PlainWater
States → California

Community Water System · PWS CA4110012

Cuesta la Honda Guild Inc

La Honda, California 94020 - drinking water served from surface water sources to 915 people, tracked in EPA SDWIS and UCMR5.

915
People served
74
EPA violations
10
Health-based
Untested
UCMR5 result

The verdict

EPA records 74 drinking-water violations at Cuesta la Honda Guild Inc, 14% of them health-based - above the California per-system average.

74
Total EPA violations on record
14%
Health-based (MCL / treatment failure)
915
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Cuesta la Honda Guild Inc

Cuesta la Honda Guild Inc is a private-owned community water system that delivers drinking water to 915 residents in La Honda, California (San Mateo County) through 299 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 74 total violations for this system , of which 10 (14%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 64 monitoring and reporting violations are on file. The most recent violation on record dates to 2021.

The most frequently cited contaminant at this system is Total Haloacetic Acids (HAA5), recorded in 8 violations (MCL, health-based). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across California, EPA tracks 7,249 public water systems serving 42,404,883 people, with 153,308 cumulative violations and 63,983 health-based violations on record. About 89% of systems in the state carry at least one violation, and state-wide the average per system is 21.1 violations. Statewide, 447 of 694 UCMR5-tested systems have reported PFAS detections (64.4%).

Cuesta la Honda Guild Inc's 74 violations sit above the California average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
915
Total Violations
74
Health-Based Violations
10
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Private
Connections
299
County
San Mateo
School/Daycare
No
MCL Violations
8
Monitoring Violations
64
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Total Haloacetic Acids (HAA5) MCL 8 2021
Surface Water Treatment Rule TT 2 2010
Toxaphene MR 2 2019
Dalapon MR 2 2019
Endothall MR 2 2019
Simazine MR 2 2019
Picloram MR 2 2019
Hexachlorocyclopentadiene MR 2 2019
Atrazine MR 2 2019
Carbofuran MR 2 2019
LASSO MR 2 2019
Heptachlor MR 2 2019
2,4-D MR 2 2019
Benzo(a)pyrene MR 2 2019
Pentachlorophenol MR 2 2019
Total Polychlorinated Biphenyls (PCB) MR 2 2019
ETHYLENE DIBROMIDE MR 2 2019
Chlordane MR 2 2019
Coliform (TCR) MR 2 2000
2,4,5-TP MR 2 2019
BHC-GAMMA MR 2 2019
Di(2-ethylhexyl) phthalate MR 2 2019
2,3,7,8-TCDD MR 2 2019
Glyphosate MR 2 2019
1,2-DIBROMO-3-CHLOROPROPANE MR 2 2019
OXAMYL MR 2 2019
Endrin MR 2 2019
Heptachlor epoxide MR 2 2019
HEXACHLOROBENZENE MR 2 2019
Diquat MR 2 2019

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Cuesta la Honda Guild Inc.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID CA4110012 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

California Drinking Water Authority

California State Water Resources Control Board, Division of Drinking Water is the primacy agency that licenses and inspects Cuesta la Honda Guild Inc under EPA-delegated authority.

Open CA regulator portal

Source: California State Water Resources Control Board, Division of Drinking Water

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2021 Total Haloacetic Acids (HAA5) MCL 8 SDWIS / CA4110012 / 2456
2019 Toxaphene MR 2 SDWIS / CA4110012 / 2020
2019 Dalapon MR 2 SDWIS / CA4110012 / 2031
2019 Endothall MR 2 SDWIS / CA4110012 / 2033
2019 Simazine MR 2 SDWIS / CA4110012 / 2037
2019 Picloram MR 2 SDWIS / CA4110012 / 2040
2019 Hexachlorocyclopentadiene MR 2 SDWIS / CA4110012 / 2042
2019 Atrazine MR 2 SDWIS / CA4110012 / 2050
2019 Carbofuran MR 2 SDWIS / CA4110012 / 2046
2019 LASSO MR 2 SDWIS / CA4110012 / 2051
2019 Heptachlor MR 2 SDWIS / CA4110012 / 2065
2019 2,4-D MR 2 SDWIS / CA4110012 / 2105
2019 Benzo(a)pyrene MR 2 SDWIS / CA4110012 / 2306
2019 Pentachlorophenol MR 2 SDWIS / CA4110012 / 2326
2019 Total Polychlorinated Biphenyls (PCB) MR 2 SDWIS / CA4110012 / 2383

How Cuesta la Honda Guild Inc Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Cuesta la Honda Guild Inc California avg Federal benchmark
Total violations 74 21.1 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 10 8.8 Indicates a contaminant exceeded a federal MCL
PFAS detection None 64.4% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 915 5,850 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 7,249 regulated public water systems in California.

Federal MCL reference, Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Cuesta la Honda Guild Inc water safe to drink? ▼
Cuesta la Honda Guild Inc (PWS ID: CA4110012) has 74 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 915 people using Surface Water sources.
How many people does Cuesta la Honda Guild Inc serve? ▼
Cuesta la Honda Guild Inc serves 915 people in La Honda, California. It is a Private-owned system using Surface Water water sources with 299 service connections.
What type of violations does Cuesta la Honda Guild Inc have? ▼
Cuesta la Honda Guild Inc has 74 total violations: 10 health-based violations (MCL exceedances or treatment failures), 64 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Cuesta la Honda Guild Inc water? ▼
No PFAS testing data is available for Cuesta la Honda Guild Inc under the EPA's UCMR5 monitoring program.
What water source does Cuesta la Honda Guild Inc use? ▼
Cuesta la Honda Guild Inc uses Surface Water as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.