The Waste Disposal Inc. Superfund Site is an oil-contaminated site in the industrial city of Santa Fe Springs in Los Angeles County, California. It is about 38 hectares (15 acres), with St. Paul's high school bordering directly on the northeast corner of the site. About 15,000 residents of Santa Fe Springs get drinking water from a well within three miles (4.8 km) of the site.
Video The Waste Disposal Inc. Superfund site
Histori
With a capacity of 42 million gallons (160,000,000 l) and a diameter of about 600 feet (200 m), the site was originally built into an in-ground and concrete-lined reservoir to store crude oil before 1924. In 1929, the Santa Fe oil field Springs is the largest producer of petroleum products in the country. Booming oil production produces a large number of dangerous oil by-products in both liquid and solid form. The site is then used to store various liquid and solid wastes, because Waste Disposal Inc. (WDI) received permission from Los Angeles County to operate industrial waste disposal, which continued until 1964. Wastes disposed on site include mud drilling, construction debris, refinery waste, sludge, chemical solvents and other chemicals associated with petroleum.
In July 1987, the WDI site was placed on the National Priority List (NPL) for the release of known, or threatened, dangerous substances, pollutants or contaminants. On November 11, 1988, the Agency for Toxic Substances and Disease Registry (ATSDR) released an initial health assessment of the WDI website and assigned it to public health concerns due to public exposure to contaminant soil and potential groundwater quality problems.
An Endangered Assessment published by the Environmental Protection Agency (EPA) in 1989 evaluated the risks in place of the population in relation to contaminated soil contact or migration inhaling the contaminants. Non-carcinogenic hazards are considered unacceptable for residents who contact the soil, and require corrective action. Contaminants in the soil include 11 metals, 7 chlorinated pesticides, 16 volatile organic compounds (VOCs), polyaromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). Superfund or Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) required remediation measures for their presence of contamination in soil, ground and groundwater.
Based on the results of the initial Remedial Investigation Report (RI) in 1990 and Feasibility Study (FS) in 1993, the EPA opted for an environmental solution to address contaminated soil and surface subsurface gases. In 2003, the US Department of Justice and the EPA with the US District Court in Los Angeles required 17 companies, known as the WDI Group, to clean up the WDI Superfund site.
Maps The Waste Disposal Inc. Superfund site
Community health issues
In July 1958, communities around the site formed a group against WDI surgery because of health problems. The emission of foul odor is a major problem and is related to the health problems of other residents. Excessive noise and dust are also associated with the site by local officials. The cancer surveillance program by the University of Southern California did not show an increased cancer rate in the area. The EPA RI report is the latest and extensive investigation to date, and the characteristics of the site are mainly based on its findings. The Final Report of November 1989 contains detailed description and analysis of contaminants found on the site. Contamination in place in WDI exists in soil, ground water, and sub-surface gases. Methane is the most common subsurface gas and shows the highest concentration in the reservoir area. Volatile Organic Compounds (VOCs) are also found in subsurface gases. VOCs and some metals with concentrations above the Maximum Contaminant Level (MCL) found in ground water. Pollution of the ground in the main place includes drilling mud and waste in the field. Constituents of this waste include:
- Metals - arsenic, beryllium, thallium, and lead
- VOC - toluene, methylene chloride, acetone, ethylbenzene, 2-butanone, and xylene
- Organic Compounds Semivolatil - benzo (a) pyrene, 2-chlorophenol, naphthalene, 2-methylnaphthalene, 4-nitrophenol, phenanthrene, chrysene, 1,4-dichlorobenzene, benzo (a) anthracene, anthracene, pyrron, phenanthrene, pentachlorophenol , and fluorena
- Pesticides - DDD, DDE, DDT, alpha- and gamma-chlordane, and dieldrin at ground level
- PCB at ground level
Under current conditions, possible exposure paths consist of skin contact with contaminated surface soil and particulate and volatile inhalation. The highest risk arsenic, thallium, benzene, pesticides, PCB, and vinyl chloride. While this risk for current exposure scenarios is almost within the acceptable range of EPA, they can still pose a threat to users of the site in the future.
In addition, a health-care survey was conducted among residents in 1999 by the California Department of Health Services (CDHS) which shows a consistent concern about site odor and human exposure, especially the St. Paul. CDHS specifies that WDI sites should not be a major health issue even for children playing in the field right next to the site.
Remedy app
Remedial construction by WDI contractors began in March 2004. Meanwhile, the EPA also contracted the US Army Engineer Corps to provide construction supervision. The drug works to keep contaminants on the site, blocking the migration of contamination through rainwater, air, and groundwater, and restrict direct human contact with contaminated soil. The goal is to protect individuals and the environment from exposure to contamination, rather than applying treatment to on-site contaminants. The EPA has decided that the selected drug will remain protective for human health and the environment in the long term. The estimated cost of this protective drug is approximately $ 5,170,000. The EPA considers reasonable costs for risk reduction and believes the drug will significantly reduce the risk by preventing the migration of contaminants.
The treatment of contaminated sites recommended by the US EPA in 1993 is summarized as follows:
- Excavation and contamination of contaminated soil
- Multi-layer engineering cover on top of reservoir and selected location outside of reservoir
- Groundwater contamination is unlikely to be a public health problem but requires long-term monitoring to ensure safe drinking water.
- Leachate and a free liquid collection for offsite care
- Institutional controls include access control and time limits
- Physical barriers or ventilation systems in nearby buildings
- Long-term operation and maintenance to ensure efficacy.
In a five-year review released in August 2009, the EPA determined that remedial measures had successfully retained waste at the site and blocked the exposure path. The second five-year review report released in September 2014 also stated that the drug remains protective. It is also effective in preventing direct exposure to contaminated soil. The next five-year review is scheduled to be released in 2019, as waste remaining on the site and WDI makes it impossible for unlimited use and unlimited exposure.
References
Source of the article : Wikipedia
0 Comments