Sigma assists with wastewater treatment program

nebraska city

The Sigma Group designed a three million gallon anaerobic lagoon, pump house, aeration basin and biogas recovery system for the Cargill Meat Solutions facility located in Nebraska City.

The facility generates approximately 330,000 gallons per day of wastewater containing up to 7,700 mg/l of COD from the processing of raw beef, pork and poultry products. Wastewater from the facility is fed into an anaerobic lagoon to reduce the COD. Biogas is produced in the lagoon and used as a supplemental fuel for the facility’s boilers.


The wastewater treatment system included the design and installation of a mobile pump.

After treatment the wastewater is transported to an aeration basin for aeration prior to being pumped to the Nebraska City POTW. In addition to the design, Sigma assisted Cargill by working with the state and local agencies to obtain the necessary building, air and wastewater discharge permits. Sigma also provided technical assistance to Cargill since the startup of the lagoon.

Services provided by Sigma include:

Treatability Study

Sigma provided Cargill with evaluation reports identifying budgetary capital and operating costs for treatment alternatives and recommendations for facility wastewater management systems. Sigma analyzed collected waste water samples from process waste water discharge sources, and developed a conceptual wastewater treatment system based on evaluations.

Design / Contract Documents Preparation

Sigma prepared contract documents for the bidding, permitting, and construction of a wastewater treatment system. Documents included required engineering reports, plans and specifications for state and local approval of wastewater pretreatment and conveyance system design.

System Commissioning and Construction Observation

Sigma designed a centralized wastewater pretreatment system, which included the construction of a 10,000-gallon wastewater collection vault, a pump station / building, an earthen lagoon with liner and biogas dome, 20,000-gallon concrete sludge storage basin, and biogas filtering system.