2022 Drinking Water Quality Report

A collage of images featuring Portland Water Bureau staff doing work in the lab and office, Bull Run Lake, and one of our drinking water treatment facilities.
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 2022.

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 2022 Drinking Water Quality Report contains results from the 2021 calendar year. You can also read this report as a pdf: 

 Request a paper copy of the report

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.

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 Cryptosporidium  and 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

  • 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 carbonate and carbon dioxide 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.

Planning for a hotter climate

For over 100 years, Portland residents have enjoyed safe and abundant drinking water at their taps. The next 100 years will require us to adapt to a changing climate.

The real and present heat waves, wildfires, and droughts in our region have made it clear that our climate is heating up rapidly and we are experiencing the impacts here and now.

For over two decades, the Portland Water Bureau has been evaluating climate change impacts to Portland’s water supplies. We are actively planning for a hotter climate that will make disruptions to the water system and extreme events more common.  

In 2021, Portland Water Bureau's director established three climate commitments to reduce the bureau's impact on climate change. We are also investing in our water system to be more resilient and reliable, taking steps to protect our outdoor workforce during extreme heat and wildfire smoke events, and reducing impacts on community members who are hit first and worst by climate change.

Learn more about our climate change activities

A graphic of Portland Water Bureau climate commitments. A text version of this graphic is available at the end of this section.

Text version of graphic

Portland Water Bureau climate commitments:

  • Reduce Portland Water Bureau carbon emissions by 50 percent by 2030.
  • Purchase at least 80 percent direct renewable energy by 2030.
  • Integrate meaningful climate analysis into our project planning by the end of 2022.

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 2021. 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 carbonate and carbon dioxide replaced sodium hydroxide in 2022 to further reduce the corrosion of metals such as lead. Portland’s treatment is changing more 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 Cryptosporidium in 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 7.8 and 8.5.

How can I get my water tested?

For free lead-in-water testing, order a kit from the LeadLine or503-988-4000. 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 as building reopen. 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.

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

Controlling for Legionella is a shared responsibility

Legionella, the bacteria that causes Legionnaires' disease, is found across the country in natural freshwater bodies and in building plumbing and cooling systems. The Portland Water Bureau treats drinking water to control Legionella and protect public health. However, if water quality in buildings is not maintained properly, Legionella bacteria can grow in buildings and make people sick.

The risk of getting sick from Legionella is low. Large buildings that have complex plumbing systems are at a greater risk to Legionella growth. Managers of large buildings should take steps to maintain water quality in their building.

In 2021, the Portland Water Bureau started testing for Legionella throughout the city. In collaboration with our public health partners, we voluntarily began testing our drinking water for Legionella. Legionella has not been detected in this routine testing.

Learn more on ourLegionella and drinking water page.

Graphic about water safety that reads: Steps managers of large buildings should take to maintain water quality. 1. Run water at least weekly 2. Maintain hot water at or above 140 degrees farenheit. Make sure your plumbing is working properly 4. Maintain building water treatment  systems 5. Follow CDC water management plan recommendations.

Text version of graphic

Steps managers of large buildings should take to maintain water quality:

  1. Run water at least weekly. [Icons of a showerhead and kitchen faucet.]
  2. Maintain hot water at or above 140 degrees Fahrenheit. [Icon of water heater tank.]
  3. Make sure your plumbing is working properly. [Icon of pipes in an "S" shape.]
  4. Maintain building water treatment systems. [Icon of a wrench.]
  5. Follow CDC Water Management Plan recommendations. [Icon of a book with "CDC" on the cover.]

Contaminants detected in 2021

What the EPA says can be found in drinking water

A man wearing a white lab coat is conducting water quality tests in a lab.

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.

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, or the MCL or MCLG does not apply to that result.
  • 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 2021

Data table of regulated contaminants detected in Portland's untreated source water
Regulated contaminantMinimum detectedMaximum detectedEPA standard: MCL or TTEPA standard: MCLGSources of contaminant
Turbidity (NTU)0.182.815N/AErosion of natural deposits
Fecal coliform bacteria
(% >20 colonies/100 mL in 6 months)
Not detected0%10%N/AAnimal wastes
Giardia (#/L)Not detected0.08TTN/AAnimal wastes
Data table of regulated metals and nutrients detected in Portland's treated water at the entry point
Regulated contaminantMinimum detectedMaximum detectedEPA standard: MCL or TTEPA standard: MCLGSources of contaminant
Arsenic (ppb)<0.501.02100Found in natural deposits
Barium (ppm)0.000810.0103022Found in natural deposits
Cyanide (ppb)<514200200Naturally present in the environment
Fluoride (ppm)<0.0250.16044Found in natural deposits
Lead (ppb)<0.050.15150Found in natural deposits
Nitrate (as nitrogen) (ppm)0.0120.301010Found in natural aquifer deposits, animal wastes
Data table of regulated microbial contaminants detected in Portland's treated water in the distribution system
Regulated contaminantMinimum detectedMaximum detectedEPA standard: MCL or TTEPA standard: MCLGSources of contaminant
Total coliform bacteria
(% positive per month)
Not detected0.4%TTN/AFound throughout the environment
Data table of regulated disinfection residuals and byproducts detected in Portland's treated water in the distribution system
Regulated contaminantMinimum detectedMaximum detectedEPA standard: MCL or TTEPA standard: MCLGSources of contaminant
Total chlorine residual (ppm)
running annual average
1.861.894 [MRDL]4 [MRDLG]Chlorine used to disinfect water
Total chlorine residual (ppm)
range of single results at all sites
0.342.66N/AN/AChlorine used to disinfect water
Haloacetic acids (ppb)
running annual average at any one site
22.040.860N/AByproduct of drinking water disinfection
Haloacetic acids (ppb)
range of single results at all sites
10.642.1N/AN/AByproduct of drinking water disinfection
Total trihalomethanes (ppb)
running annual average at any one site
20.936.180N/AByproduct of drinking water disinfection
Total trihalomethanes (ppb)
range of single results at all sites
15.839.8N/AN/AByproduct of drinking water disinfection
Data table of unregulated contaminants detected in Portland's treated water
Unregulated contaminantMinimum detectedAverage detectedMaximum detectedSources of contaminant
Radon (pCi/L)<50186372Found in natural deposits
Sodium (ppm)3.06.515Found in natural deposits
Manganese (ppm)0.00190.01520.0319Found in natural deposits  

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

About These Contaminants

Arsenic, barium, fluoride, lead, and manganese

These metals are elements found in the earth's crust. They can dissolve into water that is in contact with natural deposits. At the levels found in Portland’s drinking water, they are unlikely to result in negative health effects. Learn more about lead in drinking water.


Cyanide is produced by certain bacteria, fungi, algae, and plants. It is rarely detected in Portland’s water. At the levels found in Portland’s drinking water, cyanide is unlikely to result in negative health effects.

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 result in 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 result in 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

What to know about lead

The Portland Water Bureau cares about the health of the families in our community and is committed to helping you reduce your exposure to lead. If present, lead at elevated levels can cause serious health problems, especially for pregnant people and young children. Infants and children who drink water containing lead in excess of the action level could experience delays in their physical or mental development. Children could show slight deficits in attention span and learning abilities. Adults who drink this water over many years could develop kidney problems or high blood pressure.

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's blood 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. Testing results from fall 2021 showed that more than 10 percent of these homes had elevated levels of lead. Because these results exceeded the action level for lead, the Portland Water Bureau informed customers about the lead results. We also completed construction and brought improved corrosion treatment online to reduce lead levels at the tap. See the next section for more information.

Data table of lead and copper results from high-risk residential water taps
Regulated contaminantFall 2021 90th percentile resultsHomes exceeding action levelEPA standard: action levelEPA standard: MCLGSources of contamination
Lead (ppb)21.014 out of 104 (13.5%)150Corrosion of household and commercial building plumbing systems
Copper (ppm)0.2380 out of 104 (0%)1.31.3Corrosion of household and commercial building plumbing systems
  • 90th percentile: 90 percent of the samples results were less than the values shown.
  • Action level: 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

Improved treatment started this spring

Two photos showing the substances being used to treat drinking water. The image of sodium carbonate has a green scoop full of white, granular powder. The image of carbon dioxide is a glass filled with fizzy water.
Two naturally occurring substances, sodium carbonate (soda ash) and carbon dioxide, are added to water in our upgraded treatment system.

In April 2022, Portland began implementing our improved corrosion control treatment to reduce the levels of lead in drinking water for everyone. The new treatment system, built at our existing Lusted Hill treatment facility, adds two naturally occurring substances, sodium carbonate (soda ash) and carbon dioxide, to our drinking water. These adjust the alkalinity to about 25 mg/L and increase the pH to at least 8.5. We are proud to bring this improved treatment online and better support the health of our community.

How we got here

Two white towers that are part of the improved corrosion control treatment facility.

After detecting elevated levels of lead in higher risk homes in 2013, we looked for additional ways to reduce lead that can enter the water from home or building plumbing. We determined that improving our drinking water treatment is the most effective way to reduce lead levels. In 2016, we agreed with the Oregon Health Authority to install improved treatment and began construction in 2020. We found elevated levels of lead in these higher risk homes again in fall 2021, highlighting the need for improved treatment to protect public health. The improved corrosion control treatment facility began treating our drinking water in April 2022.

Progress in reducing lead levels at the tap

Our team has been working to ramp up improved treatment to full operation. We are making treatment changes in steps to allow our drinking water system to adjust to the changes in water chemistry. Throughout these changes, the treatment team is collecting water samples from around the city to track how the improved treatment is affecting lead levels. These results are helping us monitor the changes to the system and determine the correct treatment to reduce lead levels as much as possible.

Learn more about our improved corrosion control treatment

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 Cryptosporidium primarily during the rainy season. As a result, OHA determined that treatment is now necessary

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 tested200
Total number of samples positive for Cryptosporidium33
Minimum concentration detected (oocysts/L)Not detected
Maximum concentration detected (oocysts/L)0.12

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 at  800-426-4791.

Bull Run Treatment Projects: Filtration treatment by 2027

Project achieves important halfway milestone

A woman pouring water into a bottle in a lab-type setting.

Since 2017, a team of Portland Water Bureau and consultant engineers have been working to plan for and design the new water filtration facility. In 2020, the project team submitted two years of testing data confirming the best way to filter our water. They achieved a significant milestone this past year when they received OHA’s approval to design the filtration facility using the preferred treatment approach. 

Testing drinking water treatment options

The project team relied on science to help make sure the filtration process at the full-scale facility is designed for our unique Bull Run water. To do this, they used a mini-filtration facility to test how different treatment options work through seasonal changes to our water. The testing ensures that treatment at the future water filtration facility will meet our public heath goals, including removing Cryptosporidium from our drinking water.

What’s next

The project is now at its halfway point and on track to begin delivering filtered Bull Run water in 2027. The final design of the filtration facility will be complete by the end of 2022 and construction is anticipated to begin in 2023.

Learn more about our filtration project

A computer rendering of the future drinking water filtration plant. There are pools of water in the foreground, administrative buildings in the back, and green trees in the background.

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 Consortium. This year, the Consortium and its members are celebrating 25 years of service. Find out more about the Consortium and its work in water conservation, emergency preparedness, and regional coordination. 

Last updated: June 2022

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.