Case Study 4: Energy & Performance Audit Provides Huge Savings
The American Recovery and Reinvestment Act provided a northeast Louisiana city a grant for improvements to their wastewater facility. While the grant was nice, the funds provided for improvements to infrastructure whose operation was costly. The city felt their current energy bill was extremely high and the additions of new 25 horsepower aerators were expected to add significant cost.
The energy cost alone to operate the new aerators was estimated to be approximately $1.25 per horsepower per 24-hour period or approximately $1,000 per month based on 25 horsepower. That meant energy costs to run aerators were estimated to be over $78,000 per year.
Cenla Environmental Science (CES) performed an audit of the city’s Louisiana Department of Environmental Quality (LDEQ) permit and the city’s previous 24-month lab results. This provided trends as to the effectiveness of treatment processes were throughout each month of the year.
Using that data, Cenla Environmental Science determined the appropriate frequency and training for operation of the aerators to provide an adequate effect on the treatment process. The result was a significant reduction in the time the aerators were required to operate.
Cenla Environmental Science projected reducing the operation time of the aerators would lower the added cost by over $150,000. By charting and monitoring lab results, the city was able to save over $200,000 annually over the permit term.
