What is Epichlorohydrin in drinking water?

Epichlorohydrin has 109 recorded EPA SDWIS violations across 28 public water systems (lower-third volume (≤ 253 violations)).

How many water systems have Epichlorohydrin violations?

28 systems, a narrow footprint (narrow footprint (≤ 36 systems)), so the table below covers most of the affected set.

Are Epichlorohydrin violations dangerous?

38.5% are health-based. The rest are monitoring/reporting, still compliance failures, but not the same as an MCL exceedance.

Where does Epichlorohydrin sit in the national contaminant ledger?

#107 of 157 indexable contaminants by violation volume - lower-third volume (≤ 253 violations), mid load (≤ 5.8 violations per affected system).

Where does this contaminant data come from?

EPA Safe Drinking Water Information System (SDWIS) quarterly extracts. Counts are cumulative compliance records, not a live risk score for a single tap.

Contaminants →

EPA SDWIS Low-volume analyte

Epichlorohydrin in Drinking Water

Compiled by PlainWater · May 15, 2026

28 public water systems carry at least one Epichlorohydrin violation - narrow footprint (≤ 36 systems).

Browse all SDWIS contaminants →

EPA contaminant code: 2257

Total Violations

109

Systems Affected

Health-Based %

38.5%

Violations / System

3.9

Epichlorohydrin standing, low-volume SDWIS third

Epichlorohydrin is in the lower third by violation volume (109). Sparse counts make each listed system more of the story, the table below is closer to the full affected set than it is for high-volume analytes. Load sits mid-pack at 3.9 violations per affected system (mid load (≤ 5.8 violations per affected system)). Health-based share is 38.5% - a material slice of the record is exposure-relevant, with the rest monitoring or reporting. Among 157 indexable contaminants, this page is #107 by violation volume. Utilities listed below are ranked by cumulative violation count for this analyte; pair that with population served to gauge household exposure scale.

Nationwide similar contaminants

Nearest by violation volume

ManMade Beta Particle and Photon Emitter (118) Acrylamide (93) Bromobenzene (89) m-Xylene (89)

Nearest by systems affected

Chloromethane (33 systems) 1,1-Dichloroethane (34 systems) 1,1-Dichloropropene (34 systems) 1,1,1,2-Tetrachloroethane (34 systems)

Epichlorohydrin: mixed health vs monitoring split

38.5% health-based · 61.5% monitoring/reporting across 109 records.

Health-based (38.5%) Monitoring/Reporting (61.5%)

Most Affected Water Systems

System	State	Violations	Population
Creston Water Supply	IA	11	7,536
Sioux City Water Supply	IA	10	85,791
Hoh Tribe	10	8	120
George Lane	10	7	75
Cuyamaca	10	6	375
Nisqually-Leschi & West Nisqually	10	5	3,200
Skokomish	10	5	1,150
Quileute Water System	10	4	885
Malott	10	4	95
Keller	10	3	340
Omak HUD	10	3	380
Twin Lakes HUD	10	3	42
McCoy Lake	10	3	325
Ford-Newhouse Lane	10	3	160
Woonsocket Water Division	RI	3	45,828
Lake Andes	SD	3	710
Reservation Road	10	3	110
Wellpinit	10	3	525
Martha Boardman	10	3	295
Madrid Water Department	IA	3	3,090
Zearing Water Department	IA	3	528
Lucerne Water Co. - Cal Water Service	CA	2	2,129
Corner Market	IA	2	252
Murdo	SD	2	488
Rapid Valley Sanitary District	SD	2	11,408
Spring Creek Sanitary District	SD	2	465
Mission Farm R.V. Park	CA	2	110
Ctuir Pwd Mission	10	1	1,310

Context: understanding water quality data · is my water safe?

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater

Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from the EPA Safe Drinking Water Information System (SDWIS). Consult a qualified professional before making decisions based on this data.

Read our methodology - how this data is sourced, computed, and verified.

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.