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Tap water quality report

Hillsborough, CA

EPA monitoring detected 7 contaminants across the 1 water supplier serving Hillsborough. A detection doesn't automatically mean the water is unsafe — see the level at the main supplier for each below, with its EPA source and period.

1
water supplier
160
people served
7
contaminants found
California rankings Lead in California PFAS in California

What was found in Hillsborough's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate
9800 µg/L 98%
of the EPA limit 10000 µg/L
Main supplier: IL VINETO · 160 people · 2019
1/1 SYR4
Nitrate-Nitrite
9510 µg/L 95%
of the EPA limit 10000 µg/L
Main supplier: IL VINETO · 160 people · 2019
1/1 SYR4
Fluoride
186.5 µg/L 4.7%
of the EPA limit 4000 µg/L
Main supplier: IL VINETO · 160 people · 2019
1/1 SYR4
Barium
165 µg/L 8.3%
of the EPA limit 2000 µg/L
Main supplier: IL VINETO · 160 people · 2019
1/1 SYR4
Copper
108.3 µg/L 8.3%
of the EPA limit 1300 µg/L
Main supplier: IL VINETO · 160 people · 2019
1/1 SYR4
1,2-DIBROMO-3-CHLOROPROPANE
0.9265 µg/L 463%
of the EPA limit, at the 95th percentile of samples — 0.2000 µg/L
Main supplier: IL VINETO · 160 people · 2019
1/1 SYR4
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
Main supplier: IL VINETO · 160 people · 2023
1/1 LCR
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 the system's samples — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Hillsborough

SupplierPopulation served
IL VINETO 160

Frequently asked questions about Hillsborough tap water

Is Hillsborough tap water safe to drink?

EPA testing detected 7 contaminants in the water serving Hillsborough. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Hillsborough?

1 public water supplier report drinking-water monitoring for Hillsborough, California to the EPA. Each is listed above with its population served.

What contaminants are in Hillsborough's water?

The contaminants EPA monitoring detected in Hillsborough include Nitrate, Nitrate-Nitrite, Fluoride, Barium, Copper. The full list, with the level at the main supplier and the data source, is in the table above.

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.