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Portland Water Bureau

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Neighbor Frequently Asked Questions (FAQs)

Updated: April 15th, 2020

The Bull Run Filtration Project is in the planning phase with design anticipated to begin in 2020. We will continue to update the FAQs as the project progresses and more information becomes available.




Gravity Flow

Filtration Plant Size and Appearance




Cultural and Natural Resources





Wholesale Customers




 Why is the filtration facility needed? 
The filtration facility is needed to comply with federal and stated drinking water regulations and remove the microorganism Cryptosporidium from our water supply. The filtration facility will also help us reduce potential impacts to our water supply from wildfires, landslides, and other natural disasters. 

Is Cryptosporidium really a health risk?
The Environmental Protection Agency considers Cryptosporidium to be a health risk and implemented a series of regulations called the Surface Water Treatment Rules to reduce illnesses caused by Cryptosporidium and other pathogens in drinking water.In January 2017, the Portland Water Bureau began detecting Cryptosporidium in the Bull Run supply thatwhile at low levels, exceeded what is allowable by these drinking water regulations 

Has every chance for a waiver to the treatment requirement been exhausted?
Yes, every chance for a waiver has been exhausted. In December 2018, the Oregon Health Authority revoked Portland’s variance from the requirements to treat for Cryptosporidium. The variance was initially granted in 2012 based on the results of a year-long intensive sampling for Cryptosporidium, and the limited sources and low occurrence of Cryptosporidium in the Bull Run Watershed at that time. The regular detections of Cryptosporidium since 2017 have exceeded allowable levels and the Bull Run supply must be treated. The Portland Water Bureau is required to have the Bull Run Filtration Plant online by September 2027 as part of the compliance agreement with the Oregon Health Authority.

Can’t customers just filter their own water at home?
No, home filters do not meet the regulatory compliance responsibilities directed by state and federal regulators. As a public water provider, the Portland Water Bureau is required to protect public health by providing drinking water that meets state and federal drinking water regulations.   


Could Portland switch to its second source, the Columbia South Shore Well Field, rather than build a new filtration plant?
No, the Columbia South Shore Well Field does not have sufficient capacity to meet the needs of Portland and wholesale customers without the Bull Run supply. The well field was developed to augment the Bull Run supply during hot dry summers and to serve as a backup supply when higher turbidity (sediment suspended in water) caused by winter storms can impact the Bull Run supply. It is important to maintain both the Bull Run supply and the well field for overall system reliability.

Why use filtration? Why not ultraviolet treatment?
The Portland City Council selected filtration treatment for the multiple benefits it provides. Granular media filtration is a proven technology used at almost all the large filtration plants in North America. Granular media filtration protects against Cryptosporidium while providing additional water quality and reliability benefits, including:

  • Makes our water safer by removing microorganisms from the water.
  • Provides consistent, high-quality drinking water.
  • Removes sediment. Storms, fires or other natural events can add sediment in the Bull Run reservoirs, sometimes making them unusable as a source.
  • May reduce the amount of chlorine required for disinfection and produce lower levels of disinfection byproducts.
  • Meets today’s water quality standards and helps address future regulations – a good investment in our future.



Why was this site chosen over other options? What other options were considered?
Image of Bull Run Filtration plant options mapSix potential sites for the filtration plant were evaluated in 2017-18:

  • City-owned property adjacent to Carpenter Lane
  • Lusted Hill (with expansion)
  • Headworks
  • Larson’s Ranch
  • Powell Butte
  • Roslyn Lake

The City-owned property near Carpenter Lane was selected for the new filtration plant site because it was the only property that met all facility siting criteria, including maximizing gravity flow, being close to existing and future pipelines, site size, site slopes and geologic conditions, being already owned by the City of Portland, and ability to meet the compliance schedule. The Portland Water Bureau purchased the Carpenter Lane site in the 1970s to use for future water system facilities. The analysis can be found in the Bull Run Filtration Project Preferred Alternatives Report and a variety of PowerPoint presentations available on the project in the Document Library.

How did the Portland Water Bureau incorporate community input in the plant location?
The site was selected as part of the Pre-Planning Phase of the project, which included several opportunities for community input. Community input and notification during the Pre-Planning Phase included:

  • Stakeholder interviews and an online survey: Input from more than 1,700 respondents was used to identify community values. Those community values were used to evaluate and identify preferred options for the filtration plant site, technology, procurement, and capacity.
  • Notification letters: Immediate site neighbors were sent letters notifying them of investigations (geotechnical, environmental, and cultural resources) at the site. The letters noted the property was being considered as a site for a future filtration plant.
  • Portland City Council presentation: Preferred alternatives were presented at a Portland City Council work session in August 2018
  • Community Forum: Preferred alternatives were shared with the public at a Community Forum in November 2018. The forum included an opportunity to discuss options with the Portland Water Bureau Commissioner and staff, including an open house, a group questions and answers session, and opportunity to submit written questions and input.

Based on both technical analyses and community input, Portland City Council authorized selection of the preferred site, filtration technology, and capacity in December 2018.

How will the project impact property values?
There are many variables that can impact property values, including the changing economy. We do not expect the filtration facility will impact property values long term. However, we will evaluate this topic further as design progresses.


Gravity Flow

Will the filtration plant use gravity flow and why is that important?
Yes, the filtration plant will use gravity flow. This means that the water will flow from the Bull Run Watershed to Portland without reliance on electrical and mechanical systems for pumping. The filtration plant site has been selected specifically to maintain gravity flow through the plant. In addition to higher reliability, gravity flow reduces construction and operating costs while minimizing the system’s carbon footprint.

Filtration Plant Size and Appearance

How will this filtration plant fit within the character of the area?
As part of the design process, which has not yet begun, the Portland Water Bureau is committed to designing a filtration plant that is consistent with the character of the area. The Water Bureau will seek input and work with site neighbors through the Good Neighbor Plan process to help identify design considerations that reduce visual impacts and respect the rural nature of the site. We will continue to share more information as design develops. We welcome public comment on design ideas as we conclude the planning phase of the project.

How large is the filtration plant footprint?
The size and configuration of the filtration plant’s footprint on the 95-acre site has not been determined. These elements will be developed as design begins in 2020. Based on conceptual planning work, we expect the facility may use 40 to 60 acres of the site. We will develop these elements as design progresses. 


What is the height of the filtration plant and will it block neighbors’ views of Mt. Hood?
The height of the facility will be determined during the design phase of the project beginning in 2020. The Portland Water Bureau understands that preserving existing views is important to site neighbors. During design, 3D photo simulations will be used to model view lines and will be shared with site neighbors as part of project outreach. 


Will the facility be landscaped?
Yes, landscaping options for the facility will be part of the design phase of the project. The nature of the landscaping buffer will be in keeping with the character of the area. The Good Neighbor Plan process is an opportunity for site neighbors to provide input into landscape preferences.

Will there be fencing?
A filtration plant is considered critical infrastructure and is required to be secure by the Office of Homeland Security. During design, the Portland Water Bureau will evaluate and further refine options for securing process areas. To lessen the visual impact of potential fences or walls, options may include creating berms that mimic the natural landforms and hide fences or walls. Fencing and plant edges will be included in the Good Neighbor Plan process.

Are there going to be settling ponds? How will those be constructed? Will they be lined?
Settling ponds will be used to temporarily hold water containing solids left over from the treatment process. We will develop construction details, such as use of liners, during the design process.


How many pipelines will there be? How large and how deep will the pipelines be?
There will be two pipelines that carry water to and from the facility. Having two pipelines will provide system reliability by allowing us to conduct maintenance or repair without disrupting our water service. We are currently evaluating the size of the pipelines as part of pipeline planning efforts. Preliminary sizing is generally in the range of 66 to 96 inches in diameter. We will determine the depth and construction method for the pipelines during pipeline design anticipated to begin in 2021.

What are the proposed pipeline routes? How will the final routes be selected? 

We have not yet selected final pipeline routes. We are conducting field investigations to inform selection of the routes. We will continue to reach out to property owners along the potential routes to share more information as that process moves forward.Our route selection criteria include consideration of resilience/reliability, capacity, constructability, permitting, environmental and community impacts, and ratepayer costs.

How deep is the pipe? How will it be installed? What will happen to the dirt?

The depth and construction method for the pipelines will be determined as part of the pipeline design, which is anticipated to begin in 2020. Property along the pipeline route will be restored to equal or better condition within a reasonable time following construction. This includes excavated dirt, which will be used as backfill or removed from the site.  

Will the pipeline require easements or property acquisition?
The Portland Water Bureau has owned property and easements in the area for many years—the oldest easements date back to the 1890s. As the project progresses to design, the Water Bureau will identify any potential easement and property acquisition needs along the selected pipeline alignments. The Water Bureau is currently identifying the best alignment for the pipelines, including evaluating options that are in existing easements and public right-of-way.


How will the filtration plant site be accessed? Which existing roads will be used and how will neighbor impacts and roadway condition be addressed?
Multiple routes are being considered to access the filtration plant site. The route selection will occur during the project design phase and will include assessment of traffic safety and capacity. The Good Neighbor Plan process is an opportunity for site neighbors to share concerns and provide input on traffic control and safety considerations.

How much traffic will be generated during construction and operation? How will traffic impacts be limited?
Traffic impact analyses will be conducted to identify safety or capacity issues and roadway improvement needs for the construction phase and for ongoing operation of the filtration plant. Ongoing operation is not expected to have appreciable traffic impacts. For construction, traffic control plans will be developed that focus on traffic safety and minimizing impacts on the local community. Traffic control measures will be identified and implemented. Typical traffic control measures include prescribing dedicated haul routes and construction speed limits. For construction, early estimates from the project pre-planning efforts suggested 116,000 total truck trips over the span of 4 to 5 years. We will continue to review and refine these estimates as design progresses. We will develop construction traffic control plans that focus on traffic safety and minimizing impacts on the local community. We will also identify and implement appropriate traffic control measures. Typical traffic control measures include prescribing dedicated haul routes and construction speed limits.

Will the roads be improved before, during, or after construction?
The Portland Water Bureau will maintain the condition of roads used to access the filtration plant site during construction. Local roads used during construction will be restored to their pre-existing condition or better.

What measures are being taken to account for safety of school children and bicyclists given the volume and type of traffic anticipated?
The Portland Water Bureau is committed to the safety of the community. Traffic safety measures will be developed during design using community input to fully understand the needs of pedestrians, cyclists, and other road users.

Are traffic studies available?
We will prepare traffic studies as part of the project design and permitting process. A preliminary traffic impact analysis completed for the operational phase of the facility is included in the Draft Filtration Facility Overview. The study found that facility operation will not have appreciable traffic impacts. A preliminary evaluation of estimated construction traffic impacts will be available in fall 2020.


Will there be odors?
No, odors are not foreseen in normal operation of a drinking water filtration plant.

Will the facility have off-site noise impacts? Can noisy equipment be housed?
The filtration plant design and operation will include noise limiting measures required to meet local ordinances. For example, a number of plant processes will be located within buildings to address potential off-site noise impacts.

What lighting is planned? Will the filtration facility have stadium lighting?
The filtration facility will not have stadium lighting. The facility will be designed to meet applicable county code requirements and operational needs. The facility design will
include techniques to minimize potential off-site light impacts, such as:

• Light Shielding: directing light downwards, or using earthen berms or other landscape features so light is screened from neighboring properties.
• Light Levels: using separate modes of lighting for regular operation and for safety and emergency scenarios.

What is the planned staffing at the facility?
We will evaluate staffing numbers for the filtration facility during design. Facility personnel may include administrative, engineering, operations, and maintenance staff. Similar
facilities have approximately 15 to 20 certified operators and five to 10 maintenance personnel. The number of staff on site will vary depending on the time of day.

Can deliveries be limited to weekday hours? 
Restrictions on allowable delivery times and days will be specified in future vendor contracts. Weekday deliveries are a standard practice, but evening or weekend deliveries may be needed on occasion. For example, if weather prevents a regularly scheduled delivery, that delivery may need to happen on the weekend.

Cultural and Natural Resources

Will the filtration plant discharge to the Sandy River? If not, what will be done with the wastewater?
No, the filtration plant will not discharge to the Sandy River under normal operation. Non-potable water left over from the treatment process will be recycled onsite. 

How will solid waste be disposed?
Treating drinking water generates a small amount of silts, clays, and other settleable or filterable materials. These residual solids will be disposed of off-site. During design, the Portland Water Bureau will evaluate potential beneficial use options, such as using residual solids to provide daily cover for a landfill.

Will construction impact the groundwater aquifers?
We do not anticipate that construction will impact groundwater aquifers over the long term. During construction, we will need to remove water from excavated areas of the site. While this process could affect water levels in perched aquifers near the ground surface, we do not anticipate the deeper aquifers where drinking water wells are located will be affected.

What is the geology around the site?
We have been working to gather data about the local geology through ongoing field investigations and geotechnical borings. This preliminary work is described in the Draft Filtration Facility Overview.

How will this project benefit the watershed overall?
The filtration project will not directly affect the watershed. More information about our ongoing stewardship of the Bull Run Watershed is available on our website.

How will this project affect elk? 
Potential impacts to wildlife will be evaluated and mitigated consistent with applicable state and federal permitting processes.



How will the project improve resilience?
We are prioritizing improvements to the water system backbone to address high-risk infrastructure and increase overall system resilience. The new filtration facility and pipelines will be designed and constructed to withstand an earthquake and will help us meet Oregon Resilience Plan goals, such as the ability to restore service within 24 hours of a major event. The new facility will also help us address turbidity and other potential impacts to the water supply that could result from a fire, landslide, or other natural disaster.

Will the filtration facility use gravity flow and why is that important?
The new filtration facility will use gravity flow. This means our water will flow from the Bull Run Watershed to Portland without reliance on electrical and mechanical systems for pumping. We selected the filtration facility site specifically to maintain gravity flow through the facility. In addition to higher reliability, gravity flow reduces construction and operating costs while minimizing the system’s carbon footprint.



What is the land use process? The Portland Water Bureau will follow Multnomah County’s Type III Condition Use Review process for the filtration plant site. This includes a pre-application conference that is open to the public and a land use application submittal that occurs midway through the design process. The land use review process is overseen by a hearings officer, an independent decision maker hired by the County.

Will there be an archaeological investigation of the filtration plant site? What will happen if there are discoveries?
Yes, there will be an archaeological investigation of both the filtration plant site and potential pipeline alignments. If there are discoveries, they will be addressed as required by state and federal regulations. Preliminary assessments summarized in the Draft Filtration Facility Overview did not result in discovery of archaeological resources at the facility site.


What chemicals will be used? Are you planning to use chlorine or bleach?
We are identifying specific chemicals that work best with the Bull Run supply using a minifiltration facility called a pilot plant. We will only use chemicals in the treatment process that are certified as safe for use in drinking water applications by NSF International, which sets public health standards and certification programs. The chemicals we are evaluating are in common use at water treatment facilities
across the United States. We anticipate usingliquid sodium hypochlorite, similar to household bleach, for disinfection. We will make decisions on all chemicals during project design.

Will there be chemical residuals?
Water treatment uses chemicals (coagulants and polymers) to help remove suspended sediment, disease-causing pathogens, and other contaminants from drinking water. These chemicals are almost completely removed during the sedimentation and filtration steps of the water treatment process. The chemicals, as well as contaminants removed from the water, are then concentrated into a solid with a consistency similar to wet earth that can be used for landfill daily cover or other beneficial use. Some chemicals are added and remain in the treated water to make it less corrosive to piping. We currently add chlorine and ammonia to our water supply for disinfection and to provide a protective disinfectant residual in our distribution system. All chemicals used to treat our water will meet rigorous safety standards.

What are polymers?
Polymers are long-chain organic molecules that help to capture organics and particles, including disease-causing pathogens, so they can be removed from the water. The polymers are also removed from the water during the sedimentation and filtration steps of the water treatment process.

How will safety be addressed for storage and transportation of chemicals?
Safety of both the public and Portland Water Bureau staff is a top priority. The filtration plant will meet rigorous state and federal safety standards for chemical storage and transportation that are designed to protect workers and the public. For chemicals stored on site, regulations require secondary containment, such as a basin around a storage tank, to capture any chemical if the tank leaks.  

Is there a plan for catastrophic events/evacuation?
Yes, we will develop risk management and emergency action plans for the filtration plant. The safety of the community and our staff is of paramount importance, and we follow industry best practices for preparing for potential emergency situations. Additionally, as part of the design process, we will be evaluating inherently safer technologies that minimize risk to the public and plant staff.


What is the estimated cost of the Filtration project?
The Portland City Council approved a resolution in November 2019 that provided a set of priority values and expectations to guide the project.The option that will meet the Council’s priority
values has an estimated cost of $820 million in 2019 dollars with an accuracy range of -30 percent to +50 percent. As part of design, we will be further evaluating the cost and exploring a full range of needs that will inform the estimate. Project cost estimates will continue to improve as design progresses.

Who will pay for this project? How will Portland Water Bureau customers’ rates be affected?
These investments in the future of Portland’s drinking water will be funded through wholesale and retail customer rates. To manage increases in rates, the Portland Water Bureau will borrow money and pay it back over time. Borrowed money will be repaid over many years so future residents also help to cover these costs.

The Portland Water Bureau is committed to actively managing costs throughout the life of the project and continues to seek out opportunities for other project funding, including through federal infrastructure programs. Throughout, we will continue to provide support through our financial assistance program for income-qualified customers.

Does the Water Bureau have federal funding for the project?
The EPA invited us to apply for a water loan to finance up to 49 percent of the potential cost for the Bull Run Treatment Projects through the Water Infrastructure Finance and Innovation Act. If awarded, the funding will provide long-term and low-cost supplemental credit assistance that will help us minimize future rate impacts.

Wholesale Customers

How will Pleasant Home Water District and its customers be affected? Will site neighbors’ homes be served?
Pleasant Home Water District is a Portland Water Bureau wholesale customer. The District’s customers will get drinking water from the new filtration plant—through Pleasant Home Water District—by 2027 when the plant is operational.

Construction of the filtration plant will not change the Pleasant Home Water District service area. Neighbors of the plant who are not currently served by the Pleasant Home Water District will not be required to connect to their system. If neighbors who have wells would like to be served by the filtration plant, they should contact the Pleasant Home Water District to find out if and how they can connect to the District’s system.

Will the City of Sandy receive water from the filtration facility?
The City of Sandy is a Portland Water Bureau wholesale customer. The City will have the opportunity to get drinking water from the new filtration facility by 2027.

Can this facility keep pace with the City of Sandy’s growth?
The City of Sandy’s projected water use for the next 20 years is included in our water supply planning.

How will the projects change my water? What will I notice?
These projects will provide more consistent water quality that is less affected by seasonal variations in our Bull Run supply. We anticipate
most customers will not notice any changes to the taste of Bull Run water with the improved treatment systems.


How will neighbors be kept informed?
An almost 10-year project provides the opportunity for many different types of engagement—both in-person and online. We are committed to keeping our neighbors informed and involved in all phases of the project with open houses and events, mailings, email, website updates, door hangers, and other ways to stay engaged. Our Neighbor Events page has the latest information.

Will the community have input on facility
design and operation?
We are working with community members on a Good Neighbor Agreement to make sure neighbors’ concerns are considered through the life of the project, from design to construction and into ongoing operations. These Site Advisory Group meetings are open to the public and include opportunity for public comment. We post meeting times and materials to our Filtration Neighbor Information webpage and share regular updates in our project e-news.

Will the community have input on facility design and operation?
Yes, we will work with community members on a Good Neighbor Agreement that will ensure that neighbors’ concerns are considered through the life of the project, from design to construction and into ongoing operations. These meetings will be open to the public and will have public comment periods on the agenda. To sign up to be notified of meetings or for more information, please contact the project team

What opportunities are upcoming for neighbors to provide input? What will the format of those meetings be?

To learn more about neighbor engagement opportunities, visit our Neighbor Information page.

Are you engaging regional stakeholders and interest groups?
Yes, we are sharing information and gathering input from a diverse group of community stakeholders, including schools, community associations, local governments, tribes, watershed councils, other environmental groups, and water suppliers. As with all outreach, this is an iterative process that will continue to expand throughout the life of the project, and we will continue to work with all stakeholders throughout. Stakeholder groups interested in more information can contact the project team at


How long will construction take?
Construction of the Bull Run Filtration Plant is expected to take four to five years. Construction for the pipelines is expected to take approximately three years. Both projects could start as soon as late 2022 and are required to be complete by September 2027. Details about construction activities and the schedule will be available after designs are complete and contractors are selected.

What types of impacts will there be during filtration plant and pipeline construction? What is being done to limit those impacts?
We are committed to limiting construction impacts on site neighbors. The construction management plan will include ways to minimize impacts from traffic, noise, dust, and other construction concerns.  



Have more questions? Submit a comment online or email us at