Close collaboration is key to the installation of a multi-tank precast concrete wastewater treatment system for a new Menards office facility in Wisconsin.
By Mason Nichols
More than a decade ago, Tony Birrittieri, president of Petersen Onsite, contacted Mark Wieser and Andy Winkler of Wieser Concrete Products to discuss an important opportunity. The two Wisconsin-based companies had already established a great relationship, working together over the years on a wide variety of wastewater projects. But Birrittieri and the Wieser team had noticed a significant uptick in mid-sized work – projects falling between single-family home septic systems and larger, municipal-style treatment systems.
“There was a huge niche in the market that no one was serving,” Birrittieri said. “So, I sat down with Mark and Andy and said, ‘Look, let’s start using some of your larger precast tanks, customizing and compartmentalizing them so that we can install them on these mid-range wastewater jobs.’”
The two companies quickly got to work. In less than a year, they collectively generated products capable of being combined into larger systems to address complex wastewater issues. Today, many of those initial systems serve as blueprints for new work. Such was the case in early 2020, when Wieser Concrete and Petersen Onsite teamed up to provide retail giant Menards with a new precast concrete wastewater treatment system capable of handling a flow of nearly 12,000 gallons per day.
High flows, high customization
As one of the largest home improvement chains in the U.S., Menards is consistently growing, needing larger facilities and enhanced amenities for its team members. To better serve its employees in Elk Mound, Wis., Menards sought to expand a 500-person office facility. This expansion included adding a full-service restaurant, significantly elevating the on-site wastewater volume and necessitating the installation of a new treatment system.
Winkler and Birrittieri knew a mid-sized on-site system would be perfectly suited for the job due to a relatively small site and drain field. But besides limited space, the two companies faced a slew of difficulties. According to Winkler, general manager at Wieser Concrete, the site featured light and sandy soils, requiring a 1.5:1 ratio slope for the excavation.
“For every foot you go down, you must move back 1.5 feet with the crane,” he said. “With this hole, we had to be back 26 feet before the crane could be set up. So, a major challenge on this one was having to set nearly 50,000 pounds at a 50-foot radius.”
The team used a 220-ton hydraulic crane on-site to address this issue.
Another concern was the gravity sewer’s depth coming to the site. According to Birrittieri, the depth was lower than what the team wanted – meaning the tanks would have to be placed below the water table and would require additional ballast. To help solve the problem, the tanks were set at a higher elevation above the water table by installing a lift station and two grinder pumps.
Finally, there was the design of the system itself. To maximize the use of the available real estate, Wieser Concrete and Petersen Onsite collaborated to craft a highly customized, four-tank solution.
Working out the details
The relationship between Wieser Concrete and Petersen Onsite paid major dividends when designing the Menards system. With the analysis of the site completed and a better understanding of the challenges, the two companies began generating a system that could handle the high flow needs of the office facility while also remaining viable for the long-term. Birrittieri worked closely with Wieser Concrete throughout the process.
“This job was intricate with the way that the inlets and outlets of all the tanks had to line up to take advantage of the footprint,” he said. “But thankfully, Wieser Concrete is a major player in the entire process. We worked in step with them to do all the tank drawings and customize them exactly the way we needed them to be.”
Birrittieri added that Petersen’s relationship with Wieser Concrete is unique. The Wieser Concrete team generates full-scale CAD drawings for Petersen Onsite that include every component of every tank so the entire team can see how all components fit ahead of time, eliminating hiccups while on-site.
According to Winkler, when wastewater enters the system, it first runs into a 25,000-gallon, two-compartment septic tank. This initial tank, which is 12-feet-wide-by-30-feet-long, uses the walls for sediment and stop channeling and helps slow down the initial flow. From there, the wastewater enters a 20,000-gallon tank that’s divided into two compartments. This tank stabilizes the flow and doses the first treatment unit, a BioMicrobics MyFAST 1.0. With the MyFAST unit, the second tank can handle a surge capacity of up to 10,000 gallons.
As Birrittieri explained, it is vital to the success of the overall system.
“MyFAST reduces the organics and pathogens in the wastewater,” he said. “This is crucial to prevent a bio-mat from forming that would eventually clog the drain field. Overall, MyFAST reduces negative effects on the soil before the wastewater is discharged to the subsurface.”
Additionally, by significantly reducing organic matter, a smaller drain field is needed – something which was necessary for this project given the small footprint.
Next, the wastewater enters a second 20,000-gallon tank that also contains two compartments – one with another MyFAST 1.0 system and the second with a BioMicrobics MyNitriFAST 1.0 solution. These two compartments further reduce organic matter and nitrogen before the wastewater enters the final tank. This 12-foot-wide-by-20-foot-long tank filters and doses the wastewater, which is then carried out to the dispersal field.
Saving big money
After Wieser Concrete manufactured the precast tanks, team members from Petersen Onsite arrived at the plant to begin installing some of the necessary components ahead of the on-site work. This allowed for a shorter installation time at the project site and resulted in a higher-quality product.
“Working at Wieser Concrete’s shop is a lot more controlled than working in the field,” Birrittieri said. “The major treatment components are time-consuming on a job site. We’d also have to use an expensive crane to do that work on-site; here, we can just use a gantry crane at their plant.”
Once the tanks arrived in Elk Mound, the two companies continued working together, with Wieser Concrete setting the tanks in the excavation and Petersen Onsite performing the plumbing and electronics work necessary to complete the job. The time savings achieved on-site, attributed in part to the work completed in advance, allowed the tanks to be set in just one day and backfilled the next morning. According to Winkler, production began on April 23. Installation was complete just two weeks later, on May 7.
All that time saved equates to a significant reduction in cost, something other building materials can’t achieve.
“This project would have never been possible with fiberglass or cast-in-place concrete,” Birrittieri said. “It just doesn’t make sense financially to go through that process on-site. The costs would be astronomical.”
The excavation was 17 feet deep and a few hundred feet wide. Using precast concrete tanks minimized the amount of time the hole remained open, which was key to protecting everyone on-site.
A complete solution
From quality to safety, time savings and beyond, precast concrete offered the best wastewater treatment solution for the Menards office facility. And because Wieser Concrete and Peterson Onsite have worked so closely together for such an extended period, they understand what it takes to deliver high-end solutions, emphasizing just how critical collaborative work between a precast manufacturer and installer or general contractor can be.
“With excavating, tank setting, building the drain field and all the electrical work, the site was up and running in about a week,” Birrittieri said.
Winkler praised the people involved for the project’s success.
“We have in-house engineering for design and drafting, experienced plant personnel, dedicated installation staff, and a top notch quality control program,” he said. “We are very fortunate to have these highly skilled people working with us to make these large tank projects materialize.”
Mason Nichols is a Grand Rapids, Mich.-based writer and editor who has covered the precast concrete industry since 2013.