CIBA-GEIGY CORP.
TOMS RIVER, NJ
Cleanup Activities
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Background
The Ciba-Geigy Chemical Corporation site in Toms River, Dover Township, New Jersey, was owned and operated by the Ciba Specialty Chemicals Corporation which was formerly the Ciba-Geigy Chemical Corporation (Ciba-Geigy) and in April 2009, BASF bought Ciba Specialty Chemicals. The site encompasses approximately 1,400 acres, 320 of which are developed, with the remainder consisting of cleared areas, Pine Barrens and wetlands. From 1952 to 1990, Ciba-Geigy manufactured dyes, pigments, resins and epoxy additives. All commercial operations at the site ceased in December 1996 and most of the manufacturing buildings were subsequently demolished. Sludge and process wastes were disposed of in several locations on the site, including a stacked drum disposal area originally believed to contain approximately 35,000 drums and a 12-acre filtercake disposal area containing wastewater treatment plant sludge and process wastes. Wastewater treatment operations at the site also resulted in the contamination of several areas including backfilled lagoons near the Toms River and two equalization basins. Contamination from these areas and several others on-site (referred to as source areas) has leached into the groundwater. Site groundwater flows east towards the Toms River and adjacent wetlands. To the north, south and west, the site is bordered by light industrial, commercial, residential, and recreational areas. The Township of Dover has an estimated population of 90,000 persons. There are 180 residential units less than 1/2 mile to the north of the site and more than 250 residential units less than 1/2 mile from the site's southern boundary. An elementary school is adjacent to the site along the southwestern fence line.
In 1978, the State of New Jersey issued permits to close two disposal areas on site. The New Jersey Department of Environmental Protection (NJDEP) issued an Administrative Order in 1980 that required Ciba-Geigy to remove 15,000 drums from an on-site solid waste landfill and to initiate groundwater monitoring at the site. In 1985, Ciba-Geigy began pumping contaminated groundwater and discharging it with treated wastewater to the Atlantic Ocean via a ten mile pipeline. In December 1991, as an interim measure, the NJDEP granted Ciba-Geigy a permit that allowed the company to discharge treated groundwater on site to the ground surface. NJDEP also required closure of the Ocean pipeline. Wastewater and sanitary flows were directed to the Ocean County Utilities Authority (OCUA) plant in Berkeley Township. The discharge to OCUA was stopped after commercial operations ceased in 1996. This site is being addressed through a combination of Federal, State and potentially responsible parties' actions. During the late 1970s and early 1980s, in response to NJDEP directives, Ciba-Geigy performed various closure activities and geohydrologic investigations at the Site. As early as 1979, there were reports of leakage of the double-lined active landfill and remedial measures were taken under the direction of the NJDEP Solid Waste Administration. In 1980, EPA completed an identification and preliminary assessment report of the Ciba-Geigy Site under the Potential Hazardous Waste Site Program. The site was placed on the Superfund National Priorities List in 1983. In 1984, EPA began a remedial investigation of the site. EPA has focused its cleanup efforts on treating the contaminated groundwater and soil and digging up buried drums and disposing of them off site. Currently, about 1.2 million gallons of groundwater are treated each day. More than 47,000 drums have been removed. Soils were treated using bioremediation, a process that uses natural microorganisms to digest contaminates and breaks them down into non-hazardous components, and the soils were backfilled on site. The site does not pose an immediate threat to human health or the environment
What Has Been Done to Clean Up the Site?
The groundwater extraction, treatment and recharge system (GERS) is operational and now more efficient due to optimization. All contaminated residential irrigation wells were sealed by mid-1991. The local community is not affected by the contaminant plume, and the site does not pose an immediate threat to the surrounding community. Full-scale operation of the on-site groundwater treatment plant began in March 1996 and approximately 17 billion gallons of contaminated groundwater have been treated to meet EPA criteria, to date. The GERS system has also been optimized to utilize a more efficient number of monitoring wells based on the current plume status, \ two rounds of optimization began in 2010 and were completed in 2014 and 2016. All sample results for the treated groundwater are below the criteria established in site decision documents such as the ROD. Treated groundwater is recharged to an area in the north end of the site meeting the NJDPES permit requirements.
In addition, in 2014, BASF upgraded the groundwater treatment system (GTS) from the former wastewater treatment plant to a new, self-contained air stripping and liquid granular activated carbon adsorption system. Due to the high levels of iron in the aquifer, BASF added an iron removal system consisting of a sludge thickening unit and geotube. The non-hazardous sludge cake is removed and disposed of at an approved landfill. The update resulted in a more efficient water treatment system with the same end result of meeting discharge permit requirements. A final remedial action completion report, was approved by EPA in 2015.
The site is fenced and guarded, so access is limited. The local community is not impacted by the source areas because the cleanup and stabilization was concluded in 2010.
What Is the Current Site Status?
EPA determined that the greatest potential threat to human health and the environment was through contaminated groundwater. EPA decided to address cleanup of the site in two phases. The first phase focused on cleanup of the contaminated groundwater. The second phase addressed the site’s source areas.
EPA selected a remedy for contaminated groundwater in the site’s April 1989 Record of Decision, or ROD. The ROD specified that contaminated groundwater would be pumped, treated on-site, and discharged to the Toms River which would then be monitored, irrigation wells were to be closed, and the on-site sources characterized. In late 1991, community and environmental groups and Ciba-Geigy requested that EPA reconsider on-site recharge of treated groundwater instead of river discharge. EPA reevaluated on-site recharge and determined that it was technically feasible, could be implemented in the same timeframe as the original ROD remedy, and was protective of human health and the environment. EPA updated the remedy in September 1993, changing the discharge point for treated groundwater from the Toms River to recharge on-site.
Groundwater samples indicate that the plume of contaminated groundwater has shrunk and that contaminant concentrations at the edges of the plume decreased. Some degradation of the capture envelope has been observed due to operation and maintenance issues. BASF addressed these issues by optimizing performance of the pump-and-treat system. The new, optimized GTS is operational and all sample results for the treated groundwater are below the criteria established in site decision documents such as the ROD. Enhanced, in-place bioremediation of saturated soil and groundwater at the equalization basins, which remains a source, is being evaluated as part of the optimization of the groundwater remedy.
The second phase of the site investigation – to evaluate the extent and nature of contamination of the source areas – began in September 1989 and finished in 1994. EPA selected a remedy for the source areas in the site’s September 2000 ROD. The decision document called for excavation and on-site bioremediation of about 150,000 cubic yards of contaminated soil and backfilling the treated soil on-site.
Cleanup of the source areas began in October 2003. Source area soils were treated using in-place and ex-situ treatment systems. Ex-situ soil treatment began in July 2004 and finished in August 2010, treating a total of 342,877 cubic yards of soil. In-place treatment of about 65,000 cubic yards of soil started in 2003. Soil removal at the source areas, ex-situ treatment of the soil, and construction of the caps and slurry walls at certain source areas finished in 2010.
Buried drums were removed from an area known as the Stacked Drum Area, or SDA. In total, 47,055 drums were removed from the SDA. The contents of the drums were sent off site for disposal. Drum removal began in December 2003 and finished in November 2004.