Nitrate · Maryland

Nitrate in Maryland Drinking Water — 11 ZIPs Tested

EPA data analysis for nitrate in Maryland drinking water systems

ZipCheckup tracks Nitrate in Maryland drinking water: 11 ZIP codes with detected levels on record. No ZIP codes exceed the EPA limit on record. Nitrate carries a high health-risk designation.

11
ZIPs with Detections
0
ZIPs with Violations
10 mg/L (as nitrogen)
EPA Limit
High
Health Risk
Reverse Osmosis or Ion Exchange
Best Filter Method

Nitrate Contamination in Maryland

ZipCheckup analyzed drinking water data across 615 ZIP codes in Maryland for nitrate contamination. 11 ZIP codes have reported nitrate detections, and 0 have EPA violations on record.

EPA Standard for Nitrate

The EPA maximum contaminant level (MCL) for nitrate is 10 mg/L (as nitrogen), governed by the National Primary Drinking Water Regulations. Water systems that exceed this limit must take corrective action and notify consumers.

Worst ZIP Codes for Nitrate in Maryland

These ZIP codes reported the highest nitrate levels in Maryland based on CCR reports and EPA data:

Lowest Nitrate Levels in Maryland

These ZIP codes had the lowest reported nitrate detections in Maryland:

Health Effects of Nitrate

How to Remove Nitrate From Drinking Water

The most effective treatment for nitrate removal is Reverse Osmosis or Ion Exchange. Look for filters certified under NSF 53 / NSF 58 standards.

Check Your ZIP Code

Use the ZipCheckup water quality search to see nitrate data for your specific water system in Maryland.

Worst ZIP Codes for Nitrate in Maryland

Ranked by highest nitrate detection level.

Rank ZIP Code City Level Detected EPA Limit Status
1 21023 Butler 10000 ppb 10000 ppb Within Limit
2 21074 Hampstead 10000 ppb 10000 ppb Within Limit
3 21155 Upperco 10000 ppb 10000 ppb Within Limit
4 21791 Union Bridge 6000 ppb 10000 ppb Within Limit
5 21801 Salisbury 6000 ppb 10000 ppb Within Limit
6 21802 Salisbury 6000 ppb 10000 ppb Within Limit
7 21803 Salisbury 6000 ppb 10000 ppb Within Limit
8 21804 Salisbury 6000 ppb 10000 ppb Within Limit
9 21849 Parsonsburg 6000 ppb 10000 ppb Within Limit
10 21157 Westminster 5610 ppb 10000 ppb Within Limit
11 21158 Westminster 5610 ppb 10000 ppb Within Limit

Lowest Nitrate Levels in Maryland

ZIP Code City Level Detected
21158 Westminster 5610 ppb
21157 Westminster 5610 ppb
21849 Parsonsburg 6000 ppb
21804 Salisbury 6000 ppb
21803 Salisbury 6000 ppb
21802 Salisbury 6000 ppb
21801 Salisbury 6000 ppb
21791 Union Bridge 6000 ppb
21155 Upperco 10000 ppb
21074 Hampstead 10000 ppb

Cities with Nitrate Data in Maryland

5 cities in Maryland have nitrate testing data available.

Maryland Water Quality Overview: See statewide water quality rankings on the Maryland water quality page.
Learn more about Nitrate: Read the full guide on Nitrate in drinking water.
Home → Contaminants → Nitrate → Maryland

How to cite this page

APA ZipCheckup. (2026). Nitrate in Maryland Drinking Water — 11 ZIPs Tested. https://zipcheckup.com/contaminants/nitrates/maryland/
BibTeX 
@misc{zipcheckup-contaminants-nitrates-maryland,
  author = {{ZipCheckup}},
  title  = {{Nitrate in Maryland Drinking Water — 11 ZIPs Tested}},
  year   = {2026},
  url    = {https://zipcheckup.com/contaminants/nitrates/maryland/}
}

Data as of July 2026.

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