5.2. ECCSR 11-16-2016 - Laserfiche WebLink

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Elk River GHG Baseline Inventory 8 Opportunities for Reduction Recommendations: · Engage a consultant team to conduct a detailed Facility Assessment and Energy Audit and develop an energy efficiency action plan for the City of Elk River Wastewater facilities. · Explore the feasibility of installation of renewable energy generation to support City of Elk River wastewater functions. How do the provision of Water and Wastewater Utilities contribute to Greenhouse Gas Emissions? Water and energy use are inextricably linked in modern cities. Energy is required to extract, treat, and distribute water to residences and businesses. Nationally, the United States consumes over 355 billion gallons of water daily, requiring an estimated 500 billion kwh annually to distribute to users. Globally, water treatment and distribution is estimated to contribute 2-3% of total greenhouse gas emissions annually. As with water processing and distribution, Wastewater collection and treatment requires energy inputs. With our current energy grid, those energy inputs are significantly fossil fuel based. In addition to emissions associated with fossil fuel use, wastewater treatment produces significant “Biogenic” emissions associated with the microbial processing of the waste solids. The primary gas emitted during biological nitrogen removal is Nitrous Oxide (N2O), a greenhouse gas with a potency roughly 300 times that of CO2. With such potency and an observed increase of atmospheric N2O of over 17%, ongoing studies by the US EPA and Intergovernmental Panel on Climate Change (IPCC) continue to refine understanding of the origins, impacts, and reduction strategies for wastewater N2O emissions. For the purposes of GHG calculations for community carbon footprint reporting, these “Biogenic” emissions are considered to be a part of the biological carbon cycle and are not currently included in the GHG totals. Protocols may change in the future to include wastewater Biogenic N2O emissions. Daily emissions associated with Elk River Waste Water treatment represent:63,455 Cubic Feet of man-made atmosphere (Figure to scale) 13 Cubic Feet per household per day Figure to scale) City Operations Water and Wastewater Annual Greenhouse Gas equal to: 25,577,632 Cubic Feet of Man-Made Atmosphere 1,303.58 Metric Tonnes Summary of Findings* The City of Elk River operates the Elk River Waste Water Treatment plant (WWT). For the Baseline 2015 year, the WWT plant processed 463,000,000 gallons of waste water, serving 4900 customers averaging 259 gallons per customer connection per day. The Elk River WWT plant used 1,138,145 kwh of electricity and 43,486 therms of natural gas through the Baseline 2015 year, while sanitary sewer line lift stations operated by the City required 382,154 kwh of electricity. Greenhouse Gas emissions associated with WWT operations total 1,303.58 Metric Tonnes (2,873,872 pounds) CO2e, equating to 0.09 ounces per gallon of waste water treated. Water service in the City of Elk River is provided by Elk River Municipal Utilities (ERMU). Energy use and total emissions associated with the water utility are reported in the ERMU sections in this report. * Sources: energy consumption as reported by City of Elk River, emission factors based on US EPA and Excel Energy, 22.01% City Operations Total