State-by-State PFAS Drinking Water Standards Comparison
Comparison of PFAS drinking water standards across all 50 states and federal MCLs. PFOA, PFOS, and other PFAS compounds. Updated March 2026.
Overview
There is no single national PFAS drinking water standard that all states follow. The federal government established Maximum Contaminant Levels (MCLs) for PFOA and PFOS at 4 parts per trillion (ppt) in April 2024, but many states had already adopted their own standards - some more restrictive, some less, and some using entirely different approaches.
This page compiles the current drinking water standards, guidance values, and action levels for PFAS (Per- and Polyfluoroalkyl Substances) across all states that have established numeric values, alongside the federal MCLs. It is intended as a reference for environmental consultants, water system operators, attorneys, and property professionals who need to quickly identify which PFAS standards apply in a given state.
This page was last reviewed March 2026. PFAS regulations are changing rapidly at both the state and federal level. Check the linked source documents for the most current values.
Federal Standards
The federal PFAS drinking water rule (finalized April 2024) established MCLs for six PFAS compounds. As of March 2026, the status is:
Still in effect:
- PFOA: 4 ppt (MCL). MCLG (Maximum Contaminant Level Goal) = 0.
- PFOS: 4 ppt (MCL). MCLG = 0.
- Compliance deadline extended from 2029 to 2031.
Being rescinded:
- PFHxS (Perfluorohexanesulfonic acid): 10 ppt MCL - EPA intends to rescind
- PFNA (Perfluorononanoic acid): 10 ppt MCL - EPA intends to rescind
- HFPO-DA/GenX (Hexafluoropropylene oxide dimer acid): 10 ppt MCL - EPA intends to rescind
- Hazard Index for mixtures of PFHxS + PFNA + GenX + PFBS - EPA intends to rescind
The D.C. Circuit denied EPA’s request to immediately vacate the PFHxS/PFNA/GenX/PFBS standards in January 2026. EPA stated in February 2026 it will “commence the rulemaking process imminently” to rescind them. These standards remain technically in effect but their future is uncertain.
For more detail, see our PFAS MCL Status 2026 blog post.
How to Read the Comparison Table
Type describes the legal weight of the standard:
- MCL - Maximum Contaminant Level. Legally enforceable. Public water systems must comply.
- Guidance - Health advisory, action level, or screening value. Not legally enforceable but may trigger investigation, notification, or voluntary action.
- Notification - A level that triggers public notification or reporting requirements but may not require treatment.
- Interim Standard - Enforceable standard adopted on a temporary basis while permanent rulemaking is underway.
- Forthcoming MCL - State has enacted legislation or begun rulemaking to establish enforceable MCLs.
Combined vs. Individual - Some states set standards for individual PFAS compounds (e.g., Michigan: PFOA at 8 ppt, PFOS at 16 ppt). Others set a combined standard for the sum of multiple PFAS compounds (e.g., Massachusetts: 20 ppt for the sum of 6 PFAS). Combined standards are generally more restrictive in practice because a site with multiple PFAS present will hit the combined limit faster.
ppt = parts per trillion, equivalent to nanograms per liter (ng/L).
PFAS Drinking Water Standards by State
States with no values listed below have not established state-specific PFAS drinking water standards as of March 2026. These states default to the federal MCLs where applicable.
| State | PFOA (ppt) | PFOS (ppt) | Type | Other PFAS | Notes |
|---|---|---|---|---|---|
| Federal (EPA) | 4 | 4 | MCL | PFHxS, PFNA, GenX (being rescinded) | Compliance deadline 2031 |
| Alaska | 70 combined | 70 combined | Guidance | PFNA, PFHxS, PFHpA | Sum of 5 PFAS |
| California | 4 | 4 | Notification | PFHxS (3), PFBS (500) | Not enforceable MCLs |
| Colorado | 70 combined | 70 combined | Guidance | PFNA; PFHxS (700) | Translation levels |
| Connecticut | 16 | 10 | Action Level | PFNA (12), GenX (19), PFHxS (49) | Triggers notification |
| Delaware | 4 | 4 | Forthcoming MCL | PFHxS, PFNA, GenX (10 each) | Adopting federal MCLs |
| Hawaii | 4 | 4 | Guidance | 24 additional PFAS compounds | Environmental action levels |
| Illinois | 4 | 4 | Guidance | PFNA, GenX, PFHxS (10 each) | Adopted federal values |
| Maine | 20 combined | 20 combined | Interim Standard | PFHxS, PFNA, PFHpA, PFDA | Sum of 6 PFAS |
| Massachusetts | 20 combined | 20 combined | MCL | PFHxS, PFNA, PFHpA, PFDA | Sum of 6 PFAS |
| Michigan | 8 | 16 | MCL | PFNA (6), PFHxS (51) | Individual MCLs |
| Minnesota | 0.0079 | 2.3 | Guidance | PFHxS (47) | Health-based values |
| Nevada | 4 | 4 | MCL (federal) | - | Follows federal MCLs |
| New Hampshire | 12 | 15 | MCL | PFNA (11), PFHxS (18) | Enforceable |
| New Jersey | 14 | 13 | MCL | PFNA (13) | Enforceable |
| New Mexico | 70 combined | 70 combined | Guidance | PFHxS | Toxic pollutant standard |
| New York | 10 | 10 | MCL | - | Enforceable |
| North Carolina | - | - | Guidance | GenX (10) | GenX only |
| Ohio | 4 | 4 | Guidance | PFHxS, PFNA, GenX (10 each) | PFAS Action Plan, not enforceable |
| Pennsylvania | 14 | 18 | MCL | - | Enforceable |
| Rhode Island | 20 combined | 20 combined | Interim Standard | PFHxS, PFNA, PFHpA, PFDA | Sum of 6 PFAS |
| Vermont | 20 combined | 20 combined | MCL | PFHpA, PFHxS, PFNA | Sum of 5 PFAS |
| Washington | 10 | 15 | Notification | PFNA (9), PFHxS (65) | State action levels |
| Wisconsin | 4 | 4 | MCL | - | Updated from 70 ppt to 4 ppt, March 2026 |
Key Observations
Widest variation is in PFOA. State standards for PFOA range from 0.0079 ppt (Minnesota health-based guidance) to 70 ppt combined (Alaska, Colorado, New Mexico guidance values). The federal MCL of 4 ppt sits near the more restrictive end of the spectrum. Wisconsin recently updated from 70 ppt combined to 4 ppt individual, aligning with the federal MCLs (signed March 2026).
States with enforceable MCLs more restrictive than federal: Michigan (PFOA at 8 ppt, PFOS at 16 ppt, PFNA at 6 ppt), New Jersey (PFOA 14, PFOS 13, PFNA 13), New Hampshire (PFOA 12, PFOS 15), and New York (10 ppt each) all have enforceable state MCLs that predate the federal rule.
“Combined” standards add complexity. States like Massachusetts, Vermont, Maine, and Rhode Island regulate the sum of multiple PFAS at 20 ppt. A water system with 3 ppt PFOA, 3 ppt PFOS, and 15 ppt PFHxS would pass the federal PFOA/PFOS MCLs but fail a 20 ppt combined standard.
Ohio has guidance, not enforceable MCLs. Ohio’s PFAS Action Plan sets guidance values matching the federal MCLs (4 ppt PFOA/PFOS, 10 ppt for PFHxS/PFNA/GenX) but these are not enforceable state MCLs. Ohio public water systems are subject to the federal MCLs.
Most states have no state-specific PFAS standards. The majority of states rely entirely on the federal MCLs. The states listed above represent less than half of all states.
Pending State Actions
Several states are actively developing new PFAS drinking water standards as of early 2026:
- Arizona - Proposed PFAS drinking water requirements
- California - Legislation (AB 794) to establish enforceable MCLs
- Florida - Enacted legislation for MCLs/target levels, rulemaking in progress
- Georgia - Public comment on proposed PFAS drinking water rules
- Idaho - Proposed drinking water standards
- South Carolina - Proposed PFAS requirements
- Virginia - Enacted legislation for MCLs, rulemaking in progress
- Washington - Emergency rule for public water systems
Related Resources
- PFAS MCL Status 2026 - Current federal PFAS regulatory timeline
- Ohio PFAS Groundwater and Drinking Water Standards - Ohio-specific PFAS values
- PFAS Sampling Best Practices - Field guide for PFAS sampling
- Cleanup Levels vs. Screening Levels vs. MCLs - How different types of standards relate
- BCLP State-by-State PFAS Tracker - Detailed state-level analysis (external)
- ECOS PFAS Resources - Environmental Council of the States PFAS compendium
State PFAS drinking water standards for PFOA and PFOS. Updated March 2026. Note: this table covers the most commonly referenced PFAS compounds. Many states regulate additional PFAS not shown here.