Del Amo (Superfund site)
Encyclopedia
The Del Amo Superfund Site is a U.S. EPA Region 9 Superfund Site. It is one of 94 Superfund Sites in California
as of November 29, 2010.
and Carson
. The 280-acre site is the former location of a synthetic rubber manufacturing plant that was in operation from 1942 until the late 1960s or early 1970s. The facility was three separate plants: a styrene plant, a butadiene plant, and a synthetic rubber plant. Multiple companies leased and used the plants until 1955 when the Shell Chemical Company bought the plants and continued operations independently. In 1972 the site was sold to a developer that dismantled the plants, and it is now mostly an industrial park. The Environmental Protection Agency (EPA) recommended that the Del Amo site be added to the National Priorities List
(NPL) in 1991. The earliest remediation efforts began in 1995 and are ongoing.
s like benzene
and ethylbenzene
, and polycyclic aromatic hydrocarbon
s like naphthalene
, benzopyrene
, phenanthrene
and chrysene
. Benzene is known to be a human carcinogen
, and is detected most frequently and at the greatest concentrations at the waste pits.
Shallow groundwater, soil, and soil gas in the area are known to be contaminated. Contamination of soil gas is a major concern because it can enter buildings that have been built over the site.
A 1993 report states that shallow groundwater in the area was contaminated but local drinking water wells were apparently unaffected at that time. Chemicals could be detected in water up to 60 feet below the surface, but drinking water in this area comes from deep reservoirs 500 feet below the surface and was therefore considered safe to drink. However, recent data from the EPA’s Second Five Year Review indicates that volatile contaminants were migrating from the soil to groundwater reservoirs including reservoirs that are used for domestic water. Groundwater in the area may also contain contaminants from another nearby Superfund site (Montrose Superfund Site). Past and current reports indicate that steps need to be taken to ensure that shallow groundwater contamination does not seep to deeper levels.
Clean up is ongoing and concern remains that if the soil at the site is disturbed, volatile organic compound
s (VOCs) could be released into the air. The dispersal of contaminants into deep groundwater aquifers also remains a concern.
Residents report that when they were children they played at or around the waste site and saw waste material on the ground, prior to the capping and fencing of the waste area. Past and current contact with contaminants likely occurred through inhalation, ingestion, and possibly direct skin contact, both to residents and workers.
A study from the late 1980s found higher than expected reported rates of skin, eye, nose and throat irritation and earaches, dizziness and fatigue. People who had these health issues lived closer to the site than those that did not. The same study found no higher rate of cancer, miscarriage, reproductive problems, or death among residents.
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
as of November 29, 2010.
Site History
The Del Amo Superfund Site is located in southern Los Angeles County between the cities of TorranceTorrance, California
Torrance is a city incorporated in 1921 and located in the South Bay region of Los Angeles County, California, United States. Torrance has of shore-front beaches on the Pacific Ocean, quieter and less well-known by tourists than others on the Santa Monica Bay, such as those of neighboring...
and Carson
Carson, California
Carson is a city in Los Angeles County, California. As of the 2010 census, Carson had a total population of 91,714. Located south of downtown Los Angeles and approximately 14 miles away from the Los Angeles International Airport, it is known as a suburb of the city....
. The 280-acre site is the former location of a synthetic rubber manufacturing plant that was in operation from 1942 until the late 1960s or early 1970s. The facility was three separate plants: a styrene plant, a butadiene plant, and a synthetic rubber plant. Multiple companies leased and used the plants until 1955 when the Shell Chemical Company bought the plants and continued operations independently. In 1972 the site was sold to a developer that dismantled the plants, and it is now mostly an industrial park. The Environmental Protection Agency (EPA) recommended that the Del Amo site be added to the National Priorities List
National Priorities List
The National Priorities List is the list of hazardous waste sites in the United States eligible for long-term remedial action financed under the federal Superfund program. Environmental Protection Agency regulations outline a formal process for assessing hazardous waste sites and placing them on...
(NPL) in 1991. The earliest remediation efforts began in 1995 and are ongoing.
Contamination
Most of the contamination is found in a 3.7-acre waste-disposal area near the southern end of the Del Amo site area, north of Del Amo Boulevard alley. The rubber manufacturer dumped waste materials into 6 unlined pits and 3 or 4 unlined shallow ponds. Contaminants include volatile aromatic hydrocarbonAromatic hydrocarbon
An aromatic hydrocarbon or arene is a hydrocarbon with alternating double and single bonds between carbon atoms. The term 'aromatic' was assigned before the physical mechanism determining aromaticity was discovered, and was derived from the fact that many of the compounds have a sweet scent...
s like benzene
Benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
and ethylbenzene
Ethylbenzene
Ethylbenzene is an organic compound with the formula C6H5CH2CH3. This aromatic hydrocarbon is important in the petrochemical industry as an intermediate in the production of styrene, which in turn is used for making polystyrene, a common plastic material....
, and polycyclic aromatic hydrocarbon
Polycyclic aromatic hydrocarbon
Polycyclic aromatic hydrocarbons , also known as poly-aromatic hydrocarbons or polynuclear aromatic hydrocarbons, are potent atmospheric pollutants that consist of fused aromatic rings and do not contain heteroatoms or carry substituents. Naphthalene is the simplest example of a PAH...
s like naphthalene
Naphthalene
Naphthalene is an organic compound with formula . It is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings...
, benzopyrene
Benzopyrene
Benzo[a]pyrene, C20H12, is a five-ring polycyclic aromatic hydrocarbon whose metabolites are mutagenic and highly carcinogenic. Benzo[a]pyrene is listed as a Group 1 carcinogen by the IARC. It belongs to a class of polycyclic aromatic compounds known as benzopyrenes, which consist of a benzene...
, phenanthrene
Phenanthrene
Phenanthrene is a polycyclic aromatic hydrocarbon composed of three fused benzene rings. The name phenanthrene is a composite of phenyl and anthracene. In its pure form, it is found in cigarette smoke and is a known irritant, photosensitizing skin to light...
and chrysene
Chrysene
Chrysene is a polycyclic aromatic hydrocarbon with the molecular formula that consists of four fused benzene rings. It is a natural constituent of coal tar, from which it was first isolated and characterized...
. Benzene is known to be a human carcinogen
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
, and is detected most frequently and at the greatest concentrations at the waste pits.
Shallow groundwater, soil, and soil gas in the area are known to be contaminated. Contamination of soil gas is a major concern because it can enter buildings that have been built over the site.
A 1993 report states that shallow groundwater in the area was contaminated but local drinking water wells were apparently unaffected at that time. Chemicals could be detected in water up to 60 feet below the surface, but drinking water in this area comes from deep reservoirs 500 feet below the surface and was therefore considered safe to drink. However, recent data from the EPA’s Second Five Year Review indicates that volatile contaminants were migrating from the soil to groundwater reservoirs including reservoirs that are used for domestic water. Groundwater in the area may also contain contaminants from another nearby Superfund site (Montrose Superfund Site). Past and current reports indicate that steps need to be taken to ensure that shallow groundwater contamination does not seep to deeper levels.
Remediation
Remediation efforts include capping the waste area, installation of surface water controls, a soil vapor extraction and remediation facility, fencing, and long-term monitoring of the site. Contaminated soil and waste material from up to 25 meters depth was removed from one of the waste pits between 1982 and 1984. This material was taken to an appropriate disposal facility, and the excavated area was backfilled with clean soil. Contaminated soil likely exists beneath the backfill, based on samples collected later. Between 1994 and 1999 Shell Oil Company performed routine inspections of the area and secured the waste pits.Clean up is ongoing and concern remains that if the soil at the site is disturbed, volatile organic compound
Volatile organic compound
Volatile organic compounds are organic chemicals that have a high vapor pressure at ordinary, room-temperature conditions. Their high vapor pressure results from a low boiling point, which causes large numbers of molecules to evaporate or sublimate from the liquid or solid form of the compound and...
s (VOCs) could be released into the air. The dispersal of contaminants into deep groundwater aquifers also remains a concern.
Public Health
During clean up of the site, 55 of the nearest homes were bought out. Soil around two of these homes was found to contain hazardous chemicals that did not come from the Del Amo site. Additionally, surface soil near some of the bought-out homes contained amounts of Del Amo chemicals that are too small to be considered harmful to peoples’ health.Residents report that when they were children they played at or around the waste site and saw waste material on the ground, prior to the capping and fencing of the waste area. Past and current contact with contaminants likely occurred through inhalation, ingestion, and possibly direct skin contact, both to residents and workers.
A study from the late 1980s found higher than expected reported rates of skin, eye, nose and throat irritation and earaches, dizziness and fatigue. People who had these health issues lived closer to the site than those that did not. The same study found no higher rate of cancer, miscarriage, reproductive problems, or death among residents.