Most City offices closed Wednesday, June 19, to observe Juneteenth

The City of Portland recognizes Juneteenth as a formal day of remembrance to honor Black American history and the end of slavery in the United States. Learn about Juneteenth.

2021 Drinking Water Quality Report

A collection of five photos featuring women doing water quality work at the water treatment plant, in the lab testing water, outside flushing a hydrant, and at the office answering calls from customers.
This annual report contains important information about Portland's drinking water and water system.
On this page

About this report

This is a past report from 2021.

Read our most recent Drinking Water Quality Report

Each year the Portland Water Bureau provides the Drinking Water Quality Report to all of its customers. The report is required by the State and the EPA and contains important information about Portland's drinking water and water system. The following 2021 Drinking Water Quality Report contains results from the 2020 calendar year. You can also read this report as a pdf: 

Adjusting operations during the pandemic

Four people wearing masks in a lab and surrounded by lab equipment while planning on laptops and clipboards.
Operations during the pandemic: At the treatment pilot plant in the watershed, our interdisciplinary team of water quality and engineering staff continued testing treatment options for our future water filtration facility.

In March 2020, our lives turned upside down. During the uncertainty of those early days of the pandemic, the Portland Water Bureau was certain about one thing: we need to keep water safe and flowing. 

While many of our staff were able to telework, over 200 staff continued to work at the office, lab, or field sites to keep doing their essential work. Keeping that many people safe has taken a lot of creativity and changes to how we do our work. Look for the photos throughout this page that give a glimpse at some of our staff that is dedicated to serving excellent water every minute of every day.

Portland’s drinking water sources and water system

A cartoon map showing Portland's water system that starts near Mt Hood on the right and goes through Portland to Washington Park on the left. The map shows a lake and two dams and reservoirs in the Bull Run Watershed, the two water treatment facilities, the Columbia South Shore Well Field, and underground pipes and reservoirs that carry and hold our drinking water around town.

Our drinking water sources

The Bull Run Watershed, Portland’s protected surface water supply, is in the Mount Hood National Forest, 26 miles from Portland. The Portland Water Bureau and the US Forest Service carefully manage the watershed to sustain and supply clean drinking water. In a typical year, the watershed receives an astounding 135 inches of precipitation (rain and snow), which flows into the Bull Run River and then into two reservoirs that store nearly 10 billion gallons of drinking water.

A selfie of two women in the forest wearing hiking gear and masks.
Operations during the pandemic: Environmental technicians completed one of the inspections within the watershed for water quality protection.

Source water assessments are completed to identify contaminants of concern for drinking water. For the Bull Run, the only contaminants of concern are naturally occurring microorganisms, such as Giardia, Cryptosporidium, fecal coliform bacteria, and total coliform bacteria. The Portland Water Bureau regularly tests Bull Run water for these microorganisms that live in virtually all freshwater ecosystems.

The Portland Water Bureau treats water to control organisms that could make people sick but does not currently treat for Cryptosporidium. Portland is installing filtration to remove Cryptosporidiumand other contaminants from drinking water by 2027. 

The Columbia South Shore Well Field, Portland’s protected groundwater supply,provides drinking water from 25 active wells located in three different aquifers. The well field is between Portland International Airport and Blue Lake Park. Portland uses the well field for two purposes: to supplement the Bull Run supply in the summer, and to temporarily replace the Bull Run supply during turbidity events, maintenance activities, and emergencies.

The Columbia South Shore Well Field is beneath homes and businesses with a variety of potential contaminant sources. The deep aquifers that are the primary sources of water supply have natural geologic protection from pollutants present at the land surface. Portland, Gresham, and Fairview work together to protect the well field. The cities’ Groundwater Protection Programs work with residents and businesses in the well field to ensure that pollutants from this urban area do not impact the groundwater source. Portland also hosts a number of groundwater education events.

Portland’s source water assessment is available online or by calling 503-823-7525.

Sign up for treatment and source water change notifications

The Clackamas River Water District, City of Gresham, City of Lake Oswego, City of Milwaukie, Rockwood Water People’s Utility District, Sunrise Water Authority, and Tualatin Valley Water District provide drinking water to some Portland customers who live near service area boundaries. Customers who receive water from these providers will receive detailed water quality reports about these sources in addition to this report.

Our drinking water system

Two people outside with a hose connected to a hydrant that has water gushing out of it. Both people are wearing safety vests and masks. An a-frame sign says: flushing our system to maintain water quality.
Operations during the pandemic: Crews continued flushing water mains in east Portland, cleaning out and maintaining water quality in close to 200 miles of water main.
  • Portland’s water system was established in 1895.
  • Portland’s drinking water system delivers water from two high-quality sources – the Bull Run Watershed and the Columbia South Shore Well Field – to almost one million people in Portland and surrounding communities.
  • Most of Portland’s drinking water comes from the Bull Run Watershed, 26 miles east of downtown Portland.
  • Treatment operators add chlorine to control microorganisms, such as bacteria and viruses, that could make people sick.
  • Treatment operators add ammonia to form a longer-lasting disinfectant. They also add sodium hydroxide to reduce corrosion of metals.
  • Drinking water flows by gravity from Bull Run to Portland.
  • Pumps pull groundwater from the aquifers of the Columbia South Shore Well Field.
  • Reservoirs and tanks store water for everyday use, plus firefighting and emergency needs.
  • Water Bureau employees collect and test more than 11,000 water samples each year.
  • More than 2,200 miles of water mains carry water beneath the city’s streets.
  • Thousands of hydrants safeguard the city.

Managing and planning for wildfires

Wildfires in forests like the Bull Run Watershed are uncommon but not unprecedented. Forests on the west side of the Cascades, like the Bull Run, receive a lot of rain and retain much of that moisture in the trees, logs, plants, and material covering the forest floor. Large wildfires in these types of forests have historically occurred during a major wind event with hot, dry air conditions, just like the Labor Day 2020 fires. We breathed a sigh of relief in 2020 when the fires didn’t touch the watershed, but we plan for and anticipate a large fire will occur in the future. Staff from across the bureau are actively working on fire planning and resiliency. The strongest resiliency tool that we currently have is our Columbia South Shore Well Field. Groundwater, along with our future filtration plant, provides resiliency and flexibility to help ensure we keep your high-quality drinking water flowing. Learn more about our wildfire planning on our blog

Three photos of Water bureau staff that are involved in wildfire management or planning.
Left: Maile, a watershed specialist, assisted Corbett firefighters in September 2020 to put out a small fire near the Bull Run Watershed. Center: Nick, a water quality sampler, collected wildfire ash in October 2020 from the Riverside Fire. Right: Liane, our watershed manager, coordinated with the Forest Service during the 2017 Eagle Creek Fire.

Frequently asked questions about water quality

What test results will I find in this report?

The Portland Water Bureau monitors drinking water for over 200 regulated and unregulated contaminants. This report lists all of the regulated contaminants the bureau detected in drinking water in 2020. If a known, health-related contaminant is not listed in this report, the Portland Water Bureau did not detect it in drinking water.

How is Portland’s drinking water treated?

Currently, Portland’s drinking water treatment is a three-step process: 1) Chlorine disinfects against organisms, such as bacteria and viruses, that could otherwise make people sick. 2) Ammonia stabilizes chlorine to form a longer-lasting disinfectant. 3) Sodium hydroxide reduces corrosion of metals such as lead. Portland’s treatment is changing in the coming decade. 

Is Portland’s water safe from viruses such as the COVID-19 virus?

Yes, your water is safe from viruses and safe to drink. Portland controls microorganisms, including viruses, with chlorine.

Is Portland’s water filtered?

No. Neither of Portland’s sources is filtered. In response to a series of low-level detections of Cryptosporidiumin Bull Run water in 2017, Portland is installing a filtration plant to treat for Cryptosporidium. Bull Run water will be filtered by 2027.

Does the Portland Water Bureau add fluoride to the water?

No. Fluoride naturally occurs in Portland’s water at very low levels. You may want to ask your dentist or doctor about supplemental fluoride for preventing tooth decay. This is especially important for young children.

Is Portland’s water soft or hard?

Bull Run water—Portland’s main water supply—is very soft. It typically has a total hardness of 3–8 parts per million (ppm), or ¼ to ½ a grain of hardness per gallon. Portland’s groundwater supply is moderately hard: about 80 ppm, or about 5 grains per gallon.

What is the pH of Portland’s water?

The pH of Portland’s drinking water typically ranges between 7.5 and 8.5.

How can I get my water tested?

For free lead-in-water testing, order a kit from the LeadLine or 503-988-4000. For other testing, you can pay a private, accredited laboratory to test your tap water. Information about accredited labs in Oregon can be found online or by calling 503-693-4100.

What causes temporarily discolored water?

Sediment and organic material from the Bull Run Watershed settle at the bottom of water mains. These can sometimes be stirred up during hydrant use or a main break. They can also be seen in the fall as a harmless tea-colored tint. Discolored water can also be caused by older pipes in buildings that add rust to the water. Find out more at our discolored water page

How should property managers maintain water quality in large buildings?

Managers of large buildings should implement a water management program to protect their water quality and address the risk of Legionella growth. This is especially important during the pandemic and before reopening. If you are currently using less water than normal, run water weekly, check your hot water system, and take steps before reopening. Find more at our water quality in large buildings page.

I have a water quality or water pressure question not answered here or need more assistance. Where can I find more information? 

Matt is sitting in an office wearing a mask and talking on the phone while looking at two computer screens.
Operations during the pandemic: Water quality information specialists continued assisting the public with water quality questions and sending out lead test kits.

You can start by checking out our troubleshooting guides for discolored water, low water pressure or high water pressure, tastes or odors in drinking water, and measuring pH in our water. You can also contact our Water Quality Line

Contaminants detected in 2020

What the EPA Says Can Be Found in Drinking Water

Across the United States, the sources of drinking water (both tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally occurring minerals and, in some cases, radioactive material, and can pick up substances resulting from the presence of animals or from human activity.

Two people in a lab sitting at computers facing each other. Both people are wearing masks and there is a transparent plexiglass barrier between them.
Operations during the pandemic: Where lab staff couldn’t maintain six feet distance, plexiglass barriers were installed to keep everyone safe.

In order to ensure that tap water is safe to drink, the Environmental Protection Agency (EPA) has regulations that limit the amount of certain contaminants in water provided by public water systems and require monitoring for these contaminants. Food and Drug Administration regulations establish limits for contaminants in bottled water, which must provide the same protection for public health.

Contaminants in drinking water sources may include microbial contaminants, such as viruses, bacteria, and protozoa from wildlife; inorganic contaminants, such as naturally-occurring salts and metals; pesticides and herbicides, which may come from farming, urban stormwater runoff, or home and business use; organic chemical contaminants, such as byproducts from industrial processes or the result of chlorine combining with naturally occurring organic matter; and radioactive contaminants, such as naturally occurring radon.

Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the EPA’s Safe Drinking Water Hotline at 800-426-4791 or at EPA's drinking water website.

Definitions of acronyms used in data tables

  • MCL: maximum contaminant level. The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology.
  • MCLG: maximum contaminant level goal. The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.
  • MRDL: maximum residual disinfectant level. The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.
  • MRDLG: maximum residual disinfectant level goal. The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.
  • N/A: not applicable. Some contaminants do not have a health-based level or goal defined by the EPA.
  • NTU: nephelometric turbidity unit. A unit for measuring the turbidity, or cloudiness, of a water sample.
  • ppm: parts per million. Water providers use ppm to describe a small amount of a substance within the water. In terms of time, one part per million is about 32 seconds out of one year.   
  • ppb: parts per billion. Water providers use ppb to describe a very small amount of a substance within the water. In terms of time, one part per billion is about 3 seconds out of 100 years.
  • pCi/L: picocuries per liter. Picocurie is a measurement of radioactivity.
  • TT: treatment technique. A required process intended to reduce the level of a contaminant in drinking water.

Data tables of contaminants detected in 2020

Data table of regulated contaminants detected in Portland's untreated source water



Minimum detectedMaximum detectedEPA standard: MCL or TTEPA standard: MCLGSources of contaminant
Turbidity (NTU)0.223.315N/AErosion of natural deposits

Fecal coliform bacteria 

(% >20 colonies/100 mL in 6 months)

Not detected0%10%N/AAnimal wastes
Giardia (#/L)Not detected0.06TTN/AAnimal wastes
Data table of regulated metals and nutrients detected in Portland's treated water at the entry point



Minimum detectedMaximum detectedEPA standard: MCL or TTEPA standard: MCLGSources of contaminant
Arsenic (ppb)<0.500.92100Found in natural deposits
Barium (ppm)0.00090.009722Found in natural deposits
Fluoride (ppm)<0.0250.1744Found in natural deposits
Nitrate (as Nitrogen) (ppm)<0.0100.0871010Found in natural aquifer deposits, animal wastes
Data table of regulated microbial contaminants detected in Portland's treated water in the distribution system



Minimum detectedMaximum detectedEPA standard: MCL or TTEPA standard: MCLGSources of contaminant

Total coliform bacteria 

(% positive per month)

Not detected0.41%TTN/AFound throughout the environment

E. coli bacteria

(% positive per month)

Not detected0.39%See E. coli note below0Human and animal fecal waste
Data table of regulated disinfection residuals and byproducts detected in Portland's treated water in the distribution system



Minimum detectedMaximum detectedEPA standard: MCL or TTEPA standard: MCLGSources of contaminant

Total chlorine residual (ppm)

running annual average

1.791.884 [MRDL]4 [MRDLG]Chlorine used to disinfect water

Total chlorine residual (ppm)

range of single results at all sites

0.242.60N/AN/AChlorine used to disinfect water

Haloacetic acids (ppb)

running annual average at any one site

25.940.560N/AByproduct of drinking water disinfection

Haloacetic acids (ppb) 

range of single results at all sites

27.655.1N/AN/AByproduct of drinking water disinfection

Total trihalomethanes (ppb) 

running annual average at any one site

23.734.680N/AByproduct of drinking water disinfection

Total trihalomethanes (ppb) 

range of single results at all sites

19.248.0N/AN/AByproduct of drinking water disinfection
Data table of unregulated contaminants detected in Portland's treated water



Minimum detectedAverage detectedMaximum detectedSources of contaminant
Radon (pCi/L)<50170340Found in natural deposits
Sodium (ppm)2.95.612.0Found in natural deposits
Manganese (ppm)0.0020.0090.024Found in natural deposits  

Looking for additional data? Find it on our Drinking Water Test Results page.

About These Contaminants

Arsenic, barium, fluoride, and manganese

These metals are elements found in the earth's crust. They can dissolve into water that is in contact with natural deposits. Find more information about manganese testing in the 2020 report’s “Additional Testing” section. At the levels found in Portland’s drinking water, they are unlikely to lead to negative health effects.

E. coli bacteria

E. coli are bacteria that indicate that the water may be contaminated with human or animal wastes. An MCL violation occurs if routine and repeat samples are total coliform positive and either is E. coli positive. The Portland Water Bureau uses chlorine to control these bacteria.

Fecal coliform bacteria

To comply with the filtration avoidance criteria of the Surface Water Treatment Rule, water is tested for fecal coliform bacteria before disinfectant is added. The presence of fecal coliform bacteria in source water indicates that water may be contaminated with animal wastes. This is reported in percent of samples with more than 20 colonies in 100 milliliters of water during any six-month period. The Portland Water Bureau uses chlorine to control these bacteria.


Wildlife in the watershed may be hosts to Giardia, a microorganism that can cause gastrointestinal illness. The treatment technique is to remove 99.9 percent of Giardia cysts. The Portland Water Bureau uses chlorine to control Giardia.

Haloacetic acids and total trihalomethanes

Disinfection byproducts form when chlorine interacts with naturally occurring organic material in the water. High levels of disinfection byproducts can cause health problems in people. Portland adds ammonia to form a more stable disinfectant, which helps minimize disinfection byproducts.

Nitrate (as Nitrogen)

Nitrate, measured as nitrogen, can lead to bacterial and algal growth in the water. At levels that exceed the standard, nitrate can contribute to health problems. At the levels found in Portland’s drinking water, nitrate is unlikely to lead to negative health effects.


Radon is a naturally occurring radioactive gas that cannot be seen, tasted, or smelled. Radon can be detected at very low levels in the Bull Run water supply and at varying levels in Portland’s groundwater supply. Based on the historical levels of radon in groundwater combined with the limited amount of groundwater used, people in Portland are unlikely to have negative health effects from radon in water. Find more information about radon from the EPA.


There is currently no drinking water standard for sodium. At the levels found in drinking water, it is unlikely to lead to negative health effects.

Total chlorine residual

Total chlorine residual is a measure of free chlorine and combined chlorine and ammonia in the water distribution system. Chlorine residual is a low level of chlorine remaining in the water and is meant to maintain disinfection through the entire distribution system.

Total coliform bacteria

Coliforms are bacteria that are naturally present in the environment. Coliform bacteria usually do not make people sick. They are used as an indicator that other potentially harmful bacteria may be present. If more than 5 percent of samples in a month are positive for total coliforms, an investigation must be conducted to identify and correct any possible causes. The Portland Water Bureau uses chlorine to control these bacteria.


Turbidity is the cloudiness of a water sample. In Portland’s system, increased turbidity usually comes from large storms, which suspend organic material in Bull Run water. Increased turbidity can interfere with disinfection and provide an environment for microorganisms to grow. Since the Portland Water Bureau does not yet filter Bull Run water, the treatment technique is that turbidity cannot exceed 5 NTU more than two times in 12 months. When turbidity rises in the Bull Run source, Portland switches to its Columbia South Shore Well Field source.

Reducing exposure to lead and treatment changes in 2022

Sources of lead in Portland

A woman in a fluorescent yellow sweatshirt and mask sits in front of a computer with 9 monitors.
Operations during the pandemic: treatment operators continued to monitor and control the water treatment system at the watershed.

The Portland Water Bureau cares about the health of the families in our community and is committed to helping you. If present, lead at elevated levels can cause serious health problems, especially for pregnant people and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. The Portland Water Bureau is responsible for providing high-quality drinking water, but cannot control the variety of materials used in plumbing components in homes or buildings. Lead is rarely found in Portland’s source waters and there are no known lead service lines in the water system. In Portland, lead enters drinking water from the corrosion (wearing away) of household plumbing materials containing lead. These materials include lead-based solder used to join copper pipe — commonly used in homes built or plumbed between 1970 and 1985 — and brass components and faucets installed before 2014.

In Portland, the most common sources of lead exposure are lead-based paint, household dust, soil, and plumbing materials. Lead is also found in other household objects such as toys, cosmetics, pottery, and antique furniture.

What you can do

When your water has been sitting for several hours, such as overnight or while you are away at work or school, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to 2 minutes before using water for drinking or cooking. If you are concerned about lead in your drinking water, you can request a free lead-in-water test from the LeadLine (503-988-4000). Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from EPA’s Safe Drinking Water Hotline: 800-426-4791.

Additional steps to reduce exposure to lead from plumbing

Photo of a kitchen faucet that is filling a glass of water.
  • Run your water to flush the lead out.
  • Use cold, fresh water for cooking, drinking, and preparing baby formula.
  • Do not boil water to remove lead.
  • Test your child for lead.
  • Test your water for lead.
  • Consider using a filter certified to remove lead.
  • Clean your faucet aerators every few months.
  • Consider replacing faucets or fixtures installed before 2014.

The LeadLine (503-988-4000) can help keep your family safe from lead.

Lead and copper test results from homes with higher risk of lead in water

The Portland Water Bureau offers free lead-in-water tests to anyone in the service area. Twice each year, the Portland Water Bureau also collects water samples from a group of over 100 homes that have lead solder and are more likely to have higher levels of lead in water. Test results from 2020 were below the EPA action level.

Data table of lead and copper results from high-risk residential water taps
Regulated contaminantFall 2020 90th percentile resultsHomes exceeding action levelEPA standard: action levelEPA standard: MCLGSources of contamination
Lead (ppb)13.810 out of 120 (8.3%)150Corrosion of household and commercial building plumbing systems
Copper (ppm)0.2620 out of 120 (0%)1.31.3Corrosion of household and commercial building plumbing systems
  • 90th percentile definition: 90 percent of the samples results were less than the values shown.
  • Action level definition: The concentration of a contaminant which, if exceeded, triggers treatment or requirements of which a water system must follow. 
  • ppm: parts per million. Water providers use ppm to describe a small amount of a substance within the water. In terms of time, one part per million is about 32 seconds out of one year.   
  • ppb: parts per billion. Water providers use ppb to describe a very small amount of a substance within the water. In terms of time, one part per billion is about 3 seconds out of 100 years.

Bull Run Treatment Projects: Improved corrosion control treatment by 2022

Protecting public health

Four images in a 2 by 2 block: image 1 of a tool scraping paint; image 2 of traditional Mexican pottery; image 3 is of copper pipe with shiny solder on the joints; and image 4 is a hand holding a small metal bowl full of red powder.
Some sources of lead in Portland (clockwise): lead paint, traditional pottery from Mexico and Central America, Hindu powders (such as Sindoor, Kumkum, Tikka and Roli), and lead solder connecting copper plumbing.

We’re committed to public health protection. Since 1997, we have taken a comprehensive approach to reducing exposure to lead. Our Lead Hazard Reduction Program includes: corrosion control treatment; lead-in-water testing; education, outreach, and testing for all sources of lead; and home lead hazard reduction. Today, we are investing in upgraded treatment that will help reduce the levels of lead in drinking water for everyone.

Improving corrosion control treatment

An illustration of two blue circles, one has a scoop full of a white grainy powder and one has white bubbles in it.
Two naturally occurring substances, sodium carbonate (soda ash) and carbon dioxide, will be added to water in our upgraded treatment system.

Improved treatment will use naturally occurring substances to increase the water’s pH and alkalinity. Most consumers won’t notice a change to the great-tasting Bull Run water, but these changes will make the drinking water less corrosive to your plumbing. This will reduce the amount of lead that can enter the water from household or building plumbing.

Construction underway

Illustration of a building with two tall silos at the front of the building and a smaller, outbuilding with a cylinder laying horizontally.
A diagram of the new improved corrosion control treatment facility that will be online in 2022.

We’re adding the new treatment system at our Lusted Hill facility alongside the existing building. The new treatment will be in place by April 2022.

Monitoring for Cryptosporidium and treatment changes in 2027

Cryptosporidium is a potentially disease-causing microorganism that lives in virtually all freshwater ecosystems. Drinking water treatment for Cryptosporidium is required by state and federal regulations. For five years, the Oregon Health Authority (OHA) did not require the Portland Water Bureau to treat for Cryptosporidium based on data showing that Cryptosporidium was rarely found in the Bull Run Watershed. Since 2017, test results have shown low-level detections of Cryptosporidiumprimarily during the rainy season. As a result, OHA determined that treatment is now necessary. Portland has made several decisions about how to treat for Cryptosporidium, including choosing filtration as the treatment method and deciding on the location of the future treatment plant. The Portland Water Bureau is on track to have the filtration plant built and running by 2027.

Two people in a lab setting wearing white lab coats and masks. One person is pouring water and one person is taking notes on a clipboard.
Operations during the pandemic: Enhanced safety and distancing protocols allowed lab analysts to continue testing water in the lab.

The Portland Water Bureau does not currently treat for Cryptosporidium, but is required to do so under drinking water regulations. Portland is working to install filtration by 2027 under a compliance schedule with OHA. In the meantime, the Portland Water Bureau is implementing interim measures such as watershed protection and additional monitoring to protect public health. Consultation with public health officials continues to conclude that the general public does not need to take any additional precautions.

Exposure to Cryptosporidium can cause cryptosporidiosis, a serious illness. Symptoms can include diarrhea, vomiting, fever, and stomach pain. People with healthy immune systems recover without medical treatment. According to the Centers for Disease Control and Prevention (CDC), people with severely weakened immune systems are at risk for more serious disease. Symptoms may be more severe and could lead to serious life-threatening illness. Examples of people with weakened immune systems include those with AIDS, those with inherited diseases that affect the immune system, and cancer and transplant patients who are taking certain immunosuppressive drugs.

The Environmental Protection Agency has estimated that a small percentage of the population could experience gastrointestinal illness from Cryptosporidium and advises that customers who are immunocompromised and receive their drinking water from the Bull Run Watershed consult with their health care professional about the safety of drinking the tap water.

Data table of Cryptosporidium monitoring results at the raw water intake
Total number of samples testedTotal number of samples positive for CryptosporidiumMinimum concentration detected (oocysts/L)Maximum concentration detected (oocysts/L)
18539Not detected0.08

Special Notice for Immunocompromised Persons

A doctor is sitting in her office wearing a white coat and stethoscope. She is smiling a waving to someone she is video chatting with on her phone.

Some people may be more vulnerable to contaminants in drinking water than the general population. Immunocompromised persons, such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly people, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. Environmental Protection Agency (EPA)/ Centers for Disease Control and Prevention (CDC) guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline at800-426-4791.

Bull Run Treatment Projects: Filtration treatment by 2027

Making our water cleaner and safer for everyone

An illustration of the future filtration plant. There are large white buildings surrounded by green land and some generic trees and shrubs.
Preliminary design concept for the filtration facility. The final design of the facility will meet our water quality requirements as well as be adapted to its rural setting, reflecting our commitments to the filtration facility neighbors.

To keep our water safe and abundant, we’re upgrading our drinking water treatment with filtration. Filtration is a long-term investment to protect public health and economic growth for the next century and beyond.

Filtration will enhance our water system’s resilience and help us continue to meet current and future water quality requirements.

We’re currently designing the new water filtration facility and pipelines. To help build the improvements, we’ve been awarded federal financing that will save ratepayers millions. Filtration treatment will be in place by September 2027.

Our new water filtration treatment process

There are four icon circles with arrows between them. The first circle has a dam with water and forest behind it. The second circle has layers of water on top and sandy layers on the bottom with arrows pointing down. The third circle has bacteria cartoons with a slash through the whole circle. The last circle is orange with the word "lead" in white and an arrow pointing down. The captions for each of these icons are in a bullet list following this image.
  • The Bull Run Watershed will remain highly protected.
  • Filtration will remove Cryptosporidium and other potential contaminants.
  • Disinfection will control microorganisms.
  • Corrosion control treatment will continue to lower lead levels at the tap.

Learn more about our filtration project.

Additional drinking water information

Additional drinking water information from Oregon Health Authority971-673-0405. Portland Water Bureau’s Water System ID: 4100657

The Portland Water Bureau is a member of the Regional Water Providers ConsortiumThe Consortium works to improve the planning and stewardship of drinking water in our region.

Last updated: June 2021

Reports from previous years

All reports are available in Chinese, Russian, Spanish, and Vietnamese. Please call 503-823-7525 to request a translation of the report. Interpretation services are available.