Public water system · CA4700551
ActiveCopco Lake Mwc
At a glance
Copco Lake Mwc (PWSID CA4700551) is an active community water system in Siskiyou County, Arizona. It reports serving 181 people through 65 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 August 1993.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
181
Service connections
65
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Copco Lake Mwc compare with other water systems in Siskiyou County?
By EPA's size categories, Copco Lake Mwc is a very small system (500 people or fewer). Siskiyou County has 1 active public water system, and Copco Lake Mwc is the largest of them by population served. Its population served is roughly in line with the county average of 181 people per system, and accounts for 100% of the 181 people reported by systems filed under the county. Across Arizona, the 1,769 active systems average 4,369 people each. Nationally, the average active community water system reports serving 6,703 people, so Copco Lake Mwc 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. Arizona has 936 active community water systems, 53% of the state's 1,769 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,612 Arizona systems (91%) list groundwater as their primary source.
Who owns and regulates Copco Lake Mwc?
EPA lists Copco Lake Mwc 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. 1 of the 1 active systems in Siskiyou County (100%) are also privately owned.
Does Copco Lake Mwc have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in August 1993. The violations listed here began between January 1984 and August 1993. By type: 9 public notice, recordkeeping or other and 3 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (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 |
|---|---|---|---|---|
| 1993-08-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1993-07-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1993-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1984-09-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 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 |
| 1984-06-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-05-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-04-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-03-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-02-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-01-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | 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.
Copco Lake Mwc: frequently asked questions
Who runs Copco Lake Mwc?
Copco Lake Mwc (PWSID CA4700551) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Copco Lake Mwc serve?
Copco Lake Mwc reports serving 181 people through 65 service connections in Siskiyou County, Arizona.
Where does Copco Lake Mwc 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 Copco Lake Mwc 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 August 1993. 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 Copco Lake Mwc'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 August 1993. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Copco Lake Mwc's water quality report?
As a community water system, Copco Lake Mwc 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.
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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, “Copco Lake Mwc, PWSID CA4700551, Arizona”, https://aquacensus.com/water-systems/arizona/copco-lake-mwc-ca4700551 (data as of October 1, 2026).