Times Changing for Solid Waste Transfer Stations

As municipalities continue to reduce waste and increase recycling rates and commercial producers are eyeing zero waste, the operations at transfer stations, too, are changing.

After all, the waste stream itself over the past decade has changed, says Chaz Miller, state programs director for the National Waste & Recycling Association (NWRA). Paper generation is down by 18 million tons since 2002. Virtually all of the decline has come from printed grades of paper, including newspapers and magazines, as we increasingly use electronic media to transfer knowledge instead of print media.

It’s the “evolving ton,” a phrase coined by Republic Services to describe changes in the waste stream itself over about the last decade. Another issue, Miller says, is the light-weighting of the waste stream, in terms of packaging and plastics.

“The input of the recyclables is both lighter and heavier. It’s lighter because you have more plastics and it’s heavier because you have more glass. And both trends create impacts on processing because a lot of processing is weight-based.

Electronics recycling programs also are feeling the effects thanks to lighter electronics causing lower tonnage. A smartphone, for example, replaces a separate phone, camera, Walkman, video camera, pager and more.

Commercial producers, too, are looking at waste reduction in their processes. Hormel Food Corp., in Minn., for example, in 2013, diverted 1,000 tons of solid waste from landfills, and eliminated 4.72 million pounds of packaging.

“That’s just material they don’t need to buy any more,” says Miller. “That leads to the evolution of a ton also because if they don’t need to buy that material any more to make their product, that means there’s less to recycle or less to dispose of. Either way, it’s less.”

The waste stream, however, has been consistent since 2009.  “That tonnage has been pretty flat because of the evolution of the waste stream—because of the decline of paper, because of increased light-weighting, because of zero waste,” Miller says. “But people are still making solid waste. And that waste still needs to be managed in recycling centers, transfer stations, and at landfills and disposal facilities.”

It’s difficult, says Karl Hufnagel engineer at Brown & Caldwell, to differentiate between the growing emphasis on diversion, the impact of volume or tonnage going through transfer stations and the economic downturn in 2009 and its ensuring slow recovery.

In the northwest, Hufnagel says, there is a definite push for diversion of materials from the municipal solid waste stream that typically is heading to landfills.

There also is robust curbside recycling where there is a certain amount of separation by residential and commercial customers.

“As those programs have grown,” he says, “they have siphoned off material going to transfer station. That combined with the economic downturn has resulted in a reduction in tonnage going through the stations.”

That, Hufnagel says, has left many of the more progressive agencies scratching their heads and wondering what the future looks like and how agencies should be configuring or reconfiguring transfer stations to get at residual recyclables still finding their way into the waste stream.

“The direction we see is for public agencies to become much more active in trying to tap into diversion both with enhanced programs for the collection system where they’re getting it at the source already separated, and then through educational programs and the collection programs as well.”

Some are getting it right.

In 2011, Hawai’i County spent $3.9 million to repurpose the Pahoa Recycling and Transfer Station. The solar-powered facility encourages recycling and is built to help residents efficiently divert waste, says Greg Goodale, chief of the county environmental management solid waste division. It’s laid out to feature the recycling and special waste areas first and trash drop off last.

“That’s a pretty successful approach and it reflected the interest in maximizing material recovery,” says Hufnagel.

King County, Wash., is actively exploring and implementing material diversion in its transfer station through pilot projects diverting material as it comes through the door at its Bow Lake Recycling and Transfer Station. The 2,400 ton-per-day facility has an enclosed, long-span transfer building designed to protect self-haul customers from high-volume waste handling while allowing selective material recovery and baling.

An automated traffic management system regulates traffic through four vehicle scales, allowing independent re-weighing of mixed loads headed for both the transfer building and the dedicated yard waste and recycling area.

The facility was designed for on-floor diversion, says Hufnagel. setting aside floor space, to give the county the ability to separate out and bail materials including cardboard, film plastics and scrap metals, typically coming from commercial customers sending recyclables out as trash.