The Department of Ecology conducted seasonal monitoring for toxic contaminants in the Spokane River at the eastern Spokane Tribal boundary during 2015 – 2016.  This monitoring area is downstream of all known sources of PBDEs, PCBs, and metals (cadmium, copper, lead, and zinc).  Toxics monitoring was conducted to provide recommendations for establishing a long-term monitoring program for the site.

Surface water and suspended sediment samples were taken during the three major hydraulic river regimes: spring high flow, summer low flow, and winter moderate flow.  The samples were analyzed for PCBs, PBDEs, dioxins/furans, and metals (cadmium, copper, lead, and zinc).  Three collection and extraction techniques were used to ensure detection of PCBs and PBDEs in surface water: CLAM (Continuous Low-level Aqueous Monitoring device), XAD-2, and liquid-liquid extraction with two-liter composite samples.  Suspended sediments were collected with sediment traps deployed for four months at a time.

Recommendations were made to continue long-term monitoring in the Spokane River at the eastern Spokane Tribal boundary site, with minor changes in collection techniques and toxic parameters to consider for analysis.

If you have questions, contact Brandee Era-Miller at 360-407-6771 or bera461@ecy.wa.gov.