01The verdict: is Mercersburg water safe?
Mercersburg's drinking water has significant quality concerns based on EPA testing data. With a grade of F (29/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 3,262 residents using surface water (rivers, lakes, or reservoirs).
Lead is over its legal limit
Measured at 31.0 ppb against the EPA Action Level of 15 ppb. The ledger below shows how far over — and which filter removes it.
See the measurement ↓3K people, 2 systems
All figures on this page come from federal EPA compliance and testing data for the systems serving this city.
See the systems ↓90 violations in the last five years
Recent compliance history is the best predictor of future problems — the year-by-year record is below.
See the record ↓Mercersburg's drinking water received a grade of F (29 out of 100), indicating failing water quality. The city's 2 water systems serve approximately 3,262 residents using surface water.
Lead levels were measured at 31.0 ppb (90th percentile), which exceeds the EPA action level of 15 ppb. This system has not yet been tested for PFAS under the EPA UCMR 5 program. The system has 421 violations on record, including 34 health-based violations. 57 remain unresolved.
Mercersburg ranks #548 out of 559 cities in Pennsylvania for water quality, placing it among the lowest-rated in the state. The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection. Lead levels exceed the EPA action level of 15 ppb, which typically indicates aging lead service lines or lead solder in the distribution system. An NSF 53-certified filter is strongly recommended for drinking and cooking water. As a small community water system, Mercersburg may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities. The system has seen 90 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
02What's in Mercersburg's water
Every contaminant flagged in Mercersburg, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
Over Limit — EPA Action Level: 15 ppb
Exceeds the EPA action level. Lead enters at the service line, not the treatment plant — your address matters more than the city average. Lead service line replacement and an NSF 53-certified point-of-use filter are recommended.Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 31.0 | 15 | ppb | Inorganic | Over Limit |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.40 | 1.3 | mg/L | Inorganic | Over Limit |
Cities ranked by 90th-percentile lead PF PFAS in Pennsylvania
Cities ranked by compounds detected Cu Copper in Pennsylvania
Cities ranked by 90th-percentile copper
03Mercersburg's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 421 violations on record, including 34 health-based violations. 57 remain unresolved.
0 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▲ Up 29 ppb since 1993. The latest reading (31 ppb, 2013) is over the action level. Sampled at higher-risk homes (90th percentile).
1.4mg/L(2007)
One sampling round on record — 108% of the 1.3mg/L EPA action level. Sampled at higher-risk homes (90th percentile).
04Where Mercersburg's water comes from
Mercersburg's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface Water
Rivers, lakes, or reservoirs — more exposed to runoff, agriculture, and seasonal swings than groundwater.
Local treatment
Multi-barrier treatment: coagulation, sedimentation, filtration, and disinfection to meet EPA standards.
2 systems
2 water systems, operated under local government ownership.
3,262 people
Residents served across Mercersburg's service area.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards. These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge. The system is operated by local government ownership and serves approximately 3,262 people through 2 water systems.
| System name | PWSID | Population | Source |
|---|---|---|---|
| MERCERSBURG MUNI WATER AUTH | PA7280021 | 2,350 | Surface Water |
| WHITETAIL SKI RESORT | PA7280903 | 912 | Groundwater |
Water bodies near Mercersburg
As a surface-water system, these water bodies may directly influence Mercersburg's drinking water supply.
05Pressure on Mercersburg's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Industrial discharge
4 facilities within 10 miles reported 0 lb released to surface water in the latest EPA Toxics Release Inventory. Proximity doesn't equal tap contamination — treatment and hydrology decide — but it's pressure on the watershed.
Flood & storm history
10 federal disaster declarations on record for Franklin County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Drought
Franklin County is in D2 (severe drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.
06How Mercersburg compares
Scores for nearby Pennsylvania cities on one line, with the average marked.
dashed line = Pennsylvania average (49/100)
Mercersburg scores 29/100 — below the Pennsylvania average of 49/100. Full Pennsylvania rankings →
79.8 / 100FBryn Mawr, PA
34.2 / 100FPittsburgh, PA
44 / 100AMcmurray, PA
86.8 / 100DGreensburg, PA
46.7 / 100FHarrisburg, PA
35.6 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
07What to do at home
Steps matched to what testing actually found in Mercersburg's water — not generic advice.
Filter drinking & cooking water
NSF 53-certified pitcher or under-sink filter. Lead level (31.0 ppb) exceeds the EPA action level of 15 ppb
Compare tested filters →Flush taps & check your service line
Lead leaches from pipes as water sits. Run cold water 30 seconds before drinking (especially mornings), and ask the utility whether your address still has a lead service line.
Lead risks explained →Watch for Mercersburg alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is Mercersburg, PA tap water safe to drink?
Mercersburg's water quality earned a grade of F (29/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #548 out of 559 cities tested in Pennsylvania.
What contaminants are in Mercersburg's water?
Lead was measured at 31.0 ppb (90th percentile). 421 violations are on record.
How is Mercersburg's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Mercersburg?
Yes — lead levels exceed the EPA action level of 15 ppb. We recommend an NSF 53-certified filter or reverse osmosis system. Based on current data, basic filtration should suffice for additional peace of mind.
Where does Mercersburg's water come from?
Mercersburg's water is sourced from Surface water. The city has 2 water systems serving approximately 3,262 residents.
What health violations has Mercersburg's water system had?
Mercersburg has 34 health-based violations on record. The most recent violation was recorded in January 2026. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 57 violations remain unresolved.
How does Mercersburg's water compare to other cities?
Mercersburg ranks #548 out of 559 cities in Pennsylvania (better than 2% of state cities) and #15352 out of 15382 cities nationally (0th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.