Nooksack River Transboundary Technical Collaboration Group 2018-2019 annual report

The Nooksack River watershed spans part of the border between British Columbia and the State of Washington. In August 2018, the international, multi-agency Nooksack River Transboundary Technical Collaboration Group was established to implement a three-year work plan to reduce fecal bacteria concentrations in the Nooksack River watershed. As a work plan deliverable, the group produced this annual report summarizing first year project activities.

Nooksack River. Photo: Ronald Woan (CC BY-NC 2.0)
Nooksack River. Photo: Ronald Woan (CC BY-NC 2.0)

Report description

During the past year, groups in British Columbia (BC) and Washington (WA) sampled surface water throughout the Nooksack watershed, including sites located at the international border. Analysis of BC E. coli data shows that the 2018 wet season geometric means met the BC Primary Recreation guideline throughout the BC portion of the watershed. For four waterways spanning the international border, BC and WA data analysis noted higher fecal coliform concentrations in Cave and Bertrand Creeks as compared to Pepin and Fishtrap Creeks. Higher fecal coliform and E. coli concentrations typically take place during the wet season when soils are saturated or following significant rainfall events.

While the Bertrand Creek’s annual fecal coliform geometric mean increased due to high bacteria counts captured in winter 2018-2019, data trends in WA’s lower Fishtrap and Bertrand Creeks and in the Nooksack River mainstem show a decline in longer term fecal coliform concentrations since 2015.

The Nooksack River is the largest freshwater source to Portage Bay and to the Lummi Nation’s Portage Bay shellfish growing area. From 2014-2016, portions of the Portage Bay growing area experienced a series of harvest restrictions due to poor water quality conditions. By 2016, Washington State Department of Health had downgraded over 800 acres from Approved to Conditionally Approved. The Conditionally Approved portion was closed to shellfish harvest April-June and October-December each year. In 2019, due to water quality improvement, the spring harvest season was re-opened in the Conditionally Approved portion of the growing area. While harvest in the Conditionally Approved area is now allowed January through September, the area remains closed to harvest from October-December each year due to fall season elevated concentrations of fecal coliform bacteria in the marine water.

To reduce fecal bacteria pollution in the Nooksack watershed, BC and WA used multiple sampling methods to help identify potential pollution sources. Agencies acted on complaints, offering technical assistance and conducting regulatory compliance activities as appropriate. Both jurisdictions engaged agricultural and rural residential communities through non-regulatory outreach. The Nooksack River Transboundary Technical Collaboration Group (TCG) outreach subcommittee facilitated compliance promotion and shared event schedules and education materials.

A TCG subcommittee developed a recommendation for a short- and long-term E. coli concentration border benchmark. Monitoring in comparison to the short- and long-term benchmarks will be reported next year.

Based on successful first year project completion, the TCG recommends minor adaptations to the work plan for the coming year. Adjustments will help align tasks with funding developments and policy direction to improve efficiencies and communication.

Overall 2018-2019 water quality monitoring results are positive. Compliance, stewardship, and communications activities successfully reached key audiences and helped to address fecal bacteria pollution concerns. The TCG will continue to implement work plan tasks in 2019-2020.

Work for portions of this project conducted in Washington state was funded in part by the U.S. Environmental Protection Agency under assistance agreement PC-01J18001 to the Washington State Department of Health.

Download the full report and terms of reference