HRS Definitions of Site and Source
HRS definitions of site and source:
- The HRS rule, section 1.1 on page 51587:
"Site: Area(s) where a hazardous substance has been deposited, stored, disposed, or placed, or has otherwise come to be located."
"Source: Any area where a hazardous substance has been deposited, stored, disposed, or placed, plus those soils that have become contaminated from migration of a hazardous substance. Sources do not include those volumes of air, ground water, or surface water sediments that have become contaminated by migration, except: in the case of either a ground water plume with no identified source or contaminated surface water sediments with no identified source, the plume or contaminated sediments may be considered a source."
Question — There is a mine tailings pile and large area of soil contaminated by wind-blown particulate. In addition, the ground water under the pile is contaminated and there are contaminated sediments in a nearby stream. How many sources are there? ANSWER
EPA lists sites on the NPL. HRS scores are calculated based on the characteristics of sources at the site and other factors.
The site boundary generally will not be identical to the facility property boundary.
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