EPA SDWIS DataMaryland

Nitrate in Maryland Drinking Water

Maryland has 7,992 public water systems. 3891 have recorded nitrate violations.

Total Systems

7,992

With Violations

3,891

EPA MCL

10

Population Served

6.0M

Nitrate in Maryland: Key Facts

Total Water Systems

7,992

Systems with Violations

3,891

Lead Violations

56

Copper Violations

305

EPA Standard

10 mg/L as N

MCLG (goal): 10 mg/L

Water Systems with Violations in Maryland

Health Effects of Nitrate Exposure

Blue baby syndrome

Infants under 6 months can develop methemoglobinemia

Thyroid effects

May disrupt thyroid function with chronic exposure

Cancer links

Potential associations with colorectal cancer at high levels

Infants below 6 months can develop methemoglobinemia ('blue baby syndrome'). May also affect adults with certain conditions.

Frequently Asked Questions

Is there nitrate in Maryland water?

Maryland has 7,992 public water systems. 3891 have recorded nitrate violations based on EPA SDWIS data. If you are on a private well, your water is not covered by these regulations and should be tested independently.

How can I check my Maryland water for nitrate?

Search for your water system using the WaterCheck system lookup, or contact your utility and request a copy of your Consumer Confidence Report (CCR). The CCR is published annually and lists all detected contaminants, their levels, and the EPA MCLs. For private wells, contact a state-certified lab for independent testing.

What is the EPA limit for nitrate?

The EPA Maximum Contaminant Level (MCL) for nitrate is 10 mg/L as N. Systems that exceed MCLs are required to notify customers and take corrective action.

Nitrate at a Glance

Categoryinorganic
EPA MCL10 mg/L as N

Source

Runoff from fertilizer use; leaching from septic tanks and sewage; erosion of natural deposits

How to Filter Nitrate

  • +Reverse osmosis or distillation removes nitrates
  • +Boiling does NOT remove nitrates - it concentrates them
  • +Do not give well water to infants under 6 months without testing