The Marine Water Condition Index (MWCI) displays changes in the water quality of Puget Sound. Numbers greater than zero show water quality that has improved over the baseline, and numbers smaller than zero indicate decreased water quality. Two areas in or near Thurston County are tracked as part of the MWCI: South Sound, a combination of the Nisqually Reach and Dana Passage measuring stations; and Budd Inlet. These stations have exhibited wide changes from year to year, but the overall trend is worsening marine water quality.
Puget Sound Partnership, Department of Ecology, Thurston County