Areawide Soil Contamination Project

This toolbox of information and materials is designed to help individuals and organizations answer questions about area-wide soil contamination in Washington, determine whether there is the potential for exposure to elevated levels of arsenic and lead in soil at specific properties, and identify actions they can use to reduce exposure to arsenic and lead.  Area-wide soil contamination is low-to-moderate level soil contamination that is dispersed over large geographic areas, ranging from several hundred acres to many square miles.  In many areas of Washington State, soil contains low-to-moderate levels of arsenic and lead from three main historical sources: emissions from metal smelters, use of arsenical pesticides, and combustion of leaded gasoline.  The Area-Wide Soil Contamination Task Force contributed to the development of this toolbox.

In this toolbox, you’ll find:

• Background information on area-wide soil contamination.
  

• Maps and other information describing the location and extent of area-wide soil contamination in Washington.  This information is organized according to the three main sources of area-wide soil contamination:
  • historical emissions from metal smelters located in Tacoma, Harbor Island, Everett, Northport, and Trail, BC;
  • historical use of lead arsenate pesticides on apple and pear trees; and
  • emissions from combustion of leaded gasoline.  
     

• Tools for conducting individual property evaluations to determine whether there is the potential for exposure to elevated levels of lead and arsenic in soil.  These tools include:
  • Individual Property Evaluation Flowchart – to determine whether arsenic and lead soil contamination is likely to be present in soil on a property using information about the property’s location and its land-use and development history,
  • Qualitative Evaluation Checklist for Understanding Potential Exposures to Arsenic and Lead in Soil – to determine whether there is potential exposure on the property and inform decisions about whether to test soils and/or implement protection measures to reduce potential exposure, and
  • Sampling Guidance – to provide instructions for how to collect and analyze soil samples for arsenic and lead at three types of land uses: child-use areas, residential properties, and commercial properties.
     

• Information on health risks from exposure to low-to-moderate levels of arsenic and lead in soil.
   

• Examples of individual protection measures that individuals can use to limit potential exposure to arsenic and lead in soil.  In particular, individual protection measures are designed to minimize the potential for exposure of children, gardeners, and other adults who frequently work in soil.  This toolbox contains four sets of example practices:
  • Personal hygiene practices and other guidelines for how residents may reduce potential exposure, developed by Public Health – Seattle & King County
  • Actions that schools may use to reduce potential exposure of schoolchildren, developed by the Tacoma-Pierce County Health Department
  • Worker protection guidelines, developed by the Snohomish Health District for the Everett smelter area
  • Guidelines for gardening on soils that may contain elevated levels of arsenic and lead, developed by the Washington State University, Agricultural Extension

• Information describing the range of protective measures that might be taken to respond to area-wide soil contamination and providing guidance on how to implement those protective measures in an effective, practical, and affordable manner.
   

• Contact information for Federal, State, and local agencies that are available to answer questions and provide additional help.