Research / WaterSystemViolationPulse
New Health-Based Drinking Water Violations by Water System (EPA SDWIS): 2026 statistics from 459 public records
Indiana leads with 59 of 459 records (12.9%), ahead of Pennsylvania with 48 (10.5%) (as of 2026-11-04; source: U.S. EPA Safe Drinking Water Information System (SDWIS) via Envirofacts and EPA ECHO).
Data as of · Compiled by Zalwin from U.S. EPA Safe Drinking Water Information System (SDWIS) via Envirofacts and EPA ECHO
Key findings
- Zalwin's WaterSystemViolationPulse dataset holds 459 WaterSystemViolationPulse records dated 2026-05-02 to 2026-08-18 (as of 2026-11-04; source: U.S. EPA Safe Drinking Water Information System (SDWIS) via Envirofacts and EPA ECHO). #
- Indiana leads with 59 of 459 records (12.9%), ahead of Pennsylvania with 48 (10.5%) (as of 2026-11-04; source: U.S. EPA Safe Drinking Water Information System (SDWIS) via Envirofacts and EPA ECHO). #
- The most common rule group is Microbial (coliform, E. coli, treatment technique): 410 of 459 records (89.3%) (as of 2026-11-04; source: U.S. EPA Safe Drinking Water Information System (SDWIS) via Envirofacts and EPA ECHO). #
- Across 456 records with a stated population served, the total is 866,960 and the median is 142; the largest is 75,873 (Tangipahoa Parish Water District) (as of 2026-11-04; source: U.S. EPA Safe Drinking Water Information System (SDWIS) via Envirofacts and EPA ECHO). #
- The top 10% of records by population served (46 of 456) account for 82.0% of the total (as of 2026-11-04; source: U.S. EPA Safe Drinking Water Information System (SDWIS) via Envirofacts and EPA ECHO). #
- In Indiana, the leading rule group is Microbial (coliform, E. coli, treatment technique) with 59 of 59 records (100.0%) (as of 2026-11-04; source: U.S. EPA Safe Drinking Water Information System (SDWIS) via Envirofacts and EPA ECHO). #
WaterSystemViolationPulse records by state
| Group | Records | Share |
|---|---|---|
| Indiana | 59 | 12.9% |
| Pennsylvania | 48 | 10.5% |
| Arizona | 35 | 7.6% |
| Louisiana | 30 | 6.5% |
| Michigan | 28 | 6.1% |
| Colorado | 25 | 5.4% |
| North Carolina | 23 | 5.0% |
| Idaho | 19 | 4.1% |
| Alaska | 17 | 3.7% |
| Connecticut | 17 | 3.7% |
| New Mexico | 16 | 3.5% |
| Illinois | 13 | 2.8% |
| Montana | 11 | 2.4% |
| Missouri | 10 | 2.2% |
| New York | 10 | 2.2% |
WaterSystemViolationPulse records by rule group
| Group | Records | Share |
|---|---|---|
| Microbial (coliform, E. coli, treatment technique) | 410 | 89.3% |
| Chemicals (inorganic, organic, radionuclides) | 30 | 6.5% |
| Disinfectants and disinfection byproducts | 17 | 3.7% |
| Other rule | 2 | 0.4% |
Methodology and data provenance
- Sample: 459 public records dated 2026-05-02 to 2026-08-18; illustrative samples excluded.
- Source: U.S. EPA Safe Drinking Water Information System (SDWIS) via Envirofacts and EPA ECHO. Refreshed automatically about every 24 hours; figures above are as of 2026-11-04.
- Shares are of all records in the dataset; totals and medians use only records with a stated population served.
- Organization-level data only. Informational; verify individual records at the official source.
Cite this study
Zalwin Research, "WaterSystemViolationPulse statistics" (data as of 2026-11-04), https://zalwin.com/research/watersystemviolationpulse
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