Out of 210 ZIP codes with data in Maryland, these are the highest-ranked areas for pfas status. See also: National ZIP Codes with PFAS Detections in Water | All Maryland Rankings
| Statistic | Value |
|---|---|
| ZIP codes ranked | 210 |
| Highest value | 0.1 ppt |
| Median value | 0.0 ppt |
| State | Maryland |
Top 100 Worst ZIP Codes
| Rank | ZIP Code | City | State | PFAS Status | Safety Score |
|---|---|---|---|---|---|
| 1 | 21157 | Westminster | MD | 0.1 ppt | 64/100 |
| 2 | 21788 | Thurmont | MD | 0.0 ppt | 65/100 |
| 3 | 21703 | Frederick | MD | 0.0 ppt | 64/100 |
| 4 | 21921 | Elkton | MD | 0.0 ppt | 66/100 |
| 5 | 21771 | Mount Airy | MD | 0.0 ppt | 69/100 |
| 6 | 21042 | Ellicott City | MD | 0.0 ppt | 59/100 |
| 7 | 21801 | Salisbury | MD | 0.0 ppt | 59/100 |
| 8 | 21804 | Salisbury | MD | 0.0 ppt | 59/100 |
| 9 | 21074 | Hampstead | MD | 0.0 ppt | 65/100 |
| 10 | 21102 | Manchester | MD | 0.0 ppt | 70/100 |
| 11 | 20837 | Poolesville | MD | 0.0 ppt | 68/100 |
| 12 | 21787 | Taneytown | MD | 0.0 ppt | 65/100 |
| 13 | 21901 | North East | MD | 0.0 ppt | 59/100 |
| 14 | 21914 | Charlestown | MD | 0.0 ppt | 55/100 |
| 15 | 21014 | Bel Air | MD | 0.0 ppt | 57/100 |
| 16 | 21015 | Bel Air | MD | 0.0 ppt | 62/100 |
| 17 | 21047 | Fallston | MD | 0.0 ppt | 55/100 |
| 18 | 21050 | Forest Hill | MD | 0.0 ppt | 55/100 |
| 19 | 21001 | Aberdeen | MD | 0.0 ppt | 60/100 |
| 20 | 21005 | Aberdeen Proving Ground | MD | 0.0 ppt | 40/100 |
| 21 | 21769 | Middletown | MD | 0.0 ppt | 61/100 |
| 22 | 21713 | Boonsboro | MD | 0.0 ppt | 69/100 |
| 23 | 21756 | Keedysville | MD | 0.0 ppt | 53/100 |
| 24 | 21811 | Berlin | MD | 0.0 ppt | 78/100 |
| 25 | 20601 | Waldorf | MD | 0.0 ppt | 72/100 |
| 26 | 20607 | Accokeek | MD | 0.0 ppt | 78/100 |
| 27 | 20613 | Brandywine | MD | 0.0 ppt | 78/100 |
| 28 | 20623 | Cheltenham | MD | 0.0 ppt | 63/100 |
| 29 | 20705 | Beltsville | MD | 0.0 ppt | 45/100 |
| 30 | 20706 | Lanham | MD | 0.0 ppt | 50/100 |
| 31 | 20707 | Laurel | MD | 0.0 ppt | 78/100 |
| 32 | 20708 | Laurel | MD | 0.0 ppt | 78/100 |
| 33 | 20710 | Bladensburg | MD | 0.0 ppt | 53/100 |
| 34 | 20712 | Mount Rainier | MD | 0.0 ppt | 53/100 |
| 35 | 20715 | Bowie | MD | 0.0 ppt | 77/100 |
| 36 | 20716 | Bowie | MD | 0.0 ppt | 82/100 |
| 37 | 20720 | Bowie | MD | 0.0 ppt | 77/100 |
| 38 | 20721 | Bowie | MD | 0.0 ppt | 77/100 |
| 39 | 20722 | Brentwood | MD | 0.0 ppt | 45/100 |
| 40 | 20723 | Laurel | MD | 0.0 ppt | 65/100 |
| 41 | 20735 | Clinton | MD | 0.0 ppt | 50/100 |
| 42 | 20737 | Riverdale | MD | 0.0 ppt | 40/100 |
| 43 | 20738 | Riverdale | MD | 0.0 ppt | 53/100 |
| 44 | 20740 | College Park | MD | 0.0 ppt | 45/100 |
| 45 | 20742 | College Park | MD | 0.0 ppt | 40/100 |
| 46 | 20743 | Capitol Heights | MD | 0.0 ppt | 55/100 |
| 47 | 20744 | Fort Washington | MD | 0.0 ppt | 50/100 |
| 48 | 20745 | Oxon Hill | MD | 0.0 ppt | 55/100 |
| 49 | 20746 | Suitland | MD | 0.0 ppt | 55/100 |
| 50 | 20747 | District Heights | MD | 0.0 ppt | 55/100 |
| 51 | 20748 | Temple Hills | MD | 0.0 ppt | 50/100 |
| 52 | 20769 | Glenn Dale | MD | 0.0 ppt | 63/100 |
| 53 | 20770 | Greenbelt | MD | 0.0 ppt | 53/100 |
| 54 | 20771 | Greenbelt | MD | 0.0 ppt | 40/100 |
| 55 | 20772 | Upper Marlboro | MD | 0.0 ppt | 50/100 |
| 56 | 20773 | Upper Marlboro | MD | 0.0 ppt | 53/100 |
| 57 | 20774 | Upper Marlboro | MD | 0.0 ppt | 55/100 |
| 58 | 20781 | Hyattsville | MD | 0.0 ppt | 45/100 |
| 59 | 20782 | Hyattsville | MD | 0.0 ppt | 40/100 |
| 60 | 20783 | Hyattsville | MD | 0.0 ppt | 45/100 |
| 61 | 20784 | Hyattsville | MD | 0.0 ppt | 55/100 |
| 62 | 20785 | Hyattsville | MD | 0.0 ppt | 55/100 |
| 63 | 20787 | Hyattsville | MD | 0.0 ppt | 40/100 |
| 64 | 20790 | Capitol Heights | MD | 0.0 ppt | 53/100 |
| 65 | 20812 | Glen Echo | MD | 0.0 ppt | 53/100 |
| 66 | 20814 | Bethesda | MD | 0.0 ppt | 65/100 |
| 67 | 20815 | Chevy Chase | MD | 0.0 ppt | 45/100 |
| 68 | 20816 | Bethesda | MD | 0.0 ppt | 65/100 |
| 69 | 20817 | Bethesda | MD | 0.0 ppt | 60/100 |
| 70 | 20818 | Cabin John | MD | 0.0 ppt | 45/100 |
| 71 | 20830 | Olney | MD | 0.0 ppt | 40/100 |
| 72 | 20832 | Olney | MD | 0.0 ppt | 53/100 |
| 73 | 20833 | Brookeville | MD | 0.0 ppt | 53/100 |
| 74 | 20841 | Boyds | MD | 0.0 ppt | 73/100 |
| 75 | 20850 | Rockville | MD | 0.0 ppt | 53/100 |
| 76 | 20851 | Rockville | MD | 0.0 ppt | 53/100 |
| 77 | 20852 | Rockville | MD | 0.0 ppt | 45/100 |
| 78 | 20853 | Rockville | MD | 0.0 ppt | 45/100 |
| 79 | 20854 | Potomac | MD | 0.0 ppt | 35/100 |
| 80 | 20855 | Derwood | MD | 0.0 ppt | 53/100 |
| 81 | 20857 | Rockville | MD | 0.0 ppt | 40/100 |
| 82 | 20859 | Potomac | MD | 0.0 ppt | 33/100 |
| 83 | 20860 | Sandy Spring | MD | 0.0 ppt | 53/100 |
| 84 | 20861 | Ashton | MD | 0.0 ppt | 53/100 |
| 85 | 20866 | Burtonsville | MD | 0.0 ppt | 53/100 |
| 86 | 20868 | Spencerville | MD | 0.0 ppt | 40/100 |
| 87 | 20871 | Clarksburg | MD | 0.0 ppt | 64/100 |
| 88 | 20872 | Damascus | MD | 0.0 ppt | 73/100 |
| 89 | 20874 | Germantown | MD | 0.0 ppt | 45/100 |
| 90 | 20875 | Germantown | MD | 0.0 ppt | 40/100 |
| 91 | 20876 | Germantown | MD | 0.0 ppt | 53/100 |
| 92 | 20877 | Gaithersburg | MD | 0.0 ppt | 53/100 |
| 93 | 20878 | Gaithersburg | MD | 0.0 ppt | 45/100 |
| 94 | 20879 | Gaithersburg | MD | 0.0 ppt | 53/100 |
| 95 | 20880 | Washington Grove | MD | 0.0 ppt | 40/100 |
| 96 | 20882 | Gaithersburg | MD | 0.0 ppt | 53/100 |
| 97 | 20884 | Gaithersburg | MD | 0.0 ppt | 40/100 |
| 98 | 20885 | Gaithersburg | MD | 0.0 ppt | 40/100 |
| 99 | 20886 | Montgomery Village | MD | 0.0 ppt | 53/100 |
| 100 | 20892 | Bethesda | MD | 0.0 ppt | 66/100 |
Methodology
PFAS detection data comes from EPA UCMR5 monitoring, state-level testing programs, and Consumer Confidence Reports. ZIP codes are ranked by maximum PFAS concentration detected. The EPA has set MCLs of 4 ppt for PFOA and PFOS individually. PFAS are persistent chemicals that do not break down in the environment.
Data sources: EPA Safe Drinking Water Information System (SDWIS), FEMA National Flood Insurance Program, EPA radon zone maps, EIA electricity rates, and Consumer Confidence Reports. Last updated: 2026-06-04.
Frequently Asked Questions
What are PFAS?
PFAS (per- and polyfluoroalkyl substances) are synthetic chemicals used in non-stick coatings, firefighting foam, and food packaging since the 1940s. They are called "forever chemicals" because they do not break down naturally. PFAS are linked to cancer, liver damage, thyroid disease, and immune system suppression.
How can I remove PFAS from my water?
Reverse osmosis (RO) and granular activated carbon (GAC) filters are effective at removing most PFAS from drinking water. NSF/ANSI 53 or 58 certified filters are recommended. Boiling water does NOT remove PFAS.
Explore More Rankings
- Worst ZIP Codes for Lead in Water in Maryland
- ZIP Codes with Most EPA Violations in Maryland
- Lowest Home Safety Scores in Maryland
- Safest ZIP Codes in Maryland — Highest Safety Scores
- ZIP Codes with Highest Flood Risk in Maryland
- ZIP Codes with Highest Energy Costs in Maryland
- ZIP Codes with Highest Radon Risk in Maryland
- Least Reliable Water Systems in Maryland
- Environmental Justice Concern Areas in Maryland
- Worst ZIP Codes for Homebuyers in Maryland
- ZIP Codes with Worst CO & Gas Risk in Maryland
- Safest ZIP Codes for Gas & CO Risk in Maryland
- ZIP Codes with Worst Wildfire Smoke Risk in Maryland
- Safest ZIP Codes for Wildfire Smoke in Maryland
- All Rankings