Commonwealth Utilities Corp (Saipan) water quality
Saipan, MP · serves 48,524 people (11,317 connections) · Groundwater · State · EPA ID MP0000001
Data: U.S. EPA · How we read the data · How we check it
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 limitPFOS above the federal limit in EPA's 2023–2025 testing (PFOS 4.7 ppt vs a limit of 4 ppt, where ppt = parts per trillion).
- Lithium
- Above screening levelHighest result 58.4 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 level2.5 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
- Resolved14 health-based violations since 2016, most recently Nov 2023. 2 required an urgent public notice within 24 hours (the kind behind boil-water notices), most recently Nov 2023. What to do if you get a notice.
- 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.
- Got a boil-water or do-not-drink notice? What each notice means and what to do.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read Commonwealth Utilities Corp (Saipan)'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 (670) 664-4282. EPA: how to find it.
PFAS (“forever chemicals”)
EPA UCMR 5: 15 entry points tested Oct 2023 to Sep 2024. "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 Not detected Limit 4 ppt | – |
| PFOS Above limit Limit 4 ppt | 4.7 ppt 1.18× the limit |
| PFHxS One sample above limit Limit 10 ppt | 2.55 ppt 26% 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 | 0.26 |
| PFBS Detected, below limit Guideline 2,000 ppt | 1.8 ppt |
| PFBA Detected, below limit Guideline 6,000 ppt | 0 ppt |
| PFHxA Detected, below limit Guideline 3,000 ppt | 5.3 ppt |
| PFPeA Detected, no limit | 8.75 ppt |
| PFHpA Detected, no limit | 1.95 ppt |
| PFPeS Detected, no limit | 0 ppt |
| 6:2 FTS Detected, no limit | 0 ppt |
29 PFAS tested, 9 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 14 of 30 samples. Highest result 58.4 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: 2.5 ppb lead (Jan 2023 – Dec 2025). Below action level
Highest since 2016: 3.9 ppb (Dec 2022).
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2023 – Dec 2025 | 2.5 ppb |
| Jan 2020 – Dec 2022 | 3.9 ppb |
| Jan 2017 – Dec 2019 | < 0.5 ppb |
Earlier results (3)
| Jan 2019 – Jun 2019 | 2 ppb |
| Jul 2017 – Dec 2017 | 2.8 ppb |
| Jan 2016 – Jun 2016 | < 0.5 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
| When | What happened |
|---|---|
| Oct 2019 – Nov 2023 2 times | E. coli was confirmed in the water. E. coli means the water may have been contaminated with sewage or animal waste. Urgent public notice required What that means EPA record: Revised Total Coliform Rule · Maximum Contaminant Level Violation, E. coli (RTCR) Resolved |
| Oct 2023 | After positive bacteria tests, the system did not complete the required check of what went wrong. EPA record: Revised Total Coliform Rule · Treatment Technique, Level 1 Assessment (RTCR) Resolved |
| Mar 2019 – Dec 2021 10 times | An inspection found a significant problem (such as a damaged well or storage tank) that was not fixed on time. EPA record: Groundwater Rule · Failure To Address Deficiency (limit ) Resolved |
| Mar 2016 | Too many samples in a month tested positive for coliform bacteria, a sign the system may be letting germs in. EPA record: Coliform (TCR) · Maximum Contaminant Level Violation, Monthly (TCR) (limit 5% of samples) Resolved |
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 | 1 ppb | 300 ppb |
| Chlorate | 86 ppb | 210 ppb |
| Vanadium | 5.3 ppb | 21 ppb |
| Chromium-6 | 7.2 ppb | – |
| Strontium | 0.82 ppm | 1.5 ppm |
Where it serves
ZIP codes the system reported serving: 96950
Questions
Is Commonwealth Utilities Corp (Saipan) water safe to drink?
Commonwealth Utilities Corp (Saipan) had 14 health-based violations since 2016, all since resolved. 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 Commonwealth Utilities Corp (Saipan) water have PFAS?
Yes. EPA's 2023–2025 testing of Commonwealth Utilities Corp (Saipan) found 9 PFAS at least once. The highest entry-point averages were above the federal limit for PFOS: PFOS 4.7 ppt (limit 4 ppt for PFOA and PFOS, 10 ppt for the others).
What is the lead level in Commonwealth Utilities Corp (Saipan) water?
The most recent 90th-percentile lead result for Commonwealth Utilities Corp (Saipan) is 2.5 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 MP0000001: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID MP0000001).
- EPA SDWIS download: the lead results, population and violation records we use.
- The utility's annual water quality report (Consumer Confidence Report): ask Commonwealth Utilities Corp (Saipan) at (670) 664-4282, 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.