Rural Water - Quarter 1, 2016 - (Page 40)

CASE STUDY Case Study: Bubble Diffusers t Company: Environmental Dynamics International Customer: Licking River Wastewater Treatment Plant, East Newark, Ohio Project: Aeration system improvements on industrial flows Product: EDI FlexAir ® MiniPanel™ Diffusers Start-Up Date: August 2013 The city of Newark was seeking relief from excessive electric bills through significant updates. Its Licking River Wastewater Treatment Plant on the east side of the city completed installation of new, efficient EDI FlexAir MiniPanel bubble diffusers in its three aeration basins, WAS tanks, and a post-aeration tank. The total project cost was $1,875,875, of which $370,630 went for the diffuser equipment and installation. Funding for the project included a gridSMART grant from AEP Ohio that could be used to cover energy-saving expenditures. A stipulation of the grant was that expenditures must show a sevenyear return on investment, which only the diffusers could demonstrate. Newark's new diffusers have improved critical plant processes and have saved nearly $14,000 per month in electricity fees while creating excess capacity that allows more plant loading, including trucked waste streams that generate new and unexpected revenues. were replacement of 25-year-old existing equipment that was reaching the end of its service life, and significantly improving process efficiencies to reduce operating costs. Electricity powering the large, aging motors on the blowers that aerate the activated sludge was the WWTP's greatest single operating expense. Background Results The city of Newark was in the second phase of its long-term control plan to optimize interactivity between its four plants and provide EPA-compliant, reliable service at reasonable rates. Priorities for this project It was expected that the majority of electric savings would come from replacing the old blowers. What wasn't anticipated was how much more annual operating expenditures could be reduced, and that new revenue 40 FIRST QUARTER 2016 Execution An initial two-month study confirmed the project was worth pursuing on a cost/ benefit basis. An engineering study followed to determine what the primary considerations should be for new equipment. "We originally only intended to replace our two aging blowers with new, high efficiency units," said Darin Wise, the plant's superintendent. "We hadn't really thought it necessary to also replace the diffusers. But our research showed we could save more money in the long run by combining new, highly efficient diffusers with the new blowers. So we decided to do the whole project." streams could actually be generated by pairing these new blowers with the new diffusers. "These diffusers are just so much more efficient," said Wise. "Putting air in the water has associated costs, and now our transfer efficiency and bubble efficiency is better. The diffuser creates more and smaller bubbles, which also rise slower in the tank to allow more contact time with bacteria. Our air requirements have dropped significantly- sometimes to a third of what they were." The unexpected boost in efficiency allowed 100 percent treatment to be accomplished in just two of three dedicated basins. This freed up the third basin to treat trucked-in industrial waste and septage, generating new disposal fee revenues of $83,000 from Jan. 1, 2014 to Feb. 24, 2014. This third basin now represents pure profit, and the plant makes some margin on high BOD/high ammonia flows that require their efficient new aeration basin. Wise is more than pleased with the amount of savings and profit his new blower/ diffuser pairing is generating. "We initially had to spend extra on electric to allow for more air use to treat additional loading, but our electric bill still dropped significantly, between $12,000-$14,000 a month. We're installing another blower/diffuser combination now," he explains. "We'll depend on it as a redundant system." These improvements are projected to save $168,000 per year in electrical usage and, as of March 31, the plant has already taken in an extra $153,000 in loading fees this year. ●

Table of Contents for the Digital Edition of Rural Water - Quarter 1, 2016

Strategic Planning for Water Utilities
Planning for Drought
A Rally to Remember
The 17th Annual Great American Water Taste Test
USDA Rural Development Has Loans
Rural Water Association of Utah Launches Successful Training Program
Vermont Rural Water Association Continues Training; Plans More for 2016
From the President
Finance: Investing Without Borders
Emergency Management: Decontamination Strategy for the Water Sector
A Day in the Life of a Circuit Rider: Dell R. Harris, Kentucky Rural Water Association
Case Study: Bubble Diffusers
Regulatory Update
Throwing My Loop
Index to Advertisers/
From The CEO

Rural Water - Quarter 1, 2016