On Friday, June 21, 2019, the Wisconsin Department of Health Services (WDHS) recommended new or updated NR 140 groundwater quality standards for 27 groundwater contaminants. WDHS’s recommendations include very restrictive standards for combined perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), two major PFAS compounds.
WDHS’s recommendations include standards for the popular and heavily used herbicide glyphosate and other agricultural chemicals. The agency also proposed adopting the federal drinking water standard for E. coli as a state groundwater quality standard.
This is the first step in a lengthy state rulemaking process that must be completed by the Wisconsin Department of Natural Resources (WDNR) before these standards can be finalized and made enforceable. These standards can be changed during this rulemaking process.
If established by rule, the recommended standards for combined PFOA and PFOS would place Wisconsin’s standards among the most restrictive—if not the most restrictive—standards in the country.
WDHS recommended a combined Enforcement Standard of 20 nanograms/Liter (ng/L), equal to 20 parts per trillion (ppt) of PFOA and PFOS. WDHS recommended a Preventative Action Limit (PAL) of just 2 ng/L, 10 percent of the Enforcement Standard, citing “carcinogenic, teratogenic, and interactive effects,” of PFOA and PFOS.
The Enforcement Standard of 20 ng/L is well-below EPA’s health advisory level and Preliminary Remediation Goal of 70 ng/L (70 ppt). The 20 ng/L level for combined PFOA and PFOS would put Wisconsin on similar footing with Vermont, which enforces a 20 ppt standard for combined PFAS. Closer to the Midwest, Minnesota has adopted health-based guidance values of 35 ppt for PFOA and 27 ppt for PFOS. Michigan has adopted a state standard for combined PFOA and PFAS of 70 ppt.
NR 140 groundwater quality standards (both Enforcement Standards and PALs) are used to direct state agency regulatory efforts, including standards for environmental remediation and cleanup, authorized discharges of treated liquid and solid waste, use of approved agricultural chemicals, landfill regulation, and beneficial use of industrial byproducts, eligibility for private water supply grants, and bottled drinking water.
PALs can be thought of as “trigger points,” designed to inform state regulators of potential groundwater contamination problems, establish groundwater contamination levels at which agencies must consider the need for efforts to control contamination, and to provide a basis for design and management practices established in state administrative rules. As such, PALs are more than “screening levels”; compliance with PALs is required wherever technically and economically feasible, and state agencies have discretionary authority to require response actions when a PAL exceedance is observed at a regulated “point of standards application.”
While NR 140 groundwater standards are intended to protect the quality of the state’s groundwater for consumptive uses, they are not themselves drinking water standards. A WDNR official has indicated the agency may establish such limits in the future.
Glyphosate and Other Agricultural Chemicals
Among the 27 substances for which the state recommended groundwater standards were several common agricultural herbicides and insecticides, including the widely used herbicide glyphosate (trade name Roundup®).
WDHS recommended an Enforcement Standard of 10 milligrams/Liter (mg/L) for both glyphosate and aminomethylphosphonic acid (AMPA), the major breakdown product of glyphosate. It recommended a PAL of 1 mg/L for glyphosate and 2 mg/L for AMPA.
WDHS also recommended standards for three neonictinoid insecticides (clothianidin, imidacloprid, thiamethoxam), two other herbicides (sulfentrazone, isoxaflutole), and several other herbicide breakdown products (dacthal MTP, dacthal TPA, isoxaflutole DKN).
Wisconsin currently has a groundwater Enforcement Standard of zero for bacteria as total coliform. WDHS also recommends an additional NR 140 standard for bacteria using E. coli, a subset of total coliform, as the microbial indicator. WDHS recommends a standard of zero for bacteria as E. coli. This standard is consistent with EPA’s drinking water standard, or Maximum Contaminant Level (MCL), for E. coli.
The addition of E. coli as a microbial indicator for bacteria provides WDNR with an additional basis (in addition to total coliform) for requiring response actions to minimize groundwater impacts associated with fecal contamination.
State law requires WDNR to propose a rule establishing WDHS’s recommendations as rule, commencing a lengthy rulemaking process under state law that would make the standards legally enforceable.
“With the new DHS recommendations in hand, DNR will begin rulemaking immediately. However, given the multiple steps in the rule making process it may take up to 30 months to promulgate the amendments to ch. NR 140,” WDNR Secretary-designee Preston Cole said in a statement Friday.
WDNR expects to begin the rule drafting process this fall and continuing through spring 2020. The rulemaking process will also include the preparation of an economic impact analysis and public hearings. Any rule adopted by the WDNR Board would be subject to legislative review.