GWA NORTHERN WATER SYSTEM: EPA violation history, explained
GWA NORTHERN WATER SYSTEM has a health-based violation on record, but none in the last five years - an older issue, not necessarily a current one. 139,207 people get their water from it, across 39,541 connections.
GWA NORTHERN WATER SYSTEM's record against the rest of the country
16 total violations and 3 health-based ones put GWA NORTHERN WATER SYSTEM at the 61th percentile nationally for violation burden, rank 5,094 of 12,903.
How GWA NORTHERN WATER SYSTEM compares within GU
Among the 4 GU systems in this dataset, the average is 6.0 health-based violations - GWA NORTHERN WATER SYSTEM's 3 is at or below that. See the lead and copper guide for why lead counts differently.
Most recent violation on record
The last violation EPA has on record for GWA NORTHERN WATER SYSTEM is from 1987-05-01 (health-based: 1987-05-01). Last reported to EPA: 06/25/2026.
What kind of problem, specifically
GWA NORTHERN WATER SYSTEM's flagged contaminants and rule violations, grouped by what they actually mean for a filter choice rather than left as EPA's raw code list:
- Other regulated metals - flagged from: Mercury
The most severe category on record is other regulated metals, which points toward a reverse osmosis-class filter if you want to address it directly.
What this data is and is not
This is what GWA NORTHERN WATER SYSTEM reported to its state primacy agency and EPA under the Safe Drinking Water Act - real regulatory record, not a lab test of your specific tap. This record - 3 health-based violations on file for GWA NORTHERN WATER SYSTEM - stops at the meter and cannot see household plumbing on the other side of it. The guide to what this data misses covers that gap.