With little direction from the federal government, each state regulates construction and demolition debris fills a little differently.
Alaska, unlike some in the Lower 48, requires no liners or test wells of fill operators. Central Recycling Services, the company proposing debris fills for Chugiak and Palmer, doesn't plan to line them but does plan to do wells.
Construction and demolition debris fills here fall under the category of "inert monofill" -- what regulators consider a uniform kind of waste with "a low potential" to pollute air or water.
The state already oversees 19 inert monofill sites from Homer to Nome and North Pole all the way out to St. Paul Island, according to Nate Emery, an industrial waste specialist with the Alaska Department of Environmental Conservation. Many hold construction and debris waste, including existing sites at Birchwood and Palmer.
State permits address distance from the water table - generally 10 feet - as well as slope stability and other environmental safeguards, said Emery. The municipality and borough will require a long list of conditions too.
Generally it's up to dump operators to police themselves and report any problems. The state conducts annual inspections. Local code enforcers respond to citizen complaints; local governments can enforce the terms of the conditional-use permit.
"These are engineered, designed facilities, not just open dumping in the foot of a gravel pit," Emery said. "It really does take a lot more than taking a truck to the edge of a hill and offloading it."
Some red flags, however, have surfaced in federal studies of debris dumps in other states, critics of the new Alaska dumps say.
In one example, a 2009 U.S. Environmental Protection Agency inspection program at 30 debris landfills in Ohio found suspected carcinogens such as arsenic, benzene and vinyl chloride, as well as lead, in water trickling through rubble, according to a story in The Columbus Dispatch at the time. The study stopped short of saying the water migrated off the dump sites to pollute adjacent groundwater or streams.
The federal Agency for Toxic Substances and Disease Registry has fielded reports of rotten-egg smells from debris dumps in a number of states, according to that agency. The source of that smell, hydrogen sulfide, can result from the breakdown of drywall in landfills, an ATSDR report states. "Investigations at some of the sites revealed hydrogen sulfide gas at levels known to cause adverse health effects, including headaches, nausea, and fatigue, and to exacerbate existing conditions such as asthma.
Other states have toughened debris dump laws or are in the process of tightening them. Many ban the disposal of asbestos-containing waste in debris landfills, according to a report by researchers at the University of Florida and the University of Michigan.
Alaska just revised regulations governing small, conventional landfills, Emery said. He didn't know of any immediate plans to do the same for debris dumps.