Is Moses Lake, WA tap water safe?
Supplied by City of Moses Lake · serves 32,428 people (13,420 connections) · Groundwater · EPA ID WA5356300
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, PFHxS, the PFAS Hazard Index above the federal limit in EPA's 2023–2025 testing (PFOS 31.4 ppt vs a limit of 4 ppt, PFHxS 31.8 ppt vs a limit of 10 ppt, where ppt = parts per trillion).
- Lithium
- Above screening levelHighest result 35.6 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 level3.2 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 2023. 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 Moses Lake'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. EPA: how to find it.
PFAS (“forever chemicals”)
EPA UCMR 5: 18 entry points tested Aug 2023 to Jan 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 Not detected Limit 4 ppt | – |
| PFOS Above limit Limit 4 ppt | 31.4 ppt 7.85× the limit |
| PFHxS Above limit Limit 10 ppt | 31.8 ppt 3.17× 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) Above limit Limit 1 | 3.18 |
| PFBS Detected, below limit Guideline 2,000 ppt | 2.2 ppt |
| PFBA Not detected Guideline 6,000 ppt | – |
| PFHxA Detected, below limit Guideline 3,000 ppt | 3.65 ppt |
| PFPeS Detected, no limit | 2.65 ppt |
For context: the PFOS average is higher than at 99% of the Washington systems EPA tested and the PFHxS average is higher than at 99% of the Washington systems EPA tested.
29 PFAS tested, 5 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 34 of 36 samples. Highest result 35.6 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: 3.2 ppb lead (Jan 2021 – Dec 2023). Below action level
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2021 – Dec 2023 | 3.2 ppb |
| Jan 2018 – Dec 2020 | 1.9 ppb |
| Jan 2015 – Dec 2017 | 1.8 ppb |
Earlier results (9)
| Jan 2012 – Dec 2014 | 1.3 ppb |
| Jan 2009 – Dec 2011 | 2.8 ppb |
| Jan 2006 – Dec 2008 | 1.9 ppb |
| Jan 2003 – Dec 2005 | 0.8 ppb |
| Jan 2000 – Dec 2002 | 2.1 ppb |
| Jan 1996 – Dec 1998 | 2.2 ppb |
| Jul 1995 – Dec 1995 | 2 ppb |
| Jan 1994 – Dec 1994 | 2 ppb |
| Jan 1993 – Jun 1993 | 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
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 | 100 ppb | 300 ppb |
| Vanadium | 50 ppb | 21 ppb |
| Strontium | 0.4 ppm | 1.5 ppm |
| Molybdenum | 8.9 ppb | 40 ppb |
| Chromium-6 | 0.17 ppb | – |
| Chlorate | 130 ppb | 210 ppb |
Where it serves
Moses Lake
ZIP codes the system reported serving: 98837
Nearby utilities
- City of Richland Richland · 58 mi
- Benton City Water Benton City · 60 mi · PFAS above limit
- Pasco Water Department Pasco · 61 mi
- City of Kennewick Kennewick · 64 mi · PFAS above limit
- City of Yakima Water Division Yakima · 70 mi
- Fairchild Air Force Base Water System Fairchild AFB · 84 mi · PFAS above limit
Questions
Is Moses Lake tap water safe to drink?
Most of Moses Lake gets its water from City of Moses Lake. City of Moses Lake 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 Moses Lake water have PFAS?
Yes. EPA's 2023–2025 testing of City of Moses Lake found 5 PFAS at least once. The highest entry-point averages were above the federal limit for PFOS and PFHxS: PFOS 31.4 ppt, PFHxS 31.8 ppt (limit 4 ppt for PFOA and PFOS, 10 ppt for the others).
What is the lead level in Moses Lake water?
The most recent 90th-percentile lead result for City of Moses Lake is 3.2 ppb, for the period ending Dec 2023. 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 WA5356300: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID WA5356300).
- 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 Moses Lake, 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.