The City of Long Beach

Long Beach, WA 2020

In-Vessel Biosolids Composting

Client Needs:

The City of Long Beach wanted a durable solution for composting biosolids from their wastewater treatment plant in the very wet, cool, and corrosive Pacific Coast environment.  Previously, they land applied biosolids.  With increasingly limited outlets for Class B biosolids, composting offered a robust method for producing a Class A compost that is readily useable in local horticultural applications.  Some of the project goals included:

  • Given the proximity of townsfolk, very low odor emissions
  • Reliable achievement of PFRP time/temperature requirements
  • A 30-year design life
  • A small footprint

ECS Solution:

ECS offered our tunnel type in-vessel system for primary composting, a roof covered ASP for secondary composting, and a four auger feedstock mixer.  The scale-controlled mixer gently combines dewatered biosolids and groundwood to provide a BMP compliant raw mix.  The ECS CompTroller(TM) automated control and monitoring technology will maintain uniform and near optimal conditions in the vessels to maximize biodegradation rates and minimize the creation of odors.  The sealed and insulated design of the concrete vessels eliminates weather effects and prevents fugitive emissions.  The ECS low-friction aeration floors are designed to minimize fan-energy use and last for decades.  The ECS 4m x 4m vessel door system provides an easy way to handle the doors and seal and insulate the front of the vessels.  Exhaust air from the vessels is scrubbed through an ECS designed biofilter.  The compost leaving the vessels will have achieved PFRP, be substantially stabilized, and have a very low potential to generate odor.  It will then undergo weeks of low aeration rate secondary composting in an automatically controlled aerated static pile contained within a three-sided building.  Both stages of composting and the biofilter are controlled, displayed, and tracked by the ECS CompTroller(TM)

Contact ECS to learn more.

We want to learn how to support your composting goals!

4220 24th Avenue West
Seattle, Washington 98199

Tel: (206) 634-2625
Fax: (206) 634-1309