Households using on-site wastewater treatment within watersheds draining to the Puget Sound and the Strait of Juan de Fuca, Washington, 2010

This data release contains the number of households using on-site wastewater treatment for watersheds draining to the Puget Sound and the Strait of Juan de Fuca, Washington. The data, which represent the year 2010, were used as input to seasonal Spatially Referenced Regression On Watershed attributes (SPARROW) total nitrogen and total phosphorus models that were used to assess nutrient loadings to Puget Sound and the Strait of Juan de Fuca. The values constitute the total number of households using on-site wastewater treatment for each incremental catchment represented in the SPARROW models.