Staff Update to Board on Pesticide Testing in North Central Washington

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June 8, 2023

Note: The Board was recently asked for a public update on DDE testing in North Central Washington. At the June 7, 2023, Board meeting, Enforcement and Education Director Chandra Wax read from the information below.



I’m here to provide a situation update in reference to DDE contaminates found in cannabis and soil from several licensee locations in Eastern Washington. WAC 314-55-108 sets the action limit for DDE at .1 ppm. This action level was set by emergency rule in 2016 and permanent rule in 2017 through consultation with Department of Health, Department of Agriculture, and the Oregon Health Authority.


Between January and March of 2023, results from random samples collected by Enforcement and Education staff reflected positive results for DDE, a breakdown remnant of DDT. Seven 2023 results were above action limits (average .19ppm) and five results were positive but below action limits (average .0534ppm). Two additional results with DDE above action limit (.14ppm) were identified in September 2022.


The detections of DDE were traced back to the same area in North Central Washington. The identified area was defined as a five mile stretch of land along the south end of the Okanogan River and north of Lake Pateros. There are 18 licensees located in this area. Enforcement and Education Division staff sent an email to each of the 18 impacted licensees to inform them about the test results and the soil, water, and product testing that would occur.


There were five licensees with DDE above action limits and division staff called each of them on April 6, 2023, to tell them about the test results, educate them about the administrative hold that would be placed, request product records, and request a licensee-initiated recall. Afterward, the Liquor and Cannabis Board (LCB) communications team ensured a detailed message was shared with licensees, legislators from the area, local public officials, and stakeholders. At the same time, LCB staff met with our state-certified labs, impacted licensees, trade associations, and partner agencies to make sure we were being transparent and responsive.


Enforcement and Education Division staff sought out the advice of colleagues at the Departments of Ecology and Agriculture and we developed a plan to ensure there were not contaminants in the products available to the public. We also considered the lab capacity to conduct these tests and collected a number of samples that would be able to have results returned within a reasonable timeframe.


Soil and Water Sampling

On April 11, 2023, soil samples were collected. The soil samples report is not complete, but according to the Department of Ecology the levels of DDE/DDT and lead and arsenic in the soil samples are above state standards. Licensees will be notified and provided copies of the results when received.


The LCB has collected a total of 124 water and product samples from January 2023 to May 2023 from the impacted area. The LCB sought assistance from Ecology for soil samples, which were collected on April 11, 2023.


We have received results from the Dept. of Agriculture lab for 97 of those samples.

  • 54 Cannabis foliage samples
  • 40 Cannabis oil/rosin samples
  • 3 Water samples


66 of the 97 samples have DDE detections

  • 28 of those are cannabis foliage
  • 38 of those are cannabis oil/rosin


44 samples failed for DDE concentrations above action limit

  • 36 cannabis oil/rosin samples failed
  • 8 cannabis foliage samples failed


24 cannabis foliage samples may rise above action limit if concentrated (21 of those with DDE and 3 with other types of pesticides).


In the foliage samples, in addition to DDE, 10 other types of pesticides were detected, below action levels.


In the cannabis/oil samples, in addition to DDE, 17 other pesticides were detected and 23 of these samples had above action limits in the additional pesticides.

  • The highest concentration of DDE p,p’ so far is 1.7 ppm, in a cannabis oil/rosin sample.
  • The lowest concentration of DDE p,p’ so far is 0.018 ppm, in a cannabis foliage sample.
  • The average overall DDE concentration is 0.278 ppm.


We are still awaiting more test results.


Enforcement and Education Division Action Steps

As results from the collected concentrate and foliage samples are returned, the Enforcement and Education Division is taking the following actions:

  • If cannabis tested above action limit, an admin hold was retained and destruction will be pursued.

  • If cannabis tested positive for DDE but below action limit, the admin hold was lifted with regards to distribution, but the licensee was informed they cannot concentrate or extract the product without further testing.

  • If the cannabis did not reveal detectable levels of DDE, the admin hold on the product was lifted.

Of the five licensees with administrative holds, one hold has been lifted and four holds are currently still in place. Holds have also been lifted on the specific products with no detectable level of DDE. Holds have been lifted on product with DDE detected, but not above action limits, but further testing is required for moderate level results if the cannabis is extracted or concentrated. There is concern that the contaminants in the product will exceed action limits if further extracted or concentrated.


The LCB has been working with the Departments of Agriculture and Ecology to support their processes for funding awarded by the legislature for grants for farmers and a study to consider soil remediation.


We recognize the significant impact this has on licensees and the risk this poses to the public. We are acting responsibly, swiftly, and intentionally. Our goal is to ensure cannabis products are safe and licensees and stakeholders are informed as updates are available. We continue pesticide investigations statewide.


Additional Resources