Colorado Public Works Journal, Spring-Summer 2023

22┃ Colorado Public Works Journal More than an obligation, infrastructure is an opportunity. It’s a chance to make a mark, to show with lasting action that deeds matter more than words, people matter more than money, and diversity, in all forms, matters more than almost anything. At the National Western Center, energy is no exception. In fact, it’s the centerpiece of an iconic campus modernization program aimed at embracing an ethic of regeneration for the site itself. “The Sewar Heat Recovery and Central Utility Plant has to be one of the most inovative things I have ever worked on,” says Maggie Karlos of Saunders Construction. As the Project Manager for an innovative new thermal energy recovery system now serving the revitalized National Western Center campus in Denver, Karlos believes she has her hands on one of the most important projects of her career. “This system will supply 90 percent of the heating and cooling for more than a million square feet of vertical constructions using thermal energy drawn from wastewater.” Though sourcing thermal energy from either water or wastewater is not entirely new technology, doing it at this scale is certainly significant; not only as an accomplishment but in terms of what it means for the future of energy diversification and resiliency. Thermal energy exists in the water running through the sinks, toilets, showers, and appliances of buildings and homes during everyday use. After it is used that water maintains a stable temperature as it travels through One To Remember Tomorrow is here – introducing The Delgany Interceptor the sewer pipe to the wastewater treatment plant. The system captures thermal energy from the Delgany Interceptor wastewater pipeline and transfers it to clean water distribution pipes that take it to buildings at the National Western Center campus, including CSU Spur. “This system is part of National Western’s Central Utility Plant. At about 9,000 SF, the CUP is a relatively small, unassuming building, but inside there is about $15 million worth of complex heavy mechanical and electrical systems,” continues Karlos. The second of three consecutive contracts on the National Western Center campus under Saunders’ purview, the source of the energy is a 25-foot-deep, wet well at a nearby utility hole where wastewater is pulled out of the system. The wastewater is circulated through biosolids separation equipment (SHARC) within the CUP where plate and frame heat exchangers transfer heat from the wastewater to outbound pipes that serve the campus’ energy district. “Rather than each of the many buildings in this complex having independent heating and cooling systems, using a District energy system, warm water is pumped through a closed-loop network of pipes from the central plant to each building simultaneously,” Karlos shares. “The benefits include energy efficiency, a low carbon footprint, low operations costs, and reliable, resilient energy during outages. Using local, recycled energy, this project is going to eliminate the emissions equivalent to 6.6 million passenger vehicle passenger miles every year. So that’s a tremendous win. But that’s not all, there are huge wins for the community as well.” For starters, there is the obvious benefit of using a recycled, renewby Sean O’Keefe