Nothing has quite caught the attention of regulatory agencies as the March 12, 1996 promulgation of the landfill emissions rule. With its close tie-in to immediate Clean Air Act reporting requirements, various interpretations for determining landfill applicability, and the allowance for states to develop more stringent versions of the rule, the landfill gas (LFG) industry is seeing both increased costs and rapid developments of the "rule book" for landfill emissions compliance.

The intent of the New Source Performance Standards (NSPS) and Emission Guidelines (EG) is to reduce emissions of landfill gas, which is composed of NMOCs and methane. Compliance requirements are based on the design capacity of the landfill and its NMOC emission rate (tons per year) calculated by the EPA Landfill Emissions Model.

Landfills that exceed the NMOC emissions limit are required to install a LFG collection system to extract and combust LFG (e.g., in a flare, boiler, or engine generator). Operations, monitoring, record keeping, and reporting for the installed collection system must be in accordance with the stated requirements. Specific provisions of the NSPS and EG are summarized below:

  New Source Performance Standards (NSPS)

• Applies to all "new" landfills. A new landfill is defined as each municipal solid waste (MSW) landfill that started construction, or began initial waste acceptance on or after May 30, 1991. An existing landfill modification (i.e.. a lateral expansion) that occurred between May 30, 1991 and March 12, 1996 also subjects the whole landfill to the NSPS.
• Within 30 months after an MSW landfill calculates an NMOC emission rate >50 megagrams (Mg) per year, the provisions of the rule require installation and start-up of a gas collection and control system at the landfill.

  Emission Guidelines

Emission guidelines include all "existing" MSW landfills that satisfy two conditions:

• The landfill received waste on or after November 8, 1987 or has additional permitted capacity which may be filled in the future; and
• The construction, modification, or reconstruction of the landfill began before the proposal date of May 30, 1991.

The requirements of the emission guidelines are almost identical to those of the NSPS. Distinguishing characteristics of the EG and NSPS are as follows:

1. Applicability criteria are for "existing" landfills;
2. There is flexibility for a State- implemented emission standard;
3. States need to develop a plan to implement the requirements of an EG; and
4. There are different landfill compliance schedules for a state-implemented emission standard. A state has up to 9 months to address EG requirements within its state plan. The EPA has 4 months to review the plan changes. The EG becomes effective upon EPA's final action on the plan.
5. The EG implementation schedule is similar to that of the NSPS:

   - Capacity and Emission Reports within 90 days of the EG effective date.

   - Design Plan within one year of the NMOC Emission Report.

   - Start-Up within 30 months of state plan approval by U.S. EPA.

  Title V Operating Permits

Any facility with a design capacity exceeding 2.5 million Mg must obtain a Title V operating permit, whether or not the 50 Mg per year NMOC threshold is exceeded.

SCS Engineers is an environmental engineering and consulting firm with offices throughout North America. The firm has been a pioneer and leader in the landfill gas industry since 1970, and includes among its clients numerous landfill owners and operators.

Technical Bulletins are prepared by SCS Engineers to alert clients to potential issues that can affect their businesses. For more information on how SCS Engineers can assist you, call Jim Walsh at (513) 421-5353.