Facility Upgrade: Showing Return on Investment
The Water & Resource Recovery Center (WRRC) underwent a nearly $70 million facility upgrade that was completed in 2013. At the time, it was the largest capital improvement project in the city’s history. The new treatment system has been in operation for several fiscal years and is showing return on investment in the following ways:
The WRRC converts waste into electricity and heat.The anaerobic digestion process produces methane gas. The gas is captured, cleaned, and burned to power turbines that generate electricity. The heat produced through this process is used to heat the complex, and the electricity produced is used to power the facility. Currently, the facility produces enough electricity to power approximately 360 households per day, which is 70% of the electricity needed to operate the facility.
Reduced Operating Costs
Thanks to the ability to produce electricity and operational efficiencies, the facility’s demand for grid-purchased electricity has dropped by 70-75%, from 1000 kilowatts down to just 250-300 kilowatts.
Annual Electricity Cost Savings: $244,000
Annual electricity costs have dropped from $579,205 in fiscal year (FY) 2011 to $334,908 in FY2017.
Annual Fuel-Oil Cost Savings: $300,000
Before the facility upgrade, the bio-solids produced at the plant were incinerated. In FY2011, the City spent $300,000 on fuel oil for this activity at the plant. Because anaerobic digestion is now used, incineration is not needed so the City was able to reduce fuel costs by $300,000 per year.
Annual Staffing Cost Savings: $80,000
Operating efficiencies of the WRRC now allow the plant to operate with one less employee, resulting in a cost savings of $80,000 per year.
Total Annual Operating Cost Savings: $624,000
Making Methane Means More Savings
The WRRC produces more methane than can be used at the facility. The City of Dubuque and Greater Dubuque Development Corporation researched beneficial uses for this excess methane. Project requirements included: creating additional positive environmental outcomes, generating revenue or reducing costs, creating opportunity for additional economic development and growth, and not requiring additional direct investment or risk from the City.
In August of 2016, the City entered into an agreement with BioResource Development, LLC for the co-location of equipment at the WRRC which will further process all bio-gas produced at the facility. Renewable natural gas will be delivered to the Black Hills Energy Pipeline, qualifying for gas revenues and RIN (Renewable Inventory Number) payments due to its use as an advanced bio-fuel. The City will receive lease payments and a portion of gross revenues from the sale of gas and RINs.
Supporting Local Business and Jobs
Thanks to the facility upgrades, the WRRC now has the capacity to process high-strength waste, which means the facility provides a critical service to a variety of local businesses that produce high-strength waste through their production or manufacturing processes. Local companies like Hormel, Rousselot, and Western Dubuque Biodiesel can now take their waste products to the WRRC to be processed. In fact, Hormel's cost per gallon for treatment/disposal was reduced by 60%. Hormel previously hauled their high-strength waste over 90 miles to Madison, Wis., every day.
The WRRC’s ability to process these materials saves those companies the cost of having to transport that waste to other locations for disposal and makes Dubuque a more attractive location for business expansion and new businesses. Processing high-strength waste also produces revenue for the City. The WRRC expects to generate $215,000 in revenue through this activity this year.