Foundry Cove is situated in the Village of Cold Spring, in Putnam County, NY, approximately 54 miles north of Battery Park, NYC. Foundry Cove is a well defined inlet of the Hudson River; this cove contains freshwater marshes and mud flats and is tidally influenced. A railroad trestle divides the cove into east and west; flow from the Hudson River into West Foundry Cove is unrestricted, while flow into East Foundry Cove is restricted to a 65 foot wide passage under the railroad trestle. The water is generally fresh but the salinity may reach 2-6 parts per thousand in periods of low fresh water flow.
Foundry Cove, foreground, with Constitution Marsh Audubon Sanctuary at Center Left. South Cove is at the Rear
The Marathon Battery Company facility in Cold Spring, NY, was located near Foundry Cove. The plant was constructed in 1952 by the U.S. Army Corps. From 1952 through 1979 this facility manufactured nickel-cadmium (Ni-Cd) batteries, initially for military contracts. The plant was later owned by several private companies (Sonotone Corporation, Clevite Corporation, and later Gould Incorporated) that produced batteries for commercial use.
The battery manufacturing process requires the use of concentrated metal nitrate solutions that result in dilute waste solutions and metal precipitates. Both nickel and cadmium were used in large quantities; for a brief time, cobalt was used as an additive. The plant effluent was a fine suspension of nickel and cadmium hydroxides, in a pH range of 12 – 14, at a volumetric flow rate averaging 50 – 100 gallons/minute. The effluent usually contained from 10 – 100’s ml/l suspended Ni and Cd hydroxides, depending upon production values. The total waste water output ranged from 100,000 – 200,000 gallons/day (Klerks 1987).
Cd-rich sediment in Foundry Cove near outfall
Waste water from the manufacturing process was initially discharged into the Hudson River through the Cold Spring sewer system, but approximately 10% was discharged into a bypass system emptying directly into East Foundry Cove. In 1965, the NY State Department of Health concluded that the village of Cold Spring’s sewage treatment system could not handle the plant’s industrial waste water; the battery company was ordered to disconnect from the sewer system after which all waste was discharged directly into East Foundry Cove. After maximum discharge limits were set in 1971, waste waters were again discharged via the sewer system into the Hudson River. During manufacturing operations, a total of 179,105 kg of cadmium hydroxide was discharged. Of this amount, 51,004 kg of particulate Cd, and 1,569 kg of soluble cadmium were discharged directly into East Foundry cove; the remainder was discharged in the Hudson River (Klerks 1987). This earned Foundry Cove the dubious distinction of being “the most cadmium polluted site in the world”.
Distribution of cadmium in surface sediments in East Foundry Cove in 1974
Distribution of cadmium in surface sediments in East Foundry Cove in 1983
In 1971, state officials detected high cadmium levels in East Foundry Cove in violation of the Clean Water Act of 1970. A civil law suit filed against Marathon Battery Company resulted in the dredging of all sediment exceeding 900 mg/g Cd based on wet weight. In 1972 – 1973, this dredging removed 10% of Cd released into Foundry Cove. These contaminated sediments (90,000 m3) were buried in a clay-lined, underground vault on the plant property. Extremely high Cd and Ni concentrations were found in sediments in subsequent years, despite the dredging; up to 50,000 and 11,000 µg Cd and Ni per g dry weight sediment (Hazen & Kneip 1979, Occhiogrosso et al. 1979). In 1975, about 30% of the cove still had surface Cd levels in excess of 1000 ppm. In 1979, the Marathon company closed the plant and relocated. Merchandise Dynamics purchased the plant in 1980 for use as a book storage facility. In that same year Congress enacted the comprehensive Environmental Response, Compensation, and Liability Act to address the cleanup of the nation’s hazardous waste sites.
Timeline for the history of cadmium pollution of Foundry Cove
Timeline for the cleanup of Foundry Cove
Investigations into the former battery plant began again in 1983 when the NY State Department of Environmental Conservation (DEC) sampled soils on the property as well as marsh sediments in Foundry Cove. At that time, only 8% of the total area of Foundry Cove contained surface sediment Cd levels in excess of 1000 µg/g dry weight; the values for Ni and Co were much lower, but spatially strongly correlated with the Cd values. A remediation plan was designed and managed by the U.S. Environmental Protection Agency (EPA). Due to the severity and extent of cadmium contamination, the EPA added Foundry Cove to the Superfund program, a national priorities list of abandoned hazardous waste sites requiring long-term cleanup. In 1986, the EPA divided the site into 3 geographical areas and following a period of public comment, a remediation plan for the 3 areas was drafted. Dredging and excavation activities began in 1992 and were completed in 1994. Marsh replanting efforts and the demolishing of plant buildings are ongoing. The details of the cleanup are discussed in Chapter X.
Cadmium profiles with depth in the sediment, as measured in 1983
Unlike some toxic compounds, e.g., PCB’s, which can be broken down by natural processes or through remediation techniques, metals like cadmium cannot be degraded. The natural reduction of surface Cd concentrations in Foundry Cove from 1971 to 1983 (prior to EPA’s excavation and dredging activities) must be due either to: (1) deposition of new sediment, (2) transport of metals out of the cove, (3) redistribution of sediments within the cove, or (4) some combination of these processes. Depth profiles were established in order to determine if burial had occurred. At the most polluted sites sampled in 1983 (those closest to the battery plant outfall pipe [sites A – E]), there was a subsurface peak in Cd concentration, suggesting that the polluted sediment was being covered by new sediment (Knutson et al. 1987). Movement of Cd out of the cove may also account for a portion of the decreased Cd concentrations (see Chapter III). Feeding processes of invertebrates within the cove will also affect metal distributions in surface sediments as well as transfer of metals to other parts of the Hudson River ecosystem (see Chapters VII and IX).