Hyperion Dewatering Centrifuge Expansion

"Serving Los Angeles' Wastewater Needs"

How can one of the largest cities in the United States reduce its wastewater discharge into the ocean and lower complaints about odors from local residents?

That was the goal of the Hyperion Dewatering Centrifuge Expansion – Phase 2 (DiCE-2) facility in Los Angeles, which is considered one of the industry's premier models for public-private partnerships.

MWH collaborated with the City of Los Angeles on the project — which received an Honor Award at the 2000 Engineering Excellence Competition held by the American Consulting Engineers Council's California Chapter.

The results have been impressive. This complex project is the world’s largest and first full-scale installation of high-solids, high capacity centrifuges. It dewaters more than 4 million gallons daily (mgd) of digested biosolids — a greater processing capacity per square foot than previously thought possible.

The DiCE-2 facility has generated a ten-fold improvement in wastewater discharge to the Santa Monica Bay in Southern California. Local community complaints about odors have dropped dramatically. Truck-hauling traffic through surrounding beachside neighborhoods has been greatly minimized — and the city has saved nearly US $ 5 M annually on projected hauling costs compared to previous systems.

When the US $34.8 million project was completed on November 1998, it was finished one month ahead of schedule and $1.2 million below the city's estimated budget.

How Hyperion Works

DiCE-2 Hyperion was cooperatively designed and constructed by the City of Los Angeles Department of Public Works (LADPW) and MWH. The treatment facility is a key component of the city's Hyperion Treatment Plant Full Secondary Expansion capital improvement program.
DiCE-2 is the world’s largest installation of high-solids, high-capacity centrifuges for dewatering digested biosolids. The facility's six Sharples DS-906 centrifuges are the world’s first centrifuges capable of processing 600 to 1000 gallons per minute (gpm) of anaerobically digested wastewater sludge while producing a wet cake product in excess of 30 percent solids.

Hyperion's Sharples DS-906 Centrifuges are the world's largest high solids dewatering centrifuges.

Previously, the average solids content of the Hyperion plant’s wet cake was about 20 percent. By reducing the solids residual, the city has been able to slash its projected hauling costs and lower community complaints.

The wet cake product is delivered to storage silos via six Abel SH-K-25-100.2 wet cake pumps (maximum design capacity: 100 gpm) via a 700-foot pumping system. This is the industry's longest known transport system for this type of application. The enclosed pumping system prevents odor emissions from the facility. It also reduces maintenance difficulties often associated with the previously used open conveyor belt transport systems.

The facility features an operations center designed to maximize employees' comfort and efficiency. To isolate noise and environmental nuisances during operational duties, a floor was added to the building between the centrifuge and the cake pump floors where the majority of operations and maintenance activities can be carried out.

MWH and the LADPW worked closely with local environmental and citizen groups to construct a complex facility that reduced odors and prevented a negative environmental impact. At the same time, the group wanted to minimize off-site truck hauling traffic through local community neighborhoods. These goals were all achieved.

City officials report the DiCE-2 facility far exceeds the contract design criteria.

Performance requirements specified a minimum capacity of 600-gpm and 28 percent solids. Today, the DiCE-2 facility regularly runs at 800 gpm and generates 30- 32 percent solids. This improved efficiency allows the city to better manage its manpower requirements, extends the life of the facility and helps maintain lower costs.

Learn more about this project.