Is My Well Water Safe During Weed Treatments?
The quick answer is yes; wells are safe and unaffected by our planned lake weed treatments. The OLMD weed treatments follow all state and local guidelines and are performed by our licensed contractor (Aquatechnex).
Wells draw water from the aquifer, not from the lake. To draw water from the lake a property owner must apply for and receive permission from the State (LINK). To our knowledge no property owner has a permit to use lake water for domestic use (drinking, bathing, etc.). Those with a permit to use lake water for irrigation should know that there are no irrigation restrictions for the two herbicides that will be used for weed treatments on Offut Lake. Those two herbicides are Aquathol K and ClearCast and are listed on the Treatment Notice (LINK).
Offut Lake Management District, along with the other LMDs in Thurston County applied for and received a permit for aquatic plant and algae management. The permit’s acronym is APAM and that stands for Aquatic Plant and Algae Management General Permit. The effective date of this permit was March 20, 2026, and it expires on March 20, 2031. Here is a LINK for that permit.
Before issuing the APAM, the County is required to review water rights when considering the APAM application. “Water rights” refers to using surface water via an intake pulling directly from the lake. Remember, this is different from a well which provides water from an aquifer. The APAM ensures that our LMD is in compliance with all State and County environmental, safety and health requirements.
