Processing Municipal Solid Waste
In 2007, the HRRF processed about 157,000 tons of refuse and had energy sales of approximately 38,000 MWh, Semanyshyn explained. "Covanta stepped into an operation that could not sustain reliable and predictable production, and even during the two-year construction completion period, Covanta has been able to achieve significant increases in the performance of the facility," he said.
In 2009 the facility is projected to process approximately 236,016 tons of refuse, net energy sales are projected to be approximately 75,000 MWh, and the total boiler availability is projected to be approximately 80%, according to Covanta’s data based on the HRRF’s current performance rates.
Klecko explained the kind of processing and preparation of the solid waste that is performed by HRRF staff prior to converting it into energy. "Municipal solid waste and some local residual waste streams are deposited on the facility tipping floor," he said. "Typical operational procedures have Covanta employees performing visual inspections for nonprocessable and prohibited waste."
In addition, Covanta operates a transfer station adjoining the tipping floor that handles construction and demolition debris (C&D) along with any waste that is ineligible for processing at the facility. Covanta employees sort the C&D to recover permitted combustibles for thermal energy recovery, providing environmentally sound waste disposal, while generating renewable energy.
Ferrous Recovery Operations
The facility also has a ferrous recovery system that was upgraded during initial facility construction modifications. Klecko explained that "The effective removal of over 2% of the total waste stream saves landfill space and improves the community’s recycling efforts."
In addition to ferrous recovery from the residue generated during the combustion process, Covanta has supported The Harrisburg Authority’s efforts to reduce the existing ash monofill volume by excavating and recovering previously buried metals. Prior to Covanta’s operation of the facility and upgrade of the ferrous removal system, metal extraction was inefficient, according to Klecko. Consequently, significant quantities of recyclable metals that had been buried in the ash monofill were unearthed during a year-long recovery project.
Additionally, unburned material removed during the metal recovery and screening project was reprocessed in the facility, recovering its thermal energy, reducing the volume of waste, and saving valuable landfill space. This operation effectively increased the capacity of the monofill and extended its lifespan.
Looking Ahead
In addition to improving its current operations, the Harrisburg Resource Recovery Facility has plans to tackle another project in the near future. Covanta is working on a sustainability project with the City of Harrisburg to reuse effluent from its wastewater treatment plant as facility cooling tower make-up. This wastewater reuse will displace the need for approximately 270,000 gallons per day of potable water from the City of Harrisburg, which will be available for other needs in the city.
Over the past two years, the HRRF has been transformed from being ostracized as a major industrial polluter to being viewed as a valued member of the Harrisburg community that is working hard to improve its environmental performance.
"The achievements we’ve already made — thanks to our dedicated crew of employees — have been remarkable," Semanyshyn said. "We are proud of the work they have done, but as a company dedicated to continuous improvement, we are always looking for ways to improve our operational efficiency and environmental performance."
Klecko also pointed to the facility’s new focus on improving its environmental accomplishments. "Our electrical rates are competitive with other power sources," Klecko said. "Those rates, combined with the numerous environmental benefits we offer, have made energy-from-waste an attractive renewable energy source for many new communities looking to reduce their environmental footprint."
—Angela Neville, JD, is POWER’s senior editor.
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