Wastewater/Sewer
Overview
The City of Redmond Wastewater Maintenance Division maintains and operates the wastewater (sewer) system to meet the needs of existing and future customers. The wastewater system serves a residential population of 69,900 (2020) within the City limits and approximately 3,500 residential households in the Novelty Hill area.
City staff maintain the wastewater system in a manner that protects the public investment, protects the environment and human health, ensures compliance with state and federal mandates, and ensures that reliable service is available to all customers of the City utility system.
Wastewater staff provide information to commercial customers and residents about the treatment and reduction of grease and industrial discharges to the wastewater system to ensure compliance with pre-treatment standards. Wastewater Division staff also collaborate with Utility Engineering staff on long-range system development and comprehensive planning, the capital facility program, and feasibility studies.
What: Replace or rehabilitate ten wastewater lift stations in six years. At the start of the program, the Sewer Utility owned and operated 23 lift stations throughout its service area (see map for locations; stations identified for replacement are numbered). With the completion of the Lift Station 14 abandonment project, there are now 22 wastewater lift stations.
When: Now–2022
Why: If a lift station fails there is a risk that raw sewage will back up into homes or businesses, or overflow into Lake Sammamish and other natural waterways. Ten wastewater lift stations are at, or past, their useful life. Mechanical and electrical equipment in lift stations usually lasts 20-30 years. Some of the lift stations are over 30 years old, some are failing now, and some have equipment for which replacement parts are no longer available.
How: The sewer lift stations will be replaced or rehabilitated using sewer rates, development connection charges, and bonded debt so that the stations are in good working order by 2025.
Progress: In 2019, Lift Station 2 was replaced and Lift Station 14 was abandoned and a new sewer line installed. Lift Station 3 was replaced in 2020. Lift Station 13 work started in 2020 and is expected to be complete in 2021. Also in 2021, work on Lift Station 12 started. Five lift stations are currently in design for targeted equipment upgrades in 2022.
The Wastewater Division is responsible for maintenance and repair of over 230 miles of pipe ranging from 8 to 36 inches in diameter, 15 miles of easements, 7,336 manholes, and 22 pump stations.
Maintenance activities include but are not limited to:
- Closed-circuit television (CCTV) inspection
- High-pressure hydro-cleaning
- Easement and pump station maintenance
- Daily monitoring of the SCADA (Supervisory Control and Data Acquisition) system
- Activities related to providing excellent customer service
Wastewater Division staff repair lift stations, pipe, and manholes. Lift station repair involves complex electrical circuits, pumps, and equipment. Manhole repairs range from frame and cover replacement to entire channel and bench restoration. Pipeline repairs range from open trench pipe replacement to slip lining damaged sections of pipe.
You may be surprised to know that, in many ways, the City of Redmond Wastewater Maintenance Division is a front-runner when it comes to the use of existing and emerging technologies. On a daily basis, Wastewater staff use a wide variety of hardware and software to efficiently operate and maintain City infrastructure. Listed below are just a few of those technologies.
SCADA
SCADA is an acronym which stands for Supervisory Control and Data Acquisition. Quickly defined, SCADA is a computerized system which monitors (and in some applications, controls) infrastructure.
Redmond's Wastewater Division makes use of this technology to monitor 22 lift stations remotely. One advantage of using a SCADA system is the transfer of information to and from various sources is near instantaneous. This allows staff to monitor lift stations in real time and, with the knowledge delivered by SCADA, operators can make quick decisions in a number of circumstances.
With data constantly being digitally recorded, it also provides staff an opportunity to look at trends from a historical perspective. This information becomes an invaluable asset when planning preventative maintenance and corrective actions.
GIS
GIS is an acronym which stands for Geographic Information System. GIS is a system which integrates hardware, software, and data for capturing, displaying, managing, and analyzing all forms of geographically-referenced information.
The City of Redmond GIS allows Wastewater Division staff to visualize, question, interpret, and understand data, allowing us to efficiently plan for growth while continuing to maintain our existing infrastructure.
GraniteNet
GraniteNet software allows city staff to complete digital video inspections of underground wastewater pipe through the use of a computer on the Wastewater Division’s Closed Circuit Television (CCTV) truck. These inspections allow staff to determine what maintenance procedures are necessary for each segment of the wastewater pipe.
What is a lift station?
Due to hills and valleys in the landscape, sewer systems include locations where sewage needs to be pumped from low points to higher elevations, from which it will ultimately flow via gravity to a King County treatment plant. Once sewage arrives at the treatment plant it is treated and discharged to Puget Sound.
Current lift station project pages
- Wastewater Lift Station 12 @(Model.BulletStyle == CivicPlus.Entities.Modules.Layout.Enums.BulletStyle.Decimal ? "ol" : "ul")>
- Wastewater Lift Station 13 @(Model.BulletStyle == CivicPlus.Entities.Modules.Layout.Enums.BulletStyle.Decimal ? "ol" : "ul")>
- Wastewater Lift Equipment Upgrades
Septic Systems
Septic system owners need to regularly inspect and maintain their septic system (including repairs and replacements as their septic system ages). If septic systems are not properly maintained, they no longer receive their benefits. Instead, they can harm groundwater and pollute lakes, streams, and beaches. They can even cause sewage to surface in your yard or back up into your house. To prevent this, a septic system owner also needs to operate their system properly, such as throwing all food waste into the compost or trash can instead of tossing it down the drain (see more at Taking care of your septic system - King County).
For Additional Septic Information
Visit the King County Sewer System page, On-site Sewage System (OSS) Program - King County.
3 Steps to Lengthen the Life of Your Septic System
- Pump Your Septic Tank
- Septic Tanks are typically pumped every 3 to 5 years, depending on water use. Generally, septic tanks accommodating larger households will need to be pumped more frequently.
- Check for Septic System Failure
- Call your septic system professional if you experience any of these indicators of septic system failure:
- Odor
- Wet spots or standing water near the septic tank or drain field
- Backups in toilets, drains, or sinks
- Bathtubs, showers, and sinks drain very slowly
- Call your septic system professional if you experience any of these indicators of septic system failure:
- Regularly Inspect Your System
- Contact a certified septic system professional to inspect and monitor your system with the following recommended frequency:
- Gravity systems: Every three years
- Pressure distribution systems: Annually
- A proprietary system such as an aerobic treatment unit (ATU), membrane bioreactor
- (MBR), drip irrigation, and other products:
- Annually, or more often if required by the manufacturer
- Mound or sand filter systems: Annually
- Contact a certified septic system professional to inspect and monitor your system with the following recommended frequency:
Find a Certified Septic System Professional
Visit the King County Site to search for certified septic system professionals: King County list of on-site sewage system professionals.
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Report an Issue
Use the City’s request management system to report non-emergency issues, make requests, and find answers to common questions.
In case of emergency, call 911.
Report Issue or Make Request
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Customer Service
Phone: 425-556-2900, ext. 7
Report an after-hours water or sewer break
Call Police (non-emergency): 425-556-2500
- How does my wastewater get into the City of Redmond’s sewer?
- How close to my lateral sewer pipe can I plant trees?
- Can I flush wipes (cleaning, facial, or baby wipes) down the toilet even if they're labeled "flushable"?
- What can I do to prevent sanitary sewer back-ups?
- What causes a sewer to back-up?
- Can I plant over manholes or clean outs in my yard?