Summer Water Quality sampling on Green Lake begins on May 3rd and continues through October 18th. Sampling is done approximately every two weeks, on either 12 Sundays, or 12 Monday mornings.
The King County Lake Stewardship Program provides sampling equipment, training, and support. The samples are collected at an anchored float located at the deepest part of the Lake, approximately in front of the Hearthstone residences. This year’s sampling will continue the sampling done by Friends of Green Lake volunteers from kayaks every summer since 2004. The resulting data were used to help evaluate the effectiveness of the 2004 Alum Treatment and plan for the 2016 Treatment.
Sampling is performed at an anchored buoy about 100 yards offshore, opposite Sunnyside Avenue, on the east side of the lake. Sampling has been done from kayaks, rowboats, and canoes and requires the sampling party to be comfortable and competent in a small boat. In the approximately 80 samplings performed by Garman and Fleming, on only one occasion did we delay sampling one day due to windy weather.
Sampling includes measuring water temperature, clarity with a Secchi Disk, and using a Van Dorn sampler to get a 1 liter water sample from 1 meter below the surface.
Friends of Green Lake members Gayle Garman and Richard Fleming take water samples and collect information on water conditions from two kayaks positioned side-by-side as part of the King County Lakes and Streams Monitoring Group (formerly Lake Stewarship Program).
Usually notes are also made about weather, the number of anglers and geese. Two times each summer, temperature and water samples are added at mid-depth and bottom, to get a profile of changes with depth. Sampling at the buoy takes about 15 to 30 minutes, depending upon whether one or three (for a profile) samples are being collected. Sample bottles and data sheets are left in a cooler at your location, and picked up by King County staff.
If you are interested, please email or phone Richard Fleming, President – Friends of Green Lake rsfleming@centurylink.net – or 206-525-1974. I will be unavailable by phone from March 25th to March 29th. Potential volunteers may also wish to visit the King County Small Lakes Stewardship website.