How many water violations are in Linn County?

Linn County has 8,540 total drinking water violations across 83 water systems, of which 1,219 are health-based violations. 91.6% of systems have at least one violation.

How many people get water from Linn County systems?

Water systems in Linn County serve approximately 224,711 people through 83 public water systems.

Has PFAS been detected in Linn County water?

Under EPA UCMR5, 1 of 4 tested systems in Linn County had at least one PFAS detection (25.0% of the UCMR5-tested subset - not of all 83 SDWIS systems).

What types of water sources supply Linn County?

Water systems in Linn County use GW (79 systems), SW (4 systems) as their primary water sources.

Are health-based violations serious?

Health-based violations indicate that drinking water exceeded Maximum Contaminant Levels (MCLs) set by the EPA or failed treatment technique requirements. 14.3% of Linn County's violations are health-based. Among counties with any SDWIS violations, this extract puts Linn County in the middle health-based share band. Not all violations indicate immediate health risk, but they require corrective action.

Where does Linn County sit among U.S. counties for water-system population?

According to EPA SDWIS county population served used on /counties, Linn County ranks #301 of 3,254 counties by people served, and #2 of 99 counties in Iowa. Ordinals use the same total_population DESC sort as the counties directory. See /methodology#corpus-placement.

Counties → Iowa

Linn County, Iowa

Compiled by PlainWater · May 15, 2026

SDWIS compliance plate

Sheet IA113 · Linn County 83 sys · 8,540 viol · #301/3254

VIOL-SEVERE · HEALTH-LOW · RANK-TOP · PHOTO-FINISH · PFAS-MID · SRC-GW · SYS-MID · BOOK-FULL

VIOL-SEVERE 91.6% flagged
HEALTH-LOW 14.3% health
RANK-TOP #301/3254
PHOTO-FINISH ±0.1 pp
PFAS-MID 25.0% detect
SRC-GW GW lead 95%
SYS-MID 83 systems
BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Benton County (+ 0.1 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Linn County ranks #301 of 3,254 counties by people served, and #2 of 99 counties in Iowa. See methodology · corpus placement.

Linn County standing, lower-flagged corpus third

Flagged-system rate 91.6% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 14.3% is health-based share in the middle third (≤ 24.5%) . UCMR5 detect rate 25.0% is UCMR5 detect rate in the tested-pool middle third (≤ 33.3%) . Population served ranks #301 of 3,254 · #2 of 99 in Iowa.

Water Systems

System Name	Population	Violations	PFAS
Cedar Rapids Water Department	141,831	35	Clean
Marion Municipal Water Dept	41,623	36	Clean
Hiawatha Water Dept	7,183	13	Detected
Mount Vernon Water Supply	4,527	37	Clean
Fairfax Water Supply	2,828	32	-
Center Point Water Supply	2,579	27	-
Ely Water Supply	2,328	52	-
Lisbon Water Supply	2,233	75	-
Palo Water Supply	1,407	42	-
Central City Water Supply	1,264	56	-
Springville Water Supply	1,164	17	-
Eagle Ridge	1,005	0	-
Pleasant Creek St Rec Area-North	1,000	40	-
Yes Five Seasons Cedar LLC	994	0	-
Marion Village	850	79	-
North Linn High School / Middle School	724	55	-
Coggon Water Department	701	165	-
Walker Water Works	688	35	-
Alburnett Water Supply	675	107	-
Linn Co Engineer and Secondary Roads	658	107	-
Cedar Terrace Mhc	600	122	-
The Depot Walford	506	55	-
Pleasant Creek St Rec Area-South	502	57	-
Alburnett Community School District	500	13	-
Epic Event Center	404	101	-
Triple Play LLC	400	214	-
Palisades Kepler - Park Office	308	94	-
Airport National Public Golf Complex	260	46	-
Glenbrook Cove Area	233	3	-
Country Manor Estates	228	294	-
Gaddis Estates HOA	220	41	-
YMCA Camp Wapsie	207	121	-
Gardner Golf Course	206	17	-
Prairieburg Muni. Water Supply	160	60	-
Howard H Cherry Scout Reservation	155	81	-
Wanatee Park	154	69	-
Camp Tanager	150	63	-
Pinicon Ridge C	150	176	-
Matsell Bridge A	150	81	-
Vern Acres (Oliphant Addition)	150	156	-
Sobaski Real Estate	120	0	-
Culvers Lawn and Garden	120	53	-
Lincolnway Investment Group	110	414	-
St Stephens Catholic Church	103	16	-
Indian Creek Nature Center	101	0	-
Fc United Soccer Club Inc	100	57	-
Oak Valley	100	242	-
Deer Ridge Homeowners Water Assc.	94	17	-
Twin Knolls Fourth/Fifth Addition	90	165	-
Mount Vernon Community Bible Church	88	132	-

Compare beyond Iowa

Lower-flagged peers for Linn County

Cross-state counties nearest Linn County on flagged-system share (91.6%) and cumulative violation count (8,540). In-state neighbours stay on the compliance plate above.

Similar flagged-system rate

Nearest cross-state counties by % of SDWIS systems with at least one violation on record.

4 peers

Similar violation load

Nearest cross-state counties by cumulative SDWIS violation count (all systems in the county).

4 peers

Read our methodology · Check your water system - how this data is sourced, computed, and verified.

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

Compiled by PlainWater, Drinking Water Quality Editorial Process · May 15, 2026

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.