Skip to main content

OLYMPUS DIGITAL CAMERAThe County’s Environmental Lab monitors water quality at stations spread throughout central Puget Sound year round, rain or shine. The SoundGuardian research vessel makes separate north and south runs twice every month except January and December, when one set of runs occurs.

Lab crews sample water quality at the outfalls extending from wastewater treatment facilities and at control points away from those locations. When the Lab’s Trouble Call phone rings, they jump into action to investigate environmental emergencies like spills, illegal dumping, toxic algae blooms, fish kills, and beach erosion.

The SoundGuardian and her crew were called out for marine monitoring after a Feb. 9, 2017 storm damaged the West Point Treatment Plant and resulted in emergency bypass. Expanded weekly marine monitoring is ongoing as the plant is repaired.


Marine monitoring is increased during restoration of West Point Treatment Plant, with weekly monitoring of stations around West Point.

Wastewater Treatment Division (WTD) employees traveled with laboratory staff on marine runs in Dec. 2016 to watch the sampling effort that provides such valuable data for decision makers throughout the region. We got a taste of the range of conditions they experience: one day blustery and rough, powering through wind-driven waves on a flood tide, and the next run in the sun on calm waters.


Bob Window Look2Safety is key on the boat. Everyone’s personal floatation device is checked.  Environmental scientist Bob Kruger conducts a safety briefing and provides instructions on where people can stand and what directions to follow during the boat run.

On the rough weather day, Bob told passengers to lean over the rail if the waves got the better of our stomachs.

Designed to work all year long

beamseagraphicKing County’s SoundGuardian research vessel is designed and equipped so crews can continue sampling even on tough weather days. The catamaran hull is more stable in conditions where waves approach the side of the boat (sailors call this “beam sea”). The SoundGuardian uses water jet propulsion, which creates increased maneuverability over propeller driven vessels like its predecessor, the Liberty.

Jim Morning Data1

Skipper Jim Devereaux says, “We’ve been able to go out safely in weather that would have turned the old Liberty around and sent us back to the dock.”

Jim shows us how automated information system equipment translates a ship’s signal into valuable information about its size, position, and speed. We see a ship show up on the chart plotter well before the aptly nicknamed “Darth Freighter” appears:  a hulking, dark seagoing ship suddenly emerging from the fog. The kayakers onboard just shuddered.


The average ocean-going freighter is 20 times larger than the SoundGuardian.

Sampling the Sound

The main purpose for marine monitoring runs is to gather water quality information around King County WTD’s treatment plant outfalls- both regional plants and CSO treatment plants. The SoundGuardian samples at control points well away from the County’s outfalls to set a starting point for comparing data.  On the north run, the ambient station is Point Jefferson, the deepest point of Puget Sound, at a depth of 286 meters.  On the south run, it is between Blake Island and Point Williams.

At monitoring stations, field scientists from the lab lower a device that measures different aspects of water health called a Conductivity/Temperature/Depth (CTD) multi-sensor array. The CTD array collects water quality measurements 16 times a second as it is lowered through the water column from the surface to the bottom and back up again.  This generates a profile of the entire water column.

IMG_6322The high-tech array also collects samples for laboratory analysis of other useful information, like nutrients and phytoplankton (microscopic marine algae). The sensor array is deployed on a round metal frame that also holds 12 sampling bottles. As the CTD is brought back up, it triggers the closure of sample bottles at pre-programmed depths in the water column.

Once the CTD is lifted back onto the deck, scientists begin well-practiced moves to remove and sort samples, preserving some for later analysis, and then get ready for the next monitoring site. The team knows what needs to be done and by whom, and they move around the boat in a choreographed dance.

Crew Work8

In early 2017, a valuable feature was added to the CTD: real-time streaming data and real time control that allows scientists to capture a sample when the array detects an anomaly in the water column – in other words, when it detects something that is different from what is normal or expected.  The crew sees that an extra sample has been gathered for investigation.

A reputation for excellence

While consistency sounds like a dull virtue, data consistency is critical to detect environmental changes. The County’s Environmental Lab has been making these boat runs, sampling waters and analyzing those samples since the 1960’s, and ramping up in the 1970’s. Decades of data help document seasonal variations and help scientists establish long term patterns for comparisons.

Precision and accuracy also matter. The Environmental Lab is well known for reliable data that results from rigorous protocols for preparing equipment, collecting data, and handling samples. Technical staff follows different procedures for sampling and analyzing water quality, sediment, and biological components, but they follow all procedures the same way every time.

“King County is widely recognized for producing high quality data,” says Dr. Julie Keister of the University of Washington.

“It really helps our understanding of Puget Sound to have continuity in samples over a long period of time.”

Dr. Julie Keister, University of Washington


The County makes the Lab’s reliable, high quality data available to help inform management decisions about actions to maintain and improve the health of our waters. The Water and Land Resource Division’s Marine Monitoring Program provides a wealth of information about sampling methods and data to help other agencies, studies and projects.

King County’s Environmental Lab has long been a model of efficiency, solid data collection, partnerships, and data sharing. Dedicated crews carry out high quality work in all sorts of conditions, illustrating King County’s commitment to water quality all year long, every year.

Over two days in December, we got to watch this commitment in action on marine monitoring runs, rain and shine.

Oh, and in case you’re wondering, no one on board that rough, windy day needed to use the rail.

Watch the Environmental Lab at work:




Monica works as a Community Services Planner in King County Department of Resources and Parks, Wastewater Treatment Division.

%d bloggers like this: