CMAR Delivery of Fremont Wastewater Treatment Facility Leads to $6M Savings and Accelerated Construction
Federal and state environmental protection agencies demanded quick change. The City of Fremont, Ohio, wanted to update services for residents but faced severely limited funding. To solve the dilemma, the city turned to the construction manager-at-risk (CMAR) delivery method, recently approved for Ohio public works projects, to upgrade and expand its wastewater treatment plant. The collaborative CMAR approach led to savings of $5.5 million during design and more than $500,000 during construction, allowing for completion of the $60 million project ahead of the regulatory compliance deadline.
The original Fremont wastewater treatment plant, the Water Pollution Control Center (WPCC), was built in 1949, while many sections of the city's wastewater and storm water collection system dated back more than 100 years. Although the WPCC effectively processed dry weather flow, during wet weather the combined raw sewage and storm water exceeded capacity and overflowed into the Sandusky River. This project will increase the plant's capacity from 10 million gallons per day up to 24 million gallons per day.
In addition to time and money savings, the CMAR approach facilitated collaboration to more effectively overcome the challenges of complex infrastructure and maintaining plant operations throughout construction. To select the CMAR contractor, the city issued a request for qualifications, held multiple meetings with bidders, and utilized a scoring process that reflected value brought to all phases of the project. The city ultimately chose MWH Constructors (MWHC) from Broomfield, Colorado, as its CMAR contractor and involved many local firms throughout construction. The WPCC project broke ground in May 2013 and is scheduled for completion in January.
Savings Before the Shovels Hit
Efforts to reduce costs began early. At 30 percent of the design, MWHC created an initial construction cost estimate. When that number came back larger than desired, they submitted value engineering proposals. Two major changes and many smaller adjustments resulted in significant savings.
The first change combined two buildings into one. The plan originally included separate facilities for dewatering and waste thickening. Because the thickening facility would operate all the time, redundant machinery provided back-up. The dewatering facility, used intermittently, contained a single centrifuge.
"The machinery in both buildings was almost identical, so we were able to combine those two into one facility and use the dewatering equipment to back up the thickening machinery," said Bryan Canzoneri, MWHC's Project Manager. "If the thickening equipment goes down, they can stop dewatering and start thickening with the dewatering equipment. We eliminated a centrifuge, which was about $400,000, all the ancillary systems that make the machine run, and the actual building. Altogether that was over $1 million in savings."
Another of MWHC's value engineering comments involved the site's administration building. "By modifying the layout of the building slightly, they could get a typical shape of a prefabricated building, which saved approximately $500,000 up front compared to traditional design and construction," Canzoneri said.
Later in the project, MWHC realized additional savings by bidding each piece of equipment separately - and in some cases rebidding to further lower costs. For some of the equipment, "There were different manufacturers, but they're all laid out very differently so the engineer has to pick one and design around it," Canzoneri explained. "That usually precludes the other manufacturers from selling their equipment because it won't fit in the structure."
However, when MWHC received budgetary pricing considerably higher than they'd estimated, "We opened the spec up and got bids from the other manufacturers," Canzoneri added. "Then we had to consider what it would take to redesign the structure to make it fit."
MWHC utilized that process a number of times to reduce costs. With the UV disinfection equipment, for instance, they saved approximately $250,000. "The equipment itself was more than $300,000 of savings, but then we took into account the fact that the engineer needed to do some redesign work and we would have to do some modifications to the structure," Canzoneri said.
In addition to minimizing costs, the city wanted to keep as much work as possible in the local community. MWHC designed bid packages to maximize opportunities and reached out to area contractors in the pre-qualification process. Their efforts resulted in more than 50 percent of the WPCC project cost spent on local companies.
Operating Without Interruption
During preconstruction, the city, MWHC, and the design firm also worked together to pinpoint potentially troublesome areas as they transitioned from the old system to the new. For instance, "On the liquids phase, we really built a brand-new plant on the existing site, but we had some areas where we needed to tie into the existing lines," Canzoneri explained. "We held workshops with the operations folks to come up with plans to deal with that, and during the bid process we asked subcontractors to provide an approach for tying those lines in so we could see that they'd thought it through."
In another area of the project, "The influent line had a critical tie-in located really close to a lot of the new work," Canzoneri said. "We all realized it was a big risk item; we worried that if the line wasn't exactly where the as-built drawings showed it, we could accidentally drive a sheet through it during excavation. We decided that it warranted some additional exploratory work to make sure we wouldn't damage it."
It turned out the line did, in fact, lie in the middle of the excavation. "Rather than it coming up in the middle of construction and delaying work with a change order from the subcontractor, we were able to build it into the scope," Canzoneri said. "The three weeks of work to relocate the line occurred before excavation began."
Collaborative Phasing and Quality Control
With the CMAR approach, construction started before the design reached 100 percent completion. "Early on, we worked with the engineer to come up with a phased approach," Canzoneri said. "We had three separate contracts with three GMPs."
A significant portion of the site for the new plant required a mass excavation. "We told the engineer, "˜Instead of waiting until you get to 100 percent - which would be eight or nine months down the road - if you can lock down where the buildings will go and give us coordinates, and lock down what the bottom slab elevation will be, then we can go ahead and start digging,'" Canzoneri said. "They got us an early design package, which only consisted of a handful of drawings, so we could procure the earthwork contractor and get him started."
Early foundation designs also allowed installation of approximately 1,000 auger cast piles. "We didn't get the 100 percent design and get it all bid out until the end of 2013, which means we wouldn't have started digging until the spring of 2014 if we waited for the complete design; instead we dug the hole in the summer and fall of 2013 and got the piles in by the end of that year," Canzoneri said. "Working with the city and the engineer in preconstruction helped to compress the construction schedule and shorten the overhead the owner had to pay."
MWHC also implemented a collaborative quality assurance strategy. "We developed a plan that specified everything to be looked at, then we came up with a check-off sheet to make sure the third-party inspector, my superintendent, and the subcontractor's superintendent were all looking at and signing off on the work," Canzoneri said. "The most important part was the continuous inspection."
A city employee also participated in quality control. With that process in place, the design engineer only oversaw the most critical aspects. "The owner viewed that as a cost savings," Canzoneri said.
The new liquid treatments phase of the facility began operating last February. When the entire project finishes early next year, the upgraded facility will enhance environmental protection and the health of area residents while meeting state and Environmental Protection Agency regulatory requirements.