Public water system · CA3702283

Active

Mount Laguna Improvement Assn.

At a glance

Mount Laguna Improvement Assn. (PWSID CA3702283) is an active non-transient non-community water system in San Diego County, California. It reports serving 578 people through 168 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 9 violations for this system; 3 are health-based, and the most recent began in January 2022.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

578

Service connections

168

Primary source

Groundwater

System type

NTNCWS

Non-transient non-community water system

System record

PWSIDCA3702283

System typeNon-transient non-community water system

Activity statusActive

Population served578

Service connections168

Primary water sourceGroundwater

Owner typePrivate

Primacy agencyCA state drinking water program

City served—

StateCalifornia

ZIP—

CountySan Diego County

How does Mount Laguna Improvement Assn. compare with other water systems in San Diego County?

By EPA's size categories, Mount Laguna Improvement Assn. is a small system (501 to 3,300 people). San Diego County has 191 active public water systems. Its population served is well below the county average of 19,427 people per system, and accounts for less than 0.1% of the 3,710,459 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Mount Laguna Improvement Assn. is about 34% above 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. California has 1,466 active non-transient non-community water systems, 20% 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 Mount Laguna Improvement Assn.?

EPA lists Mount Laguna Improvement Assn. 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. 101 of the 191 active systems in San Diego County (53%) are also privately owned.

Does Mount Laguna Improvement Assn. have drinking water violations?

EPA's records list 9 violations for this system; 3 are health-based, and the most recent began in January 2022. The violations listed here began between January 2005 and January 2022. By type: 5 monitoring and reporting, 3 contaminant level above the legal limit and 1 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (5 of them). EPA lists 8 as resolved and 1 as addressed. 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. Addressed means the violation is not resolved or archived and is covered by formal enforcement.

Began	Violation	Contaminant or rule	Health-based	Status
2022-01-01	Monitoring and reportingMonitoring, Regular · code 03	Nitratecode 1040	No	Resolved
2019-02-01	MonitoringMonitoring, Routine (RTCR) · code 3A	Revised Total Coliform Rulecode 8000	No	Resolved
2014-05-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21	Total coliform bacteria (TCR)code 3100	Yes	Resolved
2014-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21	Total coliform bacteria (TCR)code 3100	Yes	Resolved
2011-08-28	Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52	Lead and Copper Rulecode 5000	No	Resolved
2009-04-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved
2007-06-30	Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51	Lead and Copper Rulecode 5000	No	Addressed
2005-10-01	Monitoring and reportingMonitoring, Routine Major (TCR) · code 23	Total coliform bacteria (TCR)code 3100	No	Resolved
2005-01-01	Monitoring and reportingMonitoring, Routine Major (TCR) · code 23	Total coliform bacteria (TCR)code 3100	No	Resolved

All 9 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.

Mount Laguna Improvement Assn.: frequently asked questions

Who runs Mount Laguna Improvement Assn.?

Mount Laguna Improvement Assn. (PWSID CA3702283) is a non-transient non-community water system privately owned. It is regulated by the CA state drinking water program.

How many people does Mount Laguna Improvement Assn. serve?

Mount Laguna Improvement Assn. reports serving 578 people through 168 service connections in San Diego County, California.

Where does Mount Laguna Improvement Assn. 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 Mount Laguna Improvement Assn. have any drinking water violations?

EPA's records list 9 violations for this system; 3 are health-based, and the most recent began in January 2022. 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 Mount Laguna Improvement Assn.'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 9 violations for this system; 3 are health-based, and the most recent began in January 2022. For current results, consult EPA ECHO, or the CA state drinking water program.

Where can I find Mount Laguna Improvement Assn.'s water quality report?

The annual Consumer Confidence Report requirement applies to community water systems. Mount Laguna Improvement Assn. 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 San Diego County

Water system	County	Population served	Type	Source
San Diego, City of	San Diego	1,385,379	Community	Surface water
Helix Water District	San Diego	277,668	Community	Surface water
Otay Water District	San Diego	238,008	Community	Purchased surface water
Sweetwater Authority	San Diego	191,282	Community	Surface water
Oceanside, City of	San Diego	171,483	Community	Purchased surface water
Escondido, City of	San Diego	137,044	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, “Mount Laguna Improvement Assn., PWSID CA3702283, California”, https://aquacensus.com/water-systems/california/mount-laguna-improvement-assn-ca3702283 (data as of October 1, 2026).