New Information May Change NHDES Proposed PFAS Drinking Water Standards

New Information May Change NHDES Proposed PFAS Drinking Water Standards

On December 31, 2018, the New Hampshire Department of Environmental Services (NHDES) initiated rulemaking to establish Maximum Contaminant Levels (MCLs) and Ambient Groundwater Quality Standards (AGQS) for four per- and polyfluoroalkyl substances (PFAS) – perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA) and perfluorohexanesulfonic acid (PFHxS).

After the initial proposal, new scientific information was evaluated by NHDES that may change the proposed drinking water standards. Specifically, a new assessment tool developed by the Minnesota Department of Health allows for a quantitative estimate of infant and child exposure to PFAS through breastmilk and/or formula. This peer-reviewed model was published at the beginning of January after NHDES filed its Initial Proposal. NHDES’s assessment of the exposure model for the interaction of drinking water levels of PFAS and breastfeeding (Goeden et al, 2019) indicates that health-based drinking water or groundwater standards for PFOA and PFOS would potentially be lowered significantly below the initial proposal figures of 38 parts per trillion (ppt) and 70 ppt, respectively. NHDES is continuing to review the suitability of this assessment tool for PFHxS and PFNA based on this and other studies released in 2019. NHDES will need to complete a review of the technical and cost implications of these health-based calculations, and any public comment received, prior to issuance of the Final Proposal.

NHDES feels that it is important to release this information prior to the upcoming PFAS public hearings, so that there is plenty of time for people and organizations to examine this model and its use while developing their comments.

The Rule Making Notice/Initial Proposal packages for the amendments to Env-Dw 700-800, Env-Or 603.03, and Env-Wq 402 are available on-line at:

Public Hearing Dates:

Monday, March 4, 2019, 5:30 PM; All Purpose Room, James Mastricola Upper Elementary School, Merrimack, NH

Tuesday, March 5, 2019, 1:00 PM; Auditorium, DES Offices, 29 Hazen Drive, Concord NH

Tuesday, March 12, 2019, 5:30 PM; NHDES Pease Field Office, Room A, 222 International Drive, Suite 175, Portsmouth, NH

You may submit written comments even if you do not attend a public hearing.

LAST DAY TO FILE WRITTEN COMMENTS: Friday, April 12, 2019 (4:00 PM)

 For Drinking Water Standards (MCLs) (Env-Dw 700-800) – Submit comments to:  Chip Mackey (, DWGB Drinking Water Quality Manager

For Ambient Groundwater Quality Standards (AGQS) (Env-Or 603.03) – Submit comments to: Lea Anne Atwell (, Haz. Waste Remediation Bureau, Emerging Contaminants Coordinator

For Discharges to Groundwater of Wastewater Containing Certain Perfluorochemicals (Env-Wq 402) – Submit comments to: Stephen Roy (, DWGB Technical Section Manager, Groundwater Permitting

(Primary reference: Goeden et al. 2019. A transgenerational toxicokinetic model and its use in derivation of Minnesota PFOA water guidance. Journal of Exposure Science & Environmental Epidemiology. vol 29, pages 183–195. )


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