OSWER/OSRTI 

Washington, DC 20460 

NATIONAL PRIORITIES LIST (NPL) 

***Proposed Site*** September 2011 

SEAM MASTER INDUSTRIES South Gate, California 

Los Angeles County 

 Site Location: 

The site is located in a mixed industrial, commercial, and residential area in South Gate, California. Volatile organic 

compounds, including trichloroethylene (TCE), have been found in soils and ground water at the site. 

 Site History: 

From 1972 through to the present day, the site has been occupied by a facility that manufactures hot-melt adhesive tape for 

laying carpets. Prior to 1972, Pacific Screw Products Corporation manufactured screw products at the property until the 

business went bankrupt. On the property, the main areas of concern include concrete liners in the pallet manufacturing area, 

a sump and an underground storage tank area. Historical Los Angeles County Department of Health Services Hazardous 

Waste Control Program surveys and notices of violations note the use of TCE on the property and improper disposal of 

unusable oils and solvents. 

 Site Contamination/Contaminants: 

Soil and groundwater at the site, and down gradient of the site, are contaminated with TCE. TCE was detected in onsite 

soils at levels up to 17 parts per billion (ppb) and in groundwater beneath the site at levels up to 17,000 ppb. EPA’s Safe 

Drinking Water Act Maximum Contaminant Level for TCE in drinking water is 5 ppb. 

 Potential Impacts on Surrounding Community/Environment: 

The full extent of the ground water contamination needs to be fully characterized. Although the drinking water supply wells 

immediately downgradient of the site are located in a deeper aquifer and are not currently contaminated, there is the 

potential that drinking water wells may become contaminated due to connections between the aquifers. There are at least 35 

drinking water wells within four miles of the site, serving approximately 226,000 people. In addition, due to the high 

concentrations of TCE in groundwater and the relatively shallow depth to groundwater (60 feet) there is a need to evaluate 

the potential for vapor intrusion of TCE into nearby buildings and residential areas. 

 Response Activities (to date): 

In May 2002, EPA completed a Remedial Investigation of the nearby Cooper Drum NPL site. During the Remedial 

Investigation, as EPA was investigating the extent of the Cooper Drum groundwater plume, EPA identified the Seam 

Master Industries site as an additional source of groundwater contamination in the area. Based on additional groundwater 

sampling, EPA determined that the groundwater contamination from the Seam Master Industries site was commingling 

with the Cooper Drum plume. Since the Seam Master Industries site was interfering with the Cooper Drum remedy 

implementation, EPA requested the California Department of Toxic Substances Control (DTSC) assume the lead on the 

Seam Master Industries site. DTSC requested that the property owner and operator enter into a consent order, but both 

declined. Since 2007, DTSC was unsuccessful in compelling the potentially responsible parties to conduct work at the site. 

Due to the lack of enforcement resources as well as the proximity of the site to the existing Cooper Drum NPL site, DTSC 

requested EPA assume the lead for the site to ensure that investigation work continues and cleanup work begins. 

 Need for NPL Listing: 

The State of California referred the site to EPA. Other federal and state cleanup programs were evaluated, but are not viable 

at this time. EPA received a letter of support for placing this site on the NPL from the State of California. 

[The description of the site (release) is based on information available at the time the site was evaluated with the HRS. The description may change 

as additional information is gathered on the sources and extent of contamination.] 

For more information about the hazardous substances identified in this narrative summary, including general information regarding the effects of exposure to these 

substances on human health, please see the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. ATSDR ToxFAQs can be found on the Internet 

at http://www.atsdr.cdc.gov/toxfaq.html or by telephone at 1-888-42-ATSDR or 1-888-422-8737.