County · Maryland
Harford County, Maryland: drinking water records
This overview covers 20 ZIP codes and 16 community water systems in Harford County. It also stands in for 5 ZIP codes whose utility has too little EPA data for a page of its own.
System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.
Water systems with the most complete records
| Water system | People served | PFAS survey results | PFAS found | Health-based violations | Lead, 9 in 10 homes at or below |
|---|---|---|---|---|---|
| City of Havre de Grace MD0120012 | 14,000 | 120 | 0 | 2 | 2 ppb |
| Harford County D.P.W. MD0120016 | 104,567 | 300 | 0 | 0 | 0 ppb |
| City of Aberdeen MD0120001 | 18,006 | 180 | 8 | 0 | 0 ppb |
| Chapel Hill - Aberdeen Proving Grounds MD0120002 | 15,000 | 60 | 0 | 0 | 0 ppb |
| Maryland American Water Company MD0120003 | 13,200 | 180 | 9 | 0 | 2 ppb |
| R & R Estates MD0120210 | 96 | 0 | 0 | 1 | 1.1 ppb |
| Queens Castle Mobile Home Park MD0120213 | 60 | 0 | 0 | 1 | 3 ppb |
| Fountain Green Mobile Home Park MD0120208 | 55 | 0 | 0 | 1 | 0 ppb |
| Hart Heritage MD0120021 | 37 | 0 | 0 | 1 | 10.4 ppb |
| Williams Mobile Home Park MD0120207 | 35 | 0 | 0 | 1 | 1.3 ppb |
| Clear View Mobile Home Park LLC MD0120204 | 28 | 0 | 0 | 1 | 0 ppb |
| Greenridge Subdivision MD0120011 | 2,271 | 0 | 0 | 0 | 0 ppb |
| Swan Harbour Dell Mobile Home Park MD0120215 | 500 | 0 | 0 | 0 | 6 ppb |
| Campus Hills Water Works MD0120007 | 250 | 0 | 0 | 0 | 2.4 ppb |
| Town of Darlington MD0120009 | 250 | 0 | 0 | 0 | 1.4 ppb |
| Lakeside Vista MD0120014 | 219 | 0 | 0 | 0 | 0 ppb |
ZIP reports in Harford County
No ZIP report in this county is published yet.
These ZIP codes are covered by this overview because their utility has too little EPA data for a separate page: 21028, 21084, 21132, 21160, 21161.
Sources and scope
EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Page generated 2026-09-03.
Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.