---
title: Maryland Proposes PFAS Limits for Drinking Water; About 150 Water Systems Are Over Them, MDE Says
canonical: https://marylandfeed.com/maryland-pfas-drinking-water-limits-proposed/
published: '2026-10-30T12:00:00-04:00'
updated: '2026-10-30T12:00:00-04:00'
author: MarylandFeed Staff
section: Water & Sewage
tags:
- Drinking Water
- Regulations
- Water Quality
- Department of the Environment
source: U
source_url: https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas
publisher: MarylandFeed
attribution: Copyright MarylandFeed. Quote with credit to MarylandFeed and a link to the canonical URL above.
---

# Maryland Proposes PFAS Limits for Drinking Water; About 150 Water Systems Are Over Them, MDE Says

Maryland is proposing its own limits on PFAS, the long-lasting “forever chemicals,” in public drinking water, and the state’s environment department estimates that about 150 water systems now have levels above them. Bringing those systems into line would cost about $150 million in treatment upgrades and would improve water quality for about 182,000 Marylanders, the department says.

The Maryland Department of the Environment (MDE) published the proposal in the Oct. 30 [Maryland Register](https://dsd.maryland.gov/MDRIssues/5322/Assembled.aspx) (Vol. 53, Issue 22, proposed action 26-124-P, page 1129). The public can comment through Nov. 30. “A public hearing has not been scheduled,” the notice says.

According to MDE’s estimate of economic impact, “approximately 950 water systems in Maryland will need to comply with this regulation, and of these, approximately 15 percent have PFAS concentrations that exceed the standard.” Elsewhere in the same notice, MDE says treatment costs “will be paid by the approximately 150 water systems above the MCL,” or maximum contaminant level: about 50 owned by local governments and 100 privately owned systems, which the notice says “will need to operate new PFAS treatment systems in 2029.”

![MDE's estimate of the proposal's PFAS costs and reach.](https://marylandfeed.com/media/2026/10/92044648-shot-pfas-economic-impact-1200.jpg)

MDE's estimate of the proposal's PFAS costs and reach. Source: [Maryland Register](https://dsd.maryland.gov/MDRIssues/5322/Assembled.aspx), Vol. 53, Issue 22 (Oct. 30, 2026), proposed action 26-124-P, 53:22 Md. R. 1129, Estimate of Economic Impact (excerpt).

## Who pays

MDE puts the capital cost of upgrading treatment plants at approximately $150,000,000 and says the money “will mainly come from federal grants, administered by the State.” Ongoing costs are estimated at $5,000,000 a year, $1,000,000 for sampling and analysis and $4,000,000 for treatment, and those costs “will be transferred to ratepayers,” the notice says. MDE estimates sampling at $1,000 a year per system.

The rule covers community water systems, which serve year-round residents, and non-transient non-community systems, which MDE says include schools and offices. It does not cover private wells: MDE’s [PFAS page](https://mde.maryland.gov/programs/water/water_supply/Pages/PFAS_Home.aspx) says private wells are not regulated under the Safe Drinking Water Act and that testing them is the homeowner’s responsibility.

## What PFAS are

PFAS (per- and polyfluoroalkyl substances) are “a group of man-made chemicals that include PFOA, PFOS, PFHxS, GenX, and many other chemical compounds,” according to MDE. They “are persistent in the environment and the human body, meaning they do not break down easily and can accumulate over time,” MDE says. The U.S. Environmental Protection Agency [says](https://www.epa.gov/pfas/pfas-explained) that “exposure to some PFAS in the environment may be linked to harmful health effects in humans and animals.”

## The limits Maryland would adopt

MDE says its standards would be “identical to federal regulations” and are “based on the 2024 federal rule.” The state text does not restate the numbers; it requires water systems to meet the limits in a section of federal law (40 CFR 141.61(c)(2)) in the July 1, 2026, edition of the federal code. That section, in the [current federal code](https://www.ecfr.gov/current/title-40/chapter-I/subchapter-D/part-141/subpart-G/section-141.61), sets the limits shown below, which EPA expresses in parts per trillion (ppt) on its [rule page](https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas). The Hazard Index is a combined score for mixtures of two or more of PFHxS, PFNA, HFPO-DA and PFBS. “A Hazard Index greater than 1 requires a system to take action,” the Maryland proposal says.

![The enforceable limits (MCLs) are in the right column; the middle column lists EPA’s non-enforceable health goals.](https://marylandfeed.com/media/2026/10/bff50cbc-shot-epa-pfas-mcl-table-1132.jpg)

The enforceable limits (MCLs) are in the right column; the middle column lists EPA’s non-enforceable health goals. Source: U.S. Environmental Protection Agency, [Per- and Polyfluoroalkyl Substances (PFAS) rule page](https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas), Rule Summary table, last updated May 18, 2026.

Under the proposal, systems operating by April 26, 2027, must meet the limits “by April 26, 2029.” MDE says systems must finish initial monitoring by April 2027, and “in April 2029, staff will begin enforcing compliance with the PFAS maximum contaminant levels.”

## The federal rule is being rewritten

Maryland is adopting the 2024 limits while EPA proposes to change them. In two proposals published in the Federal Register on May 20, 2026, EPA would [rescind the limits](https://www.federalregister.gov/documents/2026/05/20/2026-10085/rescission-of-regulatory-determinations-and-removal-of-related-provisions-for-four-pfas-substances) for PFHxS, PFNA, HFPO-DA and the Hazard Index mixture, and keep the PFOA and PFOS limits while letting systems that ask for it [extend the compliance date](https://www.federalregister.gov/documents/2026/05/20/2026-10086/extending-the-compliance-deadline-for-the-pfoa-and-pfos-maximum-contaminant-levels) from April 26, 2029, to April 26, 2031. Public comments on both closed July 20. The online federal code, current through Oct. 28, still lists all six limits.

Maryland Attorney General Anthony G. Brown [filed comments opposing](https://oag.maryland.gov/News/pages/Attorney-General-Brown-Opposes-the-EPA%E2%80%99s-Rollback-of-PFAS-Limits-in-Drinking-Water--.aspx) the rollback of the four limits, his office said July 22. MDE’s notice says: “If the federal PFAS drinking water rule is amended, it is MDE’s intent to adopt the updated rule consistent with State law.”

## Lead pipes and water reports, too

The same proposal adopts EPA’s revised lead and copper rules for all 462 community and 545 non-transient non-community systems in Maryland, including service line inventories and replacement of lead lines. MDE estimates replacement at $3,500 to $6,500 per line and the lead changes at $34,000 to $44,000 a year per system on average. It also adopts EPA’s revised rule for the annual water quality reports utilities send customers, which adds translations for some communities and twice-a-year reports for the 30 systems with over 10,000 customers.

## Check your system and comment

MDE’s [five-year PFAS study](https://mde.maryland.gov/programs/water/water_supply/SiteAssets/Pages/PFAS_Home/PFASSummaryReport.pdf) of public water systems, completed in 2025, analyzed 1,880 samples from 877 systems; 20.2% of samples had at least one PFAS above a federal limit or a Hazard Index above 1 (page 8). Sampling results are on MDE’s [interactive map](https://marylanddepartmentoftheenvironment.shinyapps.io/MDE_PFAS_PublicWaterSystemStudyMap/). WSSC Water, which serves most of Montgomery and Prince George’s counties, already meets the federal standard, and its capital plan budgets $297.86 million for PFAS treatment, Moderately MOCO [reported](https://moderatelymoco.com/wssc-pfas-pilot-potomac-plant-298-million/).

Comments on the proposal may be sent to Chris Watling, Chief, Safe Drinking Water Act Implementation Division, MDE, 1800 Washington Blvd, Baltimore, MD 21230, or by email to [chris.watling@maryland.gov](mailto:chris.watling@maryland.gov), through Nov. 30, 2026. The notice also lists a phone number, 410-537-3577.

Source: [U](https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas)