Safest Drinking Water in Maryland 2026
Maryland has 5 public water systems serving 4,181,331 people. The safest system is Washington Suburban Sanitary Commission in Laurel with a score of 100/100.
Top 5 Water Systems in Maryland
| # | Water System | City | Pop. Served | Source | Violations | Score |
|---|---|---|---|---|---|---|
| 1 | Washington Suburban Sanitary Commission | Laurel | 1,900,000 | Surface water | 0 | A (100) |
| 2 | Howard County D.p.w. Distribution | Columbia | 286,158 | Surface water | 0 | B (80) |
| 3 | Harford County D.p.w. | Abingdon | 104,567 | Surface water | 0 | B (80) |
| 4 | Glen Burnie-Broadneck | Millersville | 290,606 | Ground water | 1 | D (64) |
| 5 | City of Baltimore | Baltimore | 1,600,000 | Surface water | 3 | F (44) |
Water quality data for Maryland is sourced from the EPA Safe Drinking Water Information System (SDWIS), which tracks compliance for all public water systems.
Frequently Asked Questions
Washington Suburban Sanitary Commission in Laurel has the highest Water Safety Score in Maryland at 100/100 (Grade A), serving 1,900,000 people.
Maryland has 5 public water systems serving 4,181,331 people. The average Water Safety Score is 74/100.
The Water Safety Score (0-100) is based on health violations (40%), contaminant exceedances (30%), enforcement history (20%), and monitoring violations (10%). Higher scores mean cleaner, safer water.
Water Safety Score: health violations (40%), contaminant exceedances (30%), enforcement history (20%), monitoring violations (10%).
The this entity category groups every U.S. public drinking-water safety entity sharing this attribute. The list above is the data; the paragraphs below explain what the grouping means against the broader the EPA Safe Drinking Water Information System (SDWIS) distribution and how to read the relative rankings within the category.
For readers using this category as a starting point, the per-entity detail pages linked from the table above carry the underlying the EPA Safe Drinking Water Information System (SDWIS) data in full. The category-level view is the filter; the per-entity pages are the actual answer.
Source: EPA Ground Water and Drinking Water, 2026.