Public water system · IA2424027
ActiveDenison Water Supply
At a glance
Denison Water Supply (PWSID IA2424027) is an active community water system in Crawford County, Iowa. It reports serving 9,381 people through 2,930 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 3 violations for this system; none is health-based, and the most recent began in October 2000.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
9,381
Service connections
2,930
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Denison Water Supply compare with other water systems in Crawford County?
By EPA's size categories, Denison Water Supply is a medium system (3,301 to 10,000 people). Crawford County has 10 active public water systems, and Denison Water Supply is the largest of them by population served. Its population served is about 6 times the county average of 1,553 people per system, and accounts for 60% of the 15,526 people reported by systems filed under the county. Across Iowa, the 1,828 active systems average 1,718 people each. Nationally, the average active community water system reports serving 6,703 people, so Denison Water Supply is about 40% above that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Iowa has 1,084 active community water systems, 59% of the state's 1,828 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,502 Iowa systems (82%) list groundwater as their primary source.
Who owns and regulates Denison Water Supply?
EPA lists Denison Water Supply as owned by a local government. The IA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 9 of the 10 active systems in Crawford County (90%) are also owned by a local government.
Does Denison Water Supply have drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in October 2000. The violations listed here began between October 1990 and October 2000. By type: 3 monitoring and reporting. The contaminant or rule involved most often is Nitrate (2 of them). EPA lists 3 as resolved. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2000-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1992-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1990-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
All 3 violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Denison Water Supply: frequently asked questions
Who runs Denison Water Supply?
Denison Water Supply (PWSID IA2424027) is a community water system owned by a local government. It is regulated by the IA state drinking water program.
How many people does Denison Water Supply serve?
Denison Water Supply reports serving 9,381 people through 2,930 service connections in Crawford County, Iowa.
Where does Denison Water Supply get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Denison Water Supply have any drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in October 2000. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Denison Water Supply's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. EPA's records list 3 violations for this system; none is health-based, and the most recent began in October 2000. For current results, consult the system's annual water quality report, EPA ECHO, or the IA state drinking water program.
Where can I find Denison Water Supply's water quality report?
As a community water system, Denison Water Supply must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in Crawford County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| W Central Rwa - Denison Subsys | Crawford | 2,428 | Community | Purchased groundwater |
| Schleswig Munic Water Supply | Crawford | 803 | Community | Purchased groundwater |
| Manilla Muni Service Dept | Crawford | 758 | Community | Groundwater |
| Charter Oak Water Supply | Crawford | 522 | Community | Purchased groundwater |
| Dow City Water Works | Crawford | 467 | Community | Groundwater |
| Vail Water Supply | Crawford | 383 | Community | Purchased groundwater |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Denison Water Supply, PWSID IA2424027, Iowa”, https://aquacensus.com/water-systems/iowa/denison-water-supply-ia2424027 (data as of October 1, 2026).