Water Treatment Plant Modifications - East Plant Pressure Filters, City of La Porte, IN
The potable water system of La Porte, Indiana consists of two treatment plants, three elevated tanks, and seven wells. The goal for NIES Engineering, Inc. was to rehabilitate or replace the aging pressure filters in Plant 2, an unmanned 6 million gallon per day plant on the East end of town.
The approach adopted by NIES Engineering, Inc. was to analyze the condition of existing steel pressure filters and media then develop a cost analysis for available alternatives. Preliminary examination of one of the pressure filters revealed impacted media, substantial internal steel corrosion, and mineral deposits that explained the observed reduction in filter efficiency and plant capacity.
The options available were to replace the five pressure filters entirely, or rehab with either single or dual media and either water wash or combination air-water wash. The favored approach was to rehab the filters using Water Plant workers to assist in media removal. Original internal filter piping was replaced as was the underdrain plate.
The final dual media, water wash rehabilitated filters represented a cost savings over total replacement of more than 50%. External backwash piping was also replaced as were pneumatic operated valves. The whole Plant 2 system was integrated into a system wide radio controlled SCADA system that allowed full control from the Lake Street Plant. A new concrete backwash basin, high service pump replacement, fluoride pump replacements, and update of the chlorination facility completed the improvements.
The project was a success with all original goals accomplished. The City of La Porte now benefits from a reliable, unmanned, remote water plant that operates with high efficiency pumps and full control from the Lake Street Plant.
Key Points
- Improved Control
- Cost Effective Rehabilitation
- Extended Life
- Energy Efficient Pumping
