Moderate–High RiskAgricultural Contaminant

Nitrate In Drinking Water In Maryland

What residents of Maryland need to know about nitrate in drinking water — including how it enters water, which utilities have documented violations, and what steps to take.

Source: EPA SDWIS, Maryland Department of the Environment (MDE), CDC · Last reviewed: 2025-01-01

Quick Answer

Is nitrate in drinking water a real concern in Maryland?

Yes — Maryland's Eastern Shore has intensive poultry and row crop production, and private well users in Eastern Shore counties have documented elevated nitrate from agricultural sources.

Is this mostly a public-water issue, a private-well issue, or both?

Primarily private well users in the Eastern Shore counties; public water systems are monitored by MDE, but rural Eastern Shore households relying on private wells face elevated nitrate risk.

What is the main reason residents should care?

Maryland's Eastern Shore — Cecil, Kent, Queen Anne's, Talbot, Caroline, Dorchester, Wicomico, Worcester, and Somerset Counties — has very high concentrations of poultry operations and row crop farming. This region's sandy coastal plain soils allow rapid nitrate percolation to shallow aquifers used by private wells.

Key Facts

EPA Nitrate MCL10 mg/L as N
Eastern Shore contextHigh-density poultry operations — litter applied to sandy soils rapid-percolates to shallow aquifer
Chesapeake Bay requirementMaryland must reduce agricultural nitrogen loading to the Bay — acknowledging scale of the issue
Highest-risk countiesWorcester, Wicomico, Dorchester — agricultural intensity plus shallow coastal plain aquifer
State oversightMaryland Department of the Environment (MDE)

Why This Matters in Maryland

Maryland's Eastern Shore is one of the most poultry-intensive agricultural regions on the East Coast, with a very high density of chicken broiler operations. Poultry litter applied to cropland on the Eastern Shore's sandy coastal plain soils can rapidly move nitrate to the shallow aquifer. Maryland is also a Chesapeake Bay jurisdiction with significant agricultural nutrient management requirements — acknowledging the scale of nitrogen loading from Eastern Shore farming. MDE monitors public water systems for nitrate compliance. Private well users on the Eastern Shore — particularly in Worcester, Wicomico, and Dorchester Counties — should test annually.

Critical — Infants Under 6 Months

Do not use tap water that exceeds 10 mg/L nitrate-nitrogen to prepare infant formula or feed infants under six months. Boiling will concentrate nitrate — do not boil. Use bottled water or a certified reverse osmosis system (NSF/ANSI 58) until the issue is resolved.

Maryland Utilities With Nitrate Violation Records

The utilities listed below have at least one nitrate violation on record in EPA's SDWIS database. Violations may be open or resolved — see individual utility pages for current status and risk level.

How Nitrate Gets Into Drinking Water

Agricultural fertilizer and manure runoff

Nitrogen-based fertilizers and animal waste applied to Maryland cropland can leach into groundwater or run off into surface water supplies. This is the dominant nitrate pathway in most agricultural regions.

Septic system effluent

Failing or poorly sited septic systems release nitrogen-rich wastewater near drinking water wells. Rural areas with high well density and aging septic infrastructure face elevated risk.

Concentrated animal feeding operations (CAFOs)

Large livestock facilities generate significant waste. Lagoon leaks and overapplication of manure to nearby fields can create localized nitrate hotspots in groundwater.

Natural geological deposits

In some regions, naturally occurring nitrogen compounds in soil and bedrock contribute background nitrate levels to groundwater independent of agricultural activity.

Who Should Pay Closest Attention

Private well users in Maryland's Eastern Shore counties should test for nitrate annually. Families with infants using private well water on the Eastern Shore should use current test results before preparing formula.

Households with infants under six months

Pregnant residents

Private well owners in agricultural areas

Households near livestock operations or CAFOs

Rural residents on shallow groundwater wells

Households with older or failing septic systems nearby

How to Check Your Situation in Maryland

  1. 1

    Identify your water utility. Use the ZIP lookup below or browse the Maryland utility directory on this site.

  2. 2

    Read your utility's page on this site to see its current risk level and any open nitrate violations.

  3. 3

    Review your utility's most recent Consumer Confidence Report (CCR) — mailed annually or available on the utility's website. It must disclose any MCL exceedances.

  4. 4

    If you are on a private well, arrange testing at a Maryland Department of the Environment (MDE)-certified lab. Your state health department maintains a list of certified labs. Annual testing is recommended in agricultural areas.

  5. 5

    If you have an infant under six months, use bottled water or a certified RO system (NSF/ANSI 58) immediately as a precautionary measure — do not wait for test results if you are in a high-risk area.

  6. 6

    If your utility issues a nitrate exceedance notice, follow their guidance and do not use tap water for infants until the issue is resolved.

Treatment Options

Carbon filters and boiling do not remove nitrate. Only the options below are effective.

NSF/ANSI Standard 58 — Reverse Osmosis

RO systems certified to NSF/ANSI 58 reduce nitrate by 85–95% at the point of use. Under-sink installation required. The most practical residential option for nitrate concerns.

Distillation

Distillation units effectively remove nitrate along with most other dissolved contaminants. Suitable for drinking and cooking water — not whole-house use.

Anion Exchange

Ion exchange systems designed for nitrate removal exchange nitrate ions for chloride on a resin bed. Effective as a point-of-entry system; requires periodic regeneration and monitoring.

Carbon filters do NOT remove nitrate

Standard pitcher filters, faucet filters, and under-sink carbon units — including those certified NSF/ANSI 42 or 53 — do not remove nitrate. Do not use these for nitrate reduction.

See: Reverse Osmosis guide

Frequently Asked Questions

Related Pages

Data Sources & Provenance

All data on this page is sourced from official U.S. government or public datasets.

EPA — Nitrate in Drinking WaterView source
CDC — Methemoglobinemia (Nitrate)View source
EPA SDWIS — Violation and Compliance DataView source
USGS — Nitrate in GroundwaterView source
EPA — Private Wells and NitrateView source
Last updated: 2025-01-01
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