In 2020, Friends of Skagit Beaches started a citizens science project focused on understanding the types and volume of pollution that the City of Anacortes municipal separate storm sewer system (MS4) empties into the Salish Sea. About twenty volunteers make measurements at 44 of the city’s stormwater outfalls once per month for water quality. An outfall is a point where stormwater (freshwater) meets the Salish Sea.

On this website, summaries of our data are represented by a number of charts and maps. Each month these graphics will be updated with the latest measurement data from our volunteers.

Besides the basic data, we collect at the site, e.g. volunteer names, day/time, weather, flow characteristics, etc., we record measurements using one of our two professional water quality measuring instruments (YSI Pro Plus). When the volunteers visit their assigned outfalls once each month, they collect stormwater samples which they use with the meter’s probe and for subsequent analysis back at the stormwater lab (turbidity).

Our project measures for the five parameters below:

ParameterState ThresholdMust Be…Indicates…
Water temperature compared to air temperature< 3 degrees C.less than 3 degrees C (5.5 degrees F) then good.a possible unsafe chemical reaction or illicit discharge
< 500 uS/cm

If below 500 uS/cm then good.
a possible presence of chemicals in the stormwater, like fertilizers.
pH> 5 or < 9If greater than 5 but less than pH 9 then goodwhether stormwater is too acidic or alkali for marine habitat. Just like people, marine life preferes pH neutral water (pH 7).
Dissolved Oxygen
> 6 mg/L
above 6 is goodsufficiency of oxygen bubbles in the stormwater. Low oxygen levels do not support marine life.
< 50 NTU
below 50 is good
the quantity of suspended solids in stormwater. Too much turbidity hinders fish reproduction.