City of Paso Robles Water Division water quality
Paso Robles, CA · serves 31,176 people (11,014 connections) · Surface water · Local government · EPA ID CA4010007
Data: U.S. EPA · How we read the data · How we check it
Buys water from Nacimiento Water Project. Treated water bought from another system can carry that system's contaminants.
Summary
PFAS above the 2024 federal limits. Systems have until 2029 to meet the PFAS limits.
Is it an emergency? No: PFAS limits are about years of exposure, not a glass of water, and nothing in EPA's data calls for you to stop drinking the water today. If your utility ever issues a boil-water or do-not-drink notice, follow it.
- PFAS
- Above limitPFOA above the federal limit in EPA's 2023–2025 testing (PFOA 5.55 ppt vs a limit of 4 ppt, where ppt = parts per trillion).
- Lithium
- Above screening levelHighest result 49.2 ppb. EPA uses 10 ppb to decide what to study further. It is not a health limit, and there is no federal limit for lithium. About 1 in 4 systems tested were above it.
- Lead
- Below action level0 ppb (parts per billion) at the 90th percentile: 9 in 10 homes sampled were at or below it. Action level 15 ppb, falling to 10 ppb in Nov 2027. Monitoring period ending Dec 2025. Your home's pipes can make yours higher.
- Violations
- None health-basedNo health-based violations since 2016.
- Pregnant, or mixing baby formula with tap water? Babies drink more water for their size, so PFAS exposure matters more for them. Consider bottled water or a filter certified for PFAS for formula, and ask your doctor. Health effects.
- To lower your PFAS exposure now, a home filter certified for PFAS reduction works (reverse osmosis, or activated carbon certified to NSF/ANSI 53 or 58). Filters for these results.
- Built before 1986, or not sure what your service line is made of? Check your service line and test your tap. Utility data can't show your pipes.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read City of Paso Robles Water Division's annual water quality report (Consumer Confidence Report). It lists every regulated contaminant tested and is usually on the utility's website or mailed with your bill, and you can also request it at (805) 237-3861. EPA: how to find it.
PFAS (“forever chemicals”)
EPA UCMR 5: 12 entry points tested Dec 2024 to Oct 2025. "Average" is the highest entry-point average (non-detects counted as zero), the way EPA compares UCMR 5 results to the limits. ppt = parts per trillion. These results do not determine compliance.
| Contaminant | Highest average |
|---|---|
| PFOA Above limit Limit 4 ppt | 5.55 ppt 1.39× the limit |
| PFOS Not detected Limit 4 ppt | – |
| PFHxS Detected, below limit Limit 10 ppt | 4.5 ppt 45% of the limit |
| PFNA Not detected Limit 10 ppt | – |
| HFPO-DA (GenX) Not detected Limit 10 ppt | – |
| Hazard Index (a combined score for PFHxS, PFNA, GenX and PFBS, where above 1 is over the limit) Detected, below limit Limit 1 | 0.45 |
| PFBS Detected, below limit Guideline 2,000 ppt | 7.2 ppt |
| PFBA Detected, below limit Guideline 6,000 ppt | 3.05 ppt |
| PFHxA Detected, below limit Guideline 3,000 ppt | 17.5 ppt |
| PFPeA Detected, no limit | 19.5 ppt |
| PFHpA Detected, no limit | 5.5 ppt |
For context: the PFOA average is higher than at 90% of the California systems EPA tested.
29 PFAS tested, 7 detected at least once. "Not detected" means below EPA's reporting limit (about 2 to 20 ppt depending on the chemical), not proven zero. PFAS not listed were not detected. The limits for PFHxS, PFNA, GenX and the Hazard Index were proposed for rescission in May 2026. That proposal is not final. Systems have until 2029 to meet the limits.
Lithium
Detected in 21 of 26 samples. Highest result 49.2 ppb. EPA's non-enforceable screening level is 10 ppb. Above screening level The screening level is how EPA decides what to study further, not a health limit. There is no federal limit for lithium and no filter is certified to remove it. About lithium.
Lead and copper
Latest 90th percentile: 0 ppb lead (Jan 2023 – Dec 2025). Below action level
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2023 – Dec 2025 | 0 ppb |
| Jan 2020 – Dec 2022 | 0 ppb |
| Jan 2017 – Dec 2019 | 0 ppb |
Earlier results (9)
| Jan 2014 – Dec 2016 | 0 ppb |
| Jan 2011 – Dec 2013 | 0 ppb |
| Jan 2008 – Dec 2010 | 0 ppb |
| Jan 2005 – Dec 2007 | 0 ppb |
| Jan 2004 – Dec 2004 | 5 ppb |
| Jan 2002 – Dec 2004 | 0 ppb |
| Jan 2003 – Dec 2003 | 5 ppb |
| Jan 2001 – Dec 2003 | 0 ppb |
| Jan 2000 – Dec 2002 | 0 ppb |
Lead comes from pipes and fixtures, not the source water, so it varies home to home. The 90th percentile means 9 in 10 sampled homes were at or below it. More on lead.
Violations
Health-based violations mean a contaminant exceeded a limit or a required treatment step was missed. Monitoring and reporting violations mean required tests or reports were late or missing, so the water's quality during that time is unknown. The total includes every violation in EPA's records, most of them paperwork.
Earlier EPA testing (2013–2020)
| Contaminant | Highest | Guideline |
|---|---|---|
| Manganese | 47 ppb | 300 ppb |
| Molybdenum | 86 ppb | 40 ppb |
| Chlorate | 3,100 ppb | 210 ppb |
| Chromium-6 | 2.8 ppb | – |
| Strontium | 0.77 ppm | 1.5 ppm |
| Vanadium | 58 ppb | 21 ppb |
Where it serves
ZIP codes the system reported serving: 93446
Questions
Is City of Paso Robles Water Division water safe to drink?
City of Paso Robles Water Division has no health-based violations since 2016. EPA testing found PFAS above the 2024 federal limits, which systems must meet by 2029. Federal data can't tell you about your own pipes: lead comes from service lines and plumbing, so test your tap if your home was built before 1986. For the official word, read the utility's annual Consumer Confidence Report.
Does City of Paso Robles Water Division water have PFAS?
Yes. EPA's 2023–2025 testing of City of Paso Robles Water Division found 7 PFAS at least once. The highest entry-point averages were above the federal limit for PFOA: PFOA 5.55 ppt (limit 4 ppt for PFOA and PFOS, 10 ppt for the others).
What is the lead level in City of Paso Robles Water Division water?
The most recent 90th-percentile lead result for City of Paso Robles Water Division is 0 ppb, for the period ending Dec 2025. The federal action level is 15 ppb, falling to 10 ppb in November 2027. The 90th percentile means 9 in 10 homes sampled were at or below this number. Individual homes can be higher.
Check these numbers yourself
Every figure on this page comes from public EPA records. You don't have to take our word for it:
- EPA's own report for CA4010007: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID CA4010007).
- EPA SDWIS download: the lead results, population and violation records we use.
- The utility's annual water quality report (Consumer Confidence Report): ask City of Paso Robles Water Division at (805) 237-3861, or see EPA's guide to finding it.
Found something that doesn't match? Tell us and we'll check it against EPA's records. How we check our data.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.