Utilities across the United States are sharing similar challenges, especially as aging facilities require higher operation and maintenance investments. Green Bay Metropolitan Sewerage District develops biosolids and resource recovery strategies to effectively generate and utilize recovered energy.

By: Peter Burrowes, CH2M HILL Technology Fellow

Peter Burrowes presented his paper, “Strategies for Biosolids Energy and Resource Recovery for the Green Bay Metropolitan Sewerage District” on Tuesday, October 8 at 4 p.m. in TS413 at the Water Environment Federation Technical Exhibition and Conference (WEFTEC) in Chicago, Illinois. Learn more about CH2M HILL’s WEFTEC 2013 participation and technical sessions.

Energy recovery options from anaerobic digestion and biosolids incineration systems are gaining attention as utilities look for solutions to replace/upgrade aging infrastructure and reuse resources for greater optimization.

Like many utilities, Green Bay Metropolitan Sewerage District (GBMSD) is facing stricter environmental compliance standards and solids waste capacity issues, which are only exacerbated by its aging assets. To address these challenges and continue collecting, treating, and reclaiming approximately 38 million gallons of wastewater daily, GBMSD developed a Solids Management Facility Plan with the help of CH2M HILL. The plan, known as the Resource Recovery and Electrical Energy Generation System or R2E2 Project, covered a planning horizon to 2035 and includes building two anaerobic digesters that will break down biodegradable materials from human, household, and industrial waste.

At the outset of the R2E2 Project design, several alternative methods and options for recovering and generating electrical power were evaluated in an effort to maximize and optimize energy recovery. As part of the plan, we provided strategies that would allow Green Bay to recover enough energy from its R2E2 facilities to supply 100% of its energy needs in the future.

Construction on the facility is expected to be completed in 2014. Implementing the plan will help cut GBMSD’s annual energy costs in half during the first year by using the anaerobic digesters to produce a biogas that can be processed into a biofuel and turned into electricity. This process will enable GBMSD to generate more than 65% of its projected electrical power requirements by recovering heat from the new incinerator and using the recovered energy to heat the building and produce electricity.

The R2E2 Project will meet GBMSD’s goals and is an example that other municipal utilities can follow in developing energy projects from biosolids projects. GBMSD is leading the way for incorporating biosolids and resource recovery strategies at its wastewater facility. Rather than looking at all wastewater the same, GBMSD’s approach considers reuse and recovery opportunities. In light of rising energy costs, including renewable energy sources such as biogas derived from anaerobic digestion is a good strategy to reduce operating costs.

Peter Burrowes is CH2M HILL’s Global Service Leader for Wastewater Infrastructure and a Technology Fellow. Peter joined CH2M HILL in 1976 and has worked on the planning, permitting, design, construction and implementation of many biosolids management and wastewater programs across North America and internationally. He currently primarily manages and consults on biosolids management projects. Peter is considered a subject matter expert on the thermal treatment of biosolids and other organic wastes and has led some of the largest biosolids thermal treatment projects in North America. Additionally, he is an active member of WEF’s Residuals and Biosolids Committee and the BioEnergy subcommittee. Peter lives in Cambridge, Ontario, Canada and enjoys tending to his garden when not traveling.