Mill Creek · Snohomish County
Backflow testing in Mill Creek — Silver Lake Water & Sewer
Silver Lake Water & Sewer District serves more than 56,000 residents in Mill Creek and unincorporated Snohomish County. It mails a reminder when each assembly is due, and testers file through the District’s Tokay WebTest portal.
Silver Lake W&SD program
How Mill Creek’s backflow program works
The short version, summarized from the utility’s own cross-connection control materials.
Source: Silver Lake Water & Sewer District · verified October 2026 ↗Customers with irrigation, fire sprinkler or other qualifying systems must have a state-certified test performed annually.
The District mails reminder letters when each device’s annual test is due.
Test reports are submitted through the District’s Tokay WebTest portal.
The District’s backflow rules are in its Code chapter 6.20.
Report submission
We’re set up on Silver Lake’s Tokay WebTest portal and file the day we test.
Questions for the utility: backflowtests@slwsd.com · (425) 659-2304
On the ground
What we see in Mill Creek
Every city’s housing stock and commercial mix shapes what’s in the meter box.
HOA common areas
Mill Creek’s planned neighborhoods run HOA-managed irrigation with commercial-size assemblies. We test on the HOA’s calendar and report to the board.
Services in Mill Creek
Neighborhoods
Serving all of Mill Creek
Parts of the area are served by Alderwood Water & Wastewater District instead.
- Town Center
- Mill Creek East
- Thomas Lake
- Penny Creek
- Mill Creek Country Club
- Silver Firs
FAQ
Mill Creek backflow questions
01 Who can test my backflow assembly in Mill Creek?
02 How do backflow test reports get submitted to Silver Lake W&SD?
03 How much does backflow testing cost in Mill Creek?
04 What if my assembly fails in Mill Creek?
Field test report · next due
Mill Creek test due? We’ll handle it.
Book online in two minutes. We test, repair if needed, and file the report with your water utility — and remind you next year.