Harper was selected to perform work on the filters at the Seneca WTP after the initial upgrades in 2015. Work included anthracite and sand removal prior to demolition of the existing Ovivio underdrain filter. During initial exploration, the filters were found to need significantly more repairs than anticipated. The Harper team worked with the Engineer and Owner to develop a plan that was within budget and schedule. The end result was a new Phoenix Underdrain System as well as media replacement and extensive concrete repairs in the 4 filter bays.