Nooksack river basin continuous nitrate monitoring

Science Center Objects

The issue: Learning more about where and how much nitrates there are in the Nooksack river

How USGS will help: Provide continuous nitrate concentration data at three locations. Provide validation
water samples analyzing for nitrate concentration. Compute nitrate load estimates
using stream discharge data coupled with newly collected nitrate concentration data.

Problem: The Nooksack River watershed comprises the majority of the Water Resources Inventory Area 1 (WRIA 1) located in
Whatcom County in Washington State. From its headwaters in the northwestern Cascade Mountains, the
Nooksack River drains approximately 809 square miles, comprising most of western Whatcom County, including agricultural
areas and the developed lowlands surrounding the towns of Deming, Everson, Lynden, and Ferndale. The Nooksack River
enters the Lummi Indian Reservation at its eastern extent, which contains the majority of the river delta before it discharges
into the marine waters of Bellingham Bay. The Nooksack River is also the primary source of freshwater into Portage Bay,
which is located approximately 5 miles southwest of the Nooksack River delta.
Nonpoint nutrient pollution is a growing water quality problem in the United States, particularly from mixed urban and
agricultural areas. The Nooksack River basin contains some of the most productive farmland in Washington State, as well as
a high rural residential population on septic systems, making it an ideal location to study temporal and spatial dynamics of
nutrient delivery to surface water. The Portage Bay Partnership, a collaboration between Whatcom County dairy farmers
and the Lummi Nation to improve water quality in the basin, was formed in 2017 to primarily address bacterial pollution in
surface water.


  1. Collect 15 minute nitrate data at the three sites, calibrated to monthly discrete water
    samples analyzed for nutrients for up to 2 years.
  2. Use existing flow data from USGS gages to estimate loads of nitrates.