Public water system · CA4700803
ActiveShadow Mountain MHP
At a glance
Shadow Mountain MHP (PWSID CA4700803) is an active community water system in Siskiyou County, California. It reports serving 126 people through 73 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in May 2016.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
126
Service connections
73
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Shadow Mountain MHP compare with other water systems in Siskiyou County?
By EPA's size categories, Shadow Mountain MHP is a very small system (500 people or fewer). Siskiyou County has 69 active public water systems. Its population served is well below the county average of 593 people per system, and accounts for 0.3% of the 40,908 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active community water system reports serving 6,703 people, so Shadow Mountain MHP 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. California has 2,997 active community water systems, 40% of the state's 7,479 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 6,179 California systems (83%) list groundwater as their primary source.
Who owns and regulates Shadow Mountain MHP?
EPA lists Shadow Mountain MHP as privately owned. The CA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 28 of the 69 active systems in Siskiyou County (41%) are also privately owned.
Does Shadow Mountain MHP have drinking water violations?
EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in May 2016. The violations listed here began between October 1980 and May 2016. By type: 3 monitoring and reporting, 2 contaminant level above the legal limit, 2 public notice, recordkeeping or other and 1 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 4 as resolved and 4 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 |
|---|---|---|---|---|
| 2016-05-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2004-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1993-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1993-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1984-08-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-07-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1981-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
| 1980-10-30 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
All 8 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.
Shadow Mountain MHP: frequently asked questions
Who runs Shadow Mountain MHP?
Shadow Mountain MHP (PWSID CA4700803) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Shadow Mountain MHP serve?
Shadow Mountain MHP reports serving 126 people through 73 service connections in Siskiyou County, California.
Where does Shadow Mountain MHP 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 Shadow Mountain MHP have any drinking water violations?
EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in May 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 Shadow Mountain MHP'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 8 violations for this system; 2 are health-based, and the most recent began in May 2016. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Shadow Mountain MHP's water quality report?
As a community water system, Shadow Mountain MHP 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 Siskiyou County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Yreka, City of | Siskiyou | 7,825 | Community | Surface water |
| Mt. Shasta, City of | Siskiyou | 3,642 | Community | Groundwater |
| Mt. Shasta Ski Park | Siskiyou | 3,500 | Transient non-community | Groundwater |
| Lake Shastina C.S.D | Siskiyou | 2,790 | Community | Groundwater |
| Weed, City of | Siskiyou | 2,662 | Community | Groundwater |
| Lake Siskiyou Campground | Siskiyou | 1,800 | Transient non-community | Surface water |
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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, “Shadow Mountain MHP, PWSID CA4700803, California”, https://aquacensus.com/water-systems/california/shadow-mountain-mhp-ca4700803 (data as of October 1, 2026).