ANAEROBIC DIGESTERS AT
WATER RESOURCE RECOVERY FACILITIES

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LOS ANGELES COUNTY SANITATION DISTRICT

JOINT WATER POLLUTION CONTROL PLANT, CARSON, CA

SYSTEM DESIGN

Operated by the Los Angeles County Sanitation District,
the Joint Water Pollution Control Plant (JWPCP) in
Carson, CA serves 3.5 million people throughout Los
Angeles County. On an average day, the JWPCP treats
280 million gallons of wastewater, making it one of the
largest water resource recovery facilities in the world.

Solids collected during primary - and secondary
treatment are processed in anaerobic digesters. The
JWPCP uses the resulting biogas to fuel three 9 MW gas
turbines. The turbine exhaust gas heats water, producing
steam that powers an 8.7 MW steam turbine-generator.
The Total Energy Facility' typically generates 20 MW
from digester gas for on-site use, enabling the JWPCP to
meet most of its energy needs.

To boost biogas production, the JWPCP and Waste
Management (WM) have initiated a pilot project to co-
digest with food waste. WM collects food waste from
restaurants, food processing plants, and grocery stores.
The food waste is screened at WM's CORe® facility to
remove contamination (e.g. utensils) and biended into a
food waste slurry.

The slurry is loaded into tanker trucks, delivered to the
JWPCP, and then pumped into closed, sealed storage
tanks, where it is mixed for several minutes each hour
before being added to the digesters. The mixed food waste
slurry is injected into a digester at 9% food waste/S1%
wastewater solids on a volume basis. The JWPCP can
receive up to 84 tons (20,000 gallons) per day.

•	Feedstock processed: sludge & food waste

•	Capacity: 24 3.7 MG digesters

•	Through put: 4.4 MG sludge & up to 0.02 MG food
waste/day

•	Biogas generation: 5,000 cubic feet per minute

•	Biogas use: Total Energy facility and boilers

•	Generation: -20 MW

"This project leads the way in helping to meet California's
organic recycling goals and to provide operational details
and lessons to other VWVTPs around the country."

— Dave Czerniak, Senior Engineer, LACSD

PROJECT BENEFITS

The JWPCP digesters provide the following benefits:

•	Ensure the facility meets regulatory requirements

•	Control odors

•	Produce renewable energy

•	Create a nutrient-rich fertilizer product

Co-digestion has provided the following additional benefits:

•	Diverts organics from landfills, helping CA to meet
its goals to increase recycling and reduce
greenhouse gas emissions

•	Boosts biogas production, generating up to an
additional 250 kW of electricity

Date May 12, 2016


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