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Mercury in the Onondaga Lake Remedy. Betsy Henry May 22, 2008. Current Global Mercury Cycle. Fish Consumption Advisories (in US based on mercury as of 2006). 3,080 advisories in 48 states, one territory, and two tribes 14,177,175 lake acres and 882,963 river miles
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Mercury in the Onondaga LakeRemedy Betsy Henry May 22, 2008
Fish Consumption Advisories (in US based on mercury as of 2006) • 3,080 advisories in 48 states, one territory, and two tribes • 14,177,175 lake acres and 882,963 river miles • 23 states including New York have issued statewide advisories for mercury in freshwater lakes and/or rivers
1963 California Water Quality Criteria “…(mercury) is rather inert chemically and insoluble in water, hence it is unlikelyto occur as a water pollutant.” McKee and Wolf (1963)
Improved Sampling and Analysis “Reduces” Mercury Concentrations in Uncontaminated Surface Waters
Mercury Transformation Processes in Aquatic Systems Methylation Hg2+ + CH3– CH3Hg+ biological, chemical, photochemical Demethylation CH3Hg+ + H+ CH4 + Hg2+ biological, photochemical Reduction/Volatilization Hg2+ + 2e– Hg0 biological, chemical, photochemical Oxidation Hg0 Hg2+ + 2e– chemical
Allied Mercury Cell Chlor-Alkali Operations • Chlor-alkali products • Chlorine • Caustic potash (KOH) • Caustic soda (NaOH) • Bridge Street plant (1953–1979a) • Willis Avenue plant (1947–1977) • In 1970, mercury releases were reduced from 10 kg/day to less than 0.5 kg/day a LCP purchased plant in 1979 and operated it until closure in 1988.
Mercury Cell Electrolysis Source: http://www.greener-industry.org/pages/chlorine/6chlorine_PM1.htm
Onondaga Lake Remedial Investigation 1992—2000 More than 6,000 samples of lake and tributary water, lake sediment, shoreline groundwater, wetlands, fish, plankton, benthic macroinvertebrates,and plants
Methylmercury in the Aquatic Food Web of Onondaga Lake, New York in 1992
Mercury Mass Balance in Onondaga Lake Note: Units are g/May-Sept 92. First number is total mercury, second is methylmercury.
Remediation of plants and tributaries Honeywell owned sites Sites owned by others Cleanup of Mercury Sources toOnondaga Lake Dredge Spoils Area Town of Van Buren Liverpool Town of Geddes Town of Salina Town of Camillus Former LCP Plant Town of Geddes Onondaga Lake Groundwater Collection and Treatment Ninemile Creek Settling Basin 11 Settling Basins 9 & 10 Tributary 5A Ley Creek Semet Ponds Willis Ave Ballfield Syracuse NYS Fairgrounds Settling Basins 12-15 West Flume East Flume Carousel Mall LCP Mathews Ave Former Main Plant Geddes Brook Metro Harbor Brook Settling Basin B
Former LCP Plant Cleanup NYS Fairgrounds Former LCP Plant West Flume Geddes Brook Cutoff Wall LCP Mathews Ave Town of Camillus Town of Geddes Primary source of lake mercury stopped
Innovative Soil Washing Technology Former LCP Site Mercury Soil Washing 8,500 Tons of Soil Cleaned 24˝ 2,204 lb Container Nearly 8 tons of mercury recycled
Former LCP Site Cut off Wall Installation • 3,277 ft long, encompassing 17 acres • 35–70 ft deep
LCP Wetland Restoration • Completed fall 2007 • Nearly 12,000 trees and wetland plants • More than 20 native species • Consultation with SUNY-ESF, TES, and Audubon Key project completed for lake cleanup
Groundwater Collection System/Barrier Wall Route 690 Harbor Stops, collects and treats groundwater
Barrier wall construction begins 1.5 mile underground wall Being constructed in three phases Will prevent contamination from reaching lake Groundwater cleaned at Willis Ave plant to state standards GroundwaterCollection Phase 1 Lake cleanup has begun
Groundwater Collection Phase 2 Fair Grounds Semet Barrier WallCompleted 12/06 I-690 Access Road Restored Shoreline Access Road I-690 Barrier Wall Groundwater to Treatment Facility Onondaga Lake Groundwater Soil Install Collection Trench Onondaga Lake Marl Clay
Groundwater Collection and Treatment Systems Treatment facility (Operational 2006) Pumping station Collection trench and wells (Phase 1 – 2007) Storage tanks Barrier Wall (Phase 1 – 2007) I-690 Onondaga Lake Treated water to lake Groundwater Plant is Now Operating
Groundwater Treatment and Storage Storage tanks Internal equipment Treatment plant
The Onondaga Lake Remedy • Consent decree signed October 11, 2006 by Attorney General, DEC, and Honeywell, lodged January 4, 2007 • Pre-design investigation begun in 2005 to expedite schedule • Design has begun—remedial design work plan submitted early • Extensive community outreach by both DEC and Honeywell, supportive public • Commitment to aggressive 5 year schedule
Mercury Mass Balance in Onondaga Lake Note: Units are g/May-Sept 92. First number is total mercury, second is methylmercury.
Sediment Remediation • Nearshore (littoral) sediment • Dredging an estimated 2.65 million cubic yards of the most contaminated sediment • Isolation cap an estimated 425 acres—all areas exceeding sediment criteria in littoral area • Deep basin (profundal) sediment • Monitored natural recovery (MNR) • Natural processes reduce chemical concentrations, exposure, and mobility • Refinement of MNR model used to predict future concentrations • Long-term monitoring with thin layer cap as contingency • Thin layer capping • Application of thin (e.g., 4 to 6 inches) cap over sediment not expected to meet the sediment cleanup goals within 10 years following remediation
Groundwater Collection Near Shore Barrier Wall Removed During Dredging Cap Habitat Restoration Layer Contaminated Sediments Groundwater Erosion Protection(Where Needed) Chemical Isolation Layer Mixing Layer Contaminated Sediment Capping/Dredging and Habitat Restoration/ Enhancement In Onondaga Lake Onondaga Lake
TOTAL MERCURY (mg/kg) 0 10 20 30 40 50 60 70 0 10 20 30 40 50 60 70 DEPTH (cm) Natural Recovery in Deep Basin Sediment • Surface concentrations reflect ongoing inputs to the lake • Higher concentrations are permanently buried by cleaner sediment Natural recovery is already occurring in SMU 8 sediments
Resuspension Gas Ebullition Oxygen Littoral Sediment Depth Methylmercury Bioaccumulation Littoral Sediment EPILIMNION HYPOLIMNION Methylmercury Production Profundal Sediment Internal Source of Methylmercury • Methylmercury produced under anoxic conditions by sulfate-reducing bacteria • Oxygen limits methylmercury production
Nitrate Control of Methylmercury Production • Nitrate concentrations in Onondaga Lake increased when Metro started year-round nitrification in 2004 • In 2005, Syracuse University and Upstate Freshwater Institute (SU/UFI) observed that nitrate increase delayed sulfate reduction • They hypothesized that this delay would result in decreased methylmercury concentrations in the lake
Sequence of Redox Reactions Source: http://www.esf.edu/EFB/schulz/Limnology/Redox.html
Time Seriesof Metabolic Indicators,2006 and 2007 (Volume-weightedhypolimneticaverages)
Comparison of Maximum Masses of Methylmercury in the Hypolimnion
Mercury in the Onondaga Lake Remedy • Eliminate external sources of mercury • Dredging/capping • Monitored natural recovery • Oxygen/nitrate addition • Designed to meet the remedial goal of reducing mercury concentrations in • sediment, • water, and • fish to levels that are protective of human health and the environment.
Progress... • Lake agreement • Mercury source at LCP Bridge Street eliminated • Groundwater barrier wall and treatment in progress • 2008 • Lake design work plan • Phase 2 barrier wall ...on the Cleanup of Onondaga Lake