Highline Water District water quality
Kent, WA · serves 100,170 people (29,544 connections) · Purchased surface water · Local government · EPA ID WA5340650
Data: U.S. EPA · How we read the data · How we check it
Buys water from King County Water District #49, Lakehaven Water and Sewer District, Tukwila Water Department, King County Water District #20, Seattle Public Utilities. Treated water bought from another system can carry that system's contaminants.
Summary
No federal limits exceeded in EPA data.
- PFAS
- Not detectedNone of 29 PFAS found above EPA's reporting limits in 8 samples (2023–2025).
- Lead
- Below action level1.4 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.
- 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 Highline Water District'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: 3 entry points tested Aug 2024 to May 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 Not detected Limit 4 ppt | – |
| PFHxS Not detected Limit 10 ppt | – |
| 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) Not detected Limit 1 | – |
| PFBS Not detected Guideline 2,000 ppt | – |
| PFBA Not detected Guideline 6,000 ppt | – |
| PFHxA Not detected Guideline 3,000 ppt | – |
29 PFAS tested, 0 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
Not detected in 8 samples (reporting limit 9 ppb). About lithium.
Lead and copper
Latest 90th percentile: 1.4 ppb lead (Jan 2023 – Dec 2025). Below action level
Highest since 2016: 5.2 ppb (Dec 2022).
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2023 – Dec 2025 | 1.4 ppb |
| Jan 2020 – Dec 2022 | 5.2 ppb |
| Jan 2017 – Dec 2019 | 4.6 ppb |
Earlier results (9)
| Jan 2014 – Dec 2016 | 2 ppb |
| Jan 2011 – Dec 2013 | 2 ppb |
| Jan 2008 – Dec 2010 | 2 ppb |
| Jan 2005 – Dec 2007 | 2 ppb |
| Jan 2002 – Dec 2004 | 3 ppb |
| Jan 1999 – Dec 2001 | 2 ppb |
| Jan 1996 – Dec 1998 | 6 ppb |
| Jan 1995 – Jun 1995 | 4 ppb |
| Jan 1994 – Dec 1994 | 4 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 | 3.9 ppb | 300 ppb |
| Chlorate | 220 ppb | 210 ppb |
| Strontium | 0.14 ppm | 1.5 ppm |
| Chromium-6 | 0.17 ppb | – |
| Vanadium | 9 ppb | 21 ppb |
Where it serves
Kent, Auburn, Federal Way, Burien, Tukwila, Des Moines
ZIP codes the system reported serving: 98001, 98003, 98005, 98032, 98089, 98148, 98166, 98188, 98198
Nearby utilities
- Kent Water Department Kent · same area
- City of Auburn Auburn · 6 mi
- Covington Water District Auburn · 6 mi · PFAS above limit
- City of Renton Renton · 6 mi
- Soos Creek Water & Sewer District Renton · 6 mi
- Lakehaven Water and Sewer District Federal Way · 8 mi
Questions
Is Highline Water District water safe to drink?
Highline Water District has no health-based violations since 2016. EPA testing found no PFAS above the federal limits. 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 Highline Water District water have PFAS?
EPA tested Highline Water District for 29 PFAS between Aug 2024 and May 2025 and none were detected above the reporting limits (about 2 to 20 ppt depending on the chemical).
What is the lead level in Highline Water District water?
The most recent 90th-percentile lead result for Highline Water District is 1.4 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 WA5340650: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID WA5340650).
- EPA SDWIS download: the lead results, population and violation records we use.
- The utility's annual water quality report (Consumer Confidence Report): ask Highline Water District, 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.