Colusa Southern System: EPA violation history, explained

Colusa Southern System's only violations on record are reporting or monitoring lapses, not a contaminant or treatment-technique failure EPA classifies as health-based. It serves 3,474 people through 31 service connections.

Colusa Southern System's record against the rest of the country

148 total violations and 0 health-based ones put Colusa Southern System at the 28th percentile nationally for violation burden, rank 9,320 of 12,903.

How Colusa Southern System compares within CA

CA's 803 covered systems average 5.8 health-based violations each; Colusa Southern System carries 0, not more than typical for the state. See the lead and copper guide for why lead counts differently.

Most recent violation on record

The last violation EPA has on record for Colusa Southern System is from 2005-01-07. Last reported to EPA: 06/30/2026.

What this data is and is not

Colusa Southern System's numbers here come from its own required reporting to EPA under the Safe Drinking Water Act, not from an independent test of your glass of water. Between the utility's meter and Colusa Southern System's customers' taps is household plumbing, invisible to a system-level record ranked 9,320th of 12,903 by violation count. The guide to what this data misses covers that gap.