Water FAQs

In March 2026, the City completed a six-year transition from the Portland Bull Run Reservoir water system to a locally sourced and controlled groundwater system. You can find answers to commonly asked questions about this transition and our drinking water here.

If you don't see what you're looking for here, use our online form and a water team member will respond as soon as possible.

How does the new groundwater system help manage future costs for Gresham customers?

• The filtration project associated with our previous water system was originally estimated to cost $500 million in 2017 and is now expected to cost more than $2.6 billion dollars to complete. Like other major utilities, these infrastructure costs will be passed onto customers in the form of increased service fees.
• In 2020, City Council felt the path to local control over the city’s water best reflected its commitment to fiscal responsibility and affordability for Gresham residents. 
• While the Cascade Groundwater Alliance’s water system will not eliminate all future water cost increases or challenges in Gresham, it does significantly improve the City’s ability to manage those costs and risks locally, transparently, and strategically. 

How is the water transition project funded, and how does it affect the City’s general fund? How will the system impact the general fund budget moving forward?

• Gresham’s water system is and always has been paid for via water service fees. When Gresham residents pay their water bill, they are paying for the delivery of water to their tap as well as the system that carries it there from our water treatment facility. The groundwater project is funded through the water utility, not the City’s general fund. 
• A large portion of project funding came in the form of Water Infrastructure Finance and Innovation Act loans. This offers a low, fixed interest rate with flexible financial terms. These loans provided:
  • $30 million for our partners at Rockwood Water People's Utility District. 
  • $34 million for the City of Gresham. 
• The US Environmental Protection Agency (EPA) estimates that the Alliance partners will save around $18 million by financing these loans, which are repaid through revenue generated by water service fees. Water service fees can only be used for costs associated with delivering water to our customers. 

How did the City keep the community informed and involved before, during and after the water transition?

• Beginning in 2019, the Gresham City Council and City staff conducted a robust community outreach effort as they explored expanding groundwater infrastructure and moving toward a locally controlled water supply.
• After reviewing community feedback and staff recommendations, City Council, formally authorized the project and subsequent transition via council action in 2020.
• Additionally, the Cascade Groundwater Alliance has been discussed publicly by elected officials through business meetings, capital planning discussions, budget deliberations, utility rate conversations, and formal project updates to the community.
• The City provided project updates to the Gresham community through various communications channels, including engagement with local businesses, presentations to neighborhood association meetings, staff tabling at public events, and providing information in issues of GRESHAM, the City’s quarterly newsletter delivered to every household and business in Gresham.

How long will the taste and odor changes related to the water transition last?

• Recent samples show that the transition is mostly complete, but some areas still have pockets of older surface water in the system.
• The system is large, so residual surface water is more present in some parts of the network than others. As more water moves through the pipes in your area, the remaining water will continue to flush through the system and the water should continue to stabilize.

What is the City testing at customer homes, and is that the same or different than water tests done at the source of distribution?

• The City’s Water Department continues to test and monitor the water system to ensure that all water delivered to customers meets or exceeds all state and federal safety standards.
• At-home testing currently focuses on factors that can affect taste and odor, including measuring alkalinity and free chlorine. These results help the City decide where targeted system flushing may still be needed.
• You can contact the water team by emailing WaterSupply@GreshamOregon.gov or calling 503-618-2626 to request a site visit and chlorine level testing.

Why am I seeing white spots on dishes, countertops and/or appliances, and what can I do about them?

• White spots are usually caused by mineral deposits left behind when water dries.
• There are commercially available cleaning products that are sold to address mineral build up on appliances and countertops.
• Using a rinse aid in your dishwasher can help reduce spotting on dishes and glassware.

Why does Gresham use free chlorine instead of chloramine?

• Chloramine is often used in very large water systems because the added ammonia helps to carry disinfectants over greater distances. Gresham’s groundwater system is smaller, and groundwater has fewer organic materials to treat than surface water, so ammonia is not needed to maintain disinfection through the system.
• This means there is one less chemical (ammonia) in the water delivered to Gresham homes than was in the previous water system.

Should I buy home water filters, softeners, or purifiers? Are rebates available for these purchases?

• Customers may choose those products based on personal preference, but they are not required as the water delivered to your home is safe to drink.
• The City does not currently plan to reimburse residents who choose to purchase water filters, softeners, purifiers, or similar products for their homes.

Could harder water affect my home appliances or fixtures?

• The City does not expect the current water hardness levels to significantly affect normal appliance operation. However, because groundwater contains more naturally occurring minerals than surface water, customers may notice more mineral scale buildup over time on appliances, fixtures, and water heaters. Regular use of commercial descaling products can help reduce buildup.

Can groundwater be diluted with bull run surface water?

• While it would be possible to mix two water sources together, it would result in the continued instances of increased chlorine odor and taste.

What minerals are removed through the treatment of groundwater?

• Currently, the only minerals being removed during treatment is iron and manganese. Currently, tests show no or very low instances of either mineral in our system.
• The groundwater system is currently supplied by five different wells, all routed to the treatment plant. The system typically has 2-3 different wells in operation at any given time. These wells each have different amounts of minerals pre-treatment.
• The largest factor in water hardness and spotting comes from silica, which is not removed during the treatment process.

Other questions

Will Fairview’s new well system connect to Gresham’s water system?

• No, the City of Fairview well will serve only Fairview water customers.

Related links

• Cascade Groundwater Alliance
• Water Quality 
• Oregon Health Authority- Drinking Water Services