Town of Mount Airy water quality
Mount Airy, MD · serves 9,890 people (3,326 connections) · Groundwater · Local government · EPA ID MD0060007
Data: U.S. EPA · How we read the data · How we check it
Summary
PFAS above the 2024 federal limits. Systems have until 2029 to meet the PFAS limits.
Is it an emergency? No: PFAS limits are about years of exposure, not a glass of water, and nothing in EPA's data calls for you to stop drinking the water today. If your utility ever issues a boil-water or do-not-drink notice, follow it.
- PFAS
- Above limitPFOA, PFOS above the federal limit in EPA's 2023–2025 testing (PFOA 8.45 ppt vs a limit of 4 ppt, PFOS 5.95 ppt vs a limit of 4 ppt, where ppt = parts per trillion).
- Lead
- Below action level1.4 ppb (parts per billion) at the 90th percentile: 9 in 10 homes sampled were at or below it. Action level 15 ppb, falling to 10 ppb in Nov 2027. Monitoring period ending Dec 2024. Your home's pipes can make yours higher.
- Violations
- None health-basedNo health-based violations since 2016.
- Pregnant, or mixing baby formula with tap water? Babies drink more water for their size, so PFAS exposure matters more for them. Consider bottled water or a filter certified for PFAS for formula, and ask your doctor. Health effects.
- To lower your PFAS exposure now, a home filter certified for PFAS reduction works (reverse osmosis, or activated carbon certified to NSF/ANSI 53 or 58). Filters for these results.
- Built before 1986, or not sure what your service line is made of? Check your service line and test your tap. Utility data can't show your pipes.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read Town of Mount Airy's annual water quality report (Consumer Confidence Report). It lists every regulated contaminant tested and is usually on the utility's website or mailed with your bill. EPA: how to find it.
PFAS (“forever chemicals”)
EPA UCMR 5: 5 entry points tested Apr 2023 to Oct 2023. "Average" is the highest entry-point average (non-detects counted as zero), the way EPA compares UCMR 5 results to the limits. ppt = parts per trillion. These results do not determine compliance.
| Contaminant | Highest average |
|---|---|
| PFOA Above limit Limit 4 ppt | 8.45 ppt 2.11× the limit |
| PFOS Above limit Limit 4 ppt | 5.95 ppt 1.49× the limit |
| PFHxS Not detected Limit 10 ppt | – |
| PFNA Not detected Limit 10 ppt | – |
| HFPO-DA (GenX) Not detected Limit 10 ppt | – |
| Hazard Index (a combined score for PFHxS, PFNA, GenX and PFBS, where above 1 is over the limit) Detected, below limit Limit 1 | 0.0032 |
| PFBS Detected, below limit Guideline 2,000 ppt | 6.45 ppt |
| PFBA Detected, below limit Guideline 6,000 ppt | 5.8 ppt |
| PFHxA Detected, below limit Guideline 3,000 ppt | 11.5 ppt |
| PFPeA Detected, no limit | 13.8 ppt |
| PFHpA Detected, no limit | 2.95 ppt |
For context: the PFOA average is higher than at 93% of the Maryland systems EPA tested and the PFOS average is higher than at 86% of the Maryland systems EPA tested.
29 PFAS tested, 7 detected at least once. "Not detected" means below EPA's reporting limit (about 2 to 20 ppt depending on the chemical), not proven zero. PFAS not listed were not detected. The limits for PFHxS, PFNA, GenX and the Hazard Index were proposed for rescission in May 2026. That proposal is not final. Systems have until 2029 to meet the limits.
Lithium
Not detected in 10 samples (reporting limit 9 ppb). About lithium.
Lead and copper
Latest 90th percentile: 1.4 ppb lead (Jan 2022 – Dec 2024). Below action level
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2022 – Dec 2024 | 1.4 ppb |
| Jan 2018 – Dec 2020 | 1.2 ppb |
| Jan 2016 – Dec 2018 | 0 ppb |
Earlier results (9)
| Jan 2013 – Dec 2015 | -5 ppb |
| Jan 2010 – Dec 2012 | 0 ppb |
| Jan 2007 – Dec 2009 | 0 ppb |
| Jan 2004 – Dec 2006 | 0 ppb |
| Jan 2003 – Dec 2005 | 8 ppb |
| Jan 2000 – Dec 2002 | 10 ppb |
| Jan 1997 – Dec 1999 | 3 ppb |
| Jan 1996 – Dec 1998 | 6 ppb |
| Jan 1995 – Dec 1995 | 2 ppb |
Lead comes from pipes and fixtures, not the source water, so it varies home to home. The 90th percentile means 9 in 10 sampled homes were at or below it. More on lead.
Violations
Health-based violations mean a contaminant exceeded a limit or a required treatment step was missed. Monitoring and reporting violations mean required tests or reports were late or missing, so the water's quality during that time is unknown. The total includes every violation in EPA's records, most of them paperwork.
Where it serves
Mount Airy
ZIP codes the system reported serving: 21771
Nearby utilities
- City of Frederick Frederick · 14 mi
- New Design – Frederick County Water System Frederick · 14 mi
- City of Westminster Westminster · 16 mi · PFAS above limit
- City of Taneytown Taneytown · 20 mi · PFAS above limit
- Howard County Dept. of Public Works Distribution Columbia · 20 mi
- City of Rockville Rockville · 20 mi
Questions
Is Town of Mount Airy water safe to drink?
Town of Mount Airy has no health-based violations since 2016. EPA testing found PFAS above the 2024 federal limits, which systems must meet by 2029. Federal data can't tell you about your own pipes: lead comes from service lines and plumbing, so test your tap if your home was built before 1986. For the official word, read the utility's annual Consumer Confidence Report.
Does Town of Mount Airy water have PFAS?
Yes. EPA's 2023–2025 testing of Town of Mount Airy found 7 PFAS at least once. The highest entry-point averages were above the federal limit for PFOA and PFOS: PFOA 8.45 ppt, PFOS 5.95 ppt (limit 4 ppt for PFOA and PFOS, 10 ppt for the others).
What is the lead level in Town of Mount Airy water?
The most recent 90th-percentile lead result for Town of Mount Airy is 1.4 ppb, for the period ending Dec 2024. The federal action level is 15 ppb, falling to 10 ppb in November 2027. The 90th percentile means 9 in 10 homes sampled were at or below this number. Individual homes can be higher.
Check these numbers yourself
Every figure on this page comes from public EPA records. You don't have to take our word for it:
- EPA's own report for MD0060007: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID MD0060007).
- EPA SDWIS download: the lead results, population and violation records we use.
- The utility's annual water quality report (Consumer Confidence Report): ask Town of Mount Airy, or see EPA's guide to finding it.
Found something that doesn't match? Tell us and we'll check it against EPA's records. How we check our data.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.