Loop® biosolids is a natural soil amendment produced by safely extracting carbon and nutrients from wastewater at King County’s treatment plants. Superior to conventional fertilizers, Loop replenishes soil by returning essential nutrients to the land and, with its proven ability to hold rainwater like a sponge, Loop reduces runoff and erosion.
University scientists have found that in soils where Loop has been applied, it stores carbon and reduces greenhouse gas emissions into the atmosphere. These carbon offsets far outweigh the emissions associated with transportation of Loop and help offset the energy consumption associated with treating wastewater.
Total Energy Use by Location
WTD’s facilities account for about 58 percent on average of all King County government’s facility energy usage. Almost 80 percent of WTD energy is used at the three regional treatment plants. The majority of WTD’s energy use is not discretionary or wasteful – it is required to fulfill service needs.
Energy Use by Fuel Type
WTD’s daily electricity needs are more than 17 megawatts (MW), nearly 70 percent of WTD’s total energy use.
Electricity is needed to power pumps, motors, and blowers whereas natural gas and biogas, propane, and diesel fuel boilers, engines, and turbines.
Treatment Plant Electricity Breakdown
Each of King County’s five treatment plants uses electricity differently based on the specific treatment technology and process needs. For example, South Plant is the only plant in our system to scrub biogas, which requires electricity. Due to space constraints, West Point’s design includes high purity oxygen, which is generated on site and requires a significant amount of energy. And while all plants have odor control mechanisms, Brightwater odor control is especially energy-intensive.
(Click each graph for a larger version)
A facility’s energy consumption depends on factors beyond the efficiency of equipment and process systems, and includes precipitation volumes, outside air temperature, and operating characteristics.
Normalizing data is the process of equalizing the impact of these factors on energy use to compare the energy performance of facilities and operations from year to year.
NOTE: WTD’s normalized energy use does not include facilities newer than 2007, such as the Brightwater Treatment Plant or the pump stations serving Brightwater. Normalized energy use does not credit energy created and used onsite.
For more information about the Energy Program, please contact us at:
- Elizabeth Lyon
- 201 S. Jackson Street, KSC-NR-0512, Seattle, WA 98104