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Counties → Iowa

Cerro Gordo County, Iowa

SDWIS compliance plate

Sheet IA033 · Cerro Gordo County 34 sys · 3,147 viol · #1117/3254

VIOL-SEVERE · HEALTH-LOW · RANK-UPPER · PHOTO-FINISH · PFAS-CLEAN · SRC-GW · SYS-SMALL · BOOK-FULL

  • VIOL-SEVERE 97.1% flagged
  • HEALTH-LOW 17.6% health
  • RANK-UPPER #1117/3254
  • PHOTO-FINISH ±0.2 pp
  • PFAS-CLEAN 0.0% detect
  • SRC-GW GW lead 100%
  • SYS-SMALL 34 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Jones County (+ 0.2 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Cerro Gordo County ranks #1,117 of 3,254 counties by people served, and #15 of 99 counties in Iowa. See methodology · corpus placement.

Cerro Gordo County standing, mid-flagged corpus third

Flagged-system rate 97.1% is in the corpus middle third (≤ 100.0% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 17.6% is health-based share in the middle third (≤ 24.5%) . UCMR5 detect rate 0.0% is UCMR5 detect rate at or below the tested-pool lower third (≤ 0.0%) . Population served ranks #1,117 of 3,254 · #15 of 99 in Iowa.

Flagged-rate neighbourhood around Cerro Gordo County

Lowest/highest poles plus in-state counties nearest Cerro Gordo County on % of SDWIS systems with ≥1 violation. Full ladder: /counties.

0% 20% 40% 60% 80% 100% Mahaska · lowest Kossuth · near Cerro Gordo · this county Ringgold · highest 75% 96% 96.3% 96.4% 97.1% 97.2% 100%

Source: EPA SDWIS (county aggregates) As of 2026-05-15

Water Systems

System Name Population Violations PFAS
Mason City Water Department 27,338 647 Clean
Clear Lake Water Department 7,687 35 Clean
Rockwell Water Supply 1,071 40 -
Ventura Water Works 716 10 -
Thornton Water Supply 400 43 -
Plymouth Water Supply 378 119 -
Bell Harbor 352 99 -
Meservey Water Supply 222 29 -
P.m. Park Trustees-East 152 76 -
Swaledale Water Supply 144 129 -
Clear Lake Baptist Church 140 37 -
Heidelberg Materials US Cement LLC 130 99 -
Luckys Last Resort Campground 105 195 -
Lime Creek Conservation Area 81 19 -
Rock Falls Lounge 80 187 -
Camp at the Woods 69 125 -
Clear Water Campground 68 0 -
Oakwood Park Water Association 66 278 -
Oakwood RV Park 60 42 -
Oak Hills Par 30 Golf Course 60 80 -
Pine Creek Golf Course 55 328 -
Twin Oak Camp Ground 54 40 -
Buffalo Run Golf Club 51 138 -
Long Beach Mobile Park 50 51 -
Ziegler Cat (Mason City) 49 45 -
Grandview Circle Water Association 48 29 -
Four Oaks (Mason City) 38 7 -
Lakeshore Water Association 38 61 -
Mason City Red Power Inc 38 6 -
Van Wall Equipment (Mason City) 34 4 -
Wilkinson Pioneer Park 27 43 -
Linn Grove Park 27 35 -
Oakridge Homeowners Association 26 34 -
Camp Tanglefoot 25 37 -

Compare beyond Iowa

Mid-flagged peers for Cerro Gordo County

Cross-state counties nearest Cerro Gordo County on flagged-system share (97.1%) and cumulative violation count (3,147). 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

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.