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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Real EPA measurements of nitrates for Maryland water systems — Six-Year Review compliance samples 2012–2019 (historical). Methodology
These cities have nitrates levels above 50% of the EPA limit but within compliance
| City | Level | % of Limit | Population |
|---|---|---|---|
| Salisbury | 5.05 mg/L | 50.5% | 30,343 |
Every Maryland system with a nitrates result in EPA's data, sorted by level. Averages of 2012–2019 finished-water samples, non-detects counted as zero — historical, not today's tap.
| City | Level | Period | EPA Limit | % of Limit | Status |
|---|---|---|---|---|---|
| SalisburyGrade C | 5.05 mg/LAverage of 61 samples | 2012–2019 | 10.00 mg/L | 50.5% | Warning |
| WestminsterGrade C | 4.56 mg/LAverage of 125 samples | 2012–2019 | 10.00 mg/L | 45.6% | Safe |
| Bel AirGrade D | 2.94 mg/LAverage of 16 samples | 2012–2019 | 10.00 mg/L | 29.4% | Safe |
| BaltimoreGrade C | 2.08 mg/LAverage of 24 samples | 2012–2019 | 10.00 mg/L | 20.8% | Safe |
| RockvilleGrade B | 1.36 mg/LAverage of 6 samples | 2012–2019 | 10.00 mg/L | 13.6% | Safe |
| LaurelGrade A | 1.33 mg/LAverage of 206 samples | 2012–2019 | 10.00 mg/L | 13.3% | Safe |
| FrederickGrade A | 1.32 mg/LAverage of 15 samples | 2012–2019 | 10.00 mg/L | 13.2% | Safe |
| Glen BurnieGrade B | 0.691 mg/LAverage of 48 samples | 2012–2019 | 10.00 mg/L | 6.9% | Safe |
| HagerstownGrade A | 0.639 mg/LAverage of 13 samples | 2012–2019 | 10.00 mg/L | 6.4% | Safe |
| CumberlandGrade A | 0.349 mg/LAverage of 8 samples | 2012–2019 | 10.00 mg/L | 3.5% | Safe |
| BowieGrade B | 0.200 mg/LAverage of 7 samples | 2012–2019 | 10.00 mg/L | 2.0% | Safe |
| EastonGrade A | 0.057 mg/LAverage of 38 samples | 2012–2019 | 10.00 mg/L | 0.6% | Safe |
| OdentonGrade A | 0.0074 mg/LAverage of 8 samples | 2012–2019 | 10.00 mg/L | 0.1% | Safe |
| AnnapolisGrade A | 0 mg/LAverage of 6 samples | 2012–2019 | 10.00 mg/L | 0.0% | Safe |
Nitrates pose the greatest risk to infants under six months of age. High nitrate levels can cause methemoglobinemia, also known as "blue baby syndrome," which reduces the blood's oxygen-carrying capacity. Pregnant women are also at risk as nitrate exposure has been linked to neural tube defects, preterm birth, and low birth weight. IMPORTANT: Boiling water does NOT remove nitrates - it concentrates them.
Runoff from fertilizer use; leaching from septic tanks; erosion of natural deposits; agricultural runoff
Based on our analysis of EPA Safe Drinking Water Information System (SDWIS) data and local water utility reports,nitrates has been detected in 14 Maryland water systems. The average level across all tested cities is 15% of the EPA Maximum Contaminant Level (MCL), with the highest detection at 50.5% of the limit.
The EPA MCL for nitrate is 10 mg/L measured as nitrogen. The EPA MCL for nitrates is 10 mg/L. This limit is set to protect public health based on available scientific evidence about the contaminant's health effects.
14 Maryland cities have nitrates detected in their water supply. All tested cities are within EPA safety limits.
Blue baby syndrome in infants, pregnancy complications, potential cancer risk. The most vulnerable groups include infants under 6 months and pregnant women.
The most effective methods for removing nitrates include Reverse Osmosis, Ion Exchange, Distillation. Look for filters certified by NSF/ANSI for nitrates reduction.
The EPA Maximum Contaminant Level (MCL) for nitrates is 10 mg/L.The EPA MCL for nitrate is 10 mg/L measured as nitrogen.
This page shows what Maryland utilities reported for nitrates. It cannot tell you what is coming out of your own tap: utility samples are taken across a whole system and averaged, levels vary by address and season, and anything picked up after the water leaves the main never appears in their report.
Home water test kitscheck your own tap before buying any filterRecommended filtration methods for nitrates removal:
Removes 83-92% of nitrates
Specifically designed for nitrate removal
Effective but energy-intensive
Paid links. We earn a commission if you buy, at no extra cost to you. Filters are matched to the removal methods listed above for nitrates.