The Department of Public Works (DPW) in Washington, D.C., has launched a Feet on the Street recycling education campaign to improve the district’s curbside recycling program. During the eight-week campaign, the department will tag recycling carts that contain unacceptable items and reward residents whose carts exemplify best practices.
According to a news release from the department of public works, the campaign aims to eliminate plastic wrap, bags and film from single- and multifamily household recycling carts. The department says direct cart messaging can be an effective recycling education strategy since the agency’s 2018 tagging pilot resulted in a 20 percent reduction of plastic bags and film in the curbside stream.
“Collected residential recycling tonnage has increased by 20 percent thanks to our curbside collections program and the commitment of the residents we serve,” says DPW Interim Director Christine Davis. “To reach the district’s 80 percent waste diversion goal, we need to reduce more contamination from the recycling stream. Part of that involves changing behavior when necessary and also rewarding behavior when possible.”
The department says it plans to inspect carts on 16 recycling routes and leave “Oops” tags when nonrecyclable items are found, such as plastic wrap, bags and film, clothing, yard waste, ropes, chains, furniture and scrap metal.
Recycling inspectors will also look for what the department calls “recycling superstars.” The first resident in each ward identified as having perfect recycling set out will be notified, and the eight winning residents will be announced on Earth Day on April 22 through DPW and recycling partner social media channels. DPW says those winners will receive a recycling “swag bag.” DPW says having a “perfect set out” means that the recycling is contained in the residents’ D.C. government-issued recycling can or bin; does not contain any unacceptable recycling items; and includes recycled items that are emptied and rinsed.
DPW says Feet on the Street is funded in part by a grant from The Recycling Partnership, Falls Church, Virginia, which is a national nonprofit that helps recycling municipalities overcome recycling obstacles.
“Our Feet on the Street initiative works by giving district residents instant feedback on what is and is not recyclable,” says Chris Coady, director of community programs at The Recycling Partnership. “Through this personalized and real-time feedback process, we are helping D.C. capture more quality recyclables that are then transformed into new materials, creating a healthier, more circular economy, a less wasteful planet and a stronger, healthier community.”
Waste Management, Houston, announced March 15 that Sean Menke, president and CEO of Sabre Corp., and Maryrose Sylvester, former U.S. managing director and U.S. head of electrification for ABB Ltd., have been elected to its board of directors, effective immediately.
“Following a robust process to identify and add talented leaders to Waste Management’s board of directors, we are excited to welcome Maryrose and Sean, whose extensive leadership skills and diverse backgrounds will complement our existing board members,” Waste Management chairman Thomas Weidemeyer says.
According to the company, Menke is “a proven transformation leader, using his extensive experience in technology and transportation operations to bring together strategy and data to address complex issues.”
Since the end of 2016, he has served as president and CEO, as well as been a member on the board of directors of the Southlake, Texas-based Sabre Corp., a global software and technology company that powers the travel industry. Before joining Sabre, Menke spent more than 20 years in executive leadership roles in the airline industry, including at Hawaiian Airlines, Pinnacle Airlines, Frontier Airlines and Air Canada. He holds a bachelor’s degree in economics and aviation management from Ohio State University and an MBA from the University of Denver.
Sylvester, according to Waste Management, is “a strategic, growth-oriented leader who is passionate about technology, innovation and automation.”
Most recently, she served as U.S. managing director and U.S. head of electrification for ABB Group. ABB Group is a Zurich-based global technology company, operating mainly in areas of electrification, robotics, power and automation. Prior to joining ABB Group, Sylvester spent more than 30 years at GE, serving most recently as president and CEO of Current, a digital power service business that delivers integrated energy systems. She also serves on the board of directors of Harley-Davidson Inc. She holds an undergraduate degree from Bowling Green State University and an MBA from Cleveland State University.
Murphy Road Recycling to build MRF in Berlin, Connecticut
Murphy Road Recycling, headquartered in Enfield, Connecticut, has announced that it will build a $30 million material recovery facility (MRF) in Berlin, Connecticut. The All American MRF will feature a processing system supplied by Van Dyk Recycling Solutions of Norwalk, Connecticut, that includes optical sorters as well as artificial intelligence and robotics.
Murphy Road Recycling is part of a family-owned and -operated team of subsidiaries and affiliates that provide recycling and waste management services to Connecticut and western Massachusetts.
The All American system will be operational by early 2022 and will employ 200 people during the construction phase and another 50 people when fully operational. Once online, it will be capable of processing in excess of 50 tons of recyclables per hour, with a projected annual capacity of at least 200,000 tons, providing Connecticut with a critical resource to reach its 60 percent waste disposal diversion goal.
“Murphy Road Recycling and Van Dyk Recycling Solutions are proud of their deep roots in Connecticut, and we are excited to leverage our local knowledge and industry-leading expertise to modernize and transform recycling in our home state,” says Frank Antonacci of Murphy Road Recycling.
Murphy Road Recycling says it approached Van Dyk Recycling Solutions more than a year ago to help it deliver on its vision for a new MRF that would increase the quantity, quality and purity of recovered recyclables; provide an innovative and safe working environment; and have the flexibility to adapt to ever-evolving consumer habits and recycling market conditions.
“Today’s curbside material isn’t what it was 10-15 years ago,” says Jonathan Murray, director of operations for Murphy Road Recycling. “It was heavy on newspaper and relatively clean. Today, everyone reads news online and orders everything from the internet. Today’s stream is full of small cardboard boxes and shipping envelopes, and requires that we, as recyclers, innovate and change our thinking around the sorting of recyclables.”
The All American MRF will feature a fully integrated system that includes artificial intelligence and several second-chance mechanisms to ensure valuable material is recovered. The design includes equipment to target paper, cardboard, boxboard, glass and five types of plastic.
“It will employ an unprecedented 11 optical scanners, which can identify and separate materials based on their chemical composition and will utilize robotics and artificial intelligence to perform additional quality control on the final mixed-paper line before baling,” Pieter Van Dijk, CEO of Van Dyk Recycling Solutions, says. “As material trends change over time, these machines can simply be reprogrammed to adapt and prevent the system from aging out.”
He adds, “This facility will include cutting-edge technology and safety measures that will be the new industry gold standard, not just in Connecticut, but across the country.”
In addition to producing high-quality recyclables, the MRF is designed to keep its employees safer. The All American MRF’s “monolevel structure” and heightened focus on automation will create the innovative and safe working environment that Murphy Road Recycling was seeking, the company says.
“The health and safety of our employees is our No. 1 concern at Murphy Road Recycling,” Antonacci says. “That is why we invested heavily in automation to further increase the safety and productivity of the facility. We are retraining employees for positions to operate and maintain the optical sorter and other equipment, which are higher skilled, higher wage positions.”
Antonacci adds, “The All American MRF is built to solve the recycling challenges of today while investing in breakthrough technologies to address the ever-evolving recycling stream of tomorrow.”
Webster Industries acquires Action Equipment Co.
Action Equipment Co. Inc., Newburg, Oregon, has been acquired by Webster Industries. Webster Industries, based in Tiffin, Ohio, is an employee-owned manufacturer of conveyor chains, sprockets, vibrating conveyors and specialty castings.
Under the agreement, Action will continue to manufacture vibratory process equipment for a range of industries.
“It is an exciting merger—one in which both companies strategically complement each other. Action’s team is passionate about its core competence and strengths, vibratory technology and looks forward to continued marketplace growth alongside Webster. Expect new products, enhanced service for existing relationships, and as always, exceptional equipment designs,” Action President Andrew LaVeine says. “As an employee-owned organization, both Webster and Action operate as a team of owners with each person bringing their abilities, talents, experience and backgrounds for a shared purpose, which is to serve our customers.”
Dennis Eagle enters US waste truck market
Dennis Eagle Inc., with headquarters in Summerville, South Carolina, has announced it is entering the U.S. refuse truck market. Dennis Eagle, which is part of the U.K.-based Terberg RosRoca Group, is a manufacturer of refuse truck chassis and bodies.
The company will manufacture its ProView chassis out of its Summerville production facility. According to the company, its trucks offer operators greater safety and efficiency enhancements.
Dennis Eagle says its trucks feature a low-entry, walk-through cab that can comfortably seat a driver and “three-crew.” Additionally, the cab is designed with enhanced visibility to provide the driver with as much direct vision as possible to better see other drivers and obstacles around the vehicle.
“Technology and design have made such an impact in waste management that there is now a gap in the market for a specialist truck, designed and built for vocational use, and we are filling that gap,” Dennis Eagle Inc. President Ian Handley says. “This is an American truck. It is specifically designed for American operators. It’s made in America, and it uses American components. We have been trialing the vehicle for four years and are confident it will be a huge success.
“It’s big on safety and big on efficiency, and we expect it to make a major impact on the vocational market in general and waste management operations in particular here in North America,” Handley continues. “We’ve set up a network of established dealers to cover the whole of North America.”
According to the company, its first all-electric refuse truck is already in production, and units were delivered to the first U.K. customers this past fall.
Amp Robotics to operate secondary sorting facilities
Matanya Horowitz, founder and CEO of Amp Robotics Corp., a Denver-based company that develops artificial intelligence (AI) and robotics for the recycling industry, says the company has developed a “really good solution for secondary sortation” that uses robotics and artificial intelligence (AI). The company is looking for partners that could benefit from the solution, such as plastic reclaimers or material recovery facilities (MRFs) that have high disposal costs for the residue they generate.
“We are looking to be really involved and prescriptive about how this thing would work,” he says. “We are looking at it as a system rather than an individual component, like a robot.”
Operation of the facilities would be Amp’s responsibility. “The reason for that is we’ve been able to tie our technology pretty closely together, and, so to a large extent, our software is really the one operating the facility. We can really tune that facility to what some end customer might really want.”
The company has piloted an automated facility design for advanced secondary sortation at its company-owned test facility in Denver. That pilot plant offers an infrastructure model that can process and aggregate small volumes of difficult-to-recycle mixed plastics, paper and metals sourced from residue supplied by primary MRFs, Amp says in a news release about the secondary sorting system.
“Secondary sortation efforts are not new but have been held back by how to make it work economically and at scale,” Horowitz says in the news release. “Amp’s application of AI for material identification and advanced automation has matured to the point where it’s now feasible to develop low-volume secondary sortation facilities that are economical to deploy and sustain nationally. Results we’ve observed at our test facility are promising and represent an infrastructure solution that can increase recycling rates, divert recyclables from the landfill, meet the growing demand for recycled content and protect our environment.”
The company’s secondary sorting facilities apply advanced automation enabled by AI to economically sort through these low volumes of residue or mixed plastics to recover polyethylene terephthalate (PET), high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP) and polystyrene (PS), the company says. These material streams also could contain used beverage cans (UBCs) and old corrugated containers (OCC). Amp says its secondary facilities can drive down the cost of recovery while creating contamination-free, high-quality bales of recycled material for resale.
Horowitz says Amp will evaluate the material streams from the companies it partners with to determine whether and how much it will pay for the material. The company can do so by running bales from the facilities in question through the vision system at its test facility to characterize the material. If the value of the incoming material doesn’t warrant payment, Horowitz says suppliers can still benefit from avoided disposal fees, though a modest tipping fee would apply to process the material at the secondary sorting facility. He adds that by sending their residue to these facilities for secondary processing, MRFs could realize new revenue streams, changing “the equation for them.”
The company says it plans to roll out a number of secondary facilities in other parts of the country during 2021. Horowitz says large metro areas that have several MRFs are ideal locations and would be able to supply the 30,000 tons per year necessary to make a location viable. Locating in such an area also would reduce transportation costs.
City of Berkeley chooses AMCS software for waste and recycling
According to AMCS, with U.S. headquarters in Boston, its AMCS Platform best fit the requirements of the city’s Zero Waste division and scored highest in the city’s evaluation criteria.
Berkeley, located 10 miles northeast of San Francisco, is a densely populated city of more than 118,000 residents. The city is defined to a large degree, culturally and economically, by the presence of the University of California campus. As such, the city prides itself on being progressive, especially as it relates to the environment.
The city’s Zero Waste philosophy adheres to the definition adopted by the Zero Waste International Alliance (ZWIA), “Zero waste means designing and managing products and processes to systematically avoid and eliminate the volume and toxicity of waste and materials, conserve and recover all resources and not to burn or bury them.”
The city of Berkeley established the Zero Waste Commission to help divert waste from its landfill and maximize the benefits of recycling. In addition to a municipal transfer station and landfill, the commission operates a 32-truck fleet to service the community’s waste and recycling operations.
The program has been wrestling with a legacy billing and work order system, supplemented by—but not integrated with—its customer relationship management (CRM) system. After long-term internal and third-party evaluation of its technology needs, the existing solution was deemed outdated, inadequate and incapable of providing functionality for running a modern-day zero-waste program.
The inefficiencies in business workflow, delayed community response times, and limited reporting and analysis capabilities hampered efforts to manage city refuse, recycling and organics collection effectively, according to the city. In addition, the legacy tools required heavy support from its IT staff.
According to AMCS, the AMCS Platform will help alleviate inefficiencies through some of the following measures:
It will broaden constituent self-service capabilities, including online bill payment, and the AMCS self-service customer portal will empower residents and other stakeholders to access and manage their accounts online, 24/7.
It will allow the city to optimize waste routes and provide real-time mobile communications. The AMCS Mobile solution also provides GPS-based routes that are preplanned and distributed to drivers.
The AMCS integration also will help improve business processes based on best practices, improve business and system integration, eliminate duplicate data entry and improve access to data and user-friendly reporting tools. The AMCS Enterprise Management solution will streamline processes into one system with end-to-end visibility.
On the right track
Features - Waste by Rail
How a strategic series of acquisitions made Wheelabrator Technologies a dominant player in the transport of waste by rail.
In recent years, Portsmouth, New Hampshire-based Wheelabrator Technologies has become a force to be reckoned with in the New England waste and recycling market.
Currently among the most active acquirers of collection and transfer assets in the area, the almost 90-year-old company has been pursuing an aggressive vertical integration strategy since it was purchased by Macquarie Infrastructure and Real Assets (MIRA)—a division of Macquarie Group—in 2019.
In 2020 alone, the company completed a series of strategic acquisitions to further expand its collection, transfer and disposal capacity, which included the purchases of Londonderry, New Hampshire-based Charles George Companies (CGC) and Eliot, Maine-based Shipyard Waste Solutions. Most recently, Wheelabrator acquired the assets of United Material Management (UMM) in December 2020, which provided pivotal infrastructure to move the company’s waste volumes via rail.
UMM operates 34 routes from six locations in Massachusetts, including two rail-served transfer stations and an advanced construction and demolition (C&D) recycling facility. According to Wheelabrator, the acquisition of UMM’s 22,000 residential and 2,500 commercial and roll-off customers, and UMM’s rail and transfer infrastructure, expands the company’s collection and disposal services in New England while providing a direct connection to its Ohio landfills for municipal solid waste (MSW) and C&D volumes.
“UMM just completed back in early summer [of 2020] a very large waste transfer station [with rail access]. So, we felt that that infrastructure was a critical piece for us from a strategic perspective to move more waste out of the market in New England,” says Bob Boucher, president and CEO of Wheelabrator. “In addition, they were finishing up another transfer station that has capabilities to move MSW via rail to our landfills in Ohio. All in all, UMM [was a prime acquisition target] because of our ability to get two transfer stations and a hauling company in one acquisition.”
A shift towards rail
Having access to rail-served transfer stations has become increasingly desirable for waste management companies in the Northeast as many states grapple with shrinking disposal capacity. For Massachusetts in particular, the state began pushing for greater landfill diversion in the 1990s, especially for recyclable and toxic materials. Such regulations have exacerbated pressures to export volumes out of state.
“Massachusetts is a challenging marketplace in the fact that we’re probably one of the only states, maybe besides California and a couple others, that have significant waste bans in place,” says Benjamin James “BJ” Harvey, the executive vice president for E.L. Harvey, a Westborough, Massachusetts-based waste management company. “So, as landfill closures happen, there are no new landfills or waste-to-energy facilities coming online to handle the excess tonnage.”
While long-haul trucking is a viable option for many disposal companies within the state to transport their waste, Harvey says the market for it can be volatile. “What we can’t control is the price of fuel,” he says. “[We] can make a deal with the landfill for a fixed cost, but the fuel prices [are unpredictable].”
According to Boucher, this was a driving factor behind Wheelabrator’s desire to expand its waste-by-rail operations.
“There’s been established trucking routes for waste to leave the marketplace from a long-haul perspective, but we just feel that we can’t be competitive with trucking in most instances. And then over time as more landfills get closed up in this area and as more [waste is transported] by truck, we’re probably going to have a situation where truck access is not going to be as robust as it is today,” he says.
“We feel that there are good profitability opportunities in rail. For us, that’s less trucks on the road from a safety perspective and then obviously all the environmental, social and governance (ESG) opportunities,” Boucher adds. “Additionally, given where our landfills are located in Ohio, it’s difficult for us to get waste by truck out of [the New England] market and to those landfills. So, rail is our first choice.”
Wheelabrator, which owns and operates a total of 14 waste-to-energy facilities, currently processes more than 11 million tons of waste annually, with 6.7 million tons being converted into clean, renewable energy that powers 340,000 homes. However, the facilities have scheduled outages on an annual basis, leaving some waste with nowhere to go.
“[Having access to rail-served transfer stations] allows us more control in and around moving volumes to help benefit our outage schedule. Now that we have a pretty substantial amount of hauling in the New England area, [rail access] gives us more flexibility from our perspective,” says Boucher.
“It’s important from a service offering perspective … that we have other outlets for our waste. The waste removal portion of our business relies heavily on logistics; so, the ability to have assets in certain markets keeps costs down for our customers and makes us more competitive,” he adds.
MOVING FORWARD
For Wheelabrator, the acquisition of UMM has granted the company a geographical advantage in an area of the country where the waste disposal market has largely hit a standstill.
“I think fundamentally, given where the [recently acquired] transfer stations are [located], they’ve got their own waste catchment,” says Boucher. “So, the position geographically in the market and their ability to attract waste just gives us a good, solid platform to grow that business with the backstop that we have our own capacity in our own landfills.”
Wheelabrator’s broadening portfolio hasn’t stopped with the acquisition of UMM, though. Recently, the company confirmed that it will acquire Stamford, Connecticut-based Tunnel Hill Partners and rebrand as WIN Waste Innovations in a strategic merger that, at the time of this writing, is set to close March 25.
The new brand, which is forecasted to become one of the largest private companies in the U.S. waste sector, has a projected $1 billion annual revenue run rate. The brand will be formally launched in late April, with the company rolling out a new logo, colors and tagline across the organization in the next few months.
“The resources of the new combined company will ensure we more seamlessly deliver reliable waste solutions for our customers. As part of the newly expanded company, we will be operating a dedicated customer service department designed to manage the needs of every customer, across the full range of services we provide,” a Wheelabrator spokesperson says. “Our customers will still benefit from the relationships they have established with individual company representatives; however, moving forward, every customer will also have access to a more comprehensive portfolio of best-in-class services.”
Founded in 2008 by the principals at American Infrastructure MLP Funds as a platform for servicing the waste industry, Tunnel Hill is currently the largest waste-by-rail company in the U.S. With the addition of Tunnel Hill under the WIN Waste brand, the company portfolio will now include 20 transfer stations, three MRFs, 334 collection vehicles and 1,877 rail cars.
“Our goal has always been to bring together a group of the best-in-class operators and infrastructure to create a vertically integrated network of assets providing customers end-to-end service offerings. … WIN Waste Innovations will be investing in people, assets, infrastructure, technology and processes to offer a curb-to-grid model that provides essential services that benefit our customers, communities and the planet,” a Wheelabrator spokesperson says.
As reported by Moody’s, WIN Waste will issue a $1 billion seven-year term loan to fund a sponsor dividend of $629 million and repay $306 million of the existing debt of Tunnel Hill. The company will also have a $400 million five-year revolving credit facility, which is expected to be undrawn at transaction close.
The individual companies, which had been acquired separately by MIRA, still remain under private equity ownership.
“We will continue to offer solutions tailored to the needs of our customers such as a curb-to-grid model that provides essential services that benefit our customers, communities and the planet and support our customers in achieving ESG goals,” says Wheelabrator. “We have established ourselves as a vertically integrated company with operations along the entire value chain. From collection to transfer to processing and disposal, we represent a comprehensive and sustainable approach to waste management, including tailored solutions to meet our customers’ needs.”
The author is the assistant editor of Waste Today and can be reached at hrischar@gie.net.
Concrete solutions
Features - Transfer Station Design
Proactive tipping floor assessment and repair can help transfer station operators avoid unnecessary costs and related hassles.
Analyzing tipping floor composition is likely far down the list of priorities for transfer station operators focused on the day-to-day tasks of managing and moving waste. However, ensuring proper upkeep through proactive repair and replacement is essential for protecting the integrity of these floors, avoiding unnecessary shutdowns, and helping save money.
Dealing with the issues
Between constant heavy equipment traffic and the composition of the waste itself, transfer station floors are subject to a tremendous amount of abuse.
Jim Andrews, CEO of Huntington Beach, California-based American Restore Inc., has been repairing and resurfacing floors in waste facilities for close to 40 years. According to Andrews, there are several common reasons why these floors suffer aggressive wear.
According to Andrews, the busier the facility and the greater the traffic, the greater the wear. This wear occurs when waste is dumped on the floor, excavators and material handlers—especially tracked machines—traverse the floor, and buckets create friction against the ground when moving trash.
Specific to the buckets used to move waste, Andrews says that those affixed with rubber edges can accelerate wear due to added friction placed on the floor.
Then there is the issue of the operator. Andrews says that older, more experienced operators tend to exercise more caution and care. Younger and more inexperienced operators, conversely, may be more likely to exert force on the floor or slam attachments since they are not as skilled at maneuvering the equipment. Similarly, facilities that are able to retain their workforce tend to have more disciplined and seasoned operators compared to transfer stations with more turnover.
Beyond the equipment used, the material being dumped at these sites is a catalyst for floor damage. Glass and metal tend to gouge floors, accelerating wear. Additionally, decomposition from organic waste generates a caustic liquid that can speed up concrete wear issues.
“Waste has highly concentrated amounts of organic acid from food waste, restaurant waste—any waste that is decomposing,” Andrews says. “That creates ‘off pH’ liquids. This is particularly true in warm environments where these organics deteriorate faster. In the summer months or the warmer months, or in facilities located in warmer environments, those acidic materials accelerate and wear on the concrete more.”
Andrews says that these organics-derived liquids would formerly seep out of waste trucks during transport, but public pushback and environmental legislation resulted in waste trucks being designed to retain these liquids. The result is these waste byproducts end up on the bottom of a transfer station floor during dumping.
Another factor that can influence floor wear is how wet or dry the floor is kept, Andrews says.
“Wetter facilities wear out faster than dry facilities,” he notes. “People think that in a wet facility, there’s a lubricating factor of the water that helps protect the floor, but it’s not true. If it’s a wet facility, the floors are remaining cleaner. If the floors are cleaner, they’re more subject to exfoliation from abrasion. In dirty facilities, the dirt will stick to the floor. And now you’ve a protective membrane between the concrete and the environment above it.”
Organics processing and transfer facility designed and built by RRT in Ontario, Canada
Repair vs replacement
With all the variables that influence floor wear, it is difficult to ballpark repair or replacement intervals. That’s why relying on a trusted third party to assess floor composition can be a prudent strategy for operators.
RRT Design & Construction in Melville, New York, is an engineering and construction company that specializes in solid waste processing and recycling facilities.
According to Nat Egosi, president of RRT Design, his company routinely gets called to help operators assess what floor repair or replacement work might be needed.
“We have proactive customers that ask us to survey their tipping floors on a regular basis, as well as their push walls. This is part of how we inspect their entire facility. They’ve made a capital investment and they want to be proactive in understanding how their facility is being operated and how it should be maintained,” Egosi says. “These individuals want to plan their capital projects and repairs ahead of time and not have to face the potential of an emergency shutdown.
“We have other clients who suddenly run into a problem, and they need us to come out and do an evaluation of their floors. Usually in those cases, what we’re finding is the floor itself not only has worn down, but they’ve lost structural integrity. In those cases, structural engineering work is usually required. You have to put together drawings; you have to put together fit packages; panels or sections need to be removed and other sections might need to be redone, so it becomes a much larger kind of project that wasn’t necessarily planned.”
To avoid the latter scenario, operators need to be mindful of the stages of typical floor wear.
Andrews says that operators should look for worn aggregate as the first stage of decomposition. Everyday use can wear anywhere from 1/4 to 1 inch of concrete away from the floor every year. More severe cracking and signs of rebar underneath the concrete can point to immediate need to look into repair options. When concrete integrity has been compromised, rebar has been torn out or damaged, or dirt is becoming visible, complete replacement might be necessary.
“If there’s enough integrity left in the slabs, then we can overlay concrete,” Andrews explains. “If there are evidentiary signs that the slabs are weak, have lost a lot of strength from cracks and erosion, and there is slab pumping where water is shooting up from the soil below the floor due to compression or there is movement in the concrete, you really have to take a closer look because you might need to consider replacement.”
"A lot of times, people’s view of the world is, ‘Well, we got this far without spending money to repair our floor and nothing happened. Why don’t we just go six months longer?’ Inevitably, six months becomes 12 months, and 12 months becomes 24 months. Meanwhile, things are just getting worse and worse until their floor is just dirt.” –Nat Egosi, president, RRT Design
Egosi says that his teams put steel wear-bar indicators into the concrete during floor construction. Once these bars become uncovered through regular wear, it is a sign that the operator should begin to plan for repairs before the structural rebar underneath is exposed and integrity begins to get compromised.
Despite the warning signs of floor degradation, Egosi says operators often put off repair because of budgetary concerns, which can compound the problem.
“A lot of times, people’s view of the world is, ‘Well, we got this far without spending money to repair our floor and nothing happened. Why don’t we just go six months longer?’ Inevitably, six months becomes 12 months, and 12 months becomes 24 months. Meanwhile, things are just getting worse and worse until their floor is just dirt,” Egosi says.
Refusing to heed the warning signs of a floor that needs repair or replacement can have significant ramifications for operators.
Egosi says that letting a floor degrade to the point it is unsound can cause structural issues beyond the floor itself.
Ash processing and transfer station designed and built by RRT in Florida
“The concrete slab floor actually provides structural integrity to the walls in some transfer stations. In these cases, engineers are needed to come in to evaluate whether the loss of structural integrity in a floor affects just the floor or if it also affects the walls,” he says. “What would’ve cost you maybe $100,000 to repair is now going to cost you $300,000.”
In addition to alleviating additional construction challenges, taking proactive measures to repair a floor before a full replacement is needed can also be instrumental in helping prevent environmental contamination that can occur when the liquid waste stream leaches into the soil. When this happens and there are remediation issues, operators can end up spending significantly more time, energy and money addressing the issue than what would have been necessary by tackling the issue early on.
“These transfer stations, particularly the older ones, have a lot of waste material that has gone through the building over the years. And these slabs, even though they’re supposed to act as primary containment to the waste stream, they have cracks, they’ve joints, stuff goes through the slab and gets into the dirt, and that can be an enormously risky scenario,” Andrews says.
Specific to negating environmental risks, Andrews says that a concrete overlay design can be a safer bet for operators as opposed to new concrete construction, which can open up a facility to environmental contamination problems due to the exposure of the soil.
In the mix
One thing that both Andrews and Egosi stress is that not all concrete is created equal. Because concrete is made from aggregates derived from quarries, the strength and integrity of this material differs based on the geography from which it is mined.
“You want to select an aggregate that has a wear index property that’s very suitable for crushing, degradation and disintegration. That really does make a difference in the longevity of the floor,” Egosi says.
For Andrews, he says that the concrete mix his company uses has evolved over time.
“We have used a lot of different mix designs over the years, but what we always come back to is a slightly altered version of a Department of Transportation bridge mix. It’s a federal standard concrete that’s used in bridges because bridges are built in the desert, they’re built in the mountains, they are built in all these different types of environments. ... What we’ve done at American Restore is we’ve started with that mix and then we’ve altered it over the years where we’ve added some silica fume and fly ash to reduce the porosity of the concrete, and maybe we add some more cement to the mixture depending on where we are in the country since not all the aggregate is the same.”
To negate the variables of using different aggregate with different qualities, Andrews says that most of the engineered overlay American Restore uses for its concrete floor restoration is made in the same plant with the same ingredients to ensure a consistent product.
“Because of our quality assurance and quality control measures, we can do a job in New York; Seattle; Texas; or Casper, Wyoming and it’s the same exact formula. It’s the same material. So, now we can tell the owner and the engineer [of a site] with certainty what their performance expectations can be.”
Because cost can be an issue, especially for municipal clients, Andrews says that the company offers two different grades of concrete that are priced accordingly.
He says that for those on a tighter budget, companies often opt to use the tougher material in high-wear areas and use the other mix where there is less traffic and potential for wear.
Regardless of the mix, transfer station floors inevitably degrade over time. Making facility assessment a routine part of the job can help transfer station managers identify problems before they lead to significant costs—and even bigger headaches.
The author is the editor of Waste Today and can be reached at aredling@gie.net.
North America’s largest waste haulers stretch from coast to coast, generating tens of billions of dollars in revenue and employing hundreds of thousands of employees. View More