Three segments of the White Salmon River and four of its tributaries, Rattlesnake Creek, Gilmer Creek, Trout Lake Ditch, and Trout Lake Creek, were listed in 1998 under Section 303(d) of the federal Clean Water Act as not meeting Washington State water quality standards for fecal coliform bacteria (FC).
In 2009, Ecology initiated a study to determine if these waters are currently complying with FC standards. The WA Department of Ecology reported the following Conclusion.
Results of this 2009-2010 White Salmon Fecal Coliform study support the following conclusions:
• Four of the seven 303(d) listed stream segments met both parts of the water quality standards for FC. However, Rattlesnake Creek at river mile (RM) 0.1, Gilmer Creek at RM 0.1, and White Salmon River at RM 22.55 continue to not fully meet water quality standards for FC.
• Trend analysis indicated FC levels have decreased on Rattlesnake and Gilmer Creeks; however, the trends were not significant. A statistically significant increase was detected on the White Salmon River at RM 1.43; however, water quality standards were not violated.
• Sources of FC pollution on Rattlesnake Creek are suspected to be from residential properties just above station RSC-0.1. Additional sampling or onsite investigations may be needed to further determine the sources.
• Sources of FC pollution on Gilmer Creek were isolated to a livestock operation in the upper watershed. Ecology has worked with the Underwood Conservation District and the landowner to correct the problems.
• Sources of FC pollution on the White Salmon River between RM 22.55 and 25.18 are believed to be from several sources or land-use activities. Some of the possible sources include:
o An operating dairy manure lagoon adjacent to the White Salmon River just above station WS-22.55.
o Irrigation ditches running through livestock pastures between RM 22.55 and 25.18.
o Manure and irrigation management practices occurring on pastures with irrigation ditches with direct connectivity to the White Salmon River between RM 22.55 and 25.18.
• Sources of FC between RM 22.55 and 25.18 may best be remediated through a review of existing land-use practices, onsite inspections, and by working with the local conservation district and landowners. At this time, no additional FC sampling is needed to address these issues.
• An effectiveness monitoring evaluation should be conducted at such time when Ecology nonpoint pollution (Water Quality) staff believes sufficient best management practices have been implemented. Preferably, this would occur after implementation has occurred at a watershed scale, rather than a sub-watershed scale, to save costs.
• Provided that local stakeholders continue to work cooperatively with Ecology water quality managers, the development of a total maximum daily limit improvement report for FC is not necessary.