Site Assessment and Remediation
Return to Site Assessment and Remediation In this Section:
Preliminary Assessment and Site Inspection Program
In December of 1980, the United States Congress enacted the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). CERCLA, or Superfund, created a fund to collect taxes from chemical and petroleum industries. CERCLA funds are directly used to assess and clean up sites contaminated by environmentally hazardous substances, excluding petroleum and natural gas.
In 1986, Congress then amended CERCLA through the Superfund Amendments and Reauthorization Act (SARA) stressing better enforcement tools and remedies for cleaning up hazardous waste sites and the importance of state and local government involvement in the Superfund process. One important characteristic of SARA was the establishment of the National Priorities List (NPL). The NPL is a ranking of the most contaminated sites nation-wide. The NPL is part of a much larger list called the Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS). CERCLIS lists all contaminated sites nation-wide and lists them according to the state in which they are reported. Furthermore, Superfund not only provides funding for the assessment and cleaning of contaminated sites, it also tries to find those responsible for the contamination, also known as Potentially Responsible Parties (PRP) under CERCLA. The Superfund process consists of eight steps:
1. Site Discovery
2. Preliminary Assessment and Site Inspection (PA/SI)
3. Hazardous Ranking System/ National Priorities List (NPL)
4. Remedial Investigation/ Feasibility Study
5. Record of Decision/ Remedial Selection
6. Remedial Design and Action
7. Site Completion and Operation/ Maintenance
8. Closeout/ NPL Deletion
The DEQ Preliminary Assessment and Site Inspection program consists of the first two steps of the Superfund Process, which are federally funded by the U.S. Environmental Protection Agency (EPA). The first step of the DEQ PA/SI program is site discovery. Sites are discovered by Regional EPA offices, State agencies, and citizens who report sites with known or suspected release or threaten release of hazardous substances to DEQ. When a site is reported, it must go through a pre-CERCLIS screening. If a site is accepted by EPA, a CERCLIS application is submitted which will enter the site into the CERCLIS database. A preliminary assessment (PA) is then conducted at the site. The PA process collects readily available information about a site and its surrounding area. The assessment includes research and interviews to find what chemicals are used and stored at a site. Site history will also be researched.
The CNMI DEQ receives funding from EPA to conduct a preliminary assessment at sites with suspected release or threaten release of hazardous substances. CERLA Section 104 provides EPA the authority to issue 104e Information Request Letter to seek the release of information for the purpose of undertaking response activities. The purpose of the 104e letter is to seek information from any person who has or may have information relevant to the site regarding the release or threat of release of hazardous substances. Normally, the 104e letter request for the following information but is not limited to such information:
1. Property Information – Past/Present Owner, Historical Land Use, Property Transaction Information (e.g. lease agreements), etc.
2. Chemical Use/Inventory/Storage/Shipping
3. Chemical Waste Disposal Practice
4. Site Maps (Property Maps, Structural Plans, etc.)
For sites which DEQ plans to conduct a PA, EPA normally takes the lead to issue the 104e letter. The letter normally provides the recipient 30 days to respond. DEQ conducts other information search relevant the sites from other government agencies i.e. Department of Public Lands, Historic Preservation Office, Fire Department, Commonwealth Utilities Corporation, Fish & Wild Life, etc. Once DEQ is satisfied with the information obtained for the site, DEQ then uses the available information to evaluate the site using a PA Score Sheet. The outcome of the PA Score determines is the sites warrant further action, which is the SI.
A site PA score of greater than 28.5 (>28.5) will move the site to the next step, otherwise a No Further Remediation Action Planned (NFRAP) is determined. DEQ concludes the PA process by writing a site report and submitting it to EPA for concurrence. The second step of the PA/SI program is the site inspection (SI). The SI is the actual sample collection process. Environmental and waste samples are collected to determine what hazardous substances are released at the site. Groundwater, surface water, soil, and air samples are taken from the site depending on the site situation. The SI also determines the severity of these hazardous substances that have been released at the site and any nearby locations. The first stage of the SI tests the hypotheses concluded during the PA. An expanded SI may be conducted if further information is needed.
At this time, while DEQ continues to build its technical capacity and field experience, EPA takes the lead in conducting SI projects. The third step of the Superfund process is the Hazard Ranking System (HRS). Superfund has created a point-based scoring system from 0 to 100 to measure the potential relative risks to public health and the environment. Variables measured are:
1. Likelihood that site has released/ potential to release contaminants into the environment;
2. Characteristics of the hazardous substance (toxicity and quantity);
3. People or sensitive environments affected by release;
Information collected from the PA/SI are calculated and scored under the HRS system. If a site scores higher than 28.5, it will be entered into the National Priorities List. If the site scores less than 28.5, it is referred to another EPA program where it may be able to qualify..