The Solid Waste Association of North America (SWANA) released a policy in January 2020 regarding the care of landfills once the post-closure care period has ended.
That policy, “Technical Policy 9.4—The Long-Term Management of Municipal Solid Waste Landfills,” dictates that landfill owners and operators should be responsible for some upkeep in order to preserve the public’s wellbeing. The policy also says there should be a process to end long-term management obligations when site-specific monitoring data shows organic or functional stability with the final cover system in place.
Specifically, the policy advocates for three positions:
- Following termination of the regulatory post-closure care period, as recommended in T-9.3 Termination of Municipal Solid Waste Landfill Post-Closure Care Requirements, there should be provisions or institutional controls satisfactory to state, provincial or local regulatory agencies to provide long-term management for closed landfills to ensure the final landfill cover system and other environmental control systems are effective in continuing to be protective of human health and the environment. These provisions may be developed through instruments, such as deed restrictions, environmental covenants (such as those in compliance with the Unified Environmental Covenants Act), and/or a maximum of standard landfill regulatory oversight, to be determined on a case-by-case basis, based in part on the risk potential of the landfill.
- Regulatory agencies and the landfill owner/operator should recognize that there are potential costs associated with facilities in long-term management, including but not limited to, inspections to verify the integrity of the landfill cover system and other environmental control systems, and/or corrective actions. Provisions identifying responsible parties for these costs should exist on a case-by-case basis as determined by the regulatory agency, landfill owner/operator, and/or host community, as applicable.
- The long-term management of a landfill facility may cease provided all parties involved (owner, municipality and state and provincial regulatory agencies) agree that based on site-specific data, that the organic or functionally stabilized waste mass poses an acceptable level of risk to potential receptors.
SWANA’s policy was developed, in part, to provide some cohesion among state laws that can vary significantly regarding post-closure care.
“Some states had organic stability measures put in place, some states had functional stability requirements put in place,” says Tim Mitchell, former division director of SWANA’s Landfill Management Technical Division and current senior project manager with Civil & Environmental Consultants Inc. “The overwhelming majority had no requirements except Subtitle D.”
In the United States, federal Subtitle D landfill regulations were introduced in 1991. Since then, few regulatory agencies have established guidance or funding requirements for long-term management of landfills after the completion of post-closure care periods.
SWANA’s policy was put in place to determine the need for individual sites, and as such, took some time and effort to draft. Mitchell says there was a good deal of planning and consulting with outside sources during the draft process to make sure the policy covered the right bases.
“We took all external feedback into consideration, and we also consulted with the Environmental Research and Education Foundation (EREF), which is a good source of industry-driven research,” he adds.
Mitchell says EREF produced a functional stability model that demonstrated what needed to be evaluated and identified when a landfill had come to the end of its post-closure care period.
In regards to individual landfills, Mitchell says site-specific data can help inform what measures might be required for sufficient upkeep.
“I think if you were looking for specific data to evaluate, [you should be looking at] the groundwater monitoring data, the landfill gas data, leachate, and stability and cover integrity,” he says.
Mitchell adds that landfill operators should assess the data trends that have developed over time to help inform them of actions that may or may not be necessary. He says information related to groundwater, leachate and landfill gas will show trends, and if levels of emissions aren’t increasing (or have stopped altogether), that could impact the need for monitoring when that post-closure period ends.
“It doesn’t help a site operator to just start the process of data evaluation right at the end of post-closure care,” he says. “You can’t just say, ‘Hey, we’re at year 29 [of the landfill’s existence], let me show you this year’s data that points in the right direction.’ That analysis and that argument needs to be made based on years of prior information.”
How state regulations factor in
SWANA’s policy was drafted to be applicable nationwide. Since state regulations vary, Mitchell says SWANA’s policy can be a guide for all operators irrespective of location. This policy establishes a baseline of compliance that can offer direction for ensuring operators remain responsible for landfills until they are shown to be stable.
“The intent of this SWANA policy was to advocate [for something comprehensive since] every state has something different,” he says. “A lot of states really don’t have a formal policy as to how to evaluate the end of post-closure care.”
Mitchell says that if it’s determined through functional stability trends that the landfill is no longer a threat to human health or environment, operators wouldn’t be required to demonstrate their oversight anymore to SWANA.
“They would have to get [approval], of course, from each individual state regulator to make sure they’re on board with [adopting SWANA’s policy],” he says. “But they would no longer have to submit anything [to prove compliance].”
What this means for long-term care
Mitchell says this policy is important because there needs to be a standard in place to protect human health and the environment, and Subtitle D landfill regulations aren’t enough.
“Those [landfill care] expectations need to be set from both an owner and regulatory standpoint, and probably also an accounting standpoint,” he says. “Just so people know that after this post-closure care period is over, your obligations are not automatically relieved.”
Regarding the applicability of SWANA’s policy, Mitchell adds, “It establishes what the minimum requirements would be for maintaining care, and the SWANA policy is also general enough [to cover different sites in different locations]. If there are site-specific requirements that are necessary to be followed, the policy allows for that.”
Overall, Mitchell says the goal was for SWANA to establish a policy that covered all the bases but was general enough that state regulations weren’t ignored and could still factor into the long-term monitoring that was needed in each case.