Photo: See above representation of the complicated pipe work in-between the Return Activated Sludge Pump Station and the Meter Vault. The photos show SIGMA's 24x14 MJ Tees with SIGMA's ONE-LOK SLDE Wedge Restraints

The McCroskey Island Wastewater Treatment Plant is a large plant that serves a growing population in the towns of Sevierville and Pigeon Forge,TN. Pigeon Forge is a major tourist destination, featuring the Great Smoky Mountains and the hiking trails of Gatlinburg. As its name suggests, Pigeon Forge was once known for its iron and steel production, which dates back to 1795. While the Wastewater Treatment Plant working for this area isn’t quite as old as all that, it does have a long history (it was built in 1989) and has undergone numerous refurbishments. Growth in the city and suburbs and increasing demand from tourism necessitated an increase in capacity, which the old plant was unable to meet.

According to Paul Lawrence, the McCroskey Island Project Manager at Judy Construction, the wastewater capacity needed to be more than doubled, from 3.6m gallons per day (mgd) to 7.6mgd. The owner operator of the treatment plant not only wanted to build for immediate needs, but also wanted to future-proof the plant and allow for additional population growth and demands from future businesses.

In order to rehabilitate and build a new and improved treatment plant, the engineers first had to understand what they were dealing with. Over the years, new functionality and pipe had been added to the older infrastructure, resulting in a "plate of spaghetti", that is, a mixture of mapped and unmapped pipe containing water in various stages of treatment.

In a rebuild, there is a danger of running into existing pipe because of a disconnect between the information on historical construction maps and what is actually in the ground. It’s necessary to map cautiously and build out from there: 'As built' may not be accurate; the blueprints on file may not accurately reflect the pipe system in its current state. The contractor needs to be adaptable in the design and install; fittings, for example, may need to be re-routed depending on the existing pipe infrastructure. The discovery phase of the project is key.

*Pictured above: One of SIGMA’s 54inch MJ Bends, the MJ90, with SIGMA’s ONE-LOK SLDE restraint. For more information, contact* *dwilson@sigmaco.com*

SIGMA’s Role in the Project

Dennis Wilson, Technical Sales Engineer at SIGMA explained the project history:

“This was an ideal Plant Work project because the distributor did it right from Day 1. We were involved in the bidding process and were already specified as an approved supplier. This allows us to be nimble and respond to the changes that the end customer is asking of the distributor in real time. We were also available as 'boots on the ground' to pitch in if the contractor or consulting engineer hit a roadblock or needed technical advice during the specification process. The crews at Judy Construction were super professional and super experienced”.

"On a personal note, I want to draw attention to the specialist construction workers at Judy Construction including the superintendent Steve Sullivan and the pipe foreman, Chad Becraft. These men work tirelessly to make huge construction projects like McCroskey happen. Some of the team members may well live in another state; they work Monday to Thursday onsite and then travel home for the weekend. They’re the unsung heroes in the waterworks industry."

Paul Lawrence of Judy Construction adds, “We have used SIGMA products including large diameter fittings and restraints for many years. We have always been pleased with the quality of the products. Both SIGMA and the distributor, Ferguson, have played key roles proving the pipe, fittings, and restraints. All products have been delivered to the project in good condition and in a timely manner.

For information on SIGMA’s Treatment Plant Division and product lines, please contact dwilson@sigmaco.com.