Pacific Southwest, Region 9: Superfund
Serving Arizona, California, Hawaii, Nevada, the Pacific Islands, and Tribal Nations
McCormick & Baxter Creosoting Co.
EPA #: CAD009106527
County: San Joaquin
Congressional District: 11
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Description and History
NPL Listing History
NPL Status: Final
Proposed Date: 02/07/92
Final Date: 10/14/92
The McCormick & Baxter Creosoting Co. site is a 29-acre former wood-preserving facility located in an industrial area near the Port of Stockton. Old Mormon Slough, which is connected to the Stockton Deepwater Channel, borders the site on the north. Except for an 8-acre portion of the site owned by Southern Pacific Railroad Company, McCormick & Baxter owns the entire property. From 1942 to 1990, McCormick & Baxter treated utility poles and railroad ties with creosote, pentachlorophenol (PCP), and compounds of arsenic, chromium and copper. Wood treating chemicals were stored in tanks, and oily waste generated by the wood-treatment processes was stored in unlined ponds and concrete tanks on the site. The site came to the attention of state agencies in 1977 when a fish kill in New Mormon Slough and the Stockton Deepwater Channel was attributed to a release of pentachlorophenol (PCP)-contaminated stormwater runoff from the McCormick & Baxter facility. In 1978, McCormick & Baxter constructed a perimeter dike to prevent stormwater runoff from the site and installed two stormwater collection ponds. The unlined oily waste ponds were closed in 1981. Sampling has shown that soils throughout the site and groundwater in the shallow aquifer beneath the site are contaminated with PCP, various constituents of creosote, dioxin (a contaminant in industrial-grade PCP) and metals. Soil contamination extends to greater than 40 feet below ground surface (bgs) in the central processing area of the site. Site investigations indicate that the shallow aquifer (0 - 200 ft bgs) is connected with the deeper aquifer, which is a drinking water source. However, no drinking water supplies are currently threatened by site-related contamination. Approximately 105,000 people live and work within 4 miles of the site. Sediment in Old Mormon Slough adjacent to the site is also contaminated, primarily with PAHs and dioxin. Site-related contaminants have been detected in fish caught in the vicinity of the site. People fish in the Stockton Channel and in Old Mormon Slough, although the McCormick & Baxter site is fenced and posted with warning signs.
Contaminants and Risks
- Surface Water
- Soil and Sludges
- Environmentally Sensitive Area
Soils and groundwater are contaminated with PCP, dioxin, polycyclic aromatic hydrocarbons (PAHs), which are constituents of creosote, arsenic, chromium, and copper. In addition, non-aqueous phase liquids (NAPLs) are widespread beneath the site. Sediment in Old Mormon Slough adjacent to the site is also contaminated, primarily with PAHs and dioxin. Individuals who accidentally ingest or come in direct contact with contaminated soil, sediment or groundwater could be at risk. Drinking water from the deep aquifer has not been affected by any contaminants from the McCormick & Baxter site. Oily seeps from the former oily waste ponds into Old Mormon Slough occurred in the past, although the seeps are now controlled. Site-related contaminants have been found in locally-caught fish, which may be consumed by nearby fishermen and their families. Sediment contamination also poses an environmental threat to aquatic organisms in the vicinity of the site.
Who is Involved
This site is being addressed through Federal and potentially responsible parties' actions.
Investigation and Cleanup Activities
The site has been divided into three operable units (OUs) based on media. The site is being addressed in four stages: immediate actions and three long-term remedial phases focusing on cleanup of the groundwater (OU 1), soils (OU 2), and sediment (OU 3).
EPA improved site security and disposed of chemicals and sludges remaining at the site. EPA completed demolition of all site treatment vessels, structures and above-ground tanks and piping in 1994. In 1996-1997, EPA installed a 437-foot sheet piling wall along the shoreline of Old Mormon Slough to control seepages from the former oily waste ponds, excavated approximately 12,000 cubic yards of oily waste and backfilled the area with clean fill. The excavated material is contained on-site in a lined repository in the central portion of the site. A cap was installed in the central site to prevent infiltration and to control dust migration.
Groundwater (OU 1): In mid-1992, the EPA began a multi-phase investigation into the nature and extent of groundwater contamination at the site. These studies have included sampling to define the extent of non-aqueous phase liquids (NAPLs) beneath the site. EPA selected an interim groundwater remedy (pumping and treatment) in March 1999. However, the remedy was not implemented because the groundwater plume is moving very slowly. In addition, there is evidence that some of the contaminants may be naturally breaking down at the plume's edges. Groundwater investigations will continue for several more years before EPA will propose a final groundwater cleanup plan.
Soils (OU 2): In early 1993, the EPA began a two-phase study of the nature and extent of soil contamination at the site. EPA selected a final cleanup remedy for soils (on-site consolidation and capping) in March 1999. EPA and Union Pacific Rail Road (UPRR) signed a consent decree in 2006 for UPRR to conduct the remedial design/remedial action for the soil remedy. The soil capping remedial design is expected to be completed in 2008.
Sediment (OU 3): EPA began a two-phase study of sediment in Old Mormon Slough, New Mormon Slough and the Stockton Deepwater Channel in 1993. EPA selected a final cleanup remedy for sediment (in-place capping) in March 1999. EPA completed Phase I of the sediment remedy (bank stabilization) in 2003 and completed Phase II (placement of a sand cap over the contaminated sediment) in 2006. Periodic monitoring will evaluate the effectiveness of the sediment cap. EPA is currently conducting a five-year review of the sediment remedy. The five-year report is scheduled to be completed in September 2008.
Ecological Risk Assessment: EPA conducted a study of fish and benthic organisms to determine ecological impacts related to the McCormick & Baxter site. This investigation has provided information used in selecting a final remedy for sediment cleanup.
The California Regional Water Quality Control Board issued a Cleanup and Abatement Order to McCormick & Baxter in January 1978 to investigate and clean up contamination at the site. Investigations were conducted by McCormick & Baxter under state oversight while the facility was still operating. Two interim groundwater extraction wells operated for approximately 10 years, but no other remedial actions were performed by the company to address the contamination. Because the owner of this site filed for protection under Chapter 11 of the Federal Bankruptcy Code in 1988, cleanup of the site (with the exception of the soil cleanup) is being completed through Federal actions.
Cleanup Results to Date
The installation of the stormwater collection ponds and perimeter dike, site security improvements, chemical and sludge disposal, demolition and disposal of processing equipment and site structures, construction of a sheet piling wall along Old Mormon Slough, excavation and backfilling at the oily waste pond area, installation of a cap over the most heavily contaminated central portion of the site, and installation of a sand cap in Old Mormon Slough have reduced threats to public health and the environment from these areas of the site.
Potentially Responsible Parties
Potentially responsible parties (PRPs) refers to companies that are potentially responsible for generating, transporting, or disposing of the hazardous waste found at the site.
Online information about the PRPs for the site is not yet available.
Documents and Reports
1) March 1994 - Public Meeting
2) June 1995 - Visitor's Day
3) September 1998 - Proposed Plan Public Meeting & Comment Period
4) August 2006 - Open House for Sediment Capping Work
Public Information Repositories
The public information repositories for the site are at the following locations:
Cesar Chavez Central Library
605 N. El Dorado Street
Stockton, CA 95202-1907
EPA Site Manager
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Community Involvement Coordinator
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Public Information Center
After Hours (Emergency Response)