Problems with disposing construction and demolition debris cannot remain buried forever. Although C&D debris composes 15 to 30 percent of the municipal solid waste (MSW) stream, historically little information exists at the national level. And, up until now, it doesn't fit neatly into a regulated category.
However, environmental concerns and diminishing land availability is pushing C&D disposal to the legislative forefront. In fact, the U.S. Environmental Protection Agency (EPA), Washington, D.C., has finalized new regulations, while many states have adopted specific regulations for C&D wastes.
In The Beginning ... In 1976, the EPA was required by the Resource Conservation and Recovery Act (RCRA) to develop standards and guidelines for solid waste management.
In response, the EPA produced Subtitle C covering facilities generating more than 1,000 kilograms per month (kg/mo) of hazardous wastes, but conditionally exempts facilities that generate less from full regulation, and Subtitle D for all other solid wastes, including C&D.
In 1984, Congress passed the Hazardous and Solid Waste Amendments (HSWA), which created two categories of small quantity hazardous waste generators: generators of 100 kg/mo to 1,000 kg/mo and generators of less than 100 kg/mo.
HSWA added specific provisions for the first category, and the EPA defined generators of less than 100 kg/mo as conditionally-exempt small quantity generators (CESQGs), responsible for the proper management of their wastes, but exempt from many Subtitle C regulations.
CESQGs can send their wastes to different types of Subtitle D facilities including C&D landfills. But because of the minimal federal CESQG waste regulations, along with the lack of separate C&D landfill regulations under Subtitle D, these landfills were not subject to much federal supervision.
Enforcement of C&D landfill rules was left to the individual states, which, in turn, often delegated this responsibility to local boards of health or other local agencies.
C&D waste was considered relatively inert, especially compared to MSW. As a result, C&D landfill tipping fees were comparably less ex-pensive. Meanwhile, enforcing MSW landfill regs became a higher priority.
Although several types of materials are found in the average C&D load, results of a recent study show that certain elements can negatively affect public health:
* treated wood can contain heavy metals such as chromium, copper and arsenic;
* pigments of old paints can contain high levels of heavy metals including lead, chromium and barium;
* drywall and plaster consist of gypsum, which contains high levels of sulfate; and
* some types of roofing tar contain leachable petroleum products.
Several studies on C&D show that landfill groundwater can become contaminated. Although the levels were less than those found in typical MSW leachate, the groundwater surrounding C&D landfills can be contaminated enough to warrant a liner and leachate collection system.
Other C&D landfill problems include: poor inspection; disposal of non-C&D debris; and the presence of small amounts of material, such as solvents and oil, that could be stored in demolished buildings.
Prompted by these study results and knowledge of poor practices at some C&D landfills, the Sierra Club sued the EPA in October 1993. They wanted the EPA to revise CESQG final disposal regulations for non-municipal facilities, alleging that the agency had left loopholes in C&D landfill regs.
Eventually, the EPA and Sierra Club agreed on proposed new regulations requiring the upgrade of all C&D landfills to the statutory minimum requirements of RCRA which include location restrictions, groundwater monitoring and corrective action.
The EPA received a number of both positive and negative responses to these proposed regulations, which were published in the Federal Register on June 12, 1995 (60 FR 30964). Because of the varied responses, the EPA conducted further research on the effects of C&D waste before announcing the final revised regulations on June 28, 1996.
Here, the EPA states that "given the lack of data suggesting that C&D facilities pose the same risks as MSW landfills and that most states already require additional regulatory controls, the EPA does not believe it is appropriate to establish requirements that go beyond the statutory minimum requirements." The agency concluded that C&D landfills "present a small risk relative to risks presented by other environmental conditions or situations."
In the final regulation, the EPA acknowledges their concern about C&D landfills' risks in their earlier draft rule. However, they indicated in the final rule that, at that time, they did not have sufficient information to make this assumption.
The location restrictions imposed by the EPA mirror those already established for MSW landfills and will take effect on January 1, 1998:
* disposal sites in 100-year flood plains must demonstrate that a flood will not cause solid-waste wash-out;
* C&D landfills may not be located in a wetland unless the owner/operator can demonstrate that state water quality standards and the wetland will be protected; and
* An existing affected landfill that cannot show it will protect the floodplains will not be allowed to accept CESQG hazardous waste for disposal 18 months after the publication of the final rule.
Converse to MSW restrictions, the C&D rule does not set airport safety restrictions because the disposal sites do not handle wastes likely to attract birds, which could be an aircraft hazard.
The regulations are somewhat flexible, however. While sites must conduct groundwater monitoring while active and for 30 years after closure and must include monitoring wells placed up to 150 meters from the unit boundary, they can decrease the monitoring period after closure if the C&D landfill owner/ operator shows that a shorter period is adequate to protect human health and the environment.
All states - except those whose programs exceed the federal regulations - are required to adopt the new federal regulations within 18 months of the final rule's publication.
Despite the EPA's assertion that uncontrolled land disposal of C&D waste is not a threat to human health or the environment, other solid waste experts are not convinced. Out of 48 states that have separate regulations governing C&D landfills, 13 require that C&D landfills meet MSW regulations. Forty-four states specify final cover thickness, and 34 states require post- closure care.
Prepare Yourself As the potential effects of C&D waste on human health and the environment are publicized, the safety debate will continue. As a result, regulations governing disposal will continue to vary from state-to-state.
Subsequently, in order to comply with regulations, it has become important for C&D generators, disposers and landfill operators to become familiar with the new state regulations. For more information, contact your state environmental authority or board of health.