Springwells Water Treatment Plant Maintenance: Ensuring a Reliable Water Supply

Millions rely on treatment plants for clean, safe drinking water. Regular water treatment plant maintenance and upgrades are crucial to keep these facilities functioning efficiently and reliably. Recently, the Great Lakes Water Authority (GLWA) embarked on a significant five-season project at the Springwells Water Treatment Plant in Dearborn, MI, one of the largest plants in their system.

Given our expertise in commercial diving and underwater construction, UCC was chosen as a primary Design-Build (D-B) team member to perform a multitude of water treatment plant upgrade tasks.

The Springwells Water Treatment Plant is a conventional water filtration facility that draws water from the Detroit River through the Raw Water Tunnel System. With a capacity of 540 million gallons per day (MGD), this plant plays a vital role in supplying drinking water to 112 communities (approximately 2.8 million residents) in Southeast Michigan.

Since its construction in 1930, the Low Lift pump station has reliably supplied raw water to the plant using the original pumping equipment for nearly a century. But after nearly 100 years of service, the intake pumps, isolation gates, and valves had reached the end of their useful life, necessitating the replacement of these critical components.

The challenge – GLWA needed to replace these parts without disrupting the plant’s continuous operation. To meet project goals and objectives, GWLA opted for a Design-Build procurement process, allowing for a seamless collaboration between engineers, contractors, and specialty subcontractors, including UCC.

UCC’s extensive expertise in underwater construction as well as commercial and mixed gas/deep diving was crucial for the project’s success. UCC’s diving team worked 100 feet below the working surface with water depth of up to 61 feet within the narrow confines of vertical suction flumes, and conducted tasks overnight during off-peak hours, to ensure the plant remained operational to meet regional water demands.

The initial plan required complex removal of existing structural concrete and embedded gate frames, a process which posed significant risk. To mitigate concerns, the D-B team developed a comprehensive plan for investigating and assessing existing conditions. UCC’s divers performed tasks such as coring structural concrete walls for analysis and selectively sampling embedded metal frames. Laboratory testing, including metallurgical and strength testing, helped refine the design of new frame specifications, ensuring the use of the most suitable materials.

The primary objective of the project was to ensure that the Springwells Water Treatment Plant remained operational throughout the upgrade process. With the plant unable to be dewatered, all activities had to be conducted by divers, with depth playing a critical role in productivity. At 61 feet underwater, divers using standard air could only stay on the bottom for 48 minutes per day, while those using NITROX could extend to 125 minutes, greatly enhancing efficiency.

As with all UCC projects, safety was paramount. Divers faced strict velocity limits of 2 feet per second to prevent working against strong currents. Comprehensive safety planning was essential, incorporating Job Safety Analysis (JSA), dive plans, Emergency Action Plans (EAP), Lockout/Tagout (LOTO) procedures, and communication protocols. A recompression chamber was on standby, required for NITROX diving, and emergency extraction plans were clearly detailed.

One key objective was to remove and install five new bulkhead guides. This involved demolishing the existing embedded cast iron rail system by cutting and chipping concrete along the wall and floor mounting areas. The new three-piece frame system, measuring 7 feet wide by 27 feet tall and extending 8 feet above the water line, was installed using 1/2-inch epoxy anchors. Once in place, the frame was grouted after final adjustments. All dives for this task were completed on air due to the shallow water depth.

Another major task was the removal and installation of eight sets of roller gate frames and rails. This required the removal of 72-inch by 72-inch cast iron frames which were embedded in grout 61 feet below the water’s surface, and which had existing cast iron guides extending 94 feet per side. Demolition involved removing the guides from 61 feet underwater and 39 feet above water, removing bronze seal plates, and trimming 3 inches of the cast iron frame to fit a new thimble insert design.

For the suction flume roller gate replacement, the original plan to remove the existing embedded thimble was revised. Given existing conditions, the D-B team opted for a stainless-steel thimble extension. Using a drill template, 32 holes (7/8-inch) were drilled at a depth of 31 inches. The gate frame was installed to the thimble insert and grouted in place. Anchors were embedded 14 inches into the sound concrete of the existing caisson structural wall, passing through 17 inches of grout and the existing embedded semi-steel thimble. Suction flumes were angled, necessitating shims for gaps under 1 inch. Gate guides were installed up to 94 feet per side, with 100 holes (1/2-inch) drilled at a depth of 5.5 inches. Bearing pads were grouted for gaps less than 1 inch.

UCC successfully met all budget, safety, and schedule goals. Notably, UCC achieved zero safety incidents while meeting primary objectives, such as providing the means to isolate the suction well and discharge channel for future improvements and minimizing disruptions to plant operations. The strong partnership within the Design-Build team, coupled with the expertise of a well-trained construction and dive team using the correct equipment and tooling, underscored UCC’s success in executing this comprehensive underwater project.

UCC’s unwavering commitment to excellence and innovation in underwater construction and water treatment plant maintenance has proven instrumental in overcoming complex challenges. Our team’s precision, expertise, and dedication ensure that even the most demanding projects are completed safely and efficiently. If you require reliable and effective solutions for your water treatment infrastructure, you can trust UCC’s experienced professionals to deliver exceptional results. Contact us today to discuss your specific needs and discover how we can support your projects with our industry leading commercial diving and underwater construction services.