Landfill cleanup campaign started

Wednesday, April 23, 2008

As Cedar Ridge Landfill officials await a decision from the state on whether they can monitor groundwater beyond their property line, Marshall County residents and leaders agree -- monitoring of the landfill itself has increased.

"There is awareness by the Marshall County Commission and Waste Management Inc. that people are watching, and they are improving the landfill now," said Darlene Hill, one of nearly a dozen people whose research on the landfill was reported to the commission last summer.

"Do I think they've got a lot of room for improvement? You bet," Hill said Wednesday.

Terri Douglas, a Waste Management Inc. spokeswoman assigned to Cedar Ridge, agrees, and endorses the steps taken by WMI District Manager James Ashburn who's led a couple of tours at the landfill recently.

He explained that odors early this week -- which prompted more complaints about the landfill -- were a result of efforts to deal with the problem. Odor was escaping from underground. It's from decomposing garbage. To deal with it, bulldozers had to move dirt. When that was done after the weekend rains, garbage was stirred up and there was a stink raised; literally and figuratively. It had to get worse before it could get better.

Many other things are being done to control odors and prevent fire at the landfill, Ashburn and Douglas said during a Wednesday morning tour. They have taken steps to prevent a recurrence of the Easter weekend fire at the landfill where smoke fell in valleys, hollows and nearby low land looked like they were in a fog. It was during a temperature inversion, but the smoke was blown away before state inspectors could arrive. That's increased awareness among area residents.

As for when when the Tennessee Department of Environment and Conservation might issue the permit requested by Waste Management for monitoring of ground water around the landfill, Dana Coleman, spokeswoman for the Tennessee Department of Environment and Conservation, has a complicated answer.

Decisions typically take 30-90 days after the public comment period closes, Coleman said. The comment period ended Sept. 7.

"But there is no requirement that a decision be made in a certain period of time," said Coleman, adding, "It's not unusual for the department to request additional information from an applicant."

If that happens, more time is needed, she said.

Given that information, a decision might come early next month or in early December, or maybe next year.

Meanwhile, Hill and her band of volunteers -- who well-remember the efforts of the Marshall County Environmental Awareness Organization to prevent expansion of the landfill-- are still concerned about ground water and odor from the landfill.

Those activists and a growing number of Lewisburg-area residents have increased their calls to county officials about odor from the landfill, and remarkably, one of the people presenting their report to the commission in July was Don C. Ledford who's since been elected to the county commission. This month he was assigned to the commission's committee on solid waste. The day after his appointment, Ledford said he anticipated the landfill would become the No. 1 topic for the committee.

While odor has been the most noticeable issue, water quality is at the heart of Waste Management's permit application to the state and it was a concern for commissioners in July when they assigned County Emergency Management Director Bob Hopkins to monitor streams around the landfill.

"I've checked them every day" since then, Hopkins said Tuesday. "We haven't seen any problem with the streams."

He's been checking for years out of personal and professional concern, "but not on a daily basis," Hopkins said, noting after his tour of the landfill that Waste Management is now using mulch as part of what's covering sections of the landfill.

Douglas says it absorbs water and promotes the growth of grasses and other ground cover. Ashburn says it slows the flow of water, thereby reducing, if not eliminating erosion that could threaten what's covering the garbage.

Severe erosion, theoretically, could uncover garbage and release odor, but there's been no statement that that has happened at Cedar Ridge.

But fears that there may have been unseen problems for water underground were the concern of the environmental awareness organization that complained karst topography isn't the place for a landfill because of its caves, underground streams and sinkholes.

However, the spokeswoman for the Tennessee Department of Environment and Conservation, points out that karst topography is typical throughout Middle and East Tennessee.

"It's important to understand that karst topography ... is not necessarily a reason to prevent the siting or expansion of a landfill, but it does make the project more complex and impacts the engineering, design ad construction required to make the site work," Colman said.

"We have also required the company to conduct a geophysical analysis to determine the integrity of the bedrock," she said. "So, yes, karst topography is a factor, but it's a factor that is taken into consideration and addressed in the permitting process."

Glenn Youngblood, Waste Management's regional vice president, spoke to the public about the application to monitor water underground during the state's public meeting in Lewisburg on Aug. 8 at Marshall County High School. It was a meeting Hill attended.

She's since said she didn't understand why the company had to monitor ground water from places other than on the landfill.

Ashburn says it's to make sure nothing is leaking from the landfill. That's a precaution taken after double-walled pipes are used to transport leachate from collection places to a storage take before it's hauled away in trucks.

Leachate is water that's seeped through garbage and carries pollutants from the waste downhill. Such collection systems were explained during a tour provided by Waste Management for the Marshall County Tribune on Wednesday.

When engineers design landfills, they look at the lay of the land, figure out where it can be filled up and follow environmental regulations on how to protect the territory.

Clay liners have been used as a base for where garbage is dumped. Clay has been replaced with broad, thick, rubbery, plastic sheets which have a rough side to prevent them from slipping. The material is dubbed HTPE, initials for its chemical composition.

The liner is used to collect leachate, the water that's seeped, or leached through garbage.

Garbage is dumped on top of dirt that's covered a portion, or cell, of a landfill.

Typically, the liner is laid down across a slope so that water seeping through the garbage will flow downhill on top of the HTPE liner and be channeled toward a collection system.

Environmental regulations require that garbage be covered with dirt every evening after dumping has been ended for the day. Tennessee requires landfills to have a sufficient volume of dirt available to continue to cover the garbage daily, Coleman said.

When leachate is collected from the bottom of a slope, it's pumped from there through pipes to a holding tank.

The pipes used to transport leachate from the bottom of a slope to the tanks are double-walled pipes, Ashburn said. There's a pipe within a pipe. If there's a break in the pipe transporting leachate, then the surrounding pipe prevents a leak.

If there was a leak it might be called a spill of very dirty water with a very offensive odor. No indication of a spill has been revealed.

The double-walled pipes at Cedar Ridge lead to a pair of holding tanks.

Hundreds of thousands of gallons of leachate have been held, loaded to tank trucks that have a capacity of some 5,500 gallons and there could be up to a dozen trips per day to haul off leachate to a sewage treatment plant.

The volume taken away depends on how much rain has fallen, Ashburn said.

One source of odor at a landfill is leachate. Asburn and Douglas point to several systems used to deal with it.

One is an enzomatic odor system to neutralize the smell, they said.

"It puts molecules in the air to attach to odor molecules," Ashburn said.

There are household products which might be compared to the enzomatic system, but Douglas and Ashburn are clear when they say the system they use is not adding a nice smell to the air. It's chemically changing the nature of what carries the odor and that eliminates the smell.

"This is what James has been working on for 12 months," Douglas said. "The leachate tanks are one source he's been examining."

Ashburn says his next step is to enclose the loading area next to the leachate holding tanks. Inside, there will be greater opportunity to neutralize the odor when truck tanks are loaded. As a further precaution, the trucks are parked in a concrete basin to collect anything that might be spilled.

An enclosed loading area should be built and in use by the end of the year, he said.

"When we originally started this, we identified it as a source [of odor] but it didn't work as well as we wanted," Ashburn said.

A fine mist can be seen rising from the top of the leachate tanks. It's the enzomatic molecules in a mist to suppress odor at a source.

There's another volatile issue for landfill operators, although it has no odor.

Methane is a byproduct of decomposing garbage. It's flammable and environmental regulations require that it be collected and dealt with. It's burned off at Cedar Ridge and other landfills.

A system of wells are use to collect the gas which is then piped to a burner.

"It's a giant candle," Ashburn said.

The flame burns blue and is invisible during the day, but it can be seen at night.

The wells collecting methane are about 3-feet wide. A 6-8-inch pipe is inserted in the hole and washed river rock is placed around the pipe so the gas can flow to the pipe. A diesel fueled generator pumps the gas to the burner. It burns all the time.

In East Tennessee, there's a landfill that uses the heat from burning methane to generate electricity which is sold to Knoxville Utility District, the electric power system there which sells the landfill its electricity. While it may be expensive to generate electricity with methane, the East Tennessee landfill has apparently found a way to reduce its power costs.

While methane has no odor, Ashburn says Waste Management has declined to accept some wastes with an odor which is hard to control, or a substance that threatens the operation of the landfill.

He and Douglas have reached out to local officials, recognizing there have been changes on the county commission and in the county mayor's office.

Douglas says she believes the relationship between Waste Management and county officials has been good, but she's realistic about public perceptions.

"I think our reputation has been tarnished a bit, but we're working on that," Douglas said. "We are addressing issues aggressively."

She says the company welcomes requests for tours.