Ten-Million Gallon Clearwell Project Successfully Completed

Recently, ESC completed a project for a local municipality.  The project included a ten million-gallon fresh water clear well system to store and distribute drinking water to some 200,000 metered customers.  Discharge from the clear well is provided by eight 400 HP pumps powered by Variable Frequency Drives in order to maintain adequate pressure throughout the system.  Provisions were made to add two more pumps for future expansion.  As is typical, a project of this magnitude requires several years in the planning stage.  ESC was there all the way, consulting with our client as needed.

Ultimately, we were tasked with the Structural, Mechanical, and Electrical design.  Working hand in hand with our client, ESC designed a building structure to house the electrical distribution system, VFD’s, the pumps and associated piping.  A robust HVAC system was designed to maintain a constant temperature in order to keep the VFD’s and other electrical equipment within their tolerable temperature ranges.

Several building designs were considered in order to keep the structure sound, while blending in with the surrounding area.  The part of the building housing the pumps needed to be approximately 40 feet tall inside in order to remove the pumps from the well for servicing.  A bridge crane was installed to facilitate this function. The bridge crane also helped tremendously while installing the 36” discharge water piping inside the building.

The electrical distribution system consists of three (3) 2500 kVA transformers configured into a dual Main-Tie-Main arrangement.  Power is supplied to the clear well system from the three (3) possible sources with an interlocked transfer between them.  This design insures disruption of the water supply is highly unlikely.  To facilitate construction and provide a safe means to connect the transformers to the distribution system ESC utilized a custom-designed cable bus system.  Design and configuration of the eight (8) Variable Frequency Drives was created to meet the application and to strictly adhere to IEEE 519 with regards to Harmonic Distortion, assuring no electrical interference to the sensitive instrumentation associated with water testing and treatment.

During construction, ESC assisted the client and contractors with any and all questions.  ESC is proud to have played a role in the design of this system.  Our client placed the new well and pumping system into service in a short amount of time and is very pleased with its performance. Scroll through the photos below to see the finished product.


Josh Stewart