Orphan Landfills Contain Unregulated Hazards

Wes Gavett EMCON/OWT Solid Waste Services Portland, Ore., and Tim Spencer Oregon Department of Envir

Orphan landfills don't have “parents” — that is, they don't have a viable owner or responsible party. Considering the potential dangers to public health and the environment, it is surprising that orphan landfills are not better known. Many solid waste professionals have never encountered or worked with an orphan landfill.

An orphan landfill may contain any type of solid waste, including hazardous waste. These sites tend to predate today's federal regulations (Subtitle D) and never had adequate financial assurance or post-closure monitoring. To make matters worse, an orphan landfill's hazards are like booby traps — out of sight, lurking underground or under blackberry bushes. They may contaminate groundwater or expose citizens to physical hazards or to methane gas — often the most dangerous consideration.

Furthermore, a regulatory remedy for the potential risks is not always obvious. Subtitle D left the regulation of non-Subtitle D landfills to the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), which guides the cleanup of sites contaminated with hazardous substances.

Unfortunately, methane gas is not considered a hazardous substance under CERCLA. As a result, states may lack clear authority to regulate methane at old, closed or abandoned landfills, or at other non-Subtitle D sites. Oregon is one of those states.

An orphan landfill in Portland, Ore., offers an example of how these sites can contain unexpected problems and require creative solutions.

The Killingsworth Fast Disposal (KFD) Landfill, Portland, Ore., is surrounded by light industrial and modest residential areas. From the 1950s through 1980, the site was operated as a sand and gravel mine, covering 26 acres and excavated to an average depth of about 60 feet. Once the sand and gravel were depleted, the site became a special waste landfill that accepted construction, industrial and non-putrescible municipal waste when the city's landfill was not open or during peak waste periods.

At the time, the KFD landfill was state-of-the-art. Its base was shaped and sloped to a central collection point where a concrete pump station was installed. The bottom of the excavation was lined with a 6-inch layer of compacted soil amended with bentonite. A layer of sand and several perforated leachate collection pipes were installed over the soil liner and connected to the pump station. The near-vertical sidewalls were covered with a polypropylene liner. The geosynthetic liner panels were not seamed but were intended to form a barrier to prevent liquid from escaping the pit.

The site reached capacity in 1990. The site's owners then obtained a closure permit from the Oregon Department of Environmental Quality (DEQ), Portland, Ore. The landfill was capped with a 30-mil polyvinyl chloride (PVC) liner and several feet of soil. A rudimentary landfill gas (LFG) extraction system was installed, consisting of vertical extraction wells, aboveground transmission piping and blowers to extract the gas and vent it to the atmosphere.

Several years later, the parent company filed for bankruptcy. DEQ joined the bankruptcy proceedings to secure funds to maintain the KFD landfill during post-closure. Eventually, the bankruptcy court awarded DEQ a nominal settlement and placed the funds in an escrow account. But the money was not sufficient to maintain the KFD facility during the post-closure period.

Between the bankruptcy filing and the settlement, post-closure operation and maintenance activities ceased. The LFG control system's blowers and condensate management system did not receive regular maintenance. The exposed LFG transmission piping expanded and contracted with changes in temperature, causing cracks in the pipe and separation at the pipe joints. The lack of routine maintenance also caused several subsurface fires at the LFG extraction wells. The result of this neglect was a system that did not adequately control the LFG at the site.

DEQ began a review of the environmental control systems. They focused particularly on the LFG control system, which was experiencing intermittent system failure and extended downtime. When this occurred, methane concentrations would rise at the perimeter of the site, with concentrations as high as 50 percent detected during one period of extended system failure.

DEQ's audit found that the LFG control system required a major overhaul. But the limited funds available made this impossible. Although the state's Solid Waste Orphan Site Account, dedicated for cleanup of hazardous substances, had sufficient funds, the KFD landfill appeared to be ineligible because methane was not considered hazardous under state or federal (CERCLA) rules.

Ultimately, a rarely used provision in Oregon's statutes enabled DEQ to designate methane a hazardous substance at the KFD Landfill, albeit temporarily. This provision enables Oregon's Environmental Quality Commission to adopt rules designating other substances as “hazardous substances” in addition to the statutorily defined hazardous substances. Before such designation, however, the commission had to find that the “substance, because of its quantity, concentration, or physical chemical or toxic characteristics, posed a present or hazard to human health, safety or the environment should a release occur.”

At KFD, methane gas clearly met the statutory criteria. Armed with this statute, DEQ recommended that the commission establish a temporary rule designating methane a hazardous substance under the conditions found at the KFD landfill. The commission approved the rule and DEQ was able to fund construction of a new gas control system and improvements, at a cost of approximately $1.2 million.

The rule did not affect Oregon's operating or permitted landfills because, by its terms, it applied only to abandoned facilities. Oregon recognizes the need for a long-term solution to the “methane loophole” and is studying ways to improve its solid waste and hazardous substance regulations.

Not surprisingly, states vary widely in how they deal with this problem. Some expand their solid waste regulatory authority, at least where methane is concerned, to all landfills including unpermitted and abandoned sites. Others define methane and other flammable gases as hazardous substances in their hazardous substance cleanup regulations. Still others incorporate elements from both strategies.

Today, the KFD landfill still is a work in progress. But by using the temporary rule provision, the Oregon DEQ received the critical funds needed to design and construct a new LFG control system for the facility. The new system went on-line in March 2000.

The city of Portland also has offered to acquire the site, reimburse DEQ for a portion of the LFG system installation costs and take responsibility for post-closure care. Best of all, once the site is safe for public use, the city plans to turn the site into a neighborhood park.

For more information, e-mail Wes Gavett at [email protected], or Tim Spener at [email protected]. For more information about landfills, visit www.wasteage.com.