The Wastewater Treatment Division Flow Monitoring Program provides essential data used by many groups within the Wastewater Treatment Division, outside consultants, and other local agencies.
Installation of the meters generally requires confined space entry and traffic control
Installing a flow meter in a manhole
The program routinely maintains and collects data from about 80-120 portable flow meters in strategic places throughout the King County conveyance system. Without this flow data it would be difficult to determine flow trends, manage the wastewater system during peak wet weather and emergency events, plan for new facilities, and upgrade existing wastewater facilities. Flow monitoring data is an important tool in tracking trends and evaluating problems within WTD’s conveyance system.
The information gathered by flow meters can allow WTD to:
- Analyze Inflow & Infiltration
- Calculate Combined Sewer Overflow volume (NPDES permit reporting)
- Plan inspections and repair of pipelines
- Analyze conveyance system capacity
- Assess flow trends
- Manage conveyance system flows during peak and/or emergency storm events
- Plan and prioritize new projects
How is it done?
Installation of the meters generally requires confined space entry and traffic control. Flow monitoring staff receive all required and necessary safety training. Field installers can be seen wearing a harness, gas meter, and hard hat, and using equipment to lower and raise personnel into manholes
Field and office work
Facilities inspection staff perform field work including site investigations, meter installation, data collection, field verification of meter accuracy, and meter maintenance. The use of an on-site computer laptop enables weekly or bi-weekly collection of data. However, remote data collection from a wireless connection is becoming increasingly more common. In the office, collected data is analyzed and troubleshooting and flow modeling is done by WTD planning and technical resources staff.
Decennial Flow Monitoring
In 2009, the Decennial Flow Monitoring (DFM) Project began. A total of 235 flow monitoring units including 223 portable area-velocity flow meters and 12 pump station meters were installed in the separated portion of WTD’s service area. Flow data was collected over a two wet-season period from September 2009 through early-to-mid 2011. Data from the Decennial Flow Monitoring project will provide the information necessary to check and revise several planning assumptions for conveyance system projects slated for construction over the next 40 years. The final data will also be used for project design and be available to component agencies for their use in planning and design. Download DFM meter location maps.