Water Quality Report 2024

2024 City of Renton Water Quality Report

2024 Water Quality Report(PDF, 1MB)

Renton’s Water Sources and Treatment Process

Renton’s Water Sources

In 2023, the City of Renton obtained its drinking water from four sources: 

1. Six downtown wells located in Liberty and Cedar River Parks, which draw water from the Cedar Valley Aquifer

2. Springbrook Springs, a small spring in south Renton

3. The Maplewood wellfield located under the Maplewood Golf Course

4. An agreement to buy water from Seattle Public Utilities (SPU), who source water from the Cedar and Tolt rivers

Our agreement with SPU began in January 2012. During 2023, SPU provided approximately 28 million gallons of water. Water is purchased from SPU primarily for the Renton Boeing plant and as a backup supply during summer peak use periods. More information is available at SPU.

In 2023, the combined four water sources provided approximately 2.78 billion gallons of water to Renton customers.

Providing Safe, Clean Water

The water pumped from the downtown wells and Springbrook Springs is naturally very clean and needs minimal treatment. Chlorine is added to destroy bacteria, parasites, and viruses that could possibly enter our source water. Chlorine also protects water in the distribution system in case there is a contamination event like a water main break or backflow incident. Sodium hydroxide is added to slightly raise the pH of the water to help prevent the corrosion of household plumbing. Ortho-polyphosphates are added to reduce the internal corrosion of old cast iron water mains found in the neighborhood of West Hill. Fluoride is added to prevent tooth decay, as authorized by Renton voters in 1985. The downtown wellfield produced 65.2% of Renton’s water in 2023. Springbrook Springs produced 15.4% of Renton’s water in 2023.

Maplewood water is clean as well, but due to naturally occurring minerals, it must first be treated before it is pumped into the distribution system. The treatment process consists of removing manganese, hydrogen sulfide, and ammonia from the source water. Chlorine is added to protect the water in the distribution system and fluoride is added to prevent tooth decay. The Maplewood wellfield produced 19.4% of Renton’s water in 2023.

The city purchased 1.2% of its total amount of water sold from Seattle Public Utilities to serve the Boeing Renton Plant.

Water Utility News 

West Hill Booster Pump Station Improvements

Based on future water demand projections up to 2039, a storage deficit has been identified in the West Hill 495 Operational Area. This project will replace the three existing old pumps with one new 1,200-gallon per minute pump and two 600-gallon per minute pumps, all equipped with variable frequency drives. A new motor control center and upgrades to the electrical system will be installed. The addition of a new on-site backup emergency power generator along with the new pumps and upgrades will increase the pumping capacity to meet future demand and increase the operational reliability of the West Hill pump station. The project is expected to be completed in Fall 2024.

Windsor Hills Utility Improvements

This project will construct 7,000 feet of new 8-inch water mains, 15 fire hydrants, and the replacement of 136 water service lines including the installation of individual pressure-reducing valves to increase fire flow capacity and improve water quality in the Windsor Hills neighborhood. The project includes the construction of 4,300 feet of new storm sewer pipes, 59 new catch basins and manholes to improve the drainage system to current standards. The construction contract was awarded in late May 2024 with construction to start in Summer 2024 and to be completed by Fall 2025. 

2023 Renton Water Statistics

• 2,754,296,000 gallons produced by the City of Renton from nine wells and one spring
• 318 miles of water main in service
• 17,901 total metered connections
• 7,546,016 gallons produced on an average day
• 12,380,000 gallons produced on high demand day: August 1, 2023
• 5,139,000 gallons produced on low demand day: December 26, 2023

A Message from the EPA

Our drinking water comes from wells and springs. As our water travels through the ground to the wells, it can dissolve naturally occurring minerals as well as substances from human activity. 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 Environmental Protection Agency’s Safe Drinking Water Hotline at 800-426-4791.
Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised 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, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their healthcare providers. Environmental Protection Agency (EPA)/Centers for Disease Control (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.

Water Use Efficiency

In 2003, the Washington State Legislature passed the Municipal Water Law to address the increasing demand on the state’s water resources. The law established that all municipal water suppliers must use water more efficiently in exchange for water right certainty and flexibility to help them meet future demand. The Water Use Efficiency (WUE) Rule is part of this law and requires municipal water suppliers to report their goals and progress each year.

In 2021, Renton hosted a public forum and updated the WUE goals as part of the Water System Plan Update. The city has the following measurable WUE goals:

1. Reduce Distribution System Leakage (DSL) to 10 percent or less by 2022.
2. Limit the Maximum Daily Demand to Average Daily Demand peaking factor to less than 2.0.
3. Maintain an ERU value under 160 gpd/ERU (gallons per day/Equivalent Residential Unit)

As part of the Saving Water Partnership (SWP), the city also supports the regional 2019–2028 WUE goal to keep the total average annual retail water use of SWP members under 110 million gallons per day (mgd) through 2028 despite forecasted population growth by reducing per capita water use.

Water Consumption and Losses

Water Loss Control Action Plan

Since the three-year (2021–2023) annual average of the city’s distribution system leakage exceeds 10%, the city is required by the state to develop and implement a Water Loss Control Action Plan. The city is taking the following actions, among others, to identify and reduce water loss in the distribution system:

• Continue the annual replacement of aging and leaky water mains.
• Conduct leak testing on old underground water reservoirs and repair leaky joints on concrete floors and walls.
• Continue using Advanced Metering Infrastructure (AMI) technology to detect leaks.

Water Conservation: Watering your Garden

How to Water: Young Trees

Using a water bag is the most efficient way to water young trees. For the first five years trees need 15 – 20 gallons of water twice a week, applied close to the roots. 

How to Water: Shrubs and Perennials

Many established plants need little or no summer watering. Before you water, look for wilted leaves that don’t perk up in the evening, deciduous leaves that are yellow before autumn, or evergreen leaves that are dull or bronze.

How to Water: Annuals

Annuals generally need more water than other types of landscaping plants. Minimize your water use by waiting to water until the soil surface is dry and covering the soil with mulch in the spring.

Right Plant, Right Place

Plants that fit our Northwest climate and soils are easier to care for, need less summer watering, and look great. For more information on picking the right plant for your place, visit SavingWater.org/lawn-garden/plants.

Build Healthy Roots

Getting to the root of the issue. Plants with deep, healthy roots need less water, are more resilient, and will look their best. To build healthy roots: 

• Build healthy soil by adding compost and mulch.
• Let the top few inches of soil dry before watering again so that plant roots and soil life can breathe.
• Water deeply and infrequently to encourage roots to grow deep.

Plant perennials in the fall to build strong root systems before next year’s dry season.

Water Conservation: Toilet Tips

How Do I Know If My Toilet is Leaking?

Look, listen, and lift the lid to detect toilet leaks.

Look at the bowl of your toilet to see if water flows from the tank when you have not flushed. If water is dribbling into the bowl, you have a leak.

Listen to the tank. If it sounds like it is re-filling even when you haven’t flushed, that means you have a leak.

Lift the top off your toilet’s tank and check to see if the rubber seal or “flapper” looks worn out. If the rubber is cracking or not creating a complete seal, you have a leak.

You can detect silent leaks with food coloring. Put food coloring or a dye strip in the tank, don’t flush, and see if the color appears in the bowl. If it does, you have a leak.

Was your toilet manufactured before 2004? 

Replacing an older toilet is one of the most powerful actions you can take to save water every day. Visit savingwater.org/rebates for more information about $100 toilet rebates available to Renton’s small business, commercial, multifamily, and residential customers.

Did you know?

Leaks waste up to 12% of all water used at home. Yikes! That’s almost as much water as most homes use doing laundry each year. 

Visit savingwater.org/indoors/fixing-leaks for how-to videos and more information about fixing leaks in your home.

Water Conservation: Indoor

Bathrooms

• Fix leaks, drips, and running toilets right away. If your toilet makes noise between flushes or if you have to jiggle the handle, you have a leak.
• Shorten your shower. Save two gallons for every minute you shave off your shower.
• Upgrade your shower head or faucet. The new models work great and use less water.
• Turn the tap off while brushing your teeth. You can save enough water to fill a kiddy pool each week.
• Don’t walk away while waiting for hot water. It’s easy to lose track of time and leave the water running.

Kitchen

• Run full loads. Wait to run your dishwasher until it’s full.
• Scrape your plate and let a dishwasher do the rest. The average dishwasher uses five gallons of water or less, while washing the same number of dishes by hand can take 27 gallons.
• Compost your food scraps. Skip the garbage disposal and running your faucet whenever you can.
• Don’t walk away while waiting for hot water. It’s easy to lose track of time and leave the water running.

Laundry

• Run full loads. Wait to run your washing machine until it’s full.
• Reuse towels a few times between washing.
• Bonus tip: wash with cold water to save energy.

Water is a precious, shared resource

When you save water, you help protect salmon. This is especially important during summer and fall when stream flows are already naturally low when adult salmon are returning to our local rivers and streams to spawn.

You can also help protect this important species by practicing these salmon-safe habits…

• Never dump oil or other chemicals down storm drains, and make sure no pollutants are leaking that could get washed into waterways (including pressure washing). For more information on proper disposal methods for recycling motor oil and preventing car leaks from polluting waterways, please visit Renton’s Shift Green program at rentonwa.gov/oilrecycling.
• Sweep sidewalks and driveways instead of hosing. Put sweepings in the garbage to prevent pollutants and debris from entering streams.
• Use automatic car washes that recycle water and perform proper disposal of detergents.
• Plant native plants and trees to reduce the need for watering, pest control and fertilization; and reap multiple benefits such as controlling erosion, reducing flooding, filtering pollution, and attracting wildlife.
•  Use compost as a natural fertilizer on your lawn, flowers, and garden beds. Compost supports healthy plant roots and slowly releases water to plants. Avoid non-organic fertilizers.

Renton is a Member of the Saving Water Partnership 

IN JANUARY 2012, Renton signed an agreement to buy water from Seattle Public Utilities. As part of this agreement, the City of Renton joined the Saving

Water Partnership (SWP). The SWP, which is made up of the City of Renton and 18 water utility partners around the Puget Sound, has set a ten-year conservation goal to keep the total average annual retail water use of SWP members under 110 mgd through 2028, despite forecasted population growth, by reducing per capita water use. For 2023, the Saving Water Partnership met the goal, using 94.3 mgd.

Why conserve? It works! 

When we work together to save water, it makes a big difference. Thanks to conservation efforts, our region uses the same amount of water today that it did in the late 1950s.

Together We Provide Water Conservation Programs to the Region

• In 2023, the SWP made progress in promoting environmental education and water conservation in Renton. The SWP’s youth education program conducted 44 engaging in-classroom presentations, reaching over 1,000 students with topics such as the water cycle, salmon life cycle, and practical water-saving tips. Additionally, two successful outreach events attracted more than 1,200 participants, where educational materials on water conservation, including brochures in multiple languages about water-saving tips and leak prevention, were distributed along with Shared Waters Activity booklets. The SWP continued to provide rebates for premium toilets for both residential and commercial customers encouraging the adoption of water-efficient fixtures, which use significantly less water per flush compared to regular fixtures.
• The SWP offers technical assistance to both residential and commercial customers, addressing issues related to irrigation efficiency and indoor water use. This hands-on support helps customers optimize their water usage, reduce waste, and contribute to broader sustainability goals. These efforts collectively contributed to raising awareness and fostering sustainable practices, marking a successful year for the SWP in advancing environmental conservation and education within the community.

Please visit the Saving Water Partnership website at savingwater.org for more materials and rebates.

Water Quality Topics

Lead and Your Health

If present, elevated levels of lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. The City of Renton Water Utility is responsible for providing high-quality drinking water, but cannot control the variety of materials used in plumbing components. When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to two minutes before using water for drinking or cooking. If you are concerned about lead in your water, you may wish to have your water tested. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from the Safe Drinking Water Hotline at 800-426-4791 or epa.gov/safewater/lead.

If you flush your tap, you can use the flushed water for watering plants or general cleaning. Hot water is likely to contain higher levels of lead. Only use water from the cold-water tap for drinking, cooking, and especially for making baby formula. Homes built before 1986 are more likely to have lead pipes, fixtures, and solder. The most common problem is brass or chrome-plated brass faucets and fixtures that can leach lead into the water, especially hot water. Until ten years ago, the legal limit for “lead-free” pipes was up to 8% lead. As of January 1, 2014, all newly installed water faucets, fixtures, pipes, and fittings must meet new lead-free requirements, which reduce the amount of lead allowed to 0.25%. However, these requirements do not apply to existing fixtures, such as those found in many older homes.

Lead Prevention

Renton works to prevent the corrosion of lead as well as other metals such as copper and iron. The pH of Renton’s water is adjusted to prevent the corrosion of household plumbing­—the major potential source of lead in our water. In areas of the city with cast iron water mains, such as West Hill, ortho-polyphosphates are added to prevent corrosion. To make sure this treatment is working, water is periodically tested at residential taps. This testing is in compliance with the Department of Health (DOH)’s Lead and Copper Rule. More information is available at doh.wa.gov/leadandcopperrule.

Lead Testing in Schools

The Washington State Department of Health has developed a program to address concerns about lead in school drinking water. For updated information, please visit: doh.wa.gov/LeadinSchoolDrinkingWater.

PFAS Chemicals

PFAS is an acronym for “per- and poly-fluorinated alkyl substances.” PFAS are synthetic chemicals used in many consumer products, including food wrappers, fabrics, and carpets, to make them resistant to water, oil, grease, stains, and heat. Certain types of firefighting foam may contain PFAS. Even though PFAS compounds aren’t manufactured in Washington State, there are known cases of PFAS contamination in drinking water linked to the use of firefighting foam. 

NEW PFAS Rule and Testing

EPA recently finalized regulatory limits for six PFAS compounds – PFOA, PFOS, PFBS, PFHxS, PFNA, and Gen X chemicals. The Water Utility accelerated its UCMR5 testing timeline such that sampling was performed in March/September 2023 rather than 2024/2025 as initially scheduled. The UCMR5 samples were tested for an expanded list of 29 PFAS compounds, which included the six regulated PFAS and 25 unregulated PFAS. 

The March 2023 sampling showed one sample result from Springbrook Springs with detection of perfluorobutane sulfonic acid (PFBS). The PFBS detection was at a level significantly below the state and federal regulatory limits. Additionally, the PFBS detection was below the EPA’s established practical quantitation level of 3.0 ppt, which is the level laboratories can measure a concentration with high certainty. Follow-up sampling in September 2023 did not detect PFBS at Springbrook Springs. PFAS compounds were not detected in the March or September UCMR5 samples collected from Downtown Wells and Maplewood Wellfield.

• Springbrook Springs PFBS Result March 2023: 2.98 ppt
• Springbrook Springs PFBS Result Sept 2023: No Detection
• WA DOH PFBS State  Action Level: 345 ppt
• EPA PFBS HBWC: 2,000 ppt

The City is in full compliance with all current EPA and Washington State DOH regulatory requirements. The City will continue periodically sampling for PFAS under state and federal monitoring requirements. 

The City of Renton has continued tracking information on emerging contaminants, such as PFAS, and is dedicated to following regulatory updates to provide our customers with sound, scientific information regarding their drinking water.

For more information, please visit epa.gov/pfas and doh.wa.gov/pfas.

Renton Water Quality Topics

Water Quality for Brewers

For brewers in our community, specific water quality parameters are often of interest. Below are the values for the minerals and parameters generally requested. These numbers are the annual range of values. Renton’s water comes from multiple sources and depending upon your location, you may receive water from one source or a combination of our water sources.

How Can I Get Involved?

The City of Renton welcomes your interest in its water system. The Renton City Council is the city’s decision-making body and meets on the first four Mondays of each month at 7 p.m. Meetings are conducted via videoconference and in person at the Council Chambers on the 7th floor of City Hall.

The Utilities Committee oversees Water Utility issues. They meet the first and third Monday of the month at 3 p.m. in the Council Conference Room or via videoconference. Members of the Utilities Committee for 2024 are: 

Kim-Khánh Văn, Chair
Carmen Rivera, Vice-ChairJames Alberson Jr., Member

Call the City Clerk’s office at 425-430-6510 
for meeting or agenda information, or check the City Council calendar at rentonwa.gov/council.

Water Hardness

Renton’s water falls within the slightly hard, moderately hard, and hard range, depending upon the customer’s water source within the City. The most recent water hardness testing showed 44 ppm for the downtown wells, 69 ppm for Maplewood, and 125 ppm for Springbrook Springs. A water’s hardness is dependent upon the levels of two naturally occurring soluble minerals—calcium and magnesium. Hard water may cause scale buildup in cooking pans, sinks, and water heaters, and may require using more soap to form a lather. If you do not know which water source your drinking water comes from, the water utility can help. Please find the contact information on the last page of this report.

Water Hardness Scale

Fluoride

In 1985, the citizens of Renton voted to have fluoride added to the city’s drinking water. Fluoride levels were adjusted in 2016 to meet the DOH’s new recommended level of 0.7 ppm. More information on fluoride can be found at the CDC at cdc.gov/fluoridation/faqs.

Your Water is Safe

Water from the City of Renton and Seattle Public Utilities meets all regulatory standards, ensuring that your water is safe to drink.

2023 Renton Water Quality Results

1. Renton measures fluoride levels daily in the distribution system. Beginning in April 2016, Renton lowered the fluoride level to 0.7 ppm, which is the new level recommended by the Washington State Department of Health. Renton citizens voted to add fluoride to the drinking water in 1985. 
2. The EPA recommends 20 ppm as a level of concern for people on a sodium-restricted diet. Renton adds sodium hydroxide to prevent corrosion of plumbing. Sodium hypochlorite is added to water from the Maplewood wells for disinfection and to remove naturally occurring ammonia.
3. There were 45 samples tested for lead and copper. All of the samples tested had levels far below the Action Levels for both lead and copper.
4. EPA has established MRLs for UCMR5 based on the capability of the analytical method. It is not based on a level established as “significant” or “harmful.” The detection of a UCMR5 contaminant does not represent cause for concern, in and of itself. The purpose of unregulated contaminant monitoring is to help the EPA determine their occurrence in drinking water and potential need for future regulation.
5. There were six samples tested for 29 PFAS and lithium. Only one of six samples detected PFBS at a level at or above the MRL.

2023 SPU Water Quality Results

Since 2012, the city has purchased water from Seattle Public Utilities (SPU) to serve the Renton Boeing plant and as a backup supply during summer peak use periods. Results of the 2023 water quality monitoring requirements performed by SPU for the Cedar River and Tolt River sources are shown below.

Definitions

• AL: Action Level – The concentration of a contaminant which, if exceeded, triggers treatment or other requirements that a water system must follow.
• 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.
• MRL: Minimum Reporting Level
• NA: Not Applicable 
• ND: Not Detected
• NTU: Nephelometric Turbidity Unit – Turbidity is a measure of how clear the water looks. The turbidity MCL that applied to the Cedar supply in 2020 is 5 NTU, and for the Tolt supply it was 0.3 NTU for at least 95% of the samples in a month. 100% of Tolt samples in 2020 were below 0.3 NTU.
  pCi/L: picocuries per liter
• ppm: 1 part per million = 1 mg/L = 1 milligram per liter. 
• ppb: 1 part per billion = 1 ug/L = 1 microgram per liter. 1 ppm = 1000 ppb.
• ppt: 1 part per trillion = 1 ug/L = 1 nanogram per liter. 1 ppm = 1,000,000 ppt.
• TT: Treatment Technique – 
  A required process intended to reduce the level of a contaminant in drinking water.

Ensuring Water Safety

To ensure that tap water is safe to drink, the DOH and EPA prescribe regulations that limit the amount of certain contaminants in water provided by public water systems. 

The Food and Drug Administration and the Washington Department of Agriculture regulations establish limits for contaminants in bottled water that must provide the same protection for public health.

How Can We Help You?

Emergencies: Call 911
Questions about this report: Water Utility Engineering at 425-430-7287 or email utilitysystems@rentonwa.gov

Water discoloration, taste, or odor: Water Quality at 425-430-7400, 7 a.m.–3:30 p.m. 
or 425-430-7500 after hours or weekends

To report water pressure problems, water leaking in the streets, or water leaking at a meter: Water Maintenance at 425-430-7400, 7 a.m.–3:30 p.m. or 425-430-7500 after hours or weekends

If you are moving and need to arrange for a change of water service, or for general billing questions: Utility Billing at 425-430-6852.

This report is written and distributed in compliance with the Federal Safe Drinking Water Act, which requires water utilities to provide annual “consumer confidence” reports to their customers. You will find in this report: where our drinking water comes from; what minerals or chemicals it contains; how it compares to stringent water quality standards; what Renton is doing to protect our water supply; and what we are doing to wisely use and conserve our regional water supply. Hopefully this report will help you better understand your drinking water. We assure you that providing high quality and safe drinking water is one of Renton’s highest priorities.