Water Quality

When we talk about "water quality,” we are usually talking about the chemical, physical, and biological characteristics of water. More specifically, we are talking about the state or condition of water and how well it fits a human need or purpose, such as drinking, swimming, and fishing. Soos Creek Water & Sewer District (SCWSD) provides District residents with safe drinking water; we follow the water quality standards set by the U. S. Environmental Protection Agency and the Washington State Department of Health.

We buy your drinking water from the City of Seattle. It comes from the Cedar River watershed, over 90,000 acres of land in southeast King County owned and managed by the City of Seattle. The water is cleaned and treated to meet or exceed all state and federal drinking water standards before it reaches your house. For further information on the Cedar River watershed see: Water Supply and Treatment

SCWSD provides a water quality Consumer Confidence Report (CCR) to all customers annually:

2022 CCR

2021 CCR

2020 CCR

2019 CCR

2018 CCR

Regarding lead in drinking water: EPA lead notice

Seattle Public Utilities: Lead and Drinking Water

Regarding water fluoridation: Fluoridation Fact Sheet

PFAS Information

Find out more about man-made chemicals known as PFAS (per- and polyfluoroalkyl substances) and our water supply.

Cross Connections and Backflow

SCWSD works hard to deliver safe drinking water to your home. Inside your home improper changes in, or misuse of, your plumbing system may contaminate your drinking water and cause problems for the District.

What is a cross connection?

A plumbing cross connection is an actual or potential connection between a potable (drinkable) and non-potable water supply that may pollute water inside your home or business - a serious public health hazard. Examples of non-potable water that could contaminate the potable water supply include yard or garden irrigation systems, and boilers used for residential and commercial heating. A cross connection in your home or business could not only contaminate your drinking water but also your neighbors’ drinking water, through backflow.

What is backflow?

"Backflow” is water flowing in the opposite direction to that intended, for example into the water mains from your house rather than into your house from the mains. This could occur due to sudden loss of water pressure in the District’s mains, which creates a siphoning effect that draws the water from your home or business back into the water mains. Backflow, combined with an uncontrolled cross connection, can contaminate the public water system. Backflow assemblies prevent this contamination.

Backflow assemblies must be tested annually, per WAC 246-292-034 (3)(c). You can find more information about Washington regulations regarding backflow assemblies here.

We accept backflow assembly test reports online only, through SwiftComply. Please use our portal to submit reports.

Backflow Tester Portal

Certified Backflow Testers King County

Backflow Testing Services

SCWSD cross connection control requirements

Backflow assembly requirements

Cross connection and backflow FAQs

WAC 246-290-490 regarding cross connection control

Water Usage Questionnaire