Publication Summary

In this study, stormwater discharge quality of western Washington log yards are surveyed. Sampling was conducted at six log yards to evaluate typical concentrations of pollutants. Analyses of a suite of general chemistry, metals, and organics parameters were conducted, and bioassay tests were performed.

Results are presented, and the impact on discharge quality of site characteristics is evaluated. Site characteristics include the presence or absence of retention ponds and whether log sorting yards are paved or unpaved. Results of the study are used to evaluate current requirements for self-monitoring of log yards.

Stormwater discharged from six log yard facilities in western Washington was sampled by the Washington State Department of Ecology during December 2003 to March 2004. The samples were analyzed for a suite of general chemistry parameters, metals, TPH, and PAH as well as toxicity from Daphnia pulex acute bioassays. Results were found to vary considerably.

Sampling events were limited in number because of only a few days with qualifying conditions of rainfall 0.1 inches or greater per day, following at least 24 hours of no significant precipitation. An analysis of historic rainfall patterns showed that, although the 2003-2004 sampling season had lower than average rainfall, the number of qualifying days for sampling would not be considerably greater during other, more typical years.

Sampling was conducted to evaluate typical concentrations of pollutants and differences between sites. The presence of stormwater retention ponds was associated with relatively low concentrations of pollutants and toxicity. Even sites with small retention capacity showed lower pollutant concentrations during the first hour of collection than in subsequent samples.

Link to EIM data for User Study ID SGOL007