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Tap water quality report

Berryessa Highlands

EPA monitoring tested this supplier for 72 contaminants and detected 16. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

72
contaminants tested
16
detected
715
people served
46
health-based violations
California rankingsLead in CaliforniaPFAS in California
Water source
Surface water
Ownership
Local government
Counties served
Napa

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

46
health-based violations
59
violations on file
0
still open
ViolationTypeStatusPeriod
MCL Health-based Resolved 2020-04-01 → 2020-06-30
MCL Health-based Resolved 2020-04-01 → 2020-06-30
MCL Health-based Resolved 2020-04-01 → 2020-06-30
MCL Health-based Resolved 2020-01-01 → 2020-03-31
MCL Health-based Resolved 2020-01-01 → 2020-03-31
MCL Health-based Resolved 2020-01-01 → 2020-03-31
MCL Health-based Resolved 2019-10-01 → 2019-12-31
MCL Health-based Resolved 2019-10-01 → 2019-12-31
MCL Health-based Resolved 2019-10-01 → 2019-12-31
MCL Health-based Resolved 2019-07-01 → 2019-09-30

Other contaminants detected

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of this system's samples — over 100% is worth reading, but is not by itself a violation. Where a single sample came in higher than that percentile, it is noted under the bar. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
Bromodichloromethane
15.45 µg/L
No EPA limit set
worst single sample: 20 µg/L
52/52 SYR4 2012–2019
Chloroform
90.9 µg/L
No EPA limit set
worst single sample: 190 µg/L
52/52 SYR4 2012–2019
TTHM
110 µg/L 138%
of the EPA limit, at the 95th percentile of samples — 80 µg/L
worst single sample: 210 µg/L
52/52 SYR4 2012–2019
Dibromochloromethane
2.95 µg/L
No EPA limit set
worst single sample: 19 µg/L
51/52 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
67.56 µg/L 113%
of the EPA limit, at the 95th percentile of samples — 60 µg/L
worst single sample: 93 µg/L
49/49 SYR4 2012–2019
Trichloroacetic Acid
38.08 µg/L
No EPA limit set
worst single sample: 52.9 µg/L
49/49 SYR4 2012–2019
Dichloroacetic Acid
31.025 µg/L
No EPA limit set
worst single sample: 42 µg/L
48/49 SYR4 2012–2019
Monochloroacetic Acid
4.84 µg/L
No EPA limit set
worst single sample: 9.4 µg/L
20/49 SYR4 2012–2019
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
 14/14 LCR 2023
Nitrate
1197.8 µg/L 12%
of the EPA limit 10000 µg/L
 14/24 SYR4 2012–2019
Arsenic
2.73 µg/L 27%
of the EPA limit 10 µg/L
worst single sample: 3 µg/L
10/16 SYR4 2012–2019
Monobromoacetic Acid
16.605 µg/L
No EPA limit set
worst single sample: 21 µg/L
6/49 SYR4 2012–2019
Chromium
1.66 µg/L 1.7%
of the EPA limit 100 µg/L
worst single sample: 1.7 µg/L
5/12 SYR4 2012–2019
Dibromoacetic Acid
3.774 µg/L
No EPA limit set
worst single sample: 3.87 µg/L
4/49 SYR4 2012–2019
Fluoride
148.5 µg/L 3.7%
of the EPA limit 4000 µg/L
worst single sample: 150 µg/L
4/4 SYR4 2012–2016
Barium
130 µg/L 6.5%
of the EPA limit 2000 µg/L
 1/8 SYR4 2012–2019
56 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-Dichloroethane1,2-Dichloropropane2,4,5-TP2,4-DAntimony, TotalAsbestosAtrazineBhc-GammaBenzeneBeryllium, TotalBromoformChlorobenzeneCopperCadmiumCarbofuranCarbon TetrachlorideChlordaneDichloromethaneDalaponDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateHexachlorobenzeneHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoLeadMercuryMethoxychlorNitriteOxamylPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
SILKE, CHRISTOPHER
Phone
707-299-1755
Email
christopher.silke@countyofnapa.org

Frequently asked questions about Berryessa Highlands

Is Berryessa Highlands tap water safe to drink?

EPA monitoring detected 16 contaminants in Berryessa Highlands's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in Berryessa Highlands's water?

EPA monitoring detected Bromodichloromethane, Chloroform, TTHM, Dibromochloromethane, Total Haloacetic Acids (HAA5), and others. The full list with the level and data source for each is above.

How many people does Berryessa Highlands serve?

Berryessa Highlands reports serving 715 people in California, per its EPA record.

Has Berryessa Highlands had any water quality violations?

The EPA has 59 violations on file for Berryessa Highlands, of which 46 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.