Public water system record
Nicasio Valley Ranch Mutual
Serves Nicasio, Marin County, CA · 36 people served
Federal records show 6 health-based violations and 3 monitoring/reporting issues for Nicasio Valley Ranch Mutual in the last ten years. The most serious issue in this window was a resolved Total Trihalomethanes (TTHMs) violation.
System profile
- Health-based violations, last 10 years
- 6
- Resolved
- 6
- Unresolved
- 0
- Any acute record
- No
- Monitoring issues, last 10 years
- 3
Key facts
- Nicasio Valley Ranch Mutual draws water from 2 wells.
- Highest measured level in the last 10 years: Total Trihalomethanes (TTHMs), 140 µg/L, federal limit 80 µg/L (1.8 times the limit), 2019.
- Most recent formal enforcement: compliance order (no penalty) by California, February 2022.
- Record on file since 2002, with 5 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 0 unknown out of 13 service lines.
Check whether Nicasio Valley Ranch Mutual serves your address
Health-based violations
Since October 2016Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.
| Contaminant | Rule family | Start date | Status | Acute |
|---|---|---|---|---|
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.096 mg/L, federal limit 0.08 mg/L (1.2 times the limit)
|
220 | Oct 1, 2021 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 140 µg/L, federal limit 80 µg/L (1.8 times the limit)
|
220 | Jul 1, 2019 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 81 µg/L, federal limit 80 µg/L (at or just above the limit)
|
220 | Apr 1, 2019 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 89 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
220 | Oct 1, 2018 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 98 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
220 | Jul 1, 2018 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 130 µg/L, federal limit 80 µg/L (1.6 times the limit)
|
220 | Oct 1, 2017 | Resolved | No |
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Arsenic
Monitoring and reporting
|
Jul 1, 2020 | Resolved |
|
Arsenic
Monitoring and reporting
|
May 1, 2020 | Resolved |
|
Miscellaneous Other Rules
OTHER
|
Oct 1, 2019 | Resolved |
Full record since 2002
EPA's records for Nicasio Valley Ranch Mutual go back to 2002. Before October 19, 2016 they list 5 health-based violations (5 resolved) and 1 monitoring or reporting violation.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 2000s | 2 | 1 |
| 2010 to October 18, 2016 | 3 | 0 |
| October 19, 2016 to 2019 | 5 | 1 |
| 2020s | 1 | 2 |
Most recent health-based violation before October 19, 2016: Total Trihalomethanes (TTHMs), began October 2015, Resolved.
Show all 5 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
|
Oct 1, 2015 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.13 mg/L, federal limit 0.08 mg/L (1.6 times the limit)
|
Jul 1, 2015 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.084 mg/L, federal limit 0.08 mg/L (1.1 times the limit)
|
Apr 1, 2015 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Sep 1, 2003 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Mar 1, 2002 | Resolved |
Enforcement actions
California regulators took 6 formal enforcement actions against Nicasio Valley Ranch Mutual between 2015 and 2022. The most recent was a compliance order (no penalty) in February 2022.
| Date | By | Action | Violations covered |
|---|---|---|---|
| Feb 23, 2022 | California | Compliance order (no penalty) | 1 violation (1 health-based): Total Trihalomethanes (TTHMs) |
| Dec 4, 2020 | California | Compliance order (no penalty) | 1 violation: Arsenic |
| Nov 5, 2020 | California | Compliance order (no penalty) | 1 violation: Miscellaneous Other Rules |
| Oct 23, 2020 | California | Compliance order (no penalty) | 1 violation: Arsenic |
| Apr 27, 2020 | California | Compliance order (no penalty) | 6 violations (5 health-based): Total Trihalomethanes (TTHMs), Miscellaneous Other Rules |
| Jul 7, 2015 | California | Compliance order (no penalty) | 3 violations (3 health-based): Total Trihalomethanes (TTHMs) |
What the violations mean
Total Trihalomethanes (TTHMs)
6 incidentsDisinfection byproduct levels exceeded the federal limit
Long-term TTHM exposure may increase bladder cancer risk
Where the water comes from
Nicasio Valley Ranch Mutual draws water from 2 wells.
Annual water quality report
Nicasio Valley Ranch Mutual must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.
Systems serving 500 or fewer people may meet the rule by telling customers the report is available on request, so you may need to ask Nicasio Valley Ranch Mutual for a copy.
Find a posted report with EPA's Consumer Confidence Report search
Testing your own water
To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by California.
Certified drinking water labs by state EPA guidance for private wells