DEC Staff provided an analysis of Bowline Unit 3 impacts following the DOS CMP guidance. The impairment test requires a determination whether the proposed project would destroy the habitat or significantly impair the viability of the habitat. DEC Staff conducted an impairment test analysis for Mirant's hybrid cooling/Gunderboom proposal, concluding that the project is consistent with DOS CMP policies.

The project is consistent with the CMP, in DEC Staff's view, because the project will not result in any change of substrate, hydrology, vegetation, increased runoff, sedimentation or pollutants; and further, because CMP habitat will not be destroyed nor will any change occur in the physical, chemical or biological parameters of Haverstraw Bay as a result of the project. Additionally, DEC Staff asserts that the project advances several other coastal policies including revitalization of deteriorated waterfront areas for commercial or industrial uses, facilitating siting of water-dependent uses on or adjacent to coastal waters and conforming effluent to New York State water quality standards. DEC Staff concludes that no other reasonable location exists because the CWISs must be located in close proximity to the facility.

Assuming, arguendo, that the Gunderboom is a proven technology, then DEC Staff's CMP impairment test consistency determination should be accepted. But, the impairment test primarily evaluates the threshold question of whether the location of a CWIS in Bowline Pond is consistent with the CMP policies, not what cooling technology should be required. Assuming, arguendo, that the mitigation of adverse aquatic impacts of the hybrid cooling/Gunderboom CWISs proposal is approximately equivalent to that of a dry cooling alternative option CWISs, the dry cooling technology CWISs would not have any greater adverse CMP impacts than the proposed hybrid/Gunderboom CWISs, because it requires far less capacity than Mirant's hybrid cooling proposal.

2. Bowline Unit 3 Sedimentation Impacts

The DEC Staff and Mirant contend that once aquatic biota are freed from the Gunderboom curtain by the Air Burst system, they have been protected from entrainment and impingement. But, the Joint Intervenors contend that due to the close proximity of the Gunderboom to the intakes for Bowline Units 1 and 2, many of these organisms would be lost to entrainment or impingement by Units 1 and 2, when those Units are operational. Moreover, prior to issuance of the draft SPDES permit, this also was Mirant's view. See, Ex. 9 at 19). In contrast to this scenario, the Joint Intervenors contend that dry cooling technology would use only 0.175 mgd and would provide immediate, continuous, reliable minimization of adverse aquatic impacts due to impingement and entrainment.

Riverkeeper presented the testimony of Dr. Bruce Bell to show that sedimentation of the Gunderboom (clogging of the fabric's pores by inert matter) would reduce effectiveness or cause failure of the Gunderboom as a technology for fish exclusion. Dr. Bell identified two locational conditions during which sedimentation of the Gunderboom would be particularly problematic. First, during periods of slack tide conditions, no current would flow in Bowline Pond. Dr. Bell asserts that during slack tides, operation of the Unit 3 CWISs pump will pull back into the Gunderboom any suspended sediment or re-suspended sediment loosened by the Air Burst system.

Also, Dr. Bell contends that the effects of wind and wave induced turbulence during this slack tide condition could cause resuspension of sediments from the Pond bottom that would be drawn into the Gunderboom. He asserts that DEC Staff has oversimplified the factors affecting suspension of sediments in a water body in relying upon the general relationship between particle size and water velocity necessary for suspension. Instead, he contends that factors including channel roughness, temperature and wind induction also will affect the suspension of particles in the water body. In addition, Dr. Bell commented upon the larger pore size of the Bowline Unit 3 Gunderboom fabric sample, as compared to the Lovett fabric.

Dr. Bell concludes that DEC Staff, in omitting these factors, has underestimated the effects of sedimentation on the proposed Bowline 3 Gunderboom. With sedimentation of the Gunderboom, Dr. Bell reasons, water flow must travel through the remaining open fabric pores at an increased velocity to provide the same volume of cooling water at the Unit 3 inlet. This, he contends, will result in unanticipated stresses on the Gunderboom, contributing to its failure by overtopping or tearing of the fabric. Pursuant to the 1976 USEPA Development Document, CWIS locational factors to be considered include avoiding areas where aquatic life may be concentrated and selecting locations with strong currents to assist in carrying aquatic life past the intake structures, both factors that apply to Bowline Pond. Dr. Bell concludes that the proposed Bowline Unit 3 Gunderboom is more likely to fail due to sediment accumulation on the Gunderboom, as compared to the Lovett Gunderboom experience, due to the less favorable locational conditions of Bowline Pond.

DEC Staff characterizes Dr. Bell's testimony as speculative. DEC Staff concludes that during slack tides when Units 1 and 2 are not operating, Bowline Pond would only hold in suspension particles small enough to easily pass through the pores of the Gunderboom fabric. Although Dr. Bell hypothesized about the effects of wind and wave induced turbulence during this slack tide condition, DEC Staff performed calculations as to the effects of such turbulence under 'worst-case' conditions. DEC Staff concluded that the velocity produced by such turbulence would be insufficient to resuspend all but the smallest particles, and that only particles less than 10 microns would remain in suspension, even under the worst-case conditions. Boring logs of Bowline Pond indicate a silt and clay subsurface, not large sediment particles. Therefore, DEC Staff concludes that the possibility that the Gunderboom will become blocked by suspended particles due to wind and wave induced turbulence during slack tide conditions is unsupported by data or analyses and should be rejected.

Compared to the Lovett Gunderboom, located in the Hudson River, Mirant asserts that the Bowline Gunderboom will not be subject to strong bi-directional tidal currents and wave action. Both Mirant and DEC Staff contend that this is a favorable locational factor. But, this position is contrary to the 1976 USEPA Development Document USEPA guidance discussed above, that recommends selecting locations with strong currents to assist in carrying aquatic life past the intake structures - - in this instance, the Bowline Unit 1 and 2 intake structures.

In sum, location of a Gunderboom in Bowline Pond would be a departure from longstanding USEPA guidance for location of CWISs. The guidance recommends avoiding areas where aquatic life may be concentrated and selecting locations with strong currents to assist in carrying aquatic life past the intake structures. Reasonably, the Bowline Pond location must be characterized as an undesirable or experimental location for CWISs.

D. Construction

With respect to the 'construction' factor, the USEPA advises in the 1976 Development Document that the following should be considered: (1) loss of potential habitat associated with the space occupied by the cooling water intake structure, (2) increased turbidity levels due to erosion of unprotected slopes around the excavations, (3) increased levels of turbidity from inadequately stabilized spoil areas, and (4) filled aquatic areas associated with construction operations.⁽²¹⁾ There is no issue with respect to the captioned SPDES permit application that is related to the construction of the cooling water intake structures.

Mirant and DEC Staff presented evidence regarding adverse impacts of the cooling towers component of the project, comparing the adverse impacts of the proposed hybrid cooling towers with the adverse impacts of an alternative of dry cooling towers that necessarily would be located in a different area of the site than the hybrid cooling towers. The proposed hybrid cooling towers would not impact any wetland or the Minisceongo Creek. But, the alternative option dry cooling towers would be located behind the Unit 3 generation component of the project, further away from the Hudson River, and would impact federal wetlands and a portion of Minisceongo Creek. A dry cooling technology configuration would require either culverting a section of Minisceongo Creek under the cooling towers, or else relocating a section of approximately 600 feet of the creek bed, so that the creek would run adjacent to the dry cooling tower structure.

Regarding mitigation of adverse impacts of the dry cooling technology alternative option on Minisceongo Creek, Mirant proposed culverting a portion of the Creek under the tower (in the event this alternative technology is required). However, the DPS Project Manager de Wall Malefyt testified that relocation outside the cooling tower footprint of approximately a 600 foot section of Minisceongo Creek would minimize adverse impacts of the dry cooling tower alternative, as compared to Mirant's proposal of culverting the Creek. The DEC Staff concurred with Mr. de Wall Malefyt in this regard.

The Article X Recommended Decision concludes that adverse impacts of hybrid cooling technology as compared to the dry cooling technology alternative are similar, with dry cooling causing slightly greater adverse impacts, but not enough to warrant the selection of one technology rather than the other. Impacts of components of the project other than the CWISs component are not considered further in this report.

IV. Whether Practicable Alternate Technologies Are Available to Minimize the Adverse Environmental Effects

In this section of the BTA analysis, costs are not considered. As Scenic Hudson asserts, this step of the BTA analysis must begin with the most protective available technology option, then proceed to other options, that minimize adverse environmental impacts to a degree equivalent to that achieved by dry cooling technology.

To determine whether a particular technology produces the greatest reduction in damage to aquatic resources, it is necessary to consider whether alternative technologies are available. Whether a particular technology is available is a question of fact to be determined on a case-by-case basis. Where alternative technologies are available, they should be analyzed to determine whether they constitute the best technology available for minimizing adverse environmental impacts.

Currently, from among the cooling technologies, dry towers provide the greatest protection to aquatic resources. DEC Staff Biologist Cianci acknowledged that dry cooling technology is more effective in excluding aquatic biota than Mirant's proposed hybrid cooling/Gunderboom technology. As noted elsewhere in this report, since the Gunderboom technology has been rejected as experimental, the dry cooling technology option alternative remains the technology that 'minimizes' adverse impacts of the CWISs.

Scenic Hudson contends that the DEC Staff implicitly recognized in the draft SPDES permit that dry cooling technology is more effective than Mirant's proposed hybrid cooling/Gunderboom technology, by incorporating the requirement that the CWISs must achieve protection to the aquatic biota "approximately equivalent" to the protection afforded by a dry cooling technology CWIS. Ex 79 (draft SPDES Permit), p. 9 of 15.

But, in performing the Bowline Unit 3 BTA analysis, DEC Staff incorrectly applied the Commissioner's BTA guidance on the most feasible protective option for this site. DEC Staff considered Mirant's proposal of hybrid cooling technology with 2.0 mm wedge wire screen and a Gunderboom to be the most protective alternative. However, as indicated above, DEC Staff should have started this analysis with the dry cooling technology option. If appropriate, after the 'wholly disproportionate' cost analysis, DEC Staff then could have proceeded to evaluate whether the next most protective (or equally protective) technology - Mirant's hybrid cooling/Gunderboom proposal - is a practicable alternate technology available to minimize the adverse environmental effects at lesser cost.

Instead, DEC Staff mistakenly compared Mirant's hybrid cooling proposal with no-mitigation intakes. T. 1736 (Direct testimony of John M. Cianci, p. 9, Table 1 "Comparison of Entrainment Mortality of Various Cooling Systems and Intake Design for Bowline Unit 3";⁽²²⁾ Appendix A, attached hereto). But, in the DEC Staff's BTA determination for Bowline Unit 3, DEC Staff never explicitly considered a comparison of dry cooling technology versus hybrid cooling technology (i.e., a comparison of columns E and H in Table 1, T. 1736). Therefore, DEC Staff's conclusion that Mirant's hybrid cooling technology proposal (with Gunderboom) minimizes overall adverse environmental effects is rejected.

However, DEC Staff did present evidence that Mirant's hybrid cooling/Gunderboom proposal is approximately equivalent to the level of protection provided by dry cooling technology alternative option that requires less water for cooling (i.e., Column H in Table 1, T. 1736, T1738, lines 1-2 ). This analysis is considered further in the next step of the BTA analysis, the 'wholly disproportionate' cost factor.

V. Whether the Costs of Practicable Technologies Are Wholly Disproportionate to the Environmental Benefits Conferred by Such Measures.

A. Introduction

The Commissioner has confirmed that "[c]osts are an acceptable consideration in determining whether the intake design reflects the best technology available. The cost analysis is not a simple cost-benefit analysis, but instead requires a determination whether the cost of a different location (or different cooling technology) would be 'wholly disproportionate' to the environmental benefit to be gained. Athens Interim Decision, supra at 14, citing, 10 ERC 1257 (1977)('Seabrook');petition for review dismissed, Seacoast Anti-Pollution League v Costle, 597 F2d 306 (1^st Cir. 1979) ('Seacoast').⁽²³⁾, ⁽²⁴⁾ In Seabrook, the decision underlying Seacoast, the USEPA Administrator approved a cooling water intake structure for a nuclear power plant in Seabrook, New Hampshire. The Administrator determined that other locations for the intake structures might slightly reduce impacts on smelt and flounder, but that the cost of the different locations would be 'wholly disproportionate to the environmental benefit to be gained.' Seabrook, 10 ERC at 1261. Athens, Interim Decision, supra, at 14.

In Athens, the Commissioner amortized the incremental difference in cost between the two technologies over the estimated life of the facility. The resulting annual cost was compared to the initial construction costs of the project to determine whether the annualized incremental cost of the best technology is wholly disproportionate to the initial construction costs of the project. Athens, Interim Decision, supra, at 15.

Therefore, 'best technology available' really means 'best technology available commercially at an economically practicable cost'. The 'cost' factor in the BTA analysis requires a determination that the incremental costs of the most stringent aquatic mitigation compared to the second-best (or less costly) option are not "wholly disproportionate" to the environmental gain achieved during the expected life of the facility, as compared to the construction costs of the project. Further, since the BTA determination is site-specific, a separate determination is required for each application.

The parties do not dispute that in the BTA analysis consideration of cost properly does not occur until after a technology has been identified that minimizes adverse impacts of the CWISs. That is, prior to determining whether the cost of the proposed CWISs technology is wholly disproportionate to its environmental benefits, one must identify whether the location, design, construction and capacity of the technology 'minimizes' adverse environmental impacts of the CWISs. That analysis precedes this section of the Recommended Decision.

With the introduction of a 'cost' factor into the BTA analysis, 'minimize' no longer necessarily means minimize. Instead, it means 'reduce' to the greatest extent so that costs are not wholly disproportionate to the incremental environmental benefit to be realized.

In the BTA cost analysis, it becomes possible to reject as BTA the technology that minimizes impacts of the CWISs at a particular site (without consideration of cost), if the incremental costs of that technology are deemed wholly disproportionate to the environmental gain it would provide. In that circumstance, the next most effective technology in reducing adverse impacts of the CWISs (or the technology that is approximately equivalent in minimizing adverse impacts, but at a lower cost), would be deemed to 'minimize' adverse impacts of the CWISs for BTA. Then the analysis would repeat, until the most effective technology that minimizes or reduces adverse environmental impacts of the CWISs, and for which the incremental environmental benefits realized (as compared to the next most effective technology) are not wholly disproportionate to its costs, would be deemed BTA for that particular site.

For purposes of the preceding section of this Recommended Decision, absolute mortality numbers dictate which technology 'minimizes' adverse impacts. But, in this section evaluating costs of technologies, the Conditional Mortality Rates become important in the BTA analysis. The CMRs provide information regarding the comparative environmental benefits realized for each species population of concern, for each technology.

B. The Bowline Unit 3 Cost Analysis

Mirant's estimated construction cost of the hybrid cooling towers proposed for Bowline Unit 3 is $24,791,00.00. Initial construction costs of the Gunderboom are $380,000.00. Annual operation and maintenance costs for the Gunderboom are $163,000.00 per year.

Mirant's estimated construction cost of a dry cooling tower alternative is $38,930,000.00, or $14,139,000.00 greater cost than hybrid cooling towers.

DEC Staff estimates the life of the facility as 30 years.

The record does not contain a construction cost estimate for the proposed facility. But, reasonable estimated construction costs for a facility such as this would reasonably be in the range of $400 million to $500 million. For purposes of the 'wholly disproportionate' analysis, a facility construction cost of $400 million is assumed.

The Joint Intervenors are correct in criticizing DEC Staff for only conducting a 'wholly disproportionate' analysis between the technologies of hybrid cooling technology with 2.0 mm screen and no Gunderboom versus hybrid cooling technology with 2.0 mm screen and a Gunderboom. DEC Staff did not explicitly conduct a cost analysis comparing Mirant's hybrid cooling/Gunderboom proposal with a dry cooling technology alternative option.

Instead, as stated in the draft SPDES permit, DEC Staff summarily concluded that any additional construction cost increment for dry cooling (i.e., $14.1 million difference) is presumptively wholly disproportionate because the two technologies provide 'essentially equivalent aquatic protection'. Ex. 79, draft SPDES permit, Fact Sheet, page 7 of 12. With this statement, DEC Staff implicitly acknowledges that for the Bowline Unit 3 site, dry cooling is the technology that minimizes adverse impacts of the CWISs, notwithstanding cost. In sum, in considering costs, DEC Staff concludes that Mirant's hybrid cooling/Gunderboom proposal is BTA because it provides essentially equivalent aquatic protection for $14.139 million less than the dry cooling technology alternative.

DEC Staff supports this position by relying upon a comparison of the Conditional Mortality Rates for the two technologies. Appendix A ("Table 1"), attached hereto. Table 1, Column G, lists conditional mortality rates for Mirant's hybrid cooling/Gunderboom technology proposal, for each of the five species of concern. These CMRs are in the orders of magnitude of thousandths and ten-thousandths of a percent for Mirant's Gunderboom technology proposal. DEC Staff did not compute the CMRs for a dry cooling alternative, but instead reasoned that because dry cooling would result in fewer fish mortalities (the numerator of the CMR fraction), the dry cooling CMRs would be less than those computed for the proposed CWISs, but only fractionally so, also in the orders of magnitude of thousandths and ten-thousandths of a percent.

DEC Staff reasons that because the CMRs for the proposed CWISs are so low, the protection afforded by the proposed Gunderboom technology is essentially equivalent aquatic protection to the protection afforded by the dry cooling technology alternative. No witness offered by the Joint Intervenors presented evidence that the differences in CMRs are significant, nor did they testify that the CMR modeling was incorrect.

Since Mirant's hybrid cooling/Gunderboom proposal costs $14.139 million less than a dry cooling technology alternative, DEC Staff implicitly assumes that the costs of dry cooling are wholly disproportionate to the environmental benefits to be realized therefrom. DEC Staff did compare the costs of Mirant's hybrid cooling/Gunderboom proposal to the next less protective alternative, hybrid cooling technology with 2.0 mm wedge wire screen, (without a Gunderboom). DEC Staff concluded that the costs of Mirant's proposal are not wholly disproportionate to the environmental benefits to be realized therefrom. No party disputed this conclusion.

Assuming, arguendo, that the Gunderboom technology is an available (proven) technology for the Bowline Unit 3 project site (contrary to my recommendation herein), the Commissioner should conclude that the DEC Staff's determination is correct, that Mirant's proposal provides approximately equivalent mitigation of aquatic adverse impacts as dry cooling technology; and that the costs of Mirant's hybrid cooling technology proposal (with 2.0 mm wedge wire screen and Gunderboom) are not wholly disproportionate to the environmental benefits to be realized therefrom.

Under such circumstances, the Commissioner should conclude that the costs of dry cooling technology are wholly disproportionate to the aquatic environmental benefits it would provide. Therefore, assuming, arguendo, that the Gunderboom technology is a proven available technology for the Bowline Unit 3 project site, the Commissioner should conclude that Mirant's hybrid cooling proposal with 2.0 mm wedge wire screen and Gunderboom is the best technology available for the Bowline Unit 3 site.

But, applying the same 'wholly disproportionate' analysis to this case that the Commissioner used in Athens, the incremental cost of dry cooling over hybrid cooling (without the Gunderboom), is $14.519 million (i.e., $14.139 million + $380,000.00 initial cost of Gunderboom); the life of the facility is 30 years; and the assumed construction cost of the project is $400 million. Therefore, $14.519 million over 30 year life of the facility, is $483,967.00 per year for 30 years. See, Athens, Interim Decision, supra, at 15. In view of the minimized impact to aquatic biota arising from application of dry cooling technology and CWISs at Bowline Unit 3, and the relatively insignificant increase in the total cost of the facility from application of dry cooling technology, the costs of dry cooling are not 'wholly disproportionate' to the environmental benefits to be gained.

RECOMMENDATIONS

The Commissioner should clarify whether the characterization 'premature' in the Athens Interim Decision pertains to the configuration proposed in that case, as DEC Staff contends, or whether it pertains to the state of development of the technology itself. Reading the Athens Interim Decision in context, the recommendation of this report is the latter.

Moreover, considering the hearing record in its entirety, and in considering the several impediments characterized as indicators that the Gunderboom is an experimental technology and that the proposed location is not consistent with longstanding USEPA guidance, as discussed in the 'Design' and 'Location' sections of this report,⁽²⁵⁾ the Commissioner should conclude that the Gunderboom technology is an experimental technology.

The report also recommends that in view of the minimized impact to aquatic biota arising from application of dry cooling technology and CWISs at Bowline Unit 3, and the relatively insignificant increase in the total cost of the facility from application of dry cooling technology, the costs of dry cooling are not 'wholly disproportionate' to the environmental benefits to be gained.

Therefore, the recommendation of this report is that pursuant to 6 NYCRR 704.5, dry cooling technology is the best technology available to minimize adverse impacts of the cooling water intake structures at the Bowline Unit 3 project site. The draft SPDES permit should require a maximum intake capacity of 0.175 mgd.

FINDINGS OF FACT

1. Jurisdiction and authority to initiate this administrative proceeding are based upon Environmental Conservation Law ("ECL") Articles 70 and 17, and 6 NYCRR Parts 360 and 624 and 704.
2. In August 2000, Mirant Bowline, LLC (formerly Southern Energy Bowline, LLC; the Applicant or Mirant), applied for a Certificate of Environmental Compatibility and Public Need pursuant to Article X of the New York Public Service Law (PSL)⁽²⁶⁾ and Air Pollution Control and State Pollutant Discharge Elimination System permits pursuant to Articles 17 and 19 of the Environmental Conservation Law (ECL), to construct and operate a 750 megawatt (MW) combined cycle electric generating facility at its Bowline Generating Station.
3. The Bowline Generating Station project site is located approximately thirty miles north of New York City adjacent to the Hudson River estuary. The site is located in the Haverstraw Bay section of the Hudson River.
4. Mirant's application for an Article X Certificate also included a request for a State Pollutant Discharge Elimination System (SPDES) permit and Air Pollution Control permits (the environmental permits required pursuant to 6 NYCRR Parts 201, 231 and 750).
5. Mirant's initial application proposed that the facility would withdraw process water from the Hudson River (via Bowline Pond) for cooling purposes, employing mechanical draft cooling technology requiring 7.5 million gallons per day (mgd). A portion of the cooling water would evaporate into the atmosphere, the balance would be returned to the Hudson River.
6. The proposed combined cycle generating technology allows a reduced intake velocity and reduces intake capacity to the proposed maximum of 7.5 mgd.
7. The Staff of the N.Y.S. Department of Environmental Conservation (DEC Staff) reviewed Mirant's SPDES and Air permit applications, and subsequently developed draft SPDES and Air permits, dated January 16, 2001. The draft SPDES permit authorizes the reuse of cooling water discharge from existing Bowline Units 1 and 2 as cooling water for Bowline Unit 3, annually from October through mid-February.
8. On February 13, 2001, Mirant revised its water intake and cooling technology proposal from a mechanical draft cooling system to a hybrid cooling system with an intake structure including a 2.0 millimeter (mm) wedge wire screen and a Gunderboom^TM Marine/Aquatic Life Exclusion System (the Gunderboom MLES or Gunderboom) engineered polyester geotextile porous curtain to provide a physical barrier between the cooling water intake structures (CWISs) and the aquatic biota of Bowline Pond for exclusion of aquatic biota, primarily various developmental stages of fish species (the Applicant's hybrid cooling/Gunderboom proposal). The Gunderboom^TM curtain is comprised of three layers, two permeable fabric layers with a mesh net layer in the middle.
9. Gunderboom, Inc., is the owner of the Gunderboom MLES proprietary polyester fabric curtain technology, and in recent years, has been developing its Gunderboom product for electric power generation CWISs applications, to minimize fish mortality.
10. The proposed Bowline Unit 3 Gunderboom curtain would be suspended from the existing intake structure pumphouse (serving Units 1 and 2) to the shoreline.
11. Mirant revised the cooling/intake proposal to reduce cooling tower steam plumes, thereby further reducing adverse visual impacts of the project. The current draft SPDES permit, issued prior to the Applicant's modification of cooling tower technology, does not address the recently proposed hybrid cooling system with Gunderboom.
12. The proposed maximum water intake remains 7.5 mgd gallons per day. DEC Staff tentatively has determined that Mirant's hybrid cooling/Gunderboom proposal will comply with all terms and conditions of the draft SPDES permit.
13. The NYSDEC component of the joint adjudicatory hearing was held on September 5 through 7, 2001. A further joint adjudicatory hearing session was convened on September 20, 2001 to receive additional testimony on land use requirements and impacts for Mirant's two hybrid cooling tower location proposals and the alternatives analysis for a dry cooling tower location.
14. Dry cooling technology with a capacity limitation of 0.175 mgd will result in lower fish mortalities from the Bowline Unit 3 CWISs than Mirant's hybrid cooling/Gunderboom proposal with a capacity limitation of 7.5 mgd.

- The Cooling Water Intake Structures: The River Setting and Description of the Cooling Water Intake Structures

15. The proposed Bowline Unit 3 facility will be located next to two existing power facilities, Bowline Units 1 and 2 at the Bowline Generating Station, off Samsondale Avenue in the Town of Haverstraw, Rockland County, New York, on part of a 257-acre parcel owned by the Applicant.
16. The Bowline Power Generation Facility is located approximately at Hudson River Mile 37 (approximately 37 miles above the Battery), in the Haverstraw Bay section of the River.
17. The project site is bounded on the east by Bowline Point Park and the Hudson River, on the west by a public park (Peck's Pond), on the south by combined residential and light industry properties, and on the north by Keahon Auto Wreckers. Also to the north are approximately 97 acres of vacant land which also are part of the 257-acre Bowline Generating Station property.
18. The proposed Bowline Unit 3 facility, comprising approximately 25 acres of the Bowline Power Generation Facility, would be located on the west bank of the Hudson River, just north of Bowline Pond.
19. The project area is zoned Planned Industrial Office.
20. Bowline Unit 3 cooling water would be drawn from Bowline Pond.
21. An existing pumphouse serving Bowline Units 1 and 2 is located in Bowline Pond and currently withdraws a maximum of 1,100 mgd of water.
22. The Bowline Unit 3 cooling water intake structures (CWISs) inlet would be a new separate intake structure located in Bowline Pond, attached to the existing pumphouse serving Units 1 and 2.
23. Bowline Pond has an approximate surface area of 54 acres. The Pond is hydraulically connected to the Haverstraw Bay section of the Hudson River along the river's west bank, via an intake channel less than 100 feet wide.
24. The N.Y.S. Department of State (DOS), with the assistance of the NYSDEC, has designated Haverstraw Bay a Significant Fish and Wildlife Habitat under the Coastal Zone Management Program (CZMP or CZM). Executive Law Article 42, 19NYCRR Part 600, et seq.
25. The DEC draft SPDES permit authorizes the reuse of cooling water from Units 1 and 2, annually from October through mid-February. Ex. 79.
26. The majority of Bowline Unit 3 intake water from Bowline Pond (fed by the Hudson River) would be used for cooling purposes.
27. For Mirant's hybrid cooling technology proposal, the water demand for proposed Bowline Unit 3 would be a maximum of 7.5 mgd, under typical gas-fired operation.
28. Water would be withdrawn at a maximum through screen (inlet) velocity of 0.5 feet per second (fps). The maximum flow through velocity for the Gunderboom curtain (at 7.5 mgd), would be approximately 1.4 feet per second (fps).
29. The proposed Bowline Unit 3 intake structures include the Gunderboom porous fabric curtain barrier as the primary intended fish (ichthyoplankton) exclusion technology. Behind the Gunderboom, the CWISs inlet is enclosed by an engineered wedge wire screen with a screen opening of 2.0 mm. This 2.0 mm wedge wire screen is a secondary fish exclusion technology intended to provide exclusion of biota greater than 15 mm that may cross the primary intended exclusion technology, the Gunderboom.
30. Each year, during the period from February 15 through September 30, the Bowline Unit 3 intake will be enclosed behind the Gunderboom. But, the Gunderboom will not enclose the adjacent existing intakes for Bowline Units 1 and 2.
31. A single Gunderboom porous curtain panel would span approximately 137 feet in length oriented at a right angle with the existing intake structure serving Units 1 and 2, with water depths averaging 27.5 feet. The curtain is suspended at the water surface by vinyl-covered floatation billets. The curtain surface area of the Gunderboom will be approximately 3200 square feet.
32. The draft SPDES permit requires that the pore size of the outside boom fabric must not exceed 0.5mm, but the inside fabric may have a larger pore size to facilitate boom cleaning. The Gunderboom curtain is comprised of three layers, two permeable fabric layers with a mesh net layer in the middle. (As discussed below, the parties disputed the relationship of fabric pore size to effectiveness in ichthyoplankton exclusion.) The flow through velocity of the Gunderboom at 7.5 mgd would be approximately 1.4 feet per second. But, the maximum through screen (inlet) velocity is 0.5 feet per second. Ex. 79, pages 8 and 9.
33. The draft SPDES permit requires that the pore size of the outside boom fabric must not exceed 0.5mm, but the inside fabric may have a larger pore size to facilitate boom cleaning.
34. An anchoring system will be employed using deadweight concrete blocks of approximately 15 tons each, located about 30 feet apart on either side of the deployed boom.
35. A computer controlled air backwash system (the Air Burst system) will provide for automatic cleaning of the boom at fixed intervals, and the boom will be equipped with strain gauges and water level monitors to further detect and alert unit operators of the need for additional cleaning cycles.
36. A rubberized plastic skirt along the base of the fabric curtain boom is intended to create an effective seal along the bottom of the boom.
37. The existing multiport-high speed diffuser which serves Bowline Units 1 and 2 is adequate to accommodate the discharge of Bowline Unit 3.
38. The five fish species of concern in reviewing this project are White Perch, Bay Anchovy, River Herring, American Shad and Striped Bass. For the majority of these species the Haverstraw Bay segment of the Hudson River is an important nursery, but not an important spawning area. Primary spawning areas of these species, producing organisms more vulnerable to entrainment mortality, are found in other sections of the Hudson River, not Haverstraw Bay or Bowline Pond.
39. Conditional Mortality Rate (CMR) is a percentage reflecting the ratio of estimated fish mortality for a subject species at a particular CWIS compared to the estimated population of that species in the water body (here, the Hudson River).

- Capacity

40. All other factors being equal, the capacity of water withdrawn from a water body will be directly proportional to fish mortality of the fish population of that water body. The direct relationship between fish mortality and capacity applies to dry cooling technology.
41. Dry cooling technology is effective in minimizing fish mortality because it minimizes capacity (dry cooling technology would require a maximum cooling water intake capacity of 0.175mgd whereas Mirant's proposed hybrid cooling technology/Gunderboom system would require a maximum cooling water intake capacity of 7.5mgd, 42.9 times more than dry). However, developing technologies such as the Gunderboom hold the promise of destroying this historical relationship between capacity and fish mortality.
42. Bowline Units 1 and 2 use a combined maximum capacity of 1,100 mgd.
43. The difference between entrainment of a dry cooling intake (with 2.0 mm wedge wire screen) versus a hybrid cooling intake (with 2.0 mm wedge wire screen but without the Gunderboom) is less than 1%.

- Design

- The Lovett Gunderboom

44. The proprietary Gunderboom technology was developed for aquatic applications other than CWISs exclusion. The first application of this technology as a component of a CWISs for a power generation station was the experimental deployment at the Lovett Generating Station, Rockland County, New York, beginning in 1995.
45. The current Gunderboom configuration at Lovett is similar to Mirant's Bowline Unit 3 Gunderboom proposal, described above. The developmental history of the Gunderboom application at Lovett is recounted in the prefiled direct testimony of DEC Biologist Edward Radle. As currently configured, the curtain portion of the Gunderboom consists of two layers of porous fabric with a mesh net sandwiched between, to add structural strength. The curtain is suspended at the surface by vinyl covered floatation billets. The Lovett Gunderboom, like Mirant's proposed Bowline Unit 3 Gunderboom, is a permeable polyester fabric curtain barrier, intended to allow water and sediment to pass through, but to exclude early stages of fish life (ichthyoplankton) and other aquatic biota.
46. The Gunderboom configuration proposed for Mirant's Bowline Unit 3 Gunderboom, described above, is similar to the Gunderboom configuration developed at Lovett.⁽²⁷⁾ But, the Lovett Gunderboom is in excess of 500 feet in length. It is located in the Hudson River, subject to strong currents and estuarine tidal influences. The Lovett Gunderboom is not configured as a straight curtain, but is angled in the River. Due to its length, it is comprised of several curtain sections that have been joined together.
47. By comparison, the proposed Bowline Unit 3 Gunderboom would be approximately 137 feet in length, comprising one section and would be located in a straight line configuration in Bowline Pond. The Bowline Gunderboom would not be subject to the strong currents and tidal forces of the Hudson River.
48. Studies of the Lovett Gunderboom's effectiveness at ichthyoplankton exclusion were conducted for the 1995 and 1998 deployment seasons (prior to Athens). A third season of ichthyoplankton exclusion data were obtained during the 2000 deployment season (i.e., after the Athens Interim Decision).
49. The Lovett developmental Gunderboom has not been deemed BTA for that site.

- The Athens Gunderboom Proposal

50. The Athens Gunderboom proposal was a different configuration than the Gunderboom configuration deployed at the Lovett facility. The Athens Gunderboom proposal included several unique and previously untested design elements. By comparison, the proposed Bowline Gunderboom design and configuration is similar to the Lovett design that has been under development since 1995.
51. By comparison, the Bowline Unit 3 Gunderboom proposal includes drawings and schematics of the Gunderboom configuration and the facilities and structures to be installed as part of the Gunderboom system, descriptions of how deployment of the Gunderboom would take place, descriptions of the maintenance and support systems, biological monitoring program and a contingency plan in the event of failure of the Gunderboom. The proposed Bowline Gunderboom will be smaller than Lovett (approximately 137 linear feet versus approximately 500 linear feet), and will have less flow per unit area resulting in lower loading on the fabric and overall Gunderboom system than the Lovett system. Also, the Bowline Unit 3 Air Burst system (intended to clear clogged fabric pores) will be fully integrated into plant operations and the Bowline Unit 3 project will include a formal Gunderboom system operating monitoring program, neither of which exist at Lovett.

- Post-Athens Gunderboom Developments

52. Since the Commissioner's Athens Interim Decision in June 2000, Mirant's engineering consultant for the Lovett project has issued a Report on the Lovett Generating Station Gunderboom Deployment Program 2000 (dated April 2001) [ Ex. 115], including entrainment data that was collected during the Lovett 2000 deployment season.
53. On May 19 and 20, 2001 DEC Staff Biologist Radle conducted experiments with exposure of American shad eggs and larvae to Gunderboom fabric samples at the Pennsylvania Boat and Fish Commission, Van Dyke Anadromous Fish Hatchery.⁽²⁸⁾
54. Lastly since the Commissioner's Athens Interim Decision, Riverkeeper and Mirant have each conducted biofouling studies on Gunderboom fabric samples as part of this proceeding.
55. The Athens inlet and Gunderboom proposal was to be located in the Hudson River, whereas the Bowline Unit 3 inlet and Gunderboom proposal would not be located in the Hudson River, but in Bowline Pond (Initially, Mirant and Gunderboom, Inc., represented that stronger currents [as occur in the Hudson River] are necessary for proper functioning of the Gunderboom. But, they now contend that Bowline Pond is an appropriate site for the Gunderboom.)
56. The Athens Gunderboom design configuration was a submerged fabric panel structure enclosing the water inlet (apparently similar to the Gunderboom design proposed for the pending PSEG Bethlehem [Albany County] project), not a curtain configuration as in Lovett or the proposal here.
57. The Athens site is near a spawning area for the fish species of concern (except Bay Anchovy). In contrast, the Haverstraw Bay segment of the river at Bowline site is a significant nursery area for these species and a DOS Significant Fish and Wildlife Habitat, but not a significant spawning area.

- The Three Years of Ichthyoplankton Exclusion Data

58. Measurements of the Lovett Gunderboom effectiveness for fish (ichthyoplankton) exclusion were conducted only for three seasons: 1995, 1998 and 2000. Exhibits 146, 147 and 115. Data was gathered by comparing an intake enclosed with the Gunderboom (Lovett Unit 3) to an intake without Gunderboom technology (Lovett Unit 4). DEC Staff contends that the Gunderboom reduced entrainment at Lovett by 75% to 90% during three entrainment monitoring years.
59. Based upon the three years of Lovett exclusion data, the DEC Staff predicts an effective exclusion rate of at least 80% for the Bowline Unit 3 Gunderboom, as required in the draft SPDES permit. Moreover, DEC Staff posits that Bowline Unit 3 exclusion rates may exceed 90% due to anticipated improvements in the proposed Bowline Unit 3 Gunderboom installation.
60. For each of the three years when entrainment mitigation was evaluated at Lovett, a 75% exclusion rate (or greater) was never achieved for any one full deployment season.
61. DEC Staff's interpretation of the Lovett data as representative of effectiveness rates between 75% to 90% is based upon a selective evaluation of the data. For example, in 1995, approximately 25% of the days DEC Staff included for comparison have little or no data for the non-Gunderboom intake.
62. The selective use of seasonal data yields an invalid unreliable result. The Gunderboom has not reliably and consistently achieved such a high claimed exclusion percentage for any one full season, absent such selective interpretation of the monitoring data.
63. In 1998, the Gunderboom was deployed for a period of 12 weeks. But, Mirant and DEC Staff rely only upon a 4-week period for their conclusion that the Gunderboom operated at 76% effectiveness for exclusion.
64. Similarly, the 1999 Lovett Gunderboom Report shows that from late July through the end of the deployment on August 31, the Gunderboom system functioned at substantially reduced effectiveness, with entrainment densities that did not differ from entrainment densities of the intake absent the Gunderboom.
65. For the year 2000 Lovett deployment, the 80% effectiveness claimed by Mirant and DEC Staff pertains only to the three initial weeks of the deployment season. After six weeks of operation, effectiveness began to decline and by the end of July, the Gunderboom was not effective in exclusion of aquatic biota.
66. The Bowline Unit 3 draft SPDES permit authorizes a 'startup period' of three years of operation before Mirant is required to achieve a fully operational (80% effective) Gunderboom. And even after this 'startup period', the draft SPDES permit authorizes operation of Bowline Unit 3 for up to 15 days per year with a functional failure of the Gunderboom before Mirant has violated the SPDES permit conditions (failure is defined a operating at less than 75% entrainment efficiency when the plant is operational during a 24 hour period) . Ex. 79, page 9 of 15.
67. Use of a Gunderboom for Bowline Unit 3 could reduce entrainment and impingement losses for Unit 3, but would increase entrainment and impingement losses for Units 1 and 2 when those Units are operational. Under such circumstances, fish excluded from Unit 3 by the Gunderboom would be subject to entrainment in the adjacent inlets for Units 1 and 2.
68. Background current velocity is low in Bowline Pond, which will tend to limit the effectiveness of the Air Burst system and contribute to increased fouling rates by attached algae.

- The 2001 American Shad Impingement Experiments

69. The experiments conducted by DEC Biologist Radle included impingement of American shad eggs on Gunderboom fabric for one, two and four hours; observations of the ease of release of impinged eggs from the outside surface of the fabric (i.e., the surface of the fabric upon which impingement would occur in the deployed Bowline 3 Gunderboom); and exposure of day-old larvae in a tank to flows of 5 gpm/ft² flow through a panel of Gunderboom fabric. Testing control organisms were held for a total of 24 hours for latent mortality observation. Twelve hundred eggs were included in the experimental and control tests.
70. The highest mortality observed during the post-impingement mortality studies was 2%. Several treatments indicated no mortality. The results of the experiments suggest that the mortalities that did occur were reflective of the natural random mortality that occurs independent of the test conditions.

- The Bowline Unit 3 Pisces-Riverkeeper Biofouling Studies and Mirant's Flow Test Apparatus (FTA) Studies

71. As a general matter, non-toxic materials placed in a rich estuarine environment commonly foul with aquatic organisms.
72. In June and July, 2001 Riverkeeper conducted 29-day biofouling studies in Bowline Pond using Gunderboom fabric samples provided by Mirant and Gunderboom, Inc. The purpose of the studies was to evaluate the role of such fouling in a Bowline Unit 3 Gunderboom deployment. The results of the studies are described in the report, Gunderboom Fouling Studies in Bowline Pond, PISCES Conservation Limited (July 2001).Ex. 151.
73. Riverkeeper's studies and Applicant's FTA studies demonstrate progressive fouling of the Gunderboom with a variety of organisms. This fouling seriously limited the Gunderboom's water filtering ability.
74. On average, Riverkeeper's static Gunderboom fabric panels retained their permeability after 11 days, but were reduced to approximately 50% permeability after 20 days. By the 29^th day (the final day of the test), the panels were 62% less permeable than they were at the beginning of the test period. By day 29, obvious colonization had increased to 70% of the available surface area.
75. By comparison, the Lovett Gunderboom deployments of 1995, 1998 and 2000 showed effective filtering for periods of between four and six weeks, after which, for reasons not identified, effectiveness was severely compromised or in complete failure.
76. In the Riverkeeper's studies, quantitative analyses to assess the levels of microbes within the Gunderboom fabric all showed an increase in bacterial levels over the 29-day period of the study.
77. In response to Riverkeeper's proposed biofouling studies, Mirant conducted separate alternative Gunderboom fabric flow tests, but with fabric samples equipped with an air-burst feature similar to the feature proposed for the full Bowline Unit 3 Gunderboom deployment. The Riverkeeper studies did not include an air-burst feature. (As described above, the Air Burst system is intended to agitate or shake a fully deployed Gunderboom curtain, in situ, thereby loosening colonizing organisms [biofouling] from the Gunderboom curtain.)
78. Mirant utilized a Flow Test Apparatus device (FTA) to suspend the fabric samples used in its studies (the FTA studies). However, after the studies were completed, Mirant provided only raw data, but did not provide any report summarizing the FTA study results.
79. Instead, Mirant (and DEC Staff) rejected the validity of these studies, contending that both the Riverkeeper/PISCES biofouling studies and its own FTA studies are not relevant because the studies are microcosm experiments that cannot be extrapolated to the larger boom to the functioning of a fully deployed Gunderboom such as the Lovett Generation Station Gunderboom or as is proposed for Bowline Unit 3.
80. An essential effect of the Air Burst system is the billowing effect it has upon the fully deployed Gunderboom curtain, but that in the 29-day studies, this billowing effect did not occur because the fabric samples were too small and also because they were secured to a frame that precluded billowing.
81. Mirant's panels were in a device (the FTA) that to some extent shielded the panels from predator communities that otherwise would be expected to reduce or slow the colonization of a fully deployed Gunderboom.
82. Throughout the 29 days of the Riverkeeper and FTA studies, the Gunderboom fabric samples provided a flow of at least 5 gallons/min/sq.ft.

- Bowline Unit 3 Gunderboom Fabric Pore Size and Riverkeeper's Motion for Adverse Inference

83. The DEC draft SPDES permit requires that "the maximum pore size of the outside fabric shall be 0.5 mm, and the inside fabric may have larger holes to facilitate boom cleaning." Ex. 79 at 8 of 15.
84. The DEC draft SPDES permit does not specify a methodology for compliance with the requirement 'not to exceed 0.5 mm'.
85. Dr. Henderson measured the perforation size of the Bowline Unit 3 fabric as approximately 1 mm diameter, using an electron microscope.
86. The fabric sample that Mirant provided to Riverkeeper is the correct fabric intended for use in the Bowline Unit 3 Gunderboom.
87. Gunderboom, Inc., has revised its fabric with a larger perforation size than has been used at the Lovett Gunderboom.
88. The appropriate methodology to measure geotextile perforation size, such as the Bowline Unit 3 fabric, is the ASTM⁽²⁹⁾ Standard Test Method for Determining Apparent Opening Size (AOS) of a Geotextile, ASTM D-4751-99a (revised 1999).
89. The test identifies an AOS size that indicates the approximate largest size particle that will pass through a geotextile. Briefly, the test requires placement of a fabric sample in a sieve frame. Sized glass beads are placed on the fabric surface, then the frame is shaken by a special apparatus to induce the beads to pass through the fabric.
90. The ASTM D-4751-99a (AOS) methodology is the generally accepted standard in the field of geotextile engineering to evaluate effective or apparent opening sizes concerning a particle or an object flowing through a fabric.
91. The ASTM D-4751-99a methodology requires conducting the test on a dry fabric sample. The dry Bowline Unit 3 fabric sample has an ASTM D-4751-99a AOS of 0.5 mm.
92. Due to the proposed use of the fabric, the ASTM D-4751-99a test also was conducted on a wet fabric sample. The wet Bowline Unit 3 fabric sample has an ASTM D-4751-99a AOS of 0.425 mm.
93. For at least the past three years, the Lovett Gunderboom fabric has had 0.5 mm diameter perforations, with an AOS of approximately 0.212 mm.
94. The Lovett 2000 Report describes the fabric specifications as follows: "Gunderboom Incorporated's brochure on the Gunderboom Marine/Aquatic Life Exclusion System indicates that the Apparent Opening Size (AOS) for the Gunderboom material based on a Standard Sieve Analysis methodology is 70, which equates to a mesh opening of 212 [microns] or 0.212 mm. The effective mesh opening of the boom material is effective at limiting the passage of all planktonic organisms including fish eggs and larva [sic]." Ex. 115 at 2-1.
95. The Lovett 1999 Report states that "[t]he boom material, with a nominal mesh opening of 0.212 mm, was constructed with 0.5 mm perforations in the upstream and downstream ply and included several rows of larger perforations in the downstream ply to facilitate water passage while maintaining the filtering integrity of the material." See, Lovett 1999 Report at 3-1, in Ex. 21.
96. The 0.5 mm reference in the Bowline draft SPDES permit historically has referred to the diameter of the holes, not the AOS measurement. The Lovett Gunderboom fabric AOS historically has been 0.212 mm (approximately 2 microns).
97. The proposed Bowline Unit 3 fabric has 1.0 mm diameter holes (as measured by Dr. Henderson) and an AOS of 0.5mm, more than twice the hole size of the historically utilized Lovett Gunderboom fabrics. The Lovett Gunderboom history of exclusion effectiveness (for fabric with 0.5 mm diameter perforations and 0.212 mm AOS) does not pertain to, and is irrelevant to, the exclusion effectiveness of the proposed Bowline Unit 3 fabric (with 1.0 mm diameter perforations and 0.425 mm AOS). Therefore, the proposed Bowline Unit 3 fabric has an AOS more than twice the Lovett fabric AOS.
98. Mirant has not provided any explanation relating the performance of the Lovett fabric to the performance of the new fabric (nor has DEC Staff). Consequently, the record contains no evidence of effectiveness in exclusion of fish for the new Gunderboom fabric.

- Location

- The Coastal Zone Management Program

99. The DOS, with the assistance of the DEC, has designated the adjacent Haverstraw Bay section of the Hudson River a Coastal Zone Management Program (CMP), Significant Coastal Fish and Wildlife Habitat.
100. Although Bowline Pond is not within the DOS Haverstraw Bay designated area, the DOS CMP policies apply because a CMP consistency review is required for this project.
101. The DOS CMP includes 44 policies that are applicable to development and use proposals within or affecting New York's coastal area. A specific CMP policy regarding protection of fish and wildlife resources of statewide significance requires that, "Significant coastal fish and wildlife habitats will be protected, preserved and where practical, restored so as to maintain their viability as habitats." Other relevant CMP policies address development in the coastal zone.
102. DEC Staff provided an analysis of Bowline Unit 3 impacts following the DOS CMP guidance. The DOS CMP 'impairment test' requires a determination whether the proposed project would destroy the habitat or significantly impair the viability of the habitat.
103. DEC Staff conducted an impairment test analysis for Mirant's hybrid cooling/Gunderboom proposal, concluding that the project is consistent with DOS CMP policies, because the project will not result in any change of substrate, hydrology, vegetation, increased runoff, sedimentation or pollutants; and further, because CMP habitat will not be destroyed nor will any change occur in the physical, chemical or biological parameters of Haverstraw Bay as a result of the project.
104. No other reasonable location exists because the CWISs must be located in close proximity to the facility.

- Bowline Unit 3 Sedimentation Impacts

105. During periods of slack tide conditions, no current would flow in Bowline Pond.
106. Due to the close proximity of the Bowline Unit 3 Gunderboom to the intakes for Bowline Units 1 and 2, during periods of slack tide conditions, many organisms freed from the Gunderboom curtain by the Air Burst system would be lost to entrainment by Units 1 and 2, when those Units are operating.
107. With sedimentation of the Gunderboom, water flow must travel through the remaining open fabric pores at an increased velocity to provide the same volume of cooling water at the Unit 3 inlet.
108. Pursuant to the 1976 USEPA Development Document, CWIS locational factors to be considered include avoiding areas where aquatic life may be concentrated and selecting locations with strong currents to assist in carrying aquatic life past the intake structures, both factors that apply to Bowline Pond.
109. The velocity produced by wind and wave induced turbulence would be insufficient to resuspend all but the smallest particles. Only particles less than 10 microns would remain in suspension, even under a worst-case scenario.
110. Boring logs for Bowline Pond indicate a silt and clay subsurface, not large sediment particles.
111. Compared to the Lovett Gunderboom, located in the Hudson River, the Bowline Gunderboom will not be subject to strong bi-directional tidal currents and wave action.

- Whether Practicable Alternate Technologies Are Available to Minimize the Adverse Environmental Effects

112. Dry cooling technology is more effective in excluding aquatic biota than Mirant's proposed hybrid cooling/Gunderboom technology. In this section of the BTA analysis, costs are not considered.
113. Mirant's hybrid cooling alternative is approximately equivalent to the level of protection provided by use of dry cooling technology towers that require less water for cooling. T. 1736 (Direct testimony of John M. Cianci, p. 9, Table 1 "Comparison of Entrainment Mortality of Various Cooling Systems and Intake Design for Bowline Unit 3;⁽³⁰⁾ Appendix A, attached hereto)

- Whether the Costs of Practicable Technologies Are Wholly Disproportionate to the Environmental Benefits Conferred by Such Measures.

114. The proposed hybrid cooling technology towers system for Bowline Unit 3 is $24,791,00.00. The Gunderboom component will have an initial cost of $380,000.00. A second boom will be constructed and maintained onsite, costing an additional $100,000.00. Annual maintenance costs are $163,000.00, which includes costs for the replacement boom and biological monitoring.
115. A dry cooling technology cooling towers alternative cooling technology system for Bowline Unit 3 will cost $38,930,000.00, or $14,139,000.00 greater cost than the proposed hybrid cooling/Gunderboom system.
116. The estimated life of the Bowline Unit 3 facility is 30 years.
117. The CMRs provide information regarding the comparative environmental benefits realized for each species population of concern, for each technology.
118. Mirant's estimated construction cost of the hybrid cooling towers proposed for Bowline Unit 3 is $24,791,00.00. Initial construction costs of the Gunderboom are $380,000.00. Annual operation and maintenance costs for the Gunderboom are $163,000.00 per year.
119. Mirant's estimated construction cost of a dry cooling tower alternative is $38,930,000.00, or $14,139,000.00 greater cost than hybrid cooling towers.
120. For purposes of the 'wholly disproportionate' analysis, a facility construction cost of $400 million is assumed.
121. The Conditional Mortality Rates (CMRs)⁽³¹⁾ for the five fish species of concern, for the Applicant's hybrid cooling/Gunderboom proposal, are listed in Appendix A (attached hereto; T.1736, Table 1, [Direct Prefiled Testimony of John M. Cianci] Comparison of Entrainment Mortality of Various Cooling Systems and Intake Design for Bowline Unit 3).
122. Appendix A, Table 1, Column G, lists conditional mortality rates for Mirant's hybrid cooling/Gunderboom technology proposal, for each of the five species of concern. These CMRs are in the orders of magnitude of thousandths and ten-thousandths of a percent for Mirant's Gunderboom technology proposal.
123. DEC Staff did not compute the CMRs for a dry cooling alternative, but instead reasoned that because dry cooling would result in fewer fish mortalities (the numerator of the CMR fraction), the dry cooling CMRs would be less than those computed for the proposed CWISs, but only fractionally so, also in the orders of magnitude of thousandths and ten-thousandths of a percent.

CONCLUSIONS OF LAW

1. 'Adverse' means unfavorable, harmful, difficult or detrimental. In re Brunswick Steam Electric Plant, Initial Decision re: Permit No. NC007064, Region 4, USEPA (Nov. 7, 1977).
2. 'Available' means present and ready for use; at hand; accessible; capable of being gotten; qualified. American Heritage College Dictionary, [Third Edition, 1993]. As applied in the BTA analysis, 'available' reasonably means a proven technology, not an experimental technology; and further, a technology that is capable of being installed at a particular project site. The central issue addressed, infra, is whether Mirant's proposed application of Gunderboom technology for the Bowline 3 CWISs is a proven technology or whether at present it remains an experimental technology.
3. 'Best' means surpassing all others or to the highest degree. American Heritage College Dictionary, [Third Edition, 1993].
4. 'Cooling Water Intake Structures (CWISs)': Cooling water intake structures "may consist of one or more elements including an inlet structure (the point of water entrance), closed conduits and open channels, a pump structure or a combined screen and pump structure." Development Document for Best Technology Available for the Location, Design, Construction and Capacity of Cooling Water Intake Structures for Minimizing Adverse Environmental Impact, USEPA, 1976 at 15 (the 1976 Development Document). Further, a "[cooling water] intake structure comprises the total structure used to direct cooling water from a water body into the components of the cooling system wherein the cooling function is designed to take place . . . the intake structure includes circulating and service water pumps where those pumps are located in the cooling system prior to the heat exchangers or condensers." 1976 Development Document at 2.
5. The definition of CWISs limits the scope of 'adverse impacts' to be considered in the BTA determination. Therefore, the CWISs component of the Bowline Unit 3 project is separate from the cooling tower component or the electric generation component. In re Brunswick Steam Electric Plant, (Brunswick I), Region IV, USEPA, Initial Decision, Permit No. NC007064,(Nov. 7, 1977).
6. 'Entrainment' is the process by which smaller organisms including larval fish and fish eggs are carried along with the intake water through any intended exclusion technology such as screens (or Gunderboom), into the cooling system where they are damaged or killed. Athens Interim Decision, supra at 9.
7. 'Impingement' is the process by which larger organisms, including fish, are caught against intended exclusion technology such as screens (or Gunderboom) by the force of the intake water flows, resulting in either suffocation or injury of the organisms. Athens Interim Decision, supra at 9.
8. 'Location' refers to both the horizontal and vertical placement of the intake structure with respect to the local above-water and under-water topography . . . [including such issues as] where is the intake to be located with respect to the shoreline, navigation channels, wetlands, discharge structures, areas of important biological activity and the depth from which the water is to be drawn. 1976 Development Document at 15.
9. 'Minimize' means to reduce to the smallest possible amount, extent or degree. The absolute term 'minimize' is distinct from the relative term 'reduce' which means 'to diminish or lessen as in extent, amount or degree'. American Heritage College Dictionary, [Third Edition, 1993].

- The Reuse Issue

10. One issue identified for adjudication is the extent to which Mirant may reuse the cooling water discharged from Bowline Units 1 and 2 to cool Bowline Unit 3. The DEC draft SPDES permit authorizes reuse of cooling water discharged from Bowline Units 1 and 2 to provide cooling water makeup for Bowline Unit 3, annually from October 1 through mid-February. Ex. 79. This 'reuse' issue has been resolved by DEC Staff's revised position as set forth in its closing reply brief. DEC Staff now will allow reuse of cooling water discharged from Bowline Units 1 and 2 to cool Bowline Unit 3, whenever available throughout the year, subject to Mirant's acceptance of new permit conditions. The new conditions would specify that such reuse throughout the year does not affect any subsequent BTA determination for Bowline Units 1 and 2 (or any other existing once-through facility).
11. Since Mirant originally proposed such reuse, the issue of water reuse is resolved, irrespective of which cooling technology or capacity limitation may be authorized in a final SPDES permit for this project.
12. The federal analytical method for determining BTA has been identified by the USEPA in the Brunswick case, supra, and has been adopted in New York by the DEC Commissioner in the Athens Interim Decision, supra. That four step analysis is applied to the Bowline Unit 3 project in this Recommended Decision.

- The Scope of Impacts to be Considered in the BTA Analysis

13. Exhibit 144, a 1992 DEC Counsel's Office memorandum, is a (then) DEC staff attorney's opinion as to how a BTA analysis should be conducted. It is not a formal guidance document such as the DEC Division of Water, Technical and Operational Guidance Series (TOGS) documents. Accordingly, it is not entitled to be given as much weight as such formal agency guidance.⁽³²⁾ Instead, it is analogous to DEC Staff's legal arguments and opinions as set forth in the record.
14. Consideration of the project impacts as a whole in the BTA analysis is not appropriate. The BTA analysis of environmental impacts must focus exclusively upon adverse impacts of the CWISs component of the project. To the extent that Exhibit 144 varies from this principle, Exhibit 144 is rejected.
15. Only in the final 'cost' section of a BTA analysis would consideration of the project as a whole be appropriate.
16. Impacts of the project as a whole are reviewed under ECL Article 8 (State Environmental Quality Review Act [SEQRA]) or, in electric generation siting cases, by PSL Article X which provides for a review that is the functional equivalent of SEQRA. See, 6 NYCRR 617.5(c)(35); compare, PSL Section 168(2)(c).

- The Athens Precedent

17. In the June 2000 Athens Interim Decision, supra, the Commissioner held that the application of Gunderboom technology to the Athens project site was premature. Premature, in that Decision, means that the technology was, in June 2000, as yet unproven and experimental. The BTA analysis must begin with the proven technology that minimizes adverse impacts of the CWISs, absent cost considerations; at present, dry cooling technology.

- Whether the Facility's Cooling Water Intake Structure May Result in Adverse Environmental Impact

18. A Bowline Unit 3 CWISs located in Bowline Pond will result in adverse aquatic environmental impacts, specifically, fish mortalities.
19. The BTA 'design' requirement primarily concerns designs to reduce the fisheries impacts of the cooling water intake structure, particularly fish losses due to both entrainment and impingement. Athens Interim Decision, supra at 16.
20. Since the Gunderboom technology application for electric power generation CWISs is being developed exclusively at Lovett, that development program reasonably should be completed before the technology is applied to other CWISs. The objective milestone for completion of that development project is a Departmental determination that the Lovett CWISs with seasonal Gunderboom deployment, is BTA for that site.
21. The Department has not yet determined that the Lovett Gunderboom is BTA. Therefore, it remains an experimental development project.

- The Three Years of Lovett Exclusion Monitoring

22. The three years of Lovett monitoring data show that the Gunderboom has provided unreliable exclusion effectiveness, with a wide variation of fish exclusion effectiveness. The wide variation of effectiveness in fish exclusion is one indicator of the continuing experimental status of the Gunderboom technology as a technology for exclusion of aquatic biota at CWISs.
23. A three year startup period is not authorized under 6 NYCRR 704.5 or CWA Section 316(b), and is another indicator that the Gunderboom is experimental.
24. Such a startup period would not be necessary with dry cooling technology.

- The 2001 American Shad Impingement Experiments

25. The Radle 2000 impingement tests provide probative information that contributes to understanding and development of the Gunderboom technology, and supports a conclusion that adverse impacts of the Gunderboom related to impingement mortality would be de minimis.

- The Bowline Unit 3 Pisces-Riverkeeper Biofouling Studies and Mirant's Flow Test Apparatus (FTA) Studies

26. The Riverkeeper/PISCES studies (and Mirant's FTA studies) are relevant to an assessment of the functioning of a fully deployed Gunderboom over a period exceeding seven months, as is proposed for Bowline Unit 3. These studies do provide credible evidence suggesting that biofouling is a contributing factor limiting the Gunderboom's effective exclusion to a period not exceeding between four and six weeks.

- Bowline Unit 3 Gunderboom Fabric Pore Size and Riverkeeper's Motion for Adverse Inference

27. The Lovett Gunderboom history of exclusion effectiveness (for fabric with 0.5 mm diameter perforations and 0.212 mm AOS) does not pertain to, and is irrelevant to, the proposed Bowline Unit 3 fabric (with 1.0 mm diameter perforations and 0.425 mm AOS). Consequently, the record contains no evidence of effectiveness in exclusion of fish for the new Gunderboom fabric.
28. The ASTM D-4751-99a AOS methodology is the only generally accepted standard in the field of geotextile engineering to evaluate fabric opening sizes concerning a particle or an object flowing through a fabric.
29. The '0.5 mm' perforation diameter draft permit standard is imprecise and should be rejected in favor of an AOS standard. The draft SPDES permit should be revised to specify a maximum perforation size as determined by ASTM D-4751-99a.
30. Riverkeeper's motion for adverse inference against Mirant should be granted. Since the new Gunderboom fabric proposed for Bowline Unit 3 has an AOS perforation opening almost twice the size of the fabric used at Lovett, the Lovett exclusion history is not relevant to the exclusion effectiveness of the Bowline Unit 3 Gunderboom.
31. The DEC Staff's 2000 impingement tests provide probative information that contributes to understanding and development of the Gunderboom technology. But, these tests, and the year 1999 and year 2000 Lovett deployments, are indicative of early phases of development the Gunderboom technology for CWISs fish exclusion. These events do not advance the Gunderboom technology from its developmental experimental status in Athens, to require a determination that the technology no longer is experimental.
32. The Gunderboom technology for CWIS fish exclusion remains an experimental technology. By comparison, it is undisputed that dry cooling technology and hybrid cooling technology are proven technologies.
33. Pursuant to 6 NYCRR 704.5 and CWA Section 316(b), a dry cooling technology cooling water intake structure is best technology available for this site.

- The Coastal Zone Management Program

34. Assuming, arguendo, that the Gunderboom is a proven technology, then DEC Staff's CMP impairment test consistency determination should be accepted. But, the impairment test primarily evaluates the threshold question of whether the location of a CWIS in Bowline Pond is consistent with the CMP policies, not what cooling technology should be required.
35. Assuming, arguendo, that the mitigation of adverse aquatic impacts of the hybrid cooling/Gunderboom CWISs proposal is approximately equivalent to that of a dry cooling alternative option CWISs, the dry cooling technology CWISs would not have any greater adverse CMP impacts than the proposed hybrid/Gunderboom CWISs, because it requires far less capacity than Mirant's hybrid cooling proposal.

- Bowline Unit 3 Sedimentation Impacts

36. The proposed Bowline Unit 3 Gunderboom is more likely to fail due to sediment accumulation on the Gunderboom, as compared to the Lovett Gunderboom, due to the less favorable location of Bowline Pond.
37. The possibility that the Gunderboom will become blocked by suspended particles due to wind and wave induced turbulence during slack tide conditions is unsupported by data or analyses and is rejected.
38. Location of a Gunderboom in Bowline Pond would be a departure from longstanding USEPA guidance for location of CWISs, recommending avoiding areas where aquatic life may be concentrated and selecting locations with strong currents to assist in carrying aquatic life past the intake structures. Reasonably, the Bowline Pond location is characterized as an experimental CWIS location.

- Whether Practicable Alternate Technologies Are Available to Minimize the Adverse Environmental Effects

39. In considering whether practicable alternative technologies are available to minimize adverse effects of CWISs, costs are not considered.
40. This step of the BTA analysis must begin with the most protective feasible technology option, then proceed to other options, that minimize adverse environmental impacts to a degree equivalent to that achieved by dry cooling technology.
41. To determine whether a particular technology produces the greatest reduction in damage to aquatic resources, it is necessary to consider whether alternative technologies are available. Whether a particular technology is available is a question of fact to be determined on a case-by-case basis. Where alternative technologies are available, they should be analyzed to determine whether they constitute the best technology available for minimizing adverse environmental impacts.
42. Currently, from among the cooling technologies, dry towers provide the greatest protection to aquatic resources.

- Whether the Costs of Practicable Technologies Are Wholly Disproportionate to the Environmental Benefits Conferred by Such Measures.

43. The 'best technology available' means the best technology available commercially at an economically practicable cost. The 'cost' factor in the BTA analysis requires a determination that the incremental costs of the most stringent aquatic mitigation over the second-best (or less costly) option are not "wholly disproportionate" to the environmental gain achieved during the expected life of the facility, as compared to the construction costs of the project.
44. Further, since the BTA determination is site-specific, a separate determination is required for each application. The parties do not dispute that in the BTA analysis consideration of cost properly does not occur until after a technology has been identified that minimizes adverse impacts of the CWISs. That is, prior to determining whether the cost of the proposed CWISs technology is wholly disproportionate to its environmental benefits, one must identify whether the location, design, construction and capacity of the technology 'minimizes' adverse environmental impacts of the CWISs.
45. Costs are an acceptable consideration in determining whether the intake design reflects the best technology available. The cost analysis is not a simple cost-benefit analysis, but instead requires a determination whether the cost of a different location (or different cooling technology) would be 'wholly disproportionate' to the environmental benefit to be gained.
46. In considering a 'cost' factor, 'best technology available' means 'best technology available commercially at an economically practicable cost'. The 'cost' factor in the BTA analysis requires a determination that the incremental costs of the most stringent aquatic mitigation over the second-best (or less costly) option are not "wholly disproportionate" to the environmental gain achieved during the expected life of the facility, as compared to the construction costs of that cooling technology component of the project. Further, since the BTA determination is site-specific, a separate determination is required for each application.
47. The BTA consideration of cost properly does not occur until after a technology has been identified that minimizes adverse impacts of the CWISs. That is, prior to determining whether the cost of the proposed CWISs technology is wholly disproportionate to its environmental benefits, one must identify whether the location, design, construction and capacity of the technology 'minimizes' adverse environmental impacts of the CWISs.
48. With the introduction of a 'cost' factor into the BTA analysis, 'minimize' no longer necessarily means minimize. Instead, it can mean 'reduce' to the greatest extent that costs are not wholly disproportionate to the incremental environmental benefit to be realized.
49. The incremental cost of dry cooling over hybrid cooling (without the Gunderboom), is $14.519 million (i.e., $14.139 million + $380,000.00 initial cost of Gunderboom); the life of the facility is 30 years; and the assumed construction cost of the project is $400 million. Therefore, $14.519 million over 30 year life of the facility, is $483,967.00 per year for 30 years.
50. In view of the minimized impact to aquatic biota arising from application of dry cooling technology and CWISs at Bowline Unit 3, and the relatively insignificant increase in the total cost of the facility from application of dry cooling technology, the costs of dry cooling are not 'wholly disproportionate' to the environmental benefits to be gained.

EXCEPTIONS AND COMMENTS ON RECOMMENDED DECISION

Pursuant to 6 NYCRR §624.13, the Assistant Commissioner for Hearings has ordered circulation of this Hearing Report as a Recommended Decision to afford parties the greatest opportunity to comment on all recommendations contained in this document.

Therefore, consistent with the schedule set by the Assistant Commissioner, briefs on exceptions and comments concerning any portion of the Recommended Decision will be due in hand to the Commissioner (three copies), the Administrative Law Judge/Associate Examiner and all persons identified on the Service List for this proceeding, on or before December 18, 2001. Briefs opposing exceptions or comments will be due in the exact same manner, on or before December 28, 2001.

Consistent with prior practice in this case, the parties may serve their briefs electronically by E-mail on or before the in-hand due dates, followed by a paper copy postmarked that same date.

¹ See Department of Public Service Case No. 99-F-1164, Application by Mirant Bowline, LLC, for a Certificate of Environmental Compatibility and Public Need to Construct and Operate a 750 Megawatt Generating Facility in the Town of Haverstraw, Rockland County.

² A draft Prevention of Significant Deterioration (PSD) permit dated November 13, 2000 was the subject of public notice in local newspapers during the week of November 13, 2000.

³ An earlier public statement hearing on the related PSL Article X application was held on September 12, 2000. Since both this DEC administrative process and the companion Article X proceeding are held on a joint record, comments from the September 12, 2000 hearing are incorporated in this record.

⁴ Riverkeeper pre-filed testimony of Richard M. Seaby, Ph.D., but during the hearing, withdrew the testimony.

⁵ DPS is not a party to the DEC component of the hearing. Mirant and DEC Staff contend that terrestrial and wildlife impacts of the cooling tower must be considered in the BTA determination process. The September 20, 2001 hearing created an additional record on such impacts, particularly impacts of Mirant's second hybrid cooling tower location and comparison of that location to the location of the dry cooling tower alternative.

⁶ The ERCs Notice advertised a postmark date of November 5, 2001 for petitions and a comment postmark date of November 10, 2001. Adding 5 days for mailing, the ERC review was completed on November 15, 2001.

⁷ 33 USC §1326.

⁸ On November 9, 2001, the USEPA Administrator signed a final rule. USEPA anticipates publication of the final rule in the Federal Register soon. Thereafter, the rule will become effective nationally. (see, USEPA website: 'http://www.epa.gov/ waterscience/316b/nov9ph1pre.pdf', last visited November 14, 2001).

⁹ CWA §316(b) must be applied where it is determined that a cooling water intake structure is having an "adverse environmental impact." The threshold for what constitutes an "adverse" impact is a relatively low one. USEPA has defined the term "adverse" to mean "unfavorable, harmful, difficult, or detrimental" In re Brunswick Steam Electric Plant, Region 4, USEPA (Nov. 7, 1977; citing, Webster's Third New International Dictionary [1976]), and has specifically rejected defining "adverse" as meaning "irreversible" or "irretrievable." Id. There is no dispute here that the proposed cooling water intake structures will have an adverse environmental impact on aquatic organisms.

¹⁰ The import of this memorandum in the BTA determination previously has been characterized similarly in the Athens PSL Article X Recommended Decision at 193, fn 2, Case 99-F-1563 (Sept. 3, 1999).

¹¹ Only in the final 'cost' section of the BTA analysis (a caselaw-derived BTA consideration dependent upon the legislative history of CWA Section 316[b] for its authority), would consideration of the project as a whole be appropriate.

¹² Such a process is not inconsistent with the 'bright line' that the Commissioner and PSL Article X Siting Boards have drawn between issues related to federally delegated permit programs exclusively within the DEC's jurisdiction, and all other issues, that are within the Siting Board's jurisdiction. Impacts of the project components other than the CWISs component require site-specific determinations and pertain to non-federally delegated permit programs properly within the purview of the Siting Board. (If the view of Mirant and DEC Staff were adopted here, issues including visual, noise, terrestrial and wildlife issues would all be subsumed in the BTA review, usurping the Siting Board's role in the Article X power generation siting process, contrary to the letter and intent of PSL Article X.)

¹³ DEC Staff make the rhetorical argument that if the BTA analysis begins with dry cooling technology as the technology that currently minimizes adverse impacts, then why not consider dry cooling technology plus Gunderboom technology, which presumptively would be even more protective. But, this assumes that the Gunderboom is a proven technology. This recommended decision reaches a different conclusion. At some future time, if and when Gunderboom technology ceases to be experimental, then dry cooling with Gunderboom should become the starting point of the analysis. As discussed, infra, it is in the cost analysis that such a technology may be rejected as BTA, if the reviewer determines that the benefits realized are wholly disproportionate to the costs of that technology.

¹⁴ Actually, 7.5mgd ÷ 0.175 = 42.9 times less water.

¹⁵ The developmental history of the Gunderboom application at Lovett is recounted in the prefiled direct testimony of DEC Biologist Edward Radle.

¹⁶ Nonetheless, Mirant and DEC Staff contend that DEC Staff will soon recommend that the Commissioner approve the Lovett Gunderboom CWISs as BTA for that site. But, the Bowline project must be reviewed under present conditions, not conditions that may - or may not - occur at some future date. Therefore, I give no weight to DEC Staff's and Applicant's representations regarding a future BTA determination for Lovett.

¹⁷ The results of Mr. Radle's experiments are reported in the attachments to his prefiled testimony. Ex. 145 (ER-1).

¹⁸ American Society for Testing and Materials.

¹⁹ 1976 USEPA Development Document, p. 178.

²⁰ Brunswick, supra.

²¹ Ibid., p. 145.

²² Of the five species listed in the Table, only American Shad indicates a greater number of mortalities for Column H, dry cooling technology, than for Column E, the proposed hybrid cooling/Gunderboom technology. DEC Staff stated that the numbers reported in the table for American Shad are questionable. That is, DEC Staff expects that American Shad mortalities with a dry cooling technology system (Column H) would be fewer than mortalities with the proposed hybrid cooling/Gunderboom technology (Column E).

²³ Best technology available, "is intended to be interpreted to mean the best technology commercially available at an economically practicable cost." A Legislative History of Water Pollution Control Act Amendments of 1972, 93^rd Congress, 1^st Session at 264 (1973).

²⁴ As the Commissioner noted in Athens, the 'wholly disproportionate' standard gives presumptive weight to the value of environmental benefits and places the burden on a permit applicant to demonstrate that the relative costs are unreasonable. Athens Interim Decision, supra at 15.

²⁵ Discussion Sections III B and C.

²⁶ See Department of Public Service Case No. 99-F-1164, Application by Mirant Bowline, LLC, for a Certificate of Environmental Compatibility and Public Need to Construct and Operate a 750 Megawatt Generating Facility in the Town of Haverstraw, Rockland County.

²⁷ The developmental history of the Gunderboom application at Lovett is recounted in the prefiled direct testimony of DEC Biologist Edward Radle.

²⁸ The results of Mr. Radle's experiments are reported in the attachments to his prefiled testimony. Ex. 145 (ER-1).

²⁹ American Society for Testing and Materials.

³⁰ Of the five species listed in the Table, only American Shad indicates a greater number of mortalities for Column H, dry cooling technology, than for Column E, the proposed hybrid cooling/Gunderboom technology. DEC Staff stated that the numbers reported in the table for American Shad are questionable. That is, DEC Staff expects that American Shad mortalities with a dry cooling technology system (Column H) would be fewer than mortalities with the proposed hybrid cooling/Gunderboom technology (Column E).

³¹ As noted above, the CMR is a percentage reflecting the ratio of estimated fish mortality for a subject species at a particular CWIS compared to the estimated population of that species in the water body (here, the Hudson River).

³² The import of this memorandum in the BTA determination previously has been characterized similarly in the Athens PSL Article X Recommended Decision at 193, fn 2, Case 99-F-1563 (Sept. 3, 1999).

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