Building a model sustainable city or town is no simple or easy task. It requires broad civic support, bold, enlightened local government leadership and public-private partnerships. A key to success is the ability to craft and effectively implement an all-encompassing, integrated policy and decision-making framework for managing and maintaining municipal infrastructure, including energy, water, waste management and transpiration systems.
The city of Gresham, Oregon has made great strides in this regard. Working strategically in public-private partnership with Veolia Water NA, it’s saving about $20,000 a month operating its wastewater treatment plant by using a co-generation system that supplies 55-65 percent of the plant’s electrical power, as well as heat and hot water for the plant and its offices. A solar PV power array supplies another 8-9 percent of its electricity needs.
The city’s strategic sustainability planning doesn’t stop there. City planners and Veolia are considering ways to further boost the clean, renewable energy produced at the wastewater treatment plant, including installation of micro hydro-turbines and the addition of fats, oils and greases to the mix of waste products fed into the plant’s biodigester to produce electricity.
Viewing Municipal Infrastructure as Sustainable Assets
Gresham’s partnership with Veolia Water is part and parcel of a proactive infrastructure asset management program that strives to assure the operational and environmental integrity and sustainability of the city’s infrastructure and natural resource use.
The Oregon city’s use of clean energy, clean technology systems has reduced carbon dioxide and greenhouse gas emissions from wastewater treatment and reduced demand for electricity from the local power grid. All in all, the combined heat and power (CHP) co-generation system has yielded savings of $625,000 since it commenced operating in November, 2005.
Its recent initiatives in partnership with Veolia have come about as part of a seven-year, $21 million contract in which Veolia manages operations and maintenance of the city’s 20 million gallon-per-day wastewater treatment plant, a beneficial use biosolids management program, industrial pretreatment analyses, the co-generation operation, laboratory services and operation of nine lift stations
Wastewater Treatment: Not Just Pollution Anymore
It seems as if the waste-to-energy industry popping up everywhere. Increasing numbers of cities and municipalities have approved, or are considering, plans to build waste-to-energy systems. While the rush has prompted environmental concerns, the attraction of using waste to produce energy, along with the advent of cleaner, more efficient waste-to-energy technology is driving growth.
“I can speak to Gresham and what I’m seeing Oregon and Washington,” Paul Proctor, Veolia Water NA’s Gresham project manager, told TriplePundit.
“There’s a lot of professional organizations and companies like Veolia and municipalities looking at developing sustainable asset management programs – making use of biodigester gas, ground-based solar power systems, even windmills to reduce the cost of treatment plants, reduce their carbon footprints and improve their image. I came on with Gresham in 2005. They already had this vision of being energy independent. It’s been very exciting.”
In the past, most facilities simply flared off the biogas produced in treating wastewater. “It was just pollution,” Proctor said. “Now that’s being recovered and used very effectively.”
Regarding the environmental concerns associated with waste-to-energy systems, Proctor said that such concerns “are always valid in terms of keeping an eye on what technology is being used and how it’s being used.” He pointed out that the system in place at Gresham’s wastewater plant employs a “clean, lean burning generator,” not an incinerator that simply burns waste. “One really good thing is that engine generator technology has really improved and gotten much better in terms of pollution control,” he added.
The co-generation engine being used at the Gresham wastewater treatment plant operates at a cost about 60 percent less than that for local utility grid power. That’s yielding direct savings to the city of about $20,000 a month in utility bills.
“It’s a lot less expensive to operate, and it helps keeps rates more stable. By keeping its infrastructure in good shape, the city doesn’t have to raise wastewater treatment rates, and it can reinvest those savings into the facility’s infrastructure. That’s happening now,” Proctor noted.
Gresham’s Sustainable Cities Model: Keys to Success
The success of Gresham’s sustainable city model could not have been realized without proactive, forward looking and environmentally responsible local government. Gresham Mayor Shane Bemis and an environmentally focused City Council provide that, and they’ve benefited from community-wide support.
Leveraging public-private partnerships is integral to the city’s plans to become a national model for sustainable planning, design and development. The city has installed an electric vehicle (EV) charging station at City Hall, “one of the first ones I’ve seen,” Proctor noted.
They’re also moving forward on a study of how to use biodigester gas in other ways. Nearly the same in quality as natural gas, the wastewater treatment plant’s biogas can be used efficiently in other ways, including the possibility of supplying fuel for a natural gas fueling station, he added.
As Veolia Water points out, Gresham “has identified practical, cost-effective and realizable ways to go green after thoroughly reviewing every aspect of the city’s operations, including utilities, buildings and vehicle fleets, as well as its approach to urban design and planning, business development and the everyday habits of City employees.”
That’s a model for aspiring sustainable cities around the US.