City of Lawton Landfill


Nov 28, 2012

Komatsu dozer with KOMTRAX pays off

During the past two years, the City of Lawton, Okla., landfill completed the final phases of constructing two, new, 16-acre cells to handle the ever-growing waste stream of the city and surrounding counties, including the Fort Sill military base. In addition, the landfill takes in debris from a population base of more than 150,000 which includes Comanche and Cotton counties.

Numbered Four and Five, the new cells were built twice as large as the existing cells, which were constructed, filled, or in the process of being filled since operations began in 1971. Planning for the new cells began with the purchase of 432 acres adjacent to the landfill’s existing location just south of Lawton. The landfill now totals about 700 acres and is staffed by 11 people, including Landfill Superintendent Justin Pitts and Field Supervisor Jason Mansel.

“We made the new cells larger than the others with the idea that it would save us the work of building an additional two cells seven to eight years down the road,” said Pitts. “That planning ahead will likely save us additional time and costs in the future.”

As new cell construction took place, landfill crews stockpiled dirt and used monitoring wells to ensure the cells didn’t hit groundwater. When they reached the bottom elevation, they constructed a compacted clay liner from on-site material that Pitts said is ideal and “packs like concrete.” Crews then installed a welded plastic liner.

“Cell construction is more than just digging a hole to be filled back in,” emphasized Pitts. “We have to take environmental concerns into account, and the clay and plastic liners are measures that prevent contamination. Further, we installed a leachate system, which collects liquids and pumps them to a holding pond for evaporation.”

With those elements in place, operations to fill the cells began, starting with what Pitts calls a “fluff lift” of five to eight feet. “That first lift is extremely important to protecting the integrity of the cell and leachate system,” Pitts said. “We don’t put anything in that lift that could puncture the plastic liner, such as construction and demolition debris, which often contains nails and rebar. It’s basically just regular household waste. Once that’s compacted, covered and protected, we can put all types of materials in there, building in one- to two-foot lifts.”

Pitts estimates the landfill recycles about 30 percent of the debris it takes in, rather than putting it into cells. That includes tires, wood products, trees, metals, appliances and chemicals, such as motor oil and Freon.

“We like to see as much material as possible leave here to be reused,” he said. “Not only does it save landfill space, but recycling provides other benefits. For example, chopped-up tires can be used as playground cover, in athletic fields and as fuel in concrete kilns. It makes environmental and economic sense to recycle. Our hope is to constantly increase the recycling percentage, up to 80 or 90 percent.”

New Komatsu dozer pays off

Material that remains at the landfill is unloaded onto pads before being pushed into the cells with dozers. Last year, the landfill purchased its first Komatsu dozer, a 94,000-plus-pound D155AX-6SL with a waste-handling package. It already has about 1,800 hours on it, as the landfill uses it almost constantly, 10-hours a day, six days a week. In addition to pushing trash from the pad, the landfill uses it to maintain slopes and push rubble generated from construction and demolition debris.

“It’s a good all-around machine for us,” Pitts stated. “What I really like is that it’s smooth and operator-friendly with the joystick controls. We have a mixed staff of veteran operators and newer operators, who have to be trained on how to run machinery. It’s very easy to do that with the D155. For example, not long ago, I put a new guy with no experience in that dozer and within a couple of days he looked as if he’d been operating as long as some of our seasoned operators.”

Several pieces of equipment in the landfill’s fleet already have rippers, so the city chose to equip the D155AX-6SL with a winch. “That’s paid off in a big way. Excavation companies can shut down when the weather is bad, but we can’t. We have equipment, mainly compactors, that gets bogged down in the mud. The D155 allows us to hook on and pull them out. We’ve even winched a 127,000-pound machine. It’s got good power to handle anything we’ve given it.”

Lawton Equipment Maintenance Superintendent Dennis Bothell said the landfill is an abrasive environment that can be hard on equipment. The operation follows a strict preventive maintenance program and uses KOMTRAX to keep track of hours for scheduling services. “KOMTRAX provides us the hours and also gives me useful information, such as how many of those hours were idle versus production, how much fuel is being consumed and error codes. I know exactly what the machine is doing and where it is. KOMTRAX is a valuable tool.”

Support from Kirby-Smith Machinery is valuable too, said Bothell. The City of Lawton worked with Territory Manager Preston Brown to purchase the machine, and Product Support Representative Bud Sears calls on the landfill regularly.

“One determining factor in our machine purchases is how well the dealer stands behind and supports its products,” noted Pitts. “Kirby-Smith has impressed us every step of the way. They call us just to check in and make sure everything is going well. Some people might see that as an annoyance, but I see it as caring that we’re satisfied. We remember those things when it comes time for a new machine.”

Constantly planning

In addition to the goal of increasing the percentage of recycling, Mansel said the landfill is already planning for more cells. It’s also in the process of putting in wells to capture methane gas.

“Eventually, we want to recover the gasses, and we have some industries that have shown an interest in that,” said Mansel. “We’ve planned all the way out to construction of Cell 13, which would obviously be many years down the road. But we always have to think ahead and plan — daily, weekly and long term. The landfill is going to be here for many years and we have to have those plans in place to ensure we’re taking care of our residents, both now and in the future.”