5. Nature and Extent of Area-Wide Soil Contamination (continued)

Recommendations for Improving Our Understanding of the Nature and Extent of Area-Wide Soil Contamination in Washington

The Task Force has two types of recommendations for improving understanding of the nature and extent of area-wide soil contamination: 1) recommendations that address developing and updating maps; and 2) recommendations for additional study of roadside lead contamination (discussed in Section 11).

Developing and Updating Maps
The Task Force has four recommendations for developing and updating maps of area-wide soil contamination areas:

• The maps produced to support Task Force deliberations (many of which were based on pre-existing maps developed to support ongoing cleanup efforts associated with the Tacoma and Everett smelters) represent an important investment and should be used as the starting point for further mapping efforts, including any use of maps to describe area-wide soil contamination zones, as discussed in Section 10 of this report. They are examples of the types of maps that the Task Force believes are needed to communicate information about potential locations of area-wide soil contamination.
  
• The Agencies should use their statewide GIS capability to maintain state maps of area-wide soil contamination areas and to update the maps based on newly available data from sampling on public properties, including public schools and parks, and other public data sources.
  
• The Agencies should encourage, support, and provide financial assistance to local governments that want to identify historical orchard locations and, if appropriate, develop smaller scale maps of areas potentially affected by lead arsenate pesticide contamination. Depending on available data sources and local needs, these smaller scale maps may show areas potentially affected by lead arsenate based on land-use information and/or may more specifically show historical orchard locations. The Task Force believes that accurate, smaller-scale maps of areas potentially affected by lead arsenate pesticide contamination would be useful, but that decisions about whether to undertake this mapping should remain with local governments.
  
• The Agencies should coordinate with local governments to maintain and update smaller-scale maps of areas potentially affected by historical smelter emissions and areas potentially affected by lead arsenate pesticides. These maps should be updated on a reasonable timetable based on newly available information from sampling on public properties, including public schools and parks, and other public data sources. Data from sampling on private properties may also be used to update maps, provided that the Agencies ensure that data from sampling at residences is not recorded at the level of individual properties, except in certain circumstances (see Section 8b).

Because the areas potentially affected by historical smelter emissions are already relatively well defined, the highest priority for funding efforts to refine understanding of the nature and extent of area-wide soil contamination should be to encourage, support, and provide financial assistance to local governments to identify historical orchard locations. In order to use financial resources most effectively, the Agencies should consider first providing "seed" money to local jurisdictions to research available data sources to determine the most appropriate means of identifying and mapping areas potentially affected by lead arsenate pesticide before providing full funding for map development. Financial resources should be made uniformly available to local governments that choose to develop maps.

One Task Force member questioned the benefit of updating maps of area-wide soil contamination in the future. This Task Force member thought than limited funds would be better used to help defray the cost of soil testing for private landowners. After participating in the process, this Task Force member chose not to sign the Task Force report because of concerns over funding future mapping projects and the potential economic impact of creating area-wide soil contamination zones.

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