April 30, 2018

Non-Potable Water System Installation with an Air-Gap Break Tank to Benefit New 10 Billion-Plus Capacity Reservoir in Greater Chicago

Air Gap Break Tank System at the Metropolitan Water Reclamation District of Greater Chicago

When everything is working smoothly with a water system, whether that system is delivering potable water or removing wastewater or storm water, few people give any thought to what is taking place. When something goes wrong, however, the entire story changes and the complexities of a properly functioning water system becomes increasingly important to everyone involved.

Some of these systems, especially residential, are fairly straightforward. Others, such as the massive Metropolitan Water Reclamation District of Greater Chicago (MWRD) are much more complex. Our engineers and designers at Metropolitan Industries don’t shy away from either.

In fact, our expertise regarding pump system hardware and software allows us to seamlessly scale and customize to meet just about any project. However, when the number of gallons stretches into the billions, scaling up is no small feat and exhaustive testing prior to installation helps minimize risk and understand performance.

An Ongoing, Special-Purpose Project

The MWRD was established in 1889, a few short years before the World’s Columbian Exposition, as an award-winning government agency responsible for treating used water and managing storm water over 375 square miles. In 1972, MWRD adopted the Tunnel and Reservoir Plan (TARP) to help the district comply with state and federal water quality standards, including The Clear Water Act (CWA), in Chicago and 51 suburbs.

Ideally, TARP was designed to protect Lake Michigan from raw sewage pollution, especially during times of heavy rain and flooding, by directing the flow of this water into reservoirs where it could rest until treatment facilities had the capacity to properly treat it.

Non-Potable Water System Engineering

We know pumps of every size, and we understand that continued operation is critical to the success of system, especially one the size and significance of the MWRD. To begin, we had to first understand the end goal of the larger McCook Reservoir. Upon full completion in 2029, the reservoir will have a total capacity of 10 billion gallons achieved in two stages, with the first stage offering an impressive 3.5 billion gallons of storage capacity to protect Chicago and surrounding areas.

We worked directly and closely with MWRD to design the Main Stream Pumping Station non-potable water system with an Air-Gap Break Tank for seal water for the deep-tunnel pumps. However, design was only part of the challenge.

For us, successful completion of this project – which saw its inaugural and successful flood of water in January of this year – involved two separate, but closely related components:

  1. The Hardware – The project required the installation of piping, valving, electrical conduits, and wiring in addition to tanks and pumping equipment. The main tank components were three 304 Stainless Steel (known commercially as 18/10 or18/8 stainless steel) Break Tanks with Baffle Walls and 304 Stainless Steel Piping. Every component was American Iron & Steel (AIS) Compliant. End Suction Booster Pumps, each with 7.5 HP and 140 GPM @ 52 PSI, were used and supported by variable frequency drives (VFDs) and a hydro-pneumatic tank for low-flow pump shut-down. Finally, City Water Supply Fill Valves with provisions for the future completed the system.
  2. The Controls – The MetroTech III variable speed water booster pump controller was designed into this project because it provides operators with the ability to view real-time operating conditions and alarms. Set and command points can be changed and the integrated help screen provides easy access to assistance as needed. To help everything run as smoothly as possible, the MetroTech III is also intuitive and offers real-time troubleshooting to the team of experts tasked with monitoring and maintaining the main stream pump station.

To help ensure that the system would work as planned, Metropolitan opened our facility to representative from MWRD so rigorous testing could be conducted with all interested parties.

Testing Makes Perfect

We aren’t strangers to testing. The experts at our Romeoville, Illinois facility are well versed and the facility itself features extensive testing capabilities that were further enhanced in 2017. For larger projects, full system testing greatly reduces startup time and decreases the potential for errors – meaning adding costs and downtime – after installation.

Our state-of-the-art on-site test lab was designed to perform a full range of testing on all of our equipment. Testing capabilities include hydrostatic-pressure, hydraulic-performance, and hydronic-equipment performance testing on both individual items and large packaged/custom assemblies.

Newer additions include automated testing with programmable logic controls (PLC), actuated throttling valves, calibrated instrumentation, and, as the MWRD team learned, witness testing with our customers.

With every product we sell and every project we take on, the end goal is to have a satisfied customer, regardless of the size of the project itself. In the case of the MWRD McCook Reservoir and Mainstream Pumping Station, millions of Chicagoland residents will count on this reservoir in times of need, and we are happy to have had the opportunity to extend our expertise to each and every one of them.

Interested in Learning More on How to Protect the Potable Water Supply at Your Application?

We’d love to learn more about your upcoming project Contact Metropolitan Industries to find out how Air-Gap Break Tank Systems can work to protect your application’s potable water supply.

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