Key Contamination Information

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Key Contamination Information
Environmental Medium/Source
Type of Information to Collect
Groundwater
  • Locations and descriptions of any known or suspected sources of groundwater contamination.
  • Location, depth, and use of known and potentially contaminated wells.
  • All contaminants sampled and analyzed for, detection limits, and QA/QC information.
  • Contaminants and concentrations detected in site monitoring wells, in water supply wells, and at tap water sources, if available.
  • Vertical and lateral extent of the contaminant plume (if known) and of any free product (if present and known).
  • Location of liners or slurry walls (e.g., for landfills), if any.
  • Background conditions.
Surface water/sediment
  • All contaminants sampled and analyzed for, detection limits, and QA/QC information.
  • Contaminants and concentrations identified.
  • Surface water: Surface water sample results at the site and from upstream and downstream of the site.
  • Locations of point sources with a National Pollutant Discharge Elimination System (NPDES) permit.
  • Locations of any dikes present.
  • Sediment: Sampling results of upstream and downstream channel, impoundment, drainage ditches, streams, and/or dredged sediments (if present).
  • Background conditions.
Soil
  • All contaminants sampled and analyzed for, detection limits, and QA/QC information.
  • Contaminants and concentrations identified.
  • Contaminant concentrations before and after any removal or remedial actions.
  • Separate sample results for surface and subsurface soils. (Soil less than 3 inches deep is considered surface soil. Samples from other depths [e.g., 0 to 6 inches] are usable, but the depth must be noted. ATSDR prefers 0 to 3 inches deep, but soil samples from 0 to 12 inches may be useable if documentation proves the soil is well-mixed and contaminant concentrations are consistent from the surface down to 12 inches.)
  • Depth of samples.
  • Sample type(s) (e.g., grab vs. composite).
  • Background conditions.
Air contaminants from above-ground sources (ambient, stack, indoor air, and dust)
  • All contaminants sampled and analyzed for, detection limits, and QA/QC information.
  • Contaminants and concentrations identified from sampling results of air releases on site (production processes, stack emissions, monitoring stations, and soil gas, including buried utility lines) and off-site monitoring (including indoor air, if any).
  • Results of air modeling (if performed) of on-site air releases to potential off-site air exposure points and deposition areas, and of on-site stack and/or fugitive emissions.
  • Measurements of any flammable and explosive gases.
  • Gas pressure measurements.
  • Stack testing or trial burn results (if any).
  • Air permits held.
  • Background, local, and (if possible) site-specific meteorological conditions.
  • Descriptions of other potential contaminants found indoors ( e.g. stored chemicals or solvents, cleaners, lead paint, tobacco smoke).
Air contaminants from soil vapor intrusion (indoor air, soil gas, groundwater, free product, wet basement)
  • Descriptions of odors indoors, especially following heavy rain.
  • Note sheen on water in sump or flooded basement.
  • Source distance to occupied buildings and building types.
  • Seasonal results of paired indoor air and sub-slab gas/crawlspace air samples.
  • All contaminants sampled and analyzed for, detection limits, and QA/QC information.
  • Results of groundwater and near-source soil gas sampling.
  • Vertical and horizontal profiles of exterior soil gas sampling results.
  • Geology layers and preferential pathways.
  • Weather and on/off status of vapor mitigation systems during sampling.
  • Operation, maintenance, and monitoring plans for vapor mitigation systems.
Food chain (biota)
  • All contaminants sampled and analyzed for, detection limits, and QA/QC information.
  • Contaminants and concentrations identified from sampling results for edible portions of plants and animals on-site and off-site.
  • Information from local fish advisories such as prohibition of eating certain fish because of known contaminant concentrations.
  • Information on whether the biota use is for recreational or subsistence purposes.
Physical hazards
  • Information about the existence or lack of barriers to the site, such as fences, gates, or warning signs.
  • Descriptions of any existing confined spaces, industrial equipment, electric hazards, open pits, sinkholes, stored materials, unexploded ordnance or other explosive hazards, and wires/ropes/chains.
  • Known or suspected presence of methane or other flammable gases at the site.
Radiologic parameters
  • Radionuclides analyzed for, detection limits, and QA/QC information.
  • Radionuclides identified and their concentrations (from field and laboratory measurements)
  • Smear (removable surface radiation), air, soil, water, gamma radiation data, and radon sampling (if any).

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