McCarthy hits milestone on $168M Arizona water treatment plant expansion

Take heed to the article
4 min

This audio is auto-generated. Please tell us in case you have feedback.

Development on a $168 million enlargement of a water remedy plant in Mesa, Arizona, reached a serious milestone to begin the 12 months, however not earlier than McCarthy Constructing Cos. overcame a possible roadblock.

The builder started work on section one, which incorporates development of a second reservoir onsite, in January 2024, in response to a information launch despatched to Development Dive. The brand new 8-million-gallon reservoir measures 234 toes by 234 toes and is 25 toes tall, and sits simply south of the ability’s present reservoir, which McCarthy additionally constructed almost twenty years in the past.

However because of the tender nature of the encompassing space’s soil, the St. Louis-based common contractor knew the undertaking might doubtless result in potential settlement and leakage issues down the street.

To beat this, McCarthy and Overland Park, Kansas-based Black & Veatch, the engineer of document, adopted a leak-detection system beneath the reservoir. That meant the implementation of a number of proactive methods onsite, in response to the information launch.

For instance, groups positioned a layer of #57 rock underneath your complete footprint of the tank and put in perforated pipe in 4 quadrants tied again to a sump. The work will permit the Metropolis of Mesa to pinpoint the supply space if any leakage is ever detected sooner or later.

This sub-slab system is a notable enhancement in comparison with conventional reservoir designs, in response to McCarthy.

“Our staff was in a position to anticipate lots of the undertaking challenges, however there have been nonetheless some extremely distinctive circumstances for the undertaking staff to handle, which might not have occurred as efficiently had it not been for the cooperative and collaborative relationship between everybody on the undertaking,” Grey Wensley, senior superintendent for McCarthy’s water staff, stated within the launch. “From the deep excavation and sophisticated shoring to the leak-detection system and elevated deck, the staff discovered options and delivered a high-quality construction on a really tight web site whereas maintaining the plant absolutely operational your complete time.”

Efficient preconstruction planning accelerated the development schedule by an estimated two to 2 and half months, in response to McCarthy. The staff additionally used area at a close-by metropolis park to stockpile roughly 20,000 cubic yards of excavated materials, which prevented the expensive export and reimport of backfill.

“This reservoir is a crucial piece of our long-term water operational technique for the East Valley, and it’s been delivered with the form of care and innovation we anticipate on a undertaking of this significance,” Chris Hassert, water assets director for the Metropolis of Mesa, stated within the launch. “The staff discovered methods to avoid wasting money and time whereas including new instruments, just like the leak-detection system, that may assist us handle this asset for many years.”

Work required about 8,300 cubic yards of concrete, which McCarthy’s concrete consultants poured in 40-foot by 40-foot squares and sequenced diagonally to permit for the enlargement joints. McCarthy expects to finish this portion of the undertaking in October.

Constructing a brand new reservoir subsequent to an present one

McCarthy and Black & Veath used digital design and development modeling to plan shoring, soil nails, slopes and crane areas, in response to the discharge. The excavation section prolonged roughly 30 toes beneath grade, with about 12 toes of separation between the brand new and unique reservoirs. Crews additionally constructed a stay fiber-optic duct financial institution in between the 2 our bodies of water.

Part two of the undertaking will double the plant’s remedy capability from 24 million to 48 million gallons of water per day, in response to the discharge. Deliberate work contains the addition of a mirrored sand-ballasted flocculation system, ozone era and sodium hypochlorite era for disinfection, in response to the discharge.

McCarthy expects to finish section two of the undertaking in early summer season 2027, in response to the contractor.