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Site Characterization (SC)

The Department of Environmental Conservation (DEC), along with the Departments of Health (DOH) and Law (DOL), is responsible for ensuring the cleanup of inactive hazardous waste disposal sites across the state. Under New York State's Inactive Hazardous Waste Disposal Site Remedial Program, the process begins with the discovery of a potential hazardous waste site and follows a path of thorough investigation, remedy selection, design, construction and monitoring. This fact sheet highlights one stage in the comprehensive process, the Site Characterization (SC).

Site Characterization

DEC carries out an SC to determine whether a site is a hazardous waste site as defined by state law.

A Site Characterization (SC) is DEC's first investigation of a site where hazardous waste has or may have been disposed of illegally or improperly. The goal of the SC is to determine whether a site meets the state's definition of a hazardous waste site by confirming or denying the presence of hazardous waste and determining whether or not the site poses a significant threat to public health or the environment. The SC is performed by DEC or the potentially responsible party under DEC's oversight.

The SC is a three-step investigation to determine if the site should be classified for remediation or delisted.

The SC has three steps:

  1. Records Search: This includes a thorough background review and record check into the past uses and waste disposal activities at the site.
  2. Sampling/Surveys: This involves sampling of exposed wastes, drums, surrounding soil and surface water. Additionally geophysical and soil gas surveys may be performed.
  3. Groundwater Monitoring: This involves installing monitoring wells and analyzing water samples to check for subsurface contamination.

DEC evaluates SC information to classify or delist a site.

Each SC step ends with a decision point that can lead to one of two outcomes.

If the presence of hazardous waste and the degree of health or environmental threat can be documented, a site is classified to:

  • Class 1 (imminent danger)
  • Class 2 (significant threat)
  • Class 3 (no significant threat)

If hazardous waste cannot be documented, a site is delisted.

Built-in decision points help move sites through the remedial process.

The decision points allow DEC to classify or delist the site as soon as enough information exists to support or refute the state's criteria for defining a hazardous waste site. They provide a mechanism to move sites into remediation at the earliest opportunity. If DEC does not have enough information to make the decision to classify or delist, the SC continues to the next step.

Complex sites may require all three SC steps.

At complex sites where hazardous waste is difficult to confirm or where significant threat is difficult to determine, all three SC steps may be required before DEC makes a decision to classify or delist.

The SC concludes with a decision to classify or delist a site.

DEC reviews all investigative documentation and makes a decision supported by input from local government agencies, the Department of Health (DOH), DEC regional offices and the public. The SC ends when a site is classified or delisted.

The NYS Department of Health (DOH) plays an important role in the investigation of hazardous waste sites.

DOH participates with DEC in the SC process. Through its own early site investigation and health assessment, DOH identifies potential impacts on public health. DEC incorporates DOH information into the SC to ensure that public health concerns are fully investigated. DOH also helps DEC identify priority sites, reviews work plans and reports and contributes to the decisions to classify or delist a site.

DEC prioritizes sites for further investigation and remediation.

Once DEC decides a site needs remediation based on the SC findings, the site is ranked for further remedial investigation using the state's Priority Ranking System. DEC uses this system to first focus remedial and enforcement resources on sites with the most serious problems.

Further study and cleanup may follow an SC.

Sites that become Class 1 or 2 move to the next stage of the remedial process - the Remedial Investigation/Feasibility Study (RI/FS). During a RI/FS, the full nature and extent of contamination is defined. Sites may also be referred for Interim Remedial Measures (early cleanup actions that may not require a full-scale investigation and design). Delisted sites are removed from the registry. Some sites are delisted because they do not fit the definition of "hazardous waste disposal site" yet they contain other waste materials. These sites may be referred to other DEC programs or the Attorney General for action (e.g., closing construction and demolition debris sites or municipal landfills).

DEC can nominate a site for federal cleanup based on SC findings.

By evaluating information collected during the SC in relation to federal requirements, the DEC can decide if a site should be nominated for the US Environmental Protection Agency's National Priorities List (NPL). NPL site remediations may be paid for by the federal Superfund.

Site Characterization Steps/Outcomes

Records Search: a background review to document previous disposal practices and activities. Information that describes how the waste was handled, stored, transported and disposed of comes from a wide variety of sources including: industry disposal records, site inspections, local or county investigations, interviews with local haulers, nearby residents and others who may have witnessed activities at a site.

Decision Point - delist or classify and stop the SC, or continue to the next step.

Sampling/Surveys: conduct surficial environmental sampling (surface water, soil, waste piles, drums, etc.) and geophysical/soil gas surveys. Samples are sent to laboratories for analyses.

Decision Point - delist or classify and stop the SC or continue to the next step.

Groundwater Monitoring: install and sample monitoring wells to determine if groundwater is contaminated; may conduct additional surficial sampling.

Decision Point - delist or classify.

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