Sewage sludge disposed in forests and farms in Washington State

King County disposes of its sewage sludge in forests around Puget Sound and on farms in Eastern WA. But King County is not alone. See images below for maps and areas to which sewage sludge has been land applied in Washington State.

Sewage sludge is an ever growing problem that is an inevitability of life. Replete with chemotherapy drugs, pathogens, heavy metals and other environmental toxins, sewage sludge is often land applied to crops for human consumption. Such is the case in Eastern Washington where sewage sludge is applied to hops in the Yakima Valley and wheat fields on the Waterville Plateau. Equally disturbing is King County‘s dumping of sewage sludge on public lands in the forests around Puget Sound.

We had an opportunity to tour the farms and forests where sludge is being land applied and to ask the question, “Why doesn’t King County keep more of the sewage sludge within its jurisdictional boundaries?” The answer given was simple: “King County ran out of farm land (on which to apply it).”

Sludge dumping a joint project of King County and Washington State Department of Ecology.


Sludge pile in forest.

Sludge slinger used to sling the sewage sludge far and wide…

… and high!

“Agronomic rates” are used to determine how much sludge can be applied in the forest.

Two of Eastern Washington’s largest recipients of King County’s sewage sludge are Natural Selection Farms (Yakima, WA) and Boulder Park, Inc. (Mansfield, WA). Natural Selection Farms (NSF) land application sites include the following counties: Yakima, Benton, Kittitas and Klickitat (view maps). Boulder Park, Inc. includes the rocky agricultural lands surrounding the communities of Waterville and Mansfield in Douglas County (view).