What was found in La Honda'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.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate | 4100 µg/L 41% of the EPA limit 10000 µg/L Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019 | 3/4 | SYR4 |
| Fluoride | 447.5 µg/L 11% of the EPA limit 4000 µg/L Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019 | 4/4 | SYR4 |
| Barium | 180 µg/L 9% of the EPA limit 2000 µg/L Highest in the city: PORTOLA IMPROVEMENT ASSOCIATION MWC · 90 people · 2019 | 3/4 | SYR4 |
| Nitrate-Nitrite | 120 µg/L 1.2% of the EPA limit 10000 µg/L Highest in the city: REDWOOD TERRACE MUTUAL · 56 people · 2018 | 1/4 | SYR4 |
| TTHM | 62.7035 µg/L 78% of the EPA limit 80 µg/L Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019
Highest in the city: 113.79 µg/L — CAMP JONES GULCH · 357 people · 2019 | 4/4 | SYR4 |
| Copper | 81 µg/L 6.2% of the EPA limit 1300 µg/L Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019 | 2/4 | SYR4 |
| Total Haloacetic Acids (HAA5) | 73.035 µg/L 122% of the EPA limit, at the 95th percentile of samples — 60 µg/L Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019 | 4/4 | SYR4 |
| Chloroform | 50.0205 µg/L No EPA limit set Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019 | 4/4 | SYR4 |
| Dichloroacetic Acid | 46.295 µg/L No EPA limit set Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019 | 4/4 | SYR4 |
| Toluene | 38 µg/L 3.8% of the EPA limit 1000 µg/L Highest in the city: REDWOOD TERRACE MUTUAL · 56 people · 2018 | 1/4 | SYR4 |
| Dibromochloromethane | 5.6775 µg/L No EPA limit set Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019
Highest in the city: 37 µg/L — REDWOOD TERRACE MUTUAL · 56 people · 2018 | 4/4 | SYR4 |
| Bromodichloromethane | 12.3045 µg/L No EPA limit set Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019
Highest in the city: 36.55 µg/L — CAMP JONES GULCH · 357 people · 2019 | 4/4 | SYR4 |
| Trichloroacetic Acid | 23.6 µg/L No EPA limit set Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019 | 4/4 | SYR4 |
| Bromoform | 2.256 µg/L No EPA limit set Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019
Highest in the city: 20 µg/L — REDWOOD TERRACE MUTUAL · 56 people · 2018 | 4/4 | SYR4 |
| Diquat | 18 µg/L 90% of the EPA limit 20 µg/L Highest in the city: REDWOOD TERRACE MUTUAL · 56 people · 2017 | 1/4 | SYR4 |
| Dibromoacetic Acid | 4.065 µg/L No EPA limit set Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019
Highest in the city: 12 µg/L — REDWOOD TERRACE MUTUAL · 56 people · 2018 | 4/4 | SYR4 |
| Bromate | 11 µg/L 110% of the EPA limit, at the 95th percentile of samples — 10 µg/L Highest in the city: CAMP JONES GULCH · 357 people · 2019 | 1/4 | SYR4 |
| Lead | 7.665 µg/L 51% of the EPA limit 15 µg/L Highest in the city: REDWOOD TERRACE MUTUAL · 56 people · 2018 | 1/4 | SYR4 |
| Monochloroacetic Acid | 5.55 µg/L No EPA limit set Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019 | 2/4 | SYR4 |
| Arsenic | 3.74 µg/L 37% of the EPA limit 10 µg/L Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019 | 3/4 | SYR4 |
| Cyanide | 2.2 µg/L 1.1% of the EPA limit 200 µg/L Highest in the city: CAMP JONES GULCH · 357 people · 2019 | 1/4 | SYR4 |
| Monobromoacetic Acid | 2.08 µg/L No EPA limit set Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2019 | 4/4 | SYR4 |
| Cadmium | 1.095 µg/L 22% of the EPA limit 5 µg/L Highest in the city: PORTOLA IMPROVEMENT ASSOCIATION MWC · 90 people · 2019 | 1/4 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 0.2100 µg/L 3.5% of the EPA limit 6 µg/L Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2018 | 1/4 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: CUESTA LA HONDA GUILD INC · 915 people · 2023
Highest in the city: 0.0070 mg/L — REDWOOD TERRACE MUTUAL · 56 people · 2025 | 4/4 | 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 La Honda
| Supplier | Population served |
|---|---|
| CUESTA LA HONDA GUILD INC | 915 |
| CAMP JONES GULCH | 357 |
| PORTOLA IMPROVEMENT ASSOCIATION MWC | 90 |
| REDWOOD TERRACE MUTUAL | 56 |
Frequently asked questions about La Honda tap water
Is La Honda tap water safe to drink?
EPA testing detected 25 contaminants in the water serving La Honda. 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 La Honda?
4 public water suppliers report drinking-water monitoring for La Honda, California to the EPA. Each is listed above with its population served.
What contaminants are in La Honda's water?
The contaminants EPA monitoring detected in La Honda include Nitrate, Fluoride, Barium, Nitrate-Nitrite, TTHM. 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.