Public water system · WA5356344
ActiveSouthgate Water Company
At a glance
Southgate Water Company (PWSID WA5356344) is an active community water system in Benton County, Washington. It reports serving 175 people through 83 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
175
Service connections
83
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Southgate Water Company compare with other water systems in Benton County?
By EPA's size categories, Southgate Water Company is a very small system (500 people or fewer). Benton County has 108 active public water systems. Its population served is well below the county average of 2,712 people per system, and accounts for less than 0.1% of the 292,896 people reported by systems filed under the county. Across Washington, the 4,705 active systems average 2,172 people each. Nationally, the average active community water system reports serving 6,703 people, so Southgate Water Company is well below 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. Washington has 2,392 active community water systems, 51% of the state's 4,705 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 4,370 Washington systems (93%) list groundwater as their primary source.
Who owns and regulates Southgate Water Company?
EPA lists Southgate Water Company as privately owned. The WA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 85 of the 108 active systems in Benton County (79%) are also privately owned.
Does Southgate Water Company 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 2026. The violations listed here began between January 2020 and January 2026. By type: 12 monitoring and reporting. The contaminants or rules involved are Nitrate, p-Dichlorobenzene, trans-1,2-Dichloroethylene and 1,2-Dichloroethane. EPA lists 12 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 |
|---|---|---|---|---|
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | p-Dichlorobenzenecode 2969 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloroethanecode 2980 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | o-Dichlorobenzenecode 2968 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Vinyl chloridecode 2976 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1-Dichloroethylenecode 2977 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | cis-1,2-Dichloroethylenecode 2380 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,1-Trichloroethanecode 2981 | No | Resolved |
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.
Southgate Water Company: frequently asked questions
Who runs Southgate Water Company?
Southgate Water Company (PWSID WA5356344) is a community water system privately owned. It is regulated by the WA state drinking water program.
How many people does Southgate Water Company serve?
Southgate Water Company reports serving 175 people through 83 service connections in Benton County, Washington.
Where does Southgate Water Company 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 Southgate Water Company 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 2026. 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 Southgate Water Company'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 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find Southgate Water Company's water quality report?
As a community water system, Southgate Water Company 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 Benton County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Kennewick City of | Benton | 118,164 | Community | Surface water |
| Richland City of | Benton | 106,499 | Community | Surface water |
| West Richland City of | Benton | 21,231 | Community | Purchased surface water |
| Prosser City of | Benton | 12,070 | Community | Groundwater |
| Energy Dept of/200w | Benton | 6,351 | Non-transient non-community | Surface water |
| Benton City Water | Benton | 5,626 | 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, “Southgate Water Company, PWSID WA5356344, Washington”, https://aquacensus.com/water-systems/washington/southgate-water-company-wa5356344 (data as of October 1, 2026).