Great Lakes Water Authority and Walsh Construction Upgrade 1930s Water Facility in Detroit
Exceptional Quality is Essential: Great Lakes Water Authority and Walsh Construction Partner to Modernize the Springwells Water Treatment Facility
Responsible for providing potable water to eight southeast Michigan counties, including Detroit and Dearborn, Great Lakes Water Authority (GLWA) has embarked on a journey of updating its treatment facilities to ensure it continues to deliver water of exceptional quality.
“Water is essential for life, and we consider our business serious,” says Cheryl Porter, Chief Operating Officer of Water and Field services for GLWA in Detroit. “This has to be a sustainable industry. We’re looking at aging infrastructure and making improvements to ensure these systems continue to do what they are doing today.”
About the Facility
Formed in 2014, GLWA began operations on January 1, 2016, taking over from the Detroit Water and Sewage Department and leasing its equipment. The water authority operates five water treatment facilities, which serve nearly 4 million people, or about 40 percent of the state’s population. Springwells remains its oldest and largest.
The Springwells Water Treatment Facility was completed in 1935. At the time, it was the largest water treatment facility in the world. With an addition in 1958, it has a capacity to pump 540 million gallons of water per day.
Interestingly, GLWA can produce more water than currently in demand, something Porter attributes to conservation efforts, such as low-flow fixtures and washing machines.
Raw water drawn from the Detroit River travels through 12 miles of tunnels to the Springwells facility, where it goes into a basin for flash mixing, adding a chemical to gather suspended particles, so it clumps together and settles out. The water authority adds chlorine to kill any bacteria or viruses. During the last step, water moves through filter beds, with layers of sand and gravel, to capture any particles still in the water. Springwells adds more chlorine and fluoride before pumping the water to storage containers for distribution.
“There is a lot of work that has to be done to keep the system operational,” says Porter, adding that GLWA is exceeding federal and state water quality standards.
The current project is part of a larger plan to upgrade the facility. This project renovates the filter beds in the section built in 1958 to give the water a polished finished. Work took place inside the building.
CDM Smith of Detroit served as lead designer of the facility enhancements and engineered the upgrade. General contractor Walsh Construction of Detroit received the nearly $77 million contract for rehabilitation, which included 39 filters, enhancement to the facility laboratory and HVAC systems. Walsh has worked at the Springwells facility since 2013.
“This was a significant project for Walsh, with a complicated construction sequence,” says Dan Fish, Project Manager for Walsh. “The entire facility is roughly 2.5 million square feet.”
The depth and location of the original filters could not be altered, so GLWA reused the locations and replaced expired filter media and systems with new materials. It also added some automation to help with monitoring the water quality. “We want to modernize and innovate as much as possible,” Porter says.
Before starting, Walsh procured a FARO Focus T-5 laser scanner to survey the existing infrastructure for the comparison against the contract documents. The scanner generated a dense 3-D image used to establish a base point of control.
“The laser scanner mounted to a tri-pod, rotates 360 degrees, creating a 360-point cloud image by taking a distance measurement at every direction as the scanner rapidly captures the surface shape of objects,” Fish says. “Much of the infrastructure was supported differently than what the design showed. We needed to document where existing pipes were located and the elevation.”
Walsh consulted with schedulers, design professionals, fabricators, and material suppliers to bring together a cohesive team.
“Each of these entities offered an important and innovative advantage to deliver the most efficient sequence of construction,” Fish says.
A Walsh subcontractor used a Vactor setup assisted with booster pumps to suck out the expired sand and gravel from each filter. Crews disposed of the old filter material in a Type II landfill.
“It was a slow and tedious process,” Fish says. “Much like vacuuming the floor, they moved back and forth, gradually sucking out the media, layer by layer.”
Then crews replaced the underdrain, wash-water systems and all of the associated process piping. The filter underdrain system procured was fabricated using stainless steel approximately 1-foot-wide by 20 feet in length and covers the entire filter basin. The existing filter structure had to be modified to accept the installation of the new underdrain system.
“Walsh had to demolish the existing outdated underdrain system, retrofit the existing filters, and replace with an updated, low-profile Phoenix Underdrain System,” Fish explains. “You install these on the base of the filter, where they are leveled and securely mounted to prevent uplift.”
The new filter media arrived at the jobsite in thousands of super sacks. The material consists of a gravel support media for the base layer, sand and then topped with anthracite, a hard crushed coal. The process may include sending the water through multiple times to ready it for consumers.
“Walsh was able to manage the project with the assistance of our construction partners through a process and positive collaboration, and we focused our attention on the facility operations and their specific needs,” Fish explains. “This involved procuring input from all team members and taking an inclusive approach to construction.”
Working in an Existing Facility
The Springwells facility operates continuously and could not be taken offline for the rehabilitation.
“There’s a lot of work to keep it operational,” Porter says. “It’s not like I could shut it down during construction activities.”
Porter says she considers renovating around an operating facility the project’s biggest challenge. GLWA shut down about half of the facility’s filtration units during the rehabilitation. “Our major concern was not interrupting the active facility,” Fish says.
Communication flowed smoothly among facility employees and the construction crews. Fish agreed, adding, “When a project involves rehabilitating an existing facility, like Springwells, a facility constructed decades ago, Walsh relies on the people who run the facility. They are the authority and were essential to the successful execution of the project.”
With positive communication, transparency and through an extensive integration process, Walsh was able to avoid interruptions to facility operation.
“It was a great opportunity for the team to come together,” says Terry Daniel, Water Operations Director at GLWA. “When you have a project of this magnitude, it takes the expertise of everyone to come together to make sure we are doing a good job.”
Walsh delivered the project on time, with substantial completion occurring in January 2020. Earlier this year, Walsh was awarded a comprehensive project change order to enhance the facility’s supervisory control and data acquisition system allowing the GLWA operators the ability to run the filters either manually or remotely from a supervisory station. The construction team then tested all of the filters, running each rehabilitated filter for 40 to 60 hours to ensure proper functioning.
“I’m proud of the team’s ability to come together, communicate and solve the problems,” Daniel says. “And they did this over time without compromising production or water issues.”