Publication Summary

The Fishtrap Creek watershed, tributary to the Nooksack River in northwestern Washington, is dominated by dairy farming. Fifteen sites in mainstem Fishtrap Creek and its tributaries were surveyed for conventional water quality parameters six times between September 1993 and January 1994. The water quality investigation results showed high to very high levels of fecal coliform bacteria throughout the watershed (as high as 880,000 organisms/100 mL), low levels of dissolved oxygen in the small tributaries (as low as 2.2 mg/L), and one instance of very high ammonia levels (19.2 mg/L NH3-N).

The Fishtrap Creek watershed, tributary to the Nooksack River in northwestern Washington, is dominated by dairy farming. Fifteen sites in mainstem Fishtrap Creek and its tributaries were surveyed for conventional water quality parameters six times between September 1993 and January 1994. The water quality investigation results showed high to very high levels of fecal coliform bacteria throughout the watershed (as high as 880,000 organisms/100 mL), low levels of dissolved oxygen in the small tributaries (as low as 2.2 mg/L), and one instance of very high ammonia levels (19.2 mg/L NH3-N).

A total maximum daily load (TMDL) for fecal coliform was located as follows: the geometric mean of all samples at all sites is not to exceed 100 organisms/100 mL, with no more than 10 percent of all samples exceeding 200 organisms/100 mL. To achieve this load allocation, dairy farm "best management practices" are recommended to be implemented at dairy farms throughout the watershed. The highest priority areas are immediately upgradient of the intersection of Depot and Visser roads and near the mouth of the Benson Road Ditch. Because this is a phased TMDL, continued monitoring of progress will be necessary for successful implementation of the TMDL.

Link to EIM data for User Study ID KERI0001