Washington state lifts growing restrictions on 4 marijuana farms

Be at the forefront of cannabis and psychedelics science and innovation. Register today & Save $200 on tickets to The Emerald Conference by MJBiz Science, April 1-3 in San Diego.


Washington state regulators have lifted restrictions against four licensed cultivators that have been prohibited from growing marijuana since April for pesticide contaminations.

According to the Associated Press, the state’s Liquor and Cannabis Board (LCB) recently lifted the “administrative hold” against the operators in the north-central area of the state where random testing earlier this year detected the chemical compound DDE.

DDE is created by the breakdown of the now-banned pesticide DDT.

The north-central area was once home to fruit orchards, where DDT was used decades ago.

During initial testing, 18 cannabis cultivation licensees were located in a “five mile stretch of land along the south end of the Okanogan River and north of Lake Pateros,” with known DDE contamination, the LCB confirmed at a June meeting.

The regulators in June began lifting restrictions against some cultivation operations and cannabis products after deeming DDE levels were “not above action limits.”

The LCB provided testing results earlier this month on 108 samples:

  • 61 samples failed with results above 0.1 action limit for DDE (56%).
  • 47 passed with results below 0.1 action limit for DDE (44%).

Going forward, the LCB’s Enforcement and Education Division staff will conduct quarterly testing to ensure product safety, the agency said.

The LCB has posted a map of cannabis pesticide testing results online.