Portland Water Quality Report 2026: What’s in Your Tap Water
QUICK SUMMARY:
- Overall Rating: Good
- Top Contaminants of Concern: Disinfection byproducts (haloacetic acids and trihalomethanes) formed when chlorine meets the watershed’s natural organic matter, lead leaching from older premise plumbing into soft and historically corrosive water, and naturally occurring radon from the source geology
- Recommended Filter Type: Catalytic carbon at the tap for chloramine and disinfection byproducts, plus a lead-certified point-of-use filter if you live in an older home — see the best under sink water filters and best water filters for lead removal guides
- Water Hardness: Soft — Bull Run runs about 7–11 ppm (roughly ½ grain per gallon); the groundwater backup is moderately hard near 80 ppm (about 5 GPG)
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The Portland Water Bureau serves roughly 666,000 people from one of the best-protected surface water supplies in the country. According to the utility’s 2025 Drinking Water Quality Report, the system met every federal health-based standard, with no health-related violations. That statement is accurate, and it is also incomplete. Federal compliance is a legal threshold, not a measure of how clean the water is.
Here’s what the data actually shows. Portland’s source water is genuinely excellent — PFAS was not detected, nitrate sits near the detection limit, and arsenic appears only in trace amounts. The contaminants worth attention are narrower and specific to how this system works: the byproducts that form when chlorine disinfects an unfiltered surface supply, the lead that enters water inside older homes because Portland’s water is soft and historically corrosive, and the naturally occurring radon that comes with the geology. Each calls for a different response.
Where Does Portland Get Its Water?
Portland is primarily a surface-water city. Its main supply originates as rain and snowmelt in the Bull Run Watershed, a protected, largely roadless forest in the Mount Hood National Forest, where two dams hold the water before it travels by gravity to the city. Public access has been restricted for more than a century, which is why the raw water carries almost none of the agricultural and industrial loading that defines river-fed systems elsewhere. When Bull Run runs low — typically late summer or during maintenance — Portland switches to a secondary source, the Columbia South Shore Well Field, a set of groundwater wells along the Columbia River. The two sources have different chemistry, which becomes relevant for hardness and radon.
One fact shapes everything below: Portland does not currently filter its Bull Run water. The utility disinfects it but does not run it through a filtration plant. In response to a series of low-level Cryptosporidium detections (a chlorine-resistant parasite found in most freshwater ecosystems), Portland is required to build filtration. The federal deadline to have the plant operational is September 2027, though construction delays and a land-use dispute have pushed the city’s own expected completion closer to 2029, and Portland has asked the state for a two-year extension. Until the plant comes online, the water reaching your tap is disinfected but unfiltered — unusual for a major US system, and central to its profile.
How Portland Treats Its Water: Chlorine, Ammonia, and Chloramine
Portland’s current treatment is a three-step process. Chlorine is added first to disinfect against bacteria, viruses, and Giardia. Ammonia is then added to stabilize that chlorine into chloramine — a longer-lasting combined disinfectant that protects the water as it moves through the distribution system. Finally, sodium carbonate and carbon dioxide are added to the Bull Run supply (and sodium hydroxide to the groundwater) to raise the pH and reduce corrosion.
That sequence has two consequences for your glass. The first is disinfection byproducts, covered next. The second is the reason the corrosion step exists at all: Portland’s water is soft and, left untreated, chemically aggressive toward the metals in household plumbing. Chloramine also behaves differently from free chlorine — it does not dissipate if you leave a pitcher on the counter, and a basic carbon filter struggles with it, which matters when you choose a filter. For the full comparison, see our guide to chloramine vs chlorine in tap water.
What Contaminants Are in Portland Tap Water?
The table below draws on Portland’s 2025 Drinking Water Quality Report (results reported through 2024) and the EWG Tap Water Database. One column needs explaining first. The EPA’s Maximum Contaminant Level (MCL) is the legal limit — the number a utility cannot exceed without a violation. The EWG Health Guideline is a stricter, health-based benchmark set at roughly a one-in-one-million lifetime cancer risk. The gap between the two is where most of the meaningful risk lives, because the federal legal limits for several of these contaminants have not been updated in close to twenty years.
| Contaminant | Detected Level | EPA MCL | EWG Guideline | Health Concern |
|---|---|---|---|---|
| Haloacetic acids (HAA5) | 24.3 ppb (avg) | 60 ppb | 0.1 ppb | Cancer, reproductive harm |
| Haloacetic acids (HAA9) | 30.6 ppb (avg) | None | 0.06 ppb | Cancer |
| Total trihalomethanes (TTHMs) | 22.5 ppb (avg) | 80 ppb | 0.15 ppb | Cancer, fetal development |
| Lead (at the tap) | 4.4 ppb (90th pct) | 15 ppb (action level) | 0 ppb | Neurological damage |
| Arsenic | 0.458 ppb | 10 ppb | 0.004 ppb | Cancer |
| Radon | 152 pCi/L (avg) | None final | — | Lung cancer |
| Chromium-6 | 0.0362 ppb | None | 0.02 ppb | Cancer |
| Nitrate | 0.092 ppm | 10 ppm | 0.14 ppm | Oxygen delivery in infants |
| PFOA / PFOS | Not detected | 4 ppt | 0.09 / 0.3 ppt | Cancer, immune effects |
Read the haloacetic acids row carefully. Portland’s measured HAA5 average — about 24.3 ppb — sits well under the EPA’s legal ceiling of 60 ppb, so by the federal standard this is compliant water. Measured against the EWG health guideline of 0.1 ppb, the same number comes in at roughly 240 times the guideline. Both figures are true at once. That is precisely the point where regulators and consumers tend to talk past each other.
The disinfection byproducts deserve the most attention. They form when chlorine reacts with naturally occurring organic matter — the dissolved plant material that comes with any forested surface watershed. Because Portland does not yet filter that organic matter out before disinfecting, it carries more precursor material than a comparable filtered system. The utility’s report lists trihalomethanes up to 41 ppb at individual sites and haloacetic acids up to 33.7 ppb — within legal limits, but a real signal. The health endpoint, increased lifetime cancer risk with some evidence of harm to fetal development, is well characterized. The planned filtration plant should reduce these by removing the organic precursors before chlorine is added.
Two findings are reassuring. Nitrate was detected at roughly 0.09 ppm, about one-hundredth of the federal 10 ppm limit — a direct benefit of a protected watershed with no upstream farming. PFAS is the other: Portland has tested both sources and reports no detections of PFOA, PFOS, or the broader PFAS panel, an unusually clean result for a major US system. For households that still want a margin of safety, our best water filters for PFAS removal guide covers the certified options.
Radon is the contaminant most specific to Portland’s geology — a naturally occurring radioactive gas, detected in Bull Run water from below 12 up to 409 pCi/L (averaging about 152) and at varying levels in the groundwater. There is no final federal MCL for radon in drinking water; the EPA has long proposed limits of 300 and 4,000 pCi/L but never finalized them. The primary radon risk comes from inhaling the gas as it escapes water during showering, not from drinking it. Radon in indoor air from soil is usually the larger exposure pathway, so a home radon-in-air test is the more useful first step.
You can review the full contaminant list for your system at the EWG Tap Water Database entry for Portland Water Bureau.
The Lead Question in Portland
Lead deserves its own section because it behaves differently from everything above. The contaminants in the table arrive at the plant or form during disinfection. Lead does not — it enters water after treatment, leaching from lead solder, brass fixtures, and any remaining lead plumbing inside older buildings. The water leaving Portland’s reservoirs is essentially lead-free; what matters is the plumbing between the city main and your glass.
Portland’s situation is distinctive. The Bull Run supply is exceptionally soft, with very low mineral content and a naturally low pH, and soft, low-alkalinity water is chemically aggressive — it tends to dissolve metal from the pipes it touches. For years that corrosivity gave Portland some of the highest lead-at-the-tap results among large US systems, even though the source water itself was clean. The lead was never in the watershed; it was in the chemistry between the water and old household plumbing.
Portland improved its corrosion control treatment in 2022, adding sodium carbonate and carbon dioxide to raise the pH and alkalinity. In December 2023, the Oregon Health Authority confirmed the treatment as “optimized,” bringing the bureau into full compliance with the federal Lead and Copper Rule. The most recent sampling of high-risk homes returned a 90th-percentile lead result of 4.4 ppb — well under the 15 ppb action level — though individual homes still ranged from below 1 ppb up to 145 ppb, with one of 101 homes exceeding the action level.
That range is the part to take seriously. A citywide percentile cannot tell you what is happening at your tap, and for lead the tap is the only measurement that counts. Lead solder was legal until 1986, so if your home predates that, your exposure depends on your own pipes regardless of how well the city treats the water. Portland offers free lead-in-water test kits to anyone in its service area. If your home was built before 1986, testing is the only way to know your exposure. Our lead in drinking water guide covers sources, risks, and removal in detail.
Portland Water Hardness
Portland has soft water, and this is one of the few cases where the popular reputation is correct. Bull Run water typically measures a total hardness of 7 to 11 ppm — about half a grain per gallon, among the softest municipal water in the country. The groundwater backup is harder, near 80 ppm (about 5 grains per gallon, which the USGS classifies as moderately hard), so the water can feel slightly different during the months Portland runs on its wells. Finished-water pH typically ranges between 8.0 and 9.0 after corrosion treatment.
Soft water produces almost no scale on fixtures or water heaters and lets soap lather easily — many residents notice a slightly “slippery” feel when rinsing. There is no case for a water softener here; the water is already soft. The relevant consequence of that softness is the corrosivity discussed above — a plumbing and lead issue, not a scaling one. For the broader picture on where softeners make sense, see our hard water guide and solutions. The point for Portland residents: direct your filtration budget at disinfection byproducts and lead, not at hardness.
Best Water Filters for Portland Residents
Portland’s profile points to a clear priority order: reduce chloramine and disinfection byproducts first, and address lead at the tap if you live in an older home. Reverse osmosis is not necessary for most Portland households, because the contaminants that justify RO elsewhere — uranium, high arsenic, nitrate, PFAS — are not present here at meaningful levels. The three options below are matched to Portland’s actual issues. Each carries third-party certification (WQA or IAPMO, both accredited bodies that certify to the NSF/ANSI standards) — verify the exact model in the certifier’s database before buying, since certification is listed by model, not by brand.
Under Sink: Aquasana Claryum 3-Stage
A catalytic carbon-block under-sink system is the most direct answer to Portland’s dominant problem. The Aquasana Claryum 3-Stage is WQA-certified (the Water Quality Association is an accredited certifier, not merely a testing lab) to NSF/ANSI Standards 42, 53, and 401 — covering chlorine and chloramine taste, lead, and a range of organic compounds, the category that includes disinfection byproducts and their precursors. Because Portland uses chloramine as its residual disinfectant, that chloramine-reduction certification matters here in a way it would not in a free-chlorine city, and the Standard 53 lead certification covers the contaminant most likely to enter water inside an older Portland home.
Two real limitations. First, the cartridges are rated for roughly 800 gallons or about six months, and replacements run higher per gallon than a basic carbon filter. Second, “WQA-certified” is not “NSF certified”; the certification is genuine and verifiable in the WQA database, but you will not find it in NSF’s own listing, so confirm the model number directly rather than trusting a retail page that blurs the two. Wirecutter and the WQA listing both confirm Aquasana’s certification claims — more than can be said for many carbon systems marketed with “tested to NSF standards” language but no actual certification. For comparisons, see our best under sink water filters guide.
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Faucet Mount: Culligan FM-25
For a lower-cost option that still addresses both of Portland’s main concerns, a certified faucet-mount filter is a reasonable middle tier. The Culligan FM-25 is IAPMO-certified (IAPMO R&T is an accredited certifier; the FM-25 is listed under file 0011635) to NSF/ANSI Standards 42 and 53 for chlorine and chloramine taste, particulates, lead, mercury, cysts, and certain volatile organic compounds. Two of those certifications map directly onto Portland’s profile: chloramine and VOC reduction address the disinfection chemistry, and the Standard 53 lead certification addresses the premise-plumbing concern at a fraction of an under-sink system’s cost.
Two real limitations. First, faucet-mount filters have short cartridge life — typically 100 to 200 gallons, or two to three months for an average household — so the per-gallon cost climbs and the schedule is easy to forget. Second, it does not fit pull-out or spray-style faucets, and the diverter adds bulk at the spout. Note that its certifier is IAPMO, not NSF International — the certification is real, but stated correctly it is “IAPMO-certified to NSF/ANSI 53,” not “NSF certified.” For other options, see our best faucet water filters guide.
Budget Pitcher: ZeroWater 10-Cup Ready-Pour
For renters and households that want lead protection without installing anything, a pitcher is the practical entry point. The ZeroWater 10-Cup uses a five-stage filter and is IAPMO-certified to NSF/ANSI 53 for both lead and chromium reduction (chromium is a health-effects contaminant, so it falls under Standard 53 rather than the aesthetic Standard 42) — a reasonable hedge for an older Portland home with lead solder. Its included total-dissolved-solids meter shows when the filter is exhausted rather than guessing from the calendar.
Two real limitations. First, a pitcher’s contact time and capacity are far lower than an under-sink system, so it exhausts quickly and does little for the chloramine and disinfection byproducts that are Portland’s other concern. Second, the ion-exchange media strips nearly all dissolved solids, leaving the water flat or faintly metallic to some people; if your household will not drink it, the protection is theoretical. For other pitcher options, see our best water filter pitchers guide.
How to Test Your Portland Tap Water
The numbers in the city report are averages across the whole distribution system. They cannot tell you what is at your particular faucet — the only number that matters for lead, since lead comes from your home’s own plumbing. That is especially true in Portland, where the soft water’s corrosivity means two homes on the same block can have very different lead results depending on the age of their pipes and fixtures.
Portland offers free lead-in-water test kits to anyone in its service area, the right first step for the lead question specifically. For a fuller picture — disinfection byproducts, metals, general chemistry — an independent laboratory test gives certified-lab results for your specific tap. Get a Tap Score Test is the reference we point readers to, and our how to test your water at home guide walks through the options.
Frequently Asked Questions
Is Portland tap water safe to drink?
Portland’s tap water meets all federal health-based standards, and its Bull Run source is among the cleanest municipal supplies in the country, with no detected PFAS and negligible nitrate. The qualifications: disinfection byproducts, while within legal limits, run well above EWG’s stricter health guidelines, and lead can enter from older home plumbing because the water is soft and historically corrosive. For most households the water is safe to drink; if your home predates 1986, testing for lead is worthwhile.
Does Portland water have PFAS?
No. The Portland Water Bureau has tested both the Bull Run surface supply and the Columbia South Shore Well Field and reports no detections of PFOA, PFOS, or other PFAS compounds — an unusually clean result for a large US system, reflecting the protected, undeveloped watershed. PFAS is not a reason Portland residents need a filter.
How hard is Portland water?
Portland’s main Bull Run supply is very soft — about 7 to 11 ppm, or roughly half a grain per gallon, among the softest municipal water in the country. The groundwater backup is moderately hard, near 80 ppm (about 5 grains per gallon). There is no need for a softener; the practical consequence of the softness is corrosivity toward plumbing, a lead issue rather than a scaling one.
Do I need a water filter in Portland?
It depends on your home. If you live in a house built before 1986, a lead-certified filter at the kitchen tap is worth considering until you have tested your own water. To reduce the disinfection byproducts that form in Portland’s unfiltered, chloraminated supply, a catalytic carbon system certified to NSF/ANSI 53 and 401 is the right tool. Reverse osmosis is generally unnecessary here, since the contaminants that justify it elsewhere are absent.
Sources Cited
- EWG Tap Water Database — Portland Water Bureau (PWS ID OR4100657)
- Portland Water Bureau, 2025 Drinking Water Quality Report (data reported through 2024)
- Portland Water Bureau — Lead and Drinking Water; corrosion control and lead-in-water testing
- Oregon Health Authority — Lead and Copper Rule optimization determination (December 2023)
- Portland Water Bureau — Bull Run Filtration Project (required by 2027)
- EPA — Safe Drinking Water Information System (SDWIS) and National Primary Drinking Water Regulations
- WQA Gold Seal and IAPMO R&T certified product databases (product certification verification)
