City of Longmont Effluent Study

The City of Longmont wanted to explore if it was feasible to use their effluent from their sewer treatment plant to create a district energy system to thermal heat and cool the future development of the Sugar Mill Development (SMD)while reducing the effluent below the December anticipated effluent limits (13.8 degrees C). This innovative approach aimed to harness the thermal energy from treated wastewater, transforming it into a sustainable resource for heating and cooling. By doing so, the City will reduce its carbon footprint and will lower the effluent temperature in the winter for discharge in to the St. Vrain Creek. This will promote environmentally friendly practices in urban development. The project could serve as a model for other communities seeking to integrate renewable energy solutions into their infrastructure, paving the way for a greener future.

To create a district energy system the project would use a centralized Water Source HeatPump (WSHP) to transfer heat from the Wastewater Treatment Plant (WWTP) into a MediumTemperature Thermal Loop (MTTL). The wastewater temperature is between 55F to 75F depending on the time of year. The MTTL will be a 2-pipe closed loop thermal energy delivery system tailored to the geography of the SMD. Thermal energy (heating and chilling) is delivered at points of use (POU) via local Heat Exchangers (HX) or Water SourceHeat Pumps (WSHP).