Construction crews continue to make substantial progress on the Disinfection Byproducts Rule Compliance Improve Project aka the Chlorine Contact Tank. This project, funded by a PENNVEST Loan, will install a 260,000 gallon chlorine contact tank at the Steelton Water Filtration Plant. The tank will allow for the chlorination of water post-filtration, greatly minimizing the occurrence of disinfection byproducts.
As you will recall, this upgrade is neccesary to address recent Tier II non-emergency DBP violations.
Below is a progress report on the project including in-progress pictures.
The Steelton Water Authority sincerely thanks all residents and customers for their patience as this substantial capital improvement is made to our system.
The project is expected to be completed and operational by Fall of this year.
Installation of Geo-Piers
Under the concrete foundation of the Chlorine Contact Tank, are 60 Geopiers. These 60 Geopiers are 20 feet deep and approximately 1 ½ feet in diameter. The drilling machine is an open tube with loose chains in the bottom. As the machine is pushed down, the chains block the soil from entering the tube and displaces the soil to the side. Once the machine reaches the target depth, stone is dumped into the top funnel which enters the tube. The machine rises 1-2 feet allowing the stone to enter the hole. The machine then pushes back down to crush and compact the stone. This process is continues to the srface.
Pressure Test on Geopiers
One Geopier was selected to test the amount of pressure it would be able to withstand. At the bottom of the Geopier, a sensor plate was placed with sensor probes on it. That Geopier was excavated down to 5 feet (This will be the depth where the concrete foundation will be for the tank). 5 feet of concrete was poured on top of the Geopier. After the concrete was allowed to set, the drilling rig was placed on top of it. With a hydraulic jack, it applied 1 ½ times the amount of pressure the tank will place on each Geopier.
This test insures the Geopiers can hold the chlorine contact tank.
Rebar has been installed prior to pouring the concrete foundation of the tank. This picture represents progress on the project as of April 2017.