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 The bottles in this ice chest contain water samples taken at different locations and different depths in lakes Washington, Sammamish and Union. All sample bottles are prewashed and labeled at the laboratory. Sampling procedures include completing a field sheet for each day of sampling, immediately storing samples on ice, and transporting samples back to the lab within six hours of collection. Lab samples are identified by unique laboratory numbers, and logged into the Laboratory Information Management System by the laboratory sample management specialist. Laboratory analytical procedures follow US EPA approved methods. These methods provide detection limits that are below the federal and state regulatory criteria or guidelines to enable direct comparison with those criteria.
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 Physical water quality data is collected with a multi-parameter probe called a Hydrolab. Contained in the probe unit are several individual probes that measure depth, pH, dissolved oxygen, turbidity (how clear the water is), and conductivity. The probe is lowered into the water on a calibrated cable to take readings from 1 meter below the surface to just above the bottom of the lake. Field meters are calibrated in the laboratory prior to every sample run using standard solutions. Ten percent of all samples are obtained with randomly chosen field replicates, which are used to provide an estimate of the total precision of the measurement.
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 This is Jeff Droker, one of the scientists at the Environmental Laboratory. He is using a Hydrolab probe to collect water quality data. The readings collected at the various depths by the probe are displayed on a screen and stored in this portable data logger (blue box). Each set of readings is annotated with information on the sample location and depth. The information stored in the data logger is down loaded to personal computers at the lab and transferred to the Laboratory Information Management System.
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 Niskin bottles are used for collecting water at specific depths. The bottles are lowered into the water on a wire cable to the specified sampling depth. A messenger is then sent down the wire to quickly close the top and bottom of the bottles, trapping water inside the bottles. The bottles are then brought to the surface where the water is let out through a plastic tube into other sample collection bottles.
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 Here is the messenger that closes the top and bottom of the Niskin bottles. It is about 3 inches tall, is made of metal and weighs 1 pound. Without this little piece of equipment, water samples could not be collected! |
 This is Brian Mazikowski, another scientist at the Environmental Lab, getting a Niskin bottle ready to collect water. The hydraulic crane lowers the wire cable and the attached bottles into the water to the desired depth. This water collection system is used both in fresh water and salt water. The Niskin bottles are thoroughly rinsed before and after each sampling. |
 These Niskin bottles are full of water and ready to be sampled from. Water leaves the Niskin bottles thru a plastic tube, and the flow of this water is controlled by a valve on the Niskin bottle. |
 Scientists are removing water from the Niskin bottles and filling other collection bottles. Specific types of bottles are filled with specific amounts of water and preservatives for the various analytical tests. The water samples are measured for parameters such as concentrations of chlorophyll-a, nitrogen, phosphorous, and fecal coliform bacteria. |
 Transparency, or the clarity of the water, is measured by lowering a black and white metal disk, called a Secchi disk, into the water. The depth at which the disk is no longer visible is referred to as the Secchi depth and is used to determine the clarity of the water. Secchi depths in the lakes during the summer are typically around 3 to 5 meters. |
 The secchi disk is barely visible, so it is almost at the secchi depth. |
 The secchi disk is no longer visible! |
 The Environmental Laboratory is certified by the Washington State Department of Ecology and participates in audits and inter-laboratory studies by Ecology and US EPA. These performance and system audits have verified the adequacy of the laboratory standard operating procedures which include preventative maintenance and data reduction procedures. These procedures include duplicates (relative percent difference); spikes (percent recovery); QC checks (percent recovery); and blanks. The laboratory is located in the Fremont area of Seattle on the Ship Canal. The lab's research ship, the RV Liberty, is stationed at the lab and is used for sampling on the lakes and Puget Sound. Two other crafts are also available for additional sampling on the lakes. |
