Public water system · WA5300020
ActivePort of Royal Slope
At a glance
Port of Royal Slope (PWSID WA5300020) is an active non-transient non-community water system in Grant County, Washington. It reports serving 447 people through 12 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 2016.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
447
Service connections
12
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Port of Royal Slope compare with other water systems in Grant County?
By EPA's size categories, Port of Royal Slope is a very small system (500 people or fewer). Grant County has 265 active public water systems. Its population served is about 18% below the county average of 543 people per system, and accounts for 0.3% of the 143,944 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 Port of Royal Slope is roughly in line with 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 Port of Royal Slope?
EPA lists Port of Royal Slope as owned by a local 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. 26 of the 265 active systems in Grant County (9.8%) are also owned by a local government.
Does Port of Royal Slope 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 2016. The violations listed here began between October 2007 and January 2016. By type: 12 monitoring and reporting. The contaminant or rule involved most often is Oxamyl (2 of them). EPA lists 9 as archived and 3 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 |
|---|---|---|---|---|
| 2016-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2008-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Aldicarbcode 2047 | No | Archived |
| 2008-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Aldicarb sulfoxidecode 2043 | No | Archived |
| 2008-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Aldicarb sulfonecode 2044 | No | Archived |
| 2008-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Oxamylcode 2036 | No | Archived |
| 2008-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Carbofurancode 2046 | No | Archived |
| 2007-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Oxamylcode 2036 | No | Resolved |
| 2007-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Heptachlorcode 2065 | No | Archived |
| 2007-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | 2,4,5-TP (Silvex)code 2110 | No | Archived |
| 2007-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Endrincode 2005 | No | Archived |
| 2007-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Di(2-ethylhexyl) adipatecode 2035 | No | Archived |
| 2007-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Heptachlor epoxidecode 2067 | 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.
Port of Royal Slope: frequently asked questions
Who runs Port of Royal Slope?
Port of Royal Slope (PWSID WA5300020) is a non-transient non-community water system owned by a local government. It is regulated by the WA state drinking water program.
How many people does Port of Royal Slope serve?
Port of Royal Slope reports serving 447 people through 12 service connections in Grant County, Washington.
Where does Port of Royal Slope 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 Port of Royal Slope 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 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 Port of Royal Slope'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 2016. For current results, consult EPA ECHO, or the WA state drinking water program.
Where can I find Port of Royal Slope's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Port of Royal Slope 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 Grant County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Moses Lake City of | Grant | 32,428 | Community | Groundwater |
| Gorge Amphitheatre | Grant | 25,119 | Transient non-community | Groundwater |
| Ephrata Water Department | Grant | 8,718 | Community | Groundwater |
| Quincy Water Department City of | Grant | 8,415 | Community | Groundwater |
| Mattawa City of | Grant | 5,370 | Community | Groundwater |
| Sun Lakes State Park | Grant | 4,858 | 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, “Port of Royal Slope, PWSID WA5300020, Washington”, https://aquacensus.com/water-systems/washington/port-of-royal-slope-wa5300020 (data as of October 1, 2026).