Overview

A natural gas company has a permitted surface water withdrawal on the Ohio River for approximately 5 million gallons per day (MGD). As a condition of the permit, the company was required to provide a management and training plan for control of aquatic invasive species (AIS, zebra mussels) and aquatic pathogens (largemouth bass virus.)

Mr. Hershey led the proposal preparation and interview process to design the training program, led a team of engineers and biologists that developed the training program and personally made the presentation to the client’s staff, contractors and senior executives in Ohio, West Virginia and Colorado.

The program was such a success that Mr. Hershey was charged with evaluating multiple treatments for the control of AIS which eventually led to the preparation of a pilot test program to determine if ozone would be an effective treatment alternative. He conducted a pilot test that determined that ozone was an appropriate alternative for treatment and was the lead engineer for the design of a 5 MGD ozone treatment system. The ozone system had to treat the entire 5 MGD of water to achieve 100% mortality rate of the zebra mussel veligers prior to entry into the intake pump station that included four 400 horsepower pumps discharging 3,360 gpm at 430 psi.

Highlights of the project include:

• The entire structure is raised 20’ above finished grade on a steel platform above the 100-year floodplain.
• Three 20,000 gallon contact tanks provide a minimum of 10 minutes of contact time and One 10,000 gallon tank with coarse bubble diffuser was designed to strip any remaining ozone from the water before entering the wet well.
• The system is capable of providing 940 pounds per day (ppd) of ozone.
• A pressure swing adsorption unit is provided to provide a 93% O2 feed for the ozone generators.
• The generators produce O3.
• Two Wedeco (Xylem Brand) SMOevo 810 ozone generators, located in a heated container, provide the ozone for the system in the typical range of 9% to 13% concentration.
• One SMO 810 can provide up to approximately 17 mg/l O3. In high ozone demand conditions, such as high turbidity water during flooding, both ozone systems can be used, providing up to 24 mg/l ozone.
• The ozone generators are cooled using an external air cooled chiller.