Water Storage Tanks, Water Pumps and Water Filtration System made up of Sand Media Filters Provides a Creative Filtration Solution for Energy Company

An energy company needed to upgrade a high pressure gas line approximately one mile long that ran through Medford and Everett, Massachusetts (suburbs of Boston).  The gas pipeline services an LNG terminal and a power plant that can only store a finite amount of gas to hold over during a pipeline shut down.  The project was under serious time constraints as the contractor had 14 days from blow off of the old line to final pipeline connections and testing. 

Most of the tidal-influenced pipeline installation corridor crossed wetlands contaminated with petroleum products from years of industrial land use.  In order to keep the excavation dewatered, a large pumping and treatment system needed to be designed and installed.  It was estimated that a 300' x 20' cut could yield as much as 2,000 gpm from the excavation.  Due to the location of the project and the footprint of the equipment, the system had to be designed for space limitations. 

To provide trench dewatering, three DV-150 Power Prime™ pumps were connected to a single 12”x 3,200' HDPE header pipe.  Ten connections and isolation valves were installed along the 3,200' length of pipe.  The contractor could easily set up and move pumps from point to point without time loss or moving a lot of discharge hose and still meet the designed capacity of the treatment system.

The water was pumped under a street that services a produce distribution market that serves the entire Northeastern United States, several oil terminals, an LNG terminal and a major commuter rail terminal.  The water was injected with Chitosan Liquifloc™ to help remove sediment and increase the efficiency of the sand media filter units and then settled in ten 21,000 gallon tanks for primary treatment.  All ten tanks were manifolded on the inlet to act as one large tank. 

Two DV-150 6-inch Power Prime™ pumps were used to move the water into the second set of ten 21,000 gallon tanks used for additional solids removal.  The water was then pumped by two DV-150 Power Prime™ pumps into three 48-4 media filter units to reduce total suspended solids before carbon filtration.

After filtration, the water was pumped 2,000' away for final discharge through a 12” HDPE pipe.  The final run of HDPE was installed through an LNG terminal rack, which loads 75 tankers per day making it impossible to achieve normal HDPE pipe fusion production rates while the tanker trucks were being filled because of the flammable gases.  To install this portion of the job, Rain for Rent worked weekends.  Hot work permits were required as well as a job safety analysis for each task performed during fusion operations.  Security clearance had to be obtained and health and safety regulations had to be adhered to during the entire project while working in the terminal. 

Even though the system was designed for 2,500 gpm, the flow rates often exceeded 3,000 gpm. During the course of the project, Rain for Rent provided emergency pump needs to a directional drilling company and installed a wellpoint system to treat water in an organic lead impacted area.  To move contaminated water across railroad tracks to the treatment system, a company was hired to feed discharge hose into a 48” storm drain. 

The Rain for Rent crew was on site to monitor and troubleshoot the treatment system and to service pumps as needed for the duration of the project.