Corrections & Clarifications: A previous version of this story gave an incorrect last name and title for Sharon Smith, assistant director of Metro Nashville Public Works.

In as few as five years Tennessee’s busiest landfill in Murfreesboro could run out of space, and thousands of tons of trash each day will have to be trucked to other communities.

The region's wasteful trash habits are now coming into focus because of Middle Point Landfill's pending closure and the region's economic boom, which has generated more garbage.

Nashville, one of the most progressive cities in the state, only recycles and composts 24% of its waste — well below the national average of 35%. (That figure includes businesses; the Nashville residential recycling rate is far less).

“You ask your average person where their trash or recycling goes, and they don’t know,” said Rebecca Caldwell, the solid waste program manager at the Greater Nashville Regional Council. “It’s usually seamless and it’s usually invisible… until you have something like Middle Point.”

How much waste are we talking about?

Middle Point takes in 4,000 tons of trash — the equivalent weight of 2,600 passenger cars — on average, every single day.

Metro Nashville’s residential trash ends up at Middle Point, as does garbage from 33 other counties. The bulk of the waste, however, comes from just two counties — Davidson and Rutherford. Together, they account for about 70 percent of all waste heading to Middle Point, according to state figures.

When will Middle Point shut down?

The owner of the landfill, Arizona-based Republic Services, calculates the landfill has eight to nine years remaining, based on its current daily volume and the remaining land permitted. The Rutherford County Commission last year voted down any possibility of an expansion.

Outside observers, including representatives from the Greater Nashville Regional Council and Metro Nashville Public Works, say it could be as soon as five years, or as far out as 10 before the landfill reaches capacity. They base their projection on the industry’s volatility and the region’s rapid growth. At any given time Republic could lose a large company’s contract, or gain a new one. Also, a natural disaster could hit the region and Middle Point could receive a large unexpected volume of trash.

Where will Nashville’s waste go?

After Middle Point closes, the garbage could end up in Kentucky, or at another Republic facility in Tennessee. Landfills are typically located in rural areas. Republic’s closest municipal waste landfill in Tennessee is 140 miles west of Nashville, in Jackson.

Metro Nashville’s contract with Republic lasts until 2022, with the option for two five-year extensions. When Middle Point closes, Nashville would likely still be contracted with Republic. The company currently has no other municipal landfills in Middle Tennessee, so the waste could be shipped outside the region.

Company spokesman Keith Miles said, “We are in the process of exploring various options,” but did not provide specifics.

Some of Republic’s other clients in Middle Tennessee could shift to another company such as Waste Management, which would mean their garbage could be trucked to another community.

Waste Management owns the West Camden landfill in rural Benton County, and that facility has decades worth of space remaining. (Camden is also home to the former Environmental Waste Solutions landfill, which closed and has threatened the groundwater with toxic chemicals).

How much does Nashville recycle?

Metro Nashville officials are working to achieve “zero waste,” or to reduce the amount landfilled as much as possible. The Public Works Department is finishing its Solid Waste Master Plan.

As part of the analysis, the city’s consultants gathered 2016 data from solid waste facilities. Solid waste can be divided into three main sectors: residential, commercial and construction/demolition waste. Most of Nashville’s waste comes from commercial buildings. Construction and demolition waste has nearly doubled since 2008, during the real estate boom.

Overall, Nashville’s “municipal solid waste,” which excludes construction and demolition, had 76% heading to landfills, 18% recycled and 6% composted.

That means 24% was “diverted” from landfills. The national average was 35% in 2015, according to the Environmental Protection Agency.

Drilling into the numbers, the report identifies some areas for improvement. It estimates that 87% of all residential waste, and 99% of all construction/demolition debris, was sent to landfills.

While the commercial sector had a better recycling rate than the others, it still sent a large portion of its paper waste to landfills.

What can be done to increase recycling and composting?

Residents:

Nashville plans to start picking up curbside residential recyclables every two weeks beginning as early as next year, thanks to a grant the city recently received. Today, recycling trucks come only once a month. Officials hope the change will reduce the amount of recyclables residents are currently throwing away when their recycling bins overflow.

Also, cities need to do a better job educating residents about recycling, said Rebecca Caldwell, the solid waste program manager at the Greater Nashville Regional Council. Plastic containers, for instance, have to be completely clean, or they get tossed.

“If you don’t clean out your peanut butter jar, it takes the scenic route to the landfill,” Caldwell said. “Ultimately people want to do the right thing. ... they just don’t know the rules.”

One immediate action that residents can take is to stop placing plastic bags in curbside recycling bins. Plastic grocery bags can typically be recycled at supermarkets, but not through municipal recycling pickup.

Recycling:Plastic bags, pizza boxes and other ways you may be messing up your recycling

Businesses:

Sharon Smith, assistant director of Metro Nashville Public Works, said that small and medium-size businesses could recycle much more than they currently do: “If every business recycled the paper they generated, we’ve have a huge decrease in the amount we landfilled.” One solution would be to get a smaller trash dumpster, she said, which would reduce trash collection cost and encourage recycling.

Construction/demolition:

Also, construction crews can do a better job of recycling or reusing materials, particularly as buildings are torn down around Nashville, Smith said. They can recover scrap metal, concrete, rebar, wood and bricks. Some of the largest projects downtown already recycle, but the challenge is spreading the practice to smaller construction sites.

Doing stories that make a difference in our community takes time and resources. A digital subscription to the Tennessean helps support that effort and gives you unlimited access to reporting from throughout the USA TODAY Network. Click here for a special offer.

Reach Mike Reicher at mreicher@tennessean.com or 615-259-8228 and on Twitter @mreicher.