What is CYANIDE in drinking water?

CYANIDE averages 4.0 violations per affected system (28,582 total / 7,188 systems) in the EPA SDWIS extract.

How many water systems have CYANIDE violations?

7,188 systems sit in the mid footprint band (mid footprint (≤ 8,691 systems)).

Are CYANIDE violations dangerous?

0.3% are health-based. The rest are monitoring/reporting, still compliance failures, but not the same as an MCL exceedance.

Where does CYANIDE sit in the national contaminant ledger?

#82 of 157 indexable contaminants by violation volume - middle-third volume (≤ 49,133 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

CYANIDE in Drinking Water

Compiled by PlainWater · May 15, 2026

4.0 violations per affected system (28,582 across 7,188) - mid load (≤ 5.8 violations per affected system).

Browse all SDWIS contaminants →

EPA contaminant code: 1024

Total Violations

28,582

Systems Affected

7,188

Health-Based %

0.3%

Violations / System

4.0

CYANIDE standing, mid-volume SDWIS third

CYANIDE lands in the middle third by violation volume (28,582), large enough for peer comparisons but not one of the handful of analytes that dominate the fleet-wide SDWIS ledger. Load sits mid-pack at 4.0 violations per affected system (mid load (≤ 5.8 violations per affected system)). Health-based share is only 0.3% - almost all of this analyte's trail is monitoring/reporting rather than MCL exceedance. Among 157 indexable contaminants, this page is #82 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

Nickel (29,603) Diquat (29,815) Endothall (26,423) Glyphosate (25,105)

Nearest by systems affected

1,2-DIBROMO-3-CHLOROPROPANE (6,889 systems) Dalapon (7,487 systems) Total Polychlorinated Biphenyls (PCB) (6,785 systems) ETHYLENE DIBROMIDE (7,606 systems)

CYANIDE: mixed health vs monitoring split

0.3% health-based · 99.7% monitoring/reporting across 28,582 records.

Health-based (0.3%) Monitoring/Reporting (99.7%)

Most Affected Water Systems

System	State	Violations	Population
Ridgefield Public Works	WA	113	20,967
PA American Audubon	PA	76	8,200
Coal Mountain Water	WV	56	80
Washington Township Mua	NJ	48	48,000
Nottingham Manor M H Court	PA	48	473
Shrewsbury Borough	PA	48	4,727
Hiawatha Water	WV	46	63
Pinnacle Water Association	WV	44	85
Culvers Hill - North Webster	IN	40	75
Mount Eagle Water Assoc	PA	40	130
Elko City Of	NV	39	23,000
Tempe City Of	AZ	36	165,000
Windmill Estates	IL	36	65
Carmel Montessori Academy	IL	36	40
South Bend Water Department	WA	36	2,930
Brian Head Town Water System	UT	35	1,038
Rhodeside Acres	VT	34	65
Willow Springs MHP	IN	33	25
Deerfield Park S/D	NC	33	440
Mother Teresa Catholic Academy	IL	32	220
Hilltop Village Association	PA	32	86
Far Away Auburn	PA	32	25
Akhiok	AK	31	90
Gpwd Center	IL	30	50
Whispering Pines MHP	NC	30	305
American Precision Elctronics	IL	29	60
Central Hampshire Psd Green Spring	WV	29	1,046
Congregation Beth Judea	IL	28	25
Maybrook Village	NY	28	3,150
Robinwood Village	PA	28	70

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.