On Friday afternoon March 22, 2019, the Maine Department of Environmental Protection (DEP) announced in a memorandum to licensed facilities that land apply, compost, or process biosolids (i.e., wastewater treatment sludge) that it will require the testing of that material for per- and polyfluoroalkyl substances (PFAS), a group of chemicals that includes PFOA, PFOS, PFBS, and many other compounds. Given that these compounds are ubiquitous, and that land application of biosolids or composted biosolids as a soil amendment has been a common and long-standing practice in Maine and elsewhere, the aggressive new testing requirement is likely to have far-reaching effects.

All biosolids/sludge program licensees and biosolids/sludge composting facilities are now directed to test their material for PFOA, PFOS, and PFBS, and to update their Sampling and Analytical Work Plan (SAWP) to include sampling and analysis for these compounds, before any additional land application of these materials. DEP recommends that these facilities update their SAWP consistent with DEP’s PFAS sampling guidance (Attachment 1 to DEP’s memorandum). An updated SAWP must be submitted for DEP review and approval by April 12, 2019, and all initial sampling must be conducted by May 7, 2019. Once results are obtained, biosolids/sludge and biosolids/sludge-derived compost must not be land applied if the screening standards for these three PFAS compounds in Chapter 418, Appendix A (PFOA—.0025 mg/kg, PFOS—.0052 mg/kg, or PFBS—1.9 mg/kg) are exceeded, unless and until DEP approves resumption of land application. For facilities whose biosolids exceed these PFAS screening standards, the DEP will want to engage the licensee in further discussions about proper management of these biosolids.

Last Friday afternoon’s DEP action follows on the heels of Governor Mills’ March 6, 2019, Executive Order reported here, announcing the establishment of a task force to investigate the threats of PFAS contamination to public health and the environment. DEP’s action concerning land application of biosolids containing PFAS above specific thresholds demonstrates that DEP is not waiting for the task force to complete its work before taking steps the agency deems are necessary to protect public health and the environment. In taking Friday’s action, DEP Commissioner Jerry Reid stated, “The Department is moving forward with the additional testing requirement to ensure that any future land applications of sludge are safe.”