Heating Things Up

IN THE MIX. 2005 presented considerable challenges for mixed C&D recyclers in many parts of the country, as regulatory and environmental issues provoked questions within some end markets.

Speaking to attendees of the C&D World Conference, University of Florida researcher Tim Townsend reviewed controversies that have surrounded treated scrap wood and gypsum drywall.

In the case of drywall, the creation of malodorous (and potentially toxic) hydrogen sulfide (H₂S) gas in ground-up drywall has caused complaints from some users of alternative daily landfill cover (ADC) made from mixed C&D debris and of remediated soil (RSM) used to make berms and embankments.

The problem can be genuine and hard to deny when the rotten-egg odor begins to make its presence known, Townsend said.

He indicated, though, that the addition of certain materials might serve to stave off the creation of H₂S within ADC. Such materials can include concrete fines and lime, according to Townsend.

Additionally, the Construction Materials Recycling Association (CMRA) is working with the University of Florida to develop best management practices in the handling and sorting of mixed C&D materials to reduce the potential for H₂S problems.

Mixed C&D recyclers have also been striving to keep wood treated with chromated copper arsenate (CCA) out of their end products for several years, as the arsenic contained in CCA is undesirable in boiler fuel shipments and in mulch.

But the widespread damage caused by Gulf Coast region hurricanes is only serving to bring more treated wood into the stream in the South at a time when processors do not have the time or labor power to sort carefully.

FLOOD OF MATERIAL. Americans watched with disbelief as storm after storm struck the Southeast United States in the summer of 2005. Afterwards, cleanup crews, landfill operators and recyclers tried their best to clean up after the hurricanes.

Two government officials provided C&D World attendees with an update from the battered region.

Mark Williams of the Mississippi Department of Environmental Quality (MEQ) showed slides of the intense damage that occurred along that state’s Gulf Coast, including buildings flattened or reduced to skeletons, vehicles swept away into wooded areas and trailers from the Port of Gulfport—many of them full of commodities such as Dole bananas—swept inland well away from the loading docks and warehouses.

While recycling advocates may wish to see recycling become part of the cleanup scenario, Williams said bluntly, "Mixed debris piles really pose a problem for any kind of reclamation."

Fending off the health and environmental effects of rotting food and other decomposing materials or of engine oils and other fluids inside vehicles and machinery took top priority.

In Mississippi, where some 236 people died and some 65,000 homes were destroyed, Hurricane Katrina created an estimated 41 million cubic yards of storm debris.

Phase I of the cleanup involved addressing sewage and raw food concerns, while Phase II involved clearing rights-of-way and authorizing temporary debris collection sites, according to Williams.

In Phase III, some recycling began taking place, as abandoned appliances and vehicles began to be processed within the scrap metals recycling stream. Some vegetation debris was also processed, not only for disposal, but also for possible recycling.

Phases IV and V, currently underway, involve further cleanup and the eventual closing of the temporary collection sites.

Williams listed several obstacles to recycling in the post-Katrina environment, including the mixed nature of the debris, the presence of contamination (mold in particular) and the pressure to act quickly to clean up the damage.

Future recycling opportunities look brighter, however, particularly as landfills in the region have reached capacity.

Marcella Denton of the U.S. Army Corps of Engineers spent November and December in Mississippi, engaged in storm cleanup and debris removal.

As of December, Denton noted that debris was still on the ground in such hard hit towns as Pass Christian, Miss., and that many remaining structures are awaiting further repair.

On the positive side, the hurricanes could help spawn an infrastructure rebuilding boom that will help to heat up new construction activity, which has shown signs of cooling.

CONCRETE CONCLUSIONS. The single-family housing boom has been on an unprecedented roll that is likely slowing down, admits Edward J. Sullivan, chief economist with the Portland Cement Association, Skokie, Ill.

But in his presentation to attendees of the C&D World Expo, Sullivan predicted that what the overall construction sector loses in single-family development, it will probably gain back as commercial construction and public spending on highways rebounds.

The consumer sector, which Sullivan says now accounts for nearly 70 percent of economic activity in the United States, has buoyed the construction and demolition industries with frenzied spending on new homes the past several years.

Spending overall from consumers may slow down for a number of reasons, including increased energy prices and an exhaustion of home equity credit lines that have been spent to the maximum by many consumers.

Contractors, however, are benefiting from the passage of a new federal transportation bill in 2005, which has put into motion a number of projects in almost every state that were waiting for federal funding to come through.

Additionally, the solid consumer economy of the last few years has put money in corporate coffers, with businesses ranging from retailers, manufacturers and service providers such as hotel chains now flush with cash that is being re-invested in new projects.

Increased commercial activity, combined with renewed highway spending, is leading to building projects that are especially heavy in their use of concrete, steel and other heavy-duty materials. "For every $1 of construction activity now, we are using more and more concrete," Sullivan said.

TROUBLES IN NEW ENGLAND. Despite its key role as a sustainable activity, the recycling of C&D materials is facing serious environmental barriers in New England.