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Tap water quality report

Lopez Project

EPA monitoring tested this supplier for 63 contaminants and detected 18. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

63
contaminants tested
18
detected
1,569
people served
4
health-based violations
California rankingsLead in CaliforniaPFAS in California
Water source
Surface water
Ownership
Local government
Counties served
San Luis Obispo

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.

4
health-based violations
5
violations on file
0
still open
ViolationTypeStatusPeriod
MCL Health-based Resolved 2025-04-01 → 2025-04-30
MCL Health-based Resolved 2025-04-01 → 2025-04-30
MCL Health-based Resolved 2008-08-01 → 2008-08-31
MCL Health-based Resolved 2008-08-01 → 2008-08-31
MR Monitoring Resolved 1993-07-01 → 2000-03-01

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
Dichloroacetic Acid
29.67 µg/L
No EPA limit set
worst single sample: 38.3 µg/L
144/144 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
49.98 µg/L 83%
of the EPA limit 60 µg/L
worst single sample: 81.3 µg/L
144/144 SYR4 2012–2019
Trichloroacetic Acid
16.21 µg/L
No EPA limit set
worst single sample: 37.5 µg/L
144/144 SYR4 2012–2019
Bromodichloromethane
21.86 µg/L
No EPA limit set
worst single sample: 33.5 µg/L
143/143 SYR4 2012–2019
Chloroform
47.06 µg/L
No EPA limit set
worst single sample: 64.8 µg/L
143/143 SYR4 2012–2019
TTHM
73.44 µg/L 92%
of the EPA limit 80 µg/L
worst single sample: 106.9 µg/L
143/143 SYR4 2012–2019
Dibromochloromethane
16.35 µg/L
No EPA limit set
worst single sample: 19.3 µg/L
139/143 SYR4 2012–2019
Dibromoacetic Acid
7.8 µg/L
No EPA limit set
worst single sample: 8.9 µg/L
137/144 SYR4 2012–2019
Bromoform
7.36 µg/L
No EPA limit set
worst single sample: 12 µg/L
73/143 SYR4 2012–2019
Arsenic
7.2 µg/L 72%
of the EPA limit 10 µg/L
worst single sample: 7.6 µg/L
71/72 SYR4 2012–2019
Monochloroacetic Acid
5.26 µg/L
No EPA limit set
worst single sample: 9.2 µg/L
47/144 SYR4 2012–2019
Copper
203 µg/L 16%
of the EPA limit 1300 µg/L
worst single sample: 220 µg/L
18/19 SYR4 2012–2019
Fluoride
628.25 µg/L 16%
of the EPA limit 4000 µg/L
worst single sample: 935 µg/L
16/16 SYR4 2012–2019
Monobromoacetic Acid
1.1 µg/L
No EPA limit set
 11/144 SYR4 2012–2019
Barium
30 µg/L 1.5%
of the EPA limit 2000 µg/L
 6/18 SYR4 2012–2019
Nitrate
111.192 µg/L 1.1%
of the EPA limit 10000 µg/L
 6/32 SYR4 2012–2019
Lead
0.00079 mg/L 5.3%
of the EPA limit 0.0150 mg/L
 2/2 LCR 2025
Lead
3.09 µg/L 21%
of the EPA limit 15 µg/L
worst single sample: 3.1 µg/L
2/18 SYR4 2012–2019
45 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-DichloropropaneAntimony, TotalAsbestosAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCyanideCadmiumCarbon TetrachlorideChromiumDichloromethaneDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateEthylene DibromideEndothallEthylbenzeneHexachlorobenzeneHexachlorocyclopentadieneLassoMercuryMethoxychlorNitrate-NitriteNitriteSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
RUEDAS, DANIELLE
Phone
805-473-7156
Email
druedas@co.slo.ca.us

Frequently asked questions about Lopez Project

Is Lopez Project tap water safe to drink?

EPA monitoring detected 18 contaminants in Lopez Project'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 Lopez Project's water?

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

How many people does Lopez Project serve?

Lopez Project reports serving 1,569 people in California, per its EPA record.

Has Lopez Project had any water quality violations?

The EPA has 5 violations on file for Lopez Project, of which 4 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.