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Criterion 4 Indicator 25
Area and Percent of Forest Land Experiencing an Accumulation of Persistent Toxic Substances
If persistent toxic substances are present on forest lands, there is potential for groundwater contamination. Contaminated watersheds may harm fish and wildlife, people who consume the water, and general ecosystem stability within the watershed. It is important to know if there are any toxic substances on forest lands and to what extent, in order to deal with these problems appropriately.

Can This Indicator Be Quantified
There is little evidence that there are any accumulations of toxic substances on Oregon’s forest lands. Any concerns tend to be at the local scale. The primary sources of persistent toxic substances are industrial waste and pollution. Toxic substances may also accumulate as a result of various management practices, such as application of fertilizers or herbicides.
The Oregon Department of Environmental Quality (DEQ) has a system in place to monitor toxic sites and spills throughout Oregon. DEQ maintains a database of both reported and confirmed toxic sites and spills (available on their web site). The data includes information on the site’s location, type of substances involved, media contaminated, and status of cleanup efforts.
Accumulations of toxic substances are relatively rare and small in size on forest lands in Oregon. Currently, only three sites on DEQ’s confirmed release list are located on forest lands. Toxic sites were identified as being on forest land through the use of GIS technology. The location data from the DEQ database were cross-referenced with GIS overlays to find toxic sites located on forest lands. These sites were then checked against the confirmed release inventory to find sites with documented spills. The three sites from the confirmed release list determined to be on forest lands are all associated with industrial processes. Two of the sites result from processing forest products and one site is from an abandoned mine. See Map 25-1 in Appendix A. The substances involved include arsenic, cyanide, lead, mercury, lubricating oil, fuels, and solvents.
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Data Source and Availability
The Oregon Department of Environmental Quality maintains a database called Oregon Inventory of Hazardous Substance Sites at
and a Confirmed Release Listing is at

Reliability of Data
The listing and de-listing of hazardous substance sites on DEQ’s inventory is a formal administrative process with specific procedures. The criteria for listing are explained on the DEQ’s web site at http://www.deq.state.or.us/wmc/cleanup/vcp0.htm. The listing is updated quarterly.

Statewide by individual site.

Recommended Action for Data Collection


Selected References