Public water system · WA5348705
ActiveLower Granite Lock & Dam
At a glance
Lower Granite Lock & Dam (PWSID WA5348705) is an active non-transient non-community water system in Garfield County, Washington. It reports serving 120 people through 3 service connections. Its primary water source is groundwater, and EPA lists it as owned by the federal government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in February 2016.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
120
Service connections
3
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Lower Granite Lock & Dam compare with other water systems in Garfield County?
By EPA's size categories, Lower Granite Lock & Dam is a very small system (500 people or fewer). Garfield County has 9 active public water systems, and Lower Granite Lock & Dam is the 4th-largest of them by population served. Its population served is well below the county average of 412 people per system, and accounts for 3.2% of the 3,712 people reported by systems filed under the county. Across Washington, the 4,705 active systems average 2,172 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Lower Granite Lock & Dam is well below that figure.
What does “non-transient non-community water system” mean?
A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. Washington has 400 active non-transient non-community water systems, 8.5% 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 Lower Granite Lock & Dam?
EPA lists Lower Granite Lock & Dam as owned by the federal government. 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. 2 of the 9 active systems in Garfield County (22%) are also owned by the federal government.
Does Lower Granite Lock & Dam have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in February 2016. The violations listed here began between July 2006 and February 2016. By type: 12 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 6 as resolved and 6 as archived. 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. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2016-02-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2015-02-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2015-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2015-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2006-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Alachlor (Lasso)code 2051 | No | Archived |
| 2006-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Hexachlorocyclopentadienecode 2042 | No | Archived |
| 2006-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Heptachlorcode 2065 | No | Archived |
| 2006-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylene dibromide (EDB)code 2946 | No | Resolved |
| 2006-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Pentachlorophenolcode 2326 | No | Archived |
| 2006-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Hexachlorobenzenecode 2274 | No | Archived |
| 2006-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Oxamylcode 2036 | No | Archived |
| 2006-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dibromo-3-chloropropane (DBCP)code 2931 | 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.
Lower Granite Lock & Dam: frequently asked questions
Who runs Lower Granite Lock & Dam?
Lower Granite Lock & Dam (PWSID WA5348705) is a non-transient non-community water system owned by the federal government. It is regulated by the WA state drinking water program.
How many people does Lower Granite Lock & Dam serve?
Lower Granite Lock & Dam reports serving 120 people through 3 service connections in Garfield County, Washington.
Where does Lower Granite Lock & Dam 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 Lower Granite Lock & Dam 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 February 2016. 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 Lower Granite Lock & Dam'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 February 2016. For current results, consult EPA ECHO, or the WA state drinking water program.
Where can I find Lower Granite Lock & Dam's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Lower Granite Lock & Dam is a non-transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Garfield County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Pomeroy City of | Garfield | 1,395 | Community | Groundwater |
| Garfield County Fairgrounds | Garfield | 1,250 | Transient non-community | Groundwater |
| Alpowa Summit Rest Area | Garfield | 801 | Transient non-community | Groundwater |
| Usace Illia Residential Area | Garfield | 46 | Community | Groundwater |
| Hiway Trailer Court | Garfield | 36 | Community | Groundwater |
| Dye Seed Ranch 1 | Garfield | 30 | Transient non-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, “Lower Granite Lock & Dam, PWSID WA5348705, Washington”, https://aquacensus.com/water-systems/washington/lower-granite-lock-dam-wa5348705 (data as of October 1, 2026).