Department of Environmental Conservation

D E C banner

Onondaga Lake Bottom Site Update - Fact Sheet June 2011

Onondaga Lake Bottom Site Update on: Ongoing Construction Activities to Prepare for Dredging and Start of A Pilot Test to Add Nitrate to the Deep Lake Water

Onondaga Lake Bottom Site (#7-34-030)
Onondaga County - June 2011
Update on Construction Activities to Prepare for Dredging

The dredging of Onondaga Lake sediments is scheduled to begin in 2012. To prepare for dredging, various support facilities are being constructed. An update on construction activities follows. Photos of construction progress will be posted on Honeywell's website. (See right side bar for a link to the Honeywell website)

  • Site Preparation and Clearing - The majority of road upgrades, surveying and above-ground site clearing has been completed.
  • Water Treatment Plant (WTP) Building - Construction of the foundation is currently underway. Once the foundation has been completed, the walls and roof of the building will be constructed and water treatment plant equipment will be delivered. During dredging operations, this facility will treat the water generated from dewatering of the dredged sediments before it is piped to the Metropolitan Syracuse Wastewater Treatment Plant (Metro) for ammonia treatment, then discharged back into Onondaga Lake.
  • Sediment Consolidation Area (SCA) Construction and SCA Settlement Monitoring Instrumentation - The following work at the SCA is ongoing: berm construction using clean fill materials; installation of geotechnical equipment to monitor settling; partial placement of the composite liner system (clean gravel drainage layer, clean low-permeability soil, and geomembrane liner); limited excavation in the wastebed material for the sump area; and management of construction water.
  • Sediment Slurry Pipeline - Construction has begun on the double-walled pipe and associated pump stations that will transport the sediment slurry (sediment dredged from the lake mixed with lake water). The pipe will transport the sediment slurry from the lake shore to the SCA. Some of this construction will be visible as one travels along I-690 and I-695.
  • Shoreline Support Area - This area will be constructed later this year near the Wastebed B site along the southwest lakeshore area and will include: office trailers, equipment storage, dredge service dock, service boat dock, and debris decontamination/ temporary staging area. Some of this work will be visible as one travels along I-690.
  • SCA Basins - Two lined basins will be constructed later this year on the east and west sides of the SCA for additional water storage capacity during the operation of the SCA.
  • Material Processing Area at the SCA - Later this year, the area will be prepared to receive sediment processing equipment such as screens that will be used to separate material from the sediment slurry before the sediment slurry is pumped into the geotextile tubes within the SCA. Plumbing and electrical work will also take place.
  • Debris Management Area - A two-acre lined area within the footprint of Phase 2 of the SCA will be constructed later this year. This area will contain any debris that is allowed to remain within the footprint of the SCA.

Community Health and Safety

Construction activities are being guided by the Onondaga Lake 2011-2012 Construction Community Health and Safety Plan. The Plan (PDF) (1.15 mB) is available at the locations of reports and information listed below, and on DEC's website. As discussed in the Plan, air monitoring results are publicly available on Honeywell's website. A separate Health and Safety Plan for lake cleanup operations, which are scheduled to begin in 2012, will be developed and made available for public review prior to the start of dredging.

Pilot Test to Add Nitrate to the Bottom Waters of Onondaga Lake

Liquid calcium nitrate will be added to the hypolimnion (deep water) of Onondaga Lake during 2011, 2012 and 2013 as a three-year pilot test. A work plan (PDF) (3.44 mB) was completed in April 2011 and is available online and at the locations listed below. The objective is to determine how successful the addition of nitrate to the bottom waters of Onondaga Lake is at reducing the generation of methylmercury from the sediment to the water. Methylmercury (the form of mercury that bioaccumulates) concentrates in fish and potentially poses a risk to wildlife and humans who consume fish. The nitrate solution to be used is an agricultural fertilizer which has been in use for many years with no known human health or biota toxicity effects when used in this manner. Although nitrogen is a common nutrient needed by aquatic life forms such as algae, it is not a limiting nutrient in Onondaga Lake and its addition will not promote algae growth.

Mobilization associated with the pilot test has begun and the first application of nitrate will take place late June 2011. Nitrate will be added in liquid form during the summer through early fall of 2011, 2012, and 2013, typically starting in late June of each year and continuing until the lake turns over and the upper and lower water mixes, which is typically in early-to-mid-October. The addition of nitrate will consist of three separate stationary applications per week of a diluted calcium nitrate solution to the hypolimnion. Each application of nitrate will be conducted continuously for up to eight hours during a single day at a predetermined location. Monitoring will be conducted approximately two times during the week prior to the first application as a baseline, three days per week during the application period, and two times during the week following the last application. No recreational impacts on the lake are anticipated.

Project Contact List

If you would like to begin receiving information electronically on the Onondaga Lake Bottom site, such as this fact sheet, please sign up for the Onondaga Lake News email list by visiting the NYSDEC website. Once signed up, please also notify the NYSDEC to stop receiving printed copies in the mail. If you do not have access to email, you can receive printed copies in the mail by calling (315) 426-7403.

Location of Reports and Information

Onondaga Lake design-related documents, including the Work Plan for Pilot Test to Add Nitrate to the Hypolimnion of Onondaga Lake, and other information on the Onondaga Lake cleanup are available on the NYSDEC website and at the following locations.

Atlantic States Legal Foundation
658 West Onondaga Street
Syracuse, NY 13204
(315) 475-1170
Please call for an appointment

Camillus Town Hall
4600 West Genesee Street
Room 100
Syracuse, NY 13219
(315) 488-1234

Moon Library
1 Forestry Drive
Syracuse, NY 13210
(315) 470-6712

NYSDEC Central Office
625 Broadway
Albany, NY 12233
(518) 402-9676
Please call for an appointment

NYSDEC Region 7
615 Erie Boulevard West
Syracuse, NY 13204
(315) 426-7400
Please call for an appointment

Onondaga County Central Public Library
The Galleries
447 South Salina Street
Syracuse, NY 13202
(315) 435-1800

Solvay Public Library
615 Woods Road
Solvay, NY 13209
(315) 468-2441

This fact sheet provides you with information on the ongoing construction activities to prepare for dredging and the start of a pilot test to add nitrate to the deep lake water. Both of these activities are associated with the Onondaga Lake Bottom Site remediation. The Onondaga Lake Bottom Site is a subsite of the Onondaga Lake Superfund Site. If you have any questions, comments or would like more information about this project, please contact:

Mr. Timothy Larson P.E.
Project Manager
NYSDEC, 625 Broadway, 12th Floor
Albany, New York 12233-7013
(518) 402-9676

With respect to citizen participation inquiries, please contact:

Ms. Diane Carlton or
Ms. Stephanie Harrington
Citizen Participation Specialists
NYSDEC, 615 Erie Boulevard West
Syracuse, New York 13204-2400
(315) 426-7403

For project-related health questions, contact the New York State Department of Health (NYSDOH):

Mr. Mark Sergott, Project Manager
NYSDOH, 547 River Street
Troy, New York 12180-2216
(800) 458-1158, Ext. 27860