A couple of North Sound treaty tribes are sampling water quality at popular reservation beaches to make sure they’re safe for people to use.
The Tulalip Tribes partnered with Washington State University Beach Watchers to sample Mission Beach and found bacteria levels to be below the threshold for swimming.
“Since this is our first year, we can’t draw any patterns yet from the data,” said Val Streeter, Tulalip water resources planner. “Bacteria levels vary quite a bit in water. Samples taken minutes apart at the same location can have different levels of bacteria. Over a period of years, patterns will emerge that can be used to shed light on seasonal differences versus potential bacteria sources.”
On the Swinomish Reservation, sampling at beaches near the fishing docks, Snee-Oosh Road and Lone Tree Point also found bacteria levels low enough to be safe.
Swinomish’s Department of Environmental Protection has begun a long-term sampling effort at the three beaches with plans to develop a predictive model. Water resources technician Jason Thompson sampled the beaches five times a month throughout the summer and will continue to monitor water quality once a month off season.
The water samples are tested for Enterococci, a group of bacteria that may indicate the presence of fecal coliform and viruses that can cause gastrointestinal illness.
In addition to testing water samples for bacteria, Thompson measured depth, salinity, dissolved oxygen and wave height.
“Bacteria can be harbored in sand,” he said. “Wave energy can stir it up by moving the sediment.”
He also documented the number of people using the beach to see how increased activity affects water quality.
After a year of data has been collected, the department can develop a model. Following another year of verifying the model’s predictions, the tribe will be able to issue health advisories should bacteria levels make it unsafe for people to swim or play at the beach.
