Public water system · ID3140080
ActiveNampa City of
At a glance
City of Nampa (PWSID ID3140080) is an active community water system in Canyon County, Idaho. It reports serving 100,200 people through 38,361 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2023.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
100,200
Service connections
38,361
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does City of Nampa compare with other water systems in Canyon County?
By EPA's size categories, City of Nampa is a very large system (more than 100,000 people). Canyon County has 140 active public water systems, and City of Nampa is the largest of them by population served. Its population served is about 66 times the county average of 1,527 people per system, and accounts for 47% of the 213,824 people reported by systems filed under the county. Across Idaho, the 1,961 active systems average 899 people each. Nationally, the average active community water system reports serving 6,703 people, so City of Nampa is about 15 times 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. Idaho has 765 active community water systems, 39% of the state's 1,961 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,861 Idaho systems (95%) list groundwater as their primary source.
Who owns and regulates City of Nampa?
EPA lists City of Nampa as owned by a local government. The ID state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 16 of the 140 active systems in Canyon County (11%) are also owned by a local government.
Does City of Nampa have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2023. The violations listed here began between January 2020 and January 2023. By type: 12 monitoring and reporting. The contaminants or rules involved are Chlorine, Simazine, trans-1,2-Dichloroethylene and Lindane (gamma-BHC). EPA lists 11 as archived and 1 as resolved. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status. 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 |
|---|---|---|---|---|
| 2023-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Simazinecode 2037 | No | Archived |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | No | Archived |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Lindane (gamma-BHC)code 2010 | No | Archived |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,2-Trichloroethanecode 2985 | No | Archived |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Di(2-ethylhexyl) phthalatecode 2039 | No | Archived |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Endrincode 2005 | No | Archived |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dinosebcode 2041 | No | Archived |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Diquatcode 2032 | No | Archived |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Di(2-ethylhexyl) adipatecode 2035 | No | Archived |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Methoxychlorcode 2015 | No | Archived |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Oxamylcode 2036 | No | Archived |
The 12 most recent 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.
City of Nampa: frequently asked questions
Who runs City of Nampa?
City of Nampa (PWSID ID3140080) is a community water system owned by a local government. It is regulated by the ID state drinking water program.
How many people does City of Nampa serve?
City of Nampa reports serving 100,200 people through 38,361 service connections in Canyon County, Idaho.
Where does City of Nampa 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 City of Nampa have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2023. 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 City of Nampa'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. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2023. For current results, consult the system's annual water quality report, EPA ECHO, or the ID state drinking water program.
Where can I find City of Nampa's water quality report?
As a community water system, City of Nampa 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 Canyon County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Caldwell City of | Canyon | 74,000 | Community | Groundwater |
| Middleton City of | Canyon | 13,190 | Community | Groundwater |
| Parma City of | Canyon | 2,250 | Community | Groundwater |
| Wilder City of | Canyon | 1,690 | Community | Groundwater |
| Caldwell Housing Authority | Canyon | 1,100 | Community | Groundwater |
| Greenleaf City of | Canyon | 846 | Community | 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, “Nampa City of, PWSID ID3140080, Idaho”, https://aquacensus.com/water-systems/idaho/nampa-city-of-id3140080 (data as of October 1, 2026).