Seattle public water system guide

SPU’s wholesale customer list names separate utilities, including Cascade Water Alliance, the City of Mercer Island and Highline Water District. The list directs those customers to their own utility for service and billing. It is not a list of properties served by SPU.

The official water and sewer research map supports parcel searches. SPU says it is for preliminary planning, omits some infrastructure and may show mains that cannot accept a new connection. Confirm service with your bill, account or the utility.

The map application presents terms before use. Its landing page and utility contact path were reviewed; an address search beyond those terms was not verified.

For a boundary overview, the 2019 plan's service-area mapseparates Seattle's retail area from wholesale customer areas. It is a historical planning map, not an address-level service guarantee. The state GIS record reviewed for system 77050 has a 2016 update and no source date; a newer authoritative boundary has not been verified here. Confirm service with SPU.

See the regional utility directory and service-area evidence.

Sources: SPU water-quality concerns, contact directory, map guidance and 2025 report, physical page 11. Interpretation support does not establish that a translated or accessible report file is available.

The 2025 report identifies the Cedar River and South Fork Tolt River watersheds and a report-year source mix of 62% Cedar and 38% Tolt. That is regional context, not an address-level source assignment.

Use SPU’s water service-line map to search an address, zoom to the property and select a service line. The map describes only the portion maintained by SPU; its material information does not apply to pipes on private property. For service-line questions, its published contact is 206-684-5800. An absent line is not proof of no service.

SPU’s lead information page links to its service-line research map and Washington’s certified-laboratory directory. A system summary cannot establish the material in your property’s service line or plumbing.

The monitoring-results page says customers enrolled in Seattle’s Utility Discount Program can access free lead testing by calling 206-615-0827. Ask the lab for collection instructions and eligibility confirmation before collecting a water sample.

Other customers can use the certified-laboratory directory linked by SPU. Its lead page lists a $25–$50 analysis range and directs customers to confirm current prices and water sampling procedures with the laboratory. SPU says its lab is not set up for high volumes of residential lead water samples.

The 2025 report’s lead and copper results describe water samples from 52 homes, not every household. This page does not infer a property’s result or reproduce the utility’s broad safety claims.

2024: SPU’s annual report describes a June 21, 2024 Cedar Treatment Facility monitoring violation: equipment did not record part of the data for one of seven operating UV units. The report describes other treatment data, equipment repairs, programming changes and staff training. This is a historical disclosure, not a current advisory.

2023: The Tolt bromate footnote says an October water sample was not analyzed and SPU could not be sure of water quality during that period. The table’s printed “Passed!” marks must be read with this monitoring gap.

2022: The report lists one E. coli-positive water sample out of 3,331. It repeats the same distribution-system count under Cedar and Tolt; it is not two separate positive water samples. The report says repeat water samples did not detect either compound and describes report-period compliance.

2021: The radium-228 footnote says an initial slight detection was followed by water samples with no detections.

Sources: 2024 report (physical page 7), 2023 (page 9), 2022 (page 5), and 2021 (page 8), linked in the archive below. These report disclosures are not a complete state enforcement history.

Annual-report monitoring disclosures above, state regulatory decisions, and federal enforcement records have different dates and purposes. None is a live advisory feed. The reviewed public sources do not yet provide a reconciled state violation history or the underlying text and correction record for the 2023 storage finding below.

Sanitary surveys: 2021–2025

EPA ECHO's public survey table, reviewed September 17, 2026, contains nine state surveys. Eight list N in all 11 categories. The November 15, 2023 survey lists S for Finished Water Storage and N for the other ten categories. EPA defines S as “Significant Deficiencies” and N as “No Deficiencies or Recommendations.”

These are dated survey findings, not contaminant test results or a current advisory. The listing does not identify the affected storage facility, describe the deficiency, or supply its corrective-action closeout. Later N results do not by themselves prove that specific finding was resolved.

SPU’s Cedar facility description says lime raises pH to a target of about 8.2 to make water less corrosive to building plumbing. At Tolt, lime increases alkalinity and carbon dioxide adjusts pH; SPU describes water leaving the plant at pH 8.2 and alkalinity 19 mg/L.

These are utility operating descriptions retrieved September 16, 2026, not a new laboratory result or a dated state treatment-approval decision. Treatment does not identify the materials or lead level at an individual tap. Lead/copper report rows keep their actual testing years: 2019, 2022 and 2025.

Washington DOH’s Source Water Assessment Program map identifies state system 77050 as Seattle Public Utilities. Its Cedar River (01) and Tolt River (02) watershed records both list active, permanent surface sources and “High” susceptibility. Both records carry an update of March 16, 2026.

The annual report explains that Washington assigns surface waters this rating regardless of whether contaminants have been detected. Susceptibility is not a water-test result. The source-effective field is January 1, 1970; it does not establish the assessment date.

SPU’s Tolt watershed page describes a management plan approved in 2011, with road, aquatic-habitat and forest-management work. Its historical ownership description is 70% City and 30% national forest. Those watershed figures do not describe retail service boundaries.

SPU’s 2019 Water System Plan describes Cedar’s Limited Alternative to Filtration designation (chapter 3, page 3-5). This historical account does not establish a currently effective waiver, its expiry, or a new state decision.

SPU’s reservoir page describes six covered reservoirs: Magnolia, Lincoln, Myrtle, Beacon, West Seattle and Maple Leaf. It says Roosevelt and Volunteer are disconnected from the drinking-water system and retained as emergency resources, including firefighting.

In its April 8, 2026 supply update, SPU described refilling mountain reservoirs earlier than normal in response to low snowpack, while retaining space for spring rainfall. Its September 14 update describes managing releases for water supply and fish habitat.

These are dated operational accounts. Check that live supply page for current instructions and Saving Water Partnership for conservation guidance. Neither an earlier forecast nor this page establishes today’s restriction stage.

The 2025 report, physical page 6, records 46.2 billion gallons produced and 2.08 billion gallons lost to leakage (4.5%). Saving Water Partnership members used an average 97.9 million gallons per day, against their stated goal of less than 110 million gallons per day. Partnership demand covers the member utilities; it is not SPU retail demand. Earlier annual production and leakage figures remain with each year's report notes.

That report also marks 25 years of the Cedar River Watershed Habitat Conservation Plan, launched in 2000 for a 50-year term. It describes habitat restoration, wildlife monitoring and river-flow management for fish and other wildlife. These are source-protection activities, not contaminant measurements or proof of current treatment performance.

Compare the 15 historical reservoir records and their dates.

Washington DOH’s school lead program links results from 2018–2020 and from 2022 onward. Its May 2026 update describes a five-year retesting cycle beginning July 1, 2026 and ending June 30, 2031 for qualifying school buildings.

School results concern a specific outlet, building and collection date. They are not interchangeable with SPU’s residential lead/copper monitoring or Cedar/Tolt entry-point results. No school result is assigned to this system here without a verified provider relationship. Families can use the program’s results and the school’s action plan for that building.

SPU labels these quarterly surface-water analyses “Non-regulatory data. Informational only.” The 14 linked reports contain 56 location/date observations. Calcium hardness is not total hardness. The separately printed “Hardness, Grains” values are preserved in grains/gallon; they are not conversions calculated here.

CLT-5 and M-1A are the Cedar columns; TPT-3 and B-2 are the Tolt columns. These locations do not predict a household result. The archive has gaps; it is not a continuous quarterly series.

May 2026 prints 0.50 grains/gallon at TPT-3; May 2025 prints 0.52 at B-2. These and the other source values are retained literally. Their relationship to the calcium-hardness columns needs utility clarification before combined interpretation. No household classification, trend, or softener setting is inferred. Sources retrieved September 16, 2026.

SPU’s official project map returns 15 Water-category polygon records. Names and statuses below are the map’s labels; similarly named rehabilitation records are retained separately. “Active” does not establish work on your street today, and “Substantially Completed” does not mean every closeout task is finished.

The queried records have no individual project-page URL. Their scheduled dates have not been treated as completed work. Use the map and water-repair notices for location-specific updates; this is not a complete street-work inventory.

The 2025 annual report, physical page 5, describes a major pipeline upgrade between Volunteer Park and Maple Leaf Reservoir and work to replace the 21-million-gallon Bitter Lake reservoir while expanding the adjacent park. These are the report's project descriptions, not independently verified completion dates. Its approximately 1,900 miles of water pipes is a report-period network description.

For a drinking-water regulatory question beyond the utility’s response, Washington DOH’s county contact directory lists Laura McLaughlin for SPU at 564-669-0753. Explain the issue and ask which state process applies. This directory entry does not establish a formal complaint appeal or a response deadline.

SPU’s 2024 annual report (physical page 13) prints an interpretation-services contact: 206-684-3000. Ask for the language and report year needed, or for an accessible format. A translation phone line is not evidence that a particular translated or accessible PDF is already available.

State enforcement detail, current treatment determinations, sanitary surveys and a dated inventory covering both public and private service-line portions remain separate evidence needs. Missing records here do not mean no violations, no lead service lines, or no replacement obligations.

SPU bills include a monthly meter charge and a water-use charge. Match your provider, meter size, customer class and billing area before using these schedules. They do not calculate a total bill or describe rates charged by other utilities receiving SPU water.

Source: SPU Residential Drinking Water Rates, reviewed September 17, 2026. Amounts are U.S. dollars. One CCF is 100 cubic feet, or 748 gallons, as defined by SPU.

For the most common residential meter size, 3/4 inch or less, SPU lists these monthly base charges through December 31, 2026. Water use is charged separately.

Inside Seattle

$21.35 / month

Outside Seattle

$24.35 / month

Shoreline & Lake Forest Park*

$25.90 / month

Burien

$26.45 / month

* SPU says the Shoreline and Lake Forest Park column applies to customers in those cities, not water districts. Its master-meter footnote also excludes developments that pay Public Utility Tax directly to Washington State.

The January 22, 2018 state inventory formidentifies system 77050's owner as Seattle, City of. The 2025 report states that SPU operates the Tolt facility as of 2026, following private operation. The 2019 plan's former contractor arrangements are historical; they do not establish today's complete operator contract roster.

Seattle retail utility oversight

The City Council Governance & Utilities Committeecovers SPU finances, rates, operational policies, regional matters and the Utility Discount Program. Its September 17, 2026 page lists regular meetings on second Thursdays at 9:30 a.m. Check theCouncil calendarand the specific agenda for changes and access details.

The Council's public-comment instructionsaccept written comments at [email protected]and explain in-person and remote registration. Comments must concern an agenda item or committee business. Request accessibility or language accommodations through the linked City Clerk process. Meeting comments are not an urgent water-service request.

Regional water-supply decisions

The Seattle Water Supply Operating Boardprovides advice, direction and limited authority over regional supply matters. Its page provides agendas, minutes and a contact for older records; it lists meetings typically on first Thursdays, 1–3 p.m., with exceptions. This wholesale body is distinct from retail Council oversight and from the customer-service process at your utility.

SPU’s official archive lists 2021–2025 reports. All five files were retrieved again on September 16, 2026 and matched the previously preserved checksums. The historical reports below are official documents; their all 63 result rows across these five reports appear on the system page, with separate Cedar/Tolt values and report-period notes.