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Tap water quality report

Redwood Terrace Mutual

EPA monitoring tested this supplier for 81 contaminants and detected 19. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

81
contaminants tested
19
detected
56
people served
5
health-based violations
California rankingsLead in CaliforniaPFAS in California
Water source
Ground water under surface influence
Ownership
Private
Counties served
San Mateo

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.

5
health-based violations
134
violations on file
0
still open
ViolationTypeStatusPeriod
TT Health-based Resolved 2019-06-01
TT Health-based Resolved 2019-06-01
MCL Health-based Resolved 2002-11-01 → 2002-11-30
MCL Health-based Resolved 2002-11-01 → 2002-11-30
MCL Health-based Archived 1980-06-01 → 1982-05-31
MR Monitoring Resolved 2024-07-01
MR Monitoring Resolved 2024-07-01
MR Monitoring Resolved 2019-01-01 → 2019-12-31
MR Monitoring Resolved 2019-01-01 → 2019-12-31
MR Monitoring Resolved 2010-06-01 → 2010-06-30

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
Lead
0.0070 mg/L 47%
of the EPA limit 0.0150 mg/L
 22/22 LCR 2025
Fluoride
372.5 µg/L 9.3%
of the EPA limit 4000 µg/L
worst single sample: 410 µg/L
16/16 SYR4 2012–2018
Nitrate
858.8 µg/L 8.6%
of the EPA limit 10000 µg/L
 8/42 SYR4 2012–2018
Lead
7.665 µg/L 51%
of the EPA limit 15 µg/L
worst single sample: 7.8 µg/L
4/18 SYR4 2012–2018
Arsenic
2.88 µg/L 29%
of the EPA limit 10 µg/L
worst single sample: 2.9 µg/L
3/18 SYR4 2012–2018
Barium
28.5 µg/L 1.4%
of the EPA limit 2000 µg/L
worst single sample: 29 µg/L
3/18 SYR4 2012–2018
Total Haloacetic Acids (HAA5)
21.24 µg/L 35%
of the EPA limit 60 µg/L
worst single sample: 22 µg/L
2/3 SYR4 2016–2018
Trichloroacetic Acid
6.655 µg/L
No EPA limit set
worst single sample: 6.8 µg/L
2/3 SYR4 2016–2018
Bromodichloromethane
23 µg/L
No EPA limit set
 1/5 SYR4 2015–2018
Bromoform
20 µg/L
No EPA limit set
 1/5 SYR4 2015–2018
Chloroform
13 µg/L
No EPA limit set
 1/4 SYR4 2016–2018
Dibromoacetic Acid
12 µg/L
No EPA limit set
 1/3 SYR4 2016–2018
Dibromochloromethane
37 µg/L
No EPA limit set
 1/5 SYR4 2015–2018
Dichloroacetic Acid
4.8 µg/L
No EPA limit set
 1/3 SYR4 2016–2018
Diquat
18 µg/L 90%
of the EPA limit 20 µg/L
 1/8 SYR4 2012–2017
Monobromoacetic Acid
1.4 µg/L
No EPA limit set
 1/3 SYR4 2016–2018
Nitrate-Nitrite
120 µg/L 1.2%
of the EPA limit 10000 µg/L
 1/7 SYR4 2016–2018
TTHM
93 µg/L 116%
of the EPA limit, at the 95th percentile of samples — 80 µg/L
 1/4 SYR4 2016–2018
Toluene
38 µg/L 3.8%
of the EPA limit 1000 µg/L
 1/16 SYR4 2012–2018
62 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane2,3,7,8-TCDD2,4,5-TP2,4-DAntimony, TotalAsbestosAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCopperCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneChromiumCombined UraniumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDinosebEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateHexachlorobenzeneHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorMonochloroacetic AcidNitriteOxamylPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
MACMILLIAN, TIM
Phone
650-799-5366
Email
redwoodterracewatersystem@gmail.com

Frequently asked questions about Redwood Terrace Mutual

Is Redwood Terrace Mutual tap water safe to drink?

EPA monitoring detected 19 contaminants in Redwood Terrace Mutual'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 Redwood Terrace Mutual's water?

EPA monitoring detected Lead, Fluoride, Nitrate, Lead, Arsenic, and others. The full list with the level and data source for each is above.

How many people does Redwood Terrace Mutual serve?

Redwood Terrace Mutual reports serving 56 people in California, per its EPA record.

Has Redwood Terrace Mutual had any water quality violations?

The EPA has 134 violations on file for Redwood Terrace Mutual, of which 5 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.