Terrestrial Ecological Evaluation Process- Exclusion #3


Exposure Pathway Analysis - Area of Contiguous Undeveloped Land

This exclusion is based on the kind of substances present at your site and the proximity of the contamination to undeveloped land.  It requires the user to determine whether certain more toxic substances are present by evaluating the list of substances provided below.  The analysis also requires the user to identify the area of  contiguous undeveloped land on or within 500 feet of the contamination.  To do this, the user must identify the boundary of the area of contamination, and then draw a 500 foot perimeter around that site boundary.  Here is an aid to calculating area  and an aerial photo depicting a site, its 500 foot boundary and several labeled circles identifying various areas for reference in judging the area of undeveloped land within the 500 foot radius. 

CRITERIA:

No further evaluation is required if both of the following criteria are met:

  For sites with hazardous substances other than those listed below, there is less than 1.5 acres of contiguous undeveloped land on the site, or within 500 feet of any area of the site affected by the hazardous substances.  

  For sites with hazardous substances listed below, there is less than 0.25 acres of  contiguous undeveloped land on or within 500 feet of any area of the site affected by those hazardous substances.

Hazardous Substances of Concern:

Toxnet is a cluster of databases where you can search for information about a variety of chemicals, including those listed above.

 

Note: In providing this list of hazardous substances, the department is not intending that sampling must be conducted for each of the listed chemicals at every site.  Sampling should be conducted for those chemicals that might be present based on available information, such as current and past uses of chemicals at the site.

  A PDF form is available for documenting your decision-making.Picture Depicting Documentation

Here you may view an HTML version of the form

RATIONALE:

Even if the soil is contaminated at the point of compliance and there are insufficient physical barriers to prevent exposure to that contamination, if the area of contiguous undeveloped land (habitat) affected by soil contamination is sufficiently small, then the soil contamination is not likely to pose a threat to plants and wildlife because the receptors are not likely to be exposed to the soil contamination.

REFERENCE:

WAC 173-340-7491(1)(c)

Please contact David Sternberg if you have any questions or comments about the TEE web pages.

[Exclusions Main] [Exclusion 1 - Contaminant Analysis] [Exclusion 2 - Exposure Pathway Analysis - Incomplete Pathway] [Exclusion 3 - Exposure Pathway Analysis - Area of Contiguous Undeveloped Land] [Exclusion 4 - Contaminant Analysis - Natural Background] [Forms - Primary Exclusions] 

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