April 1, 2004

7 Min Read


MONITORING YOUR LANDFILL and meeting today's environmental regulations can sometimes be a complex and confusing adventure. Federal, state and local laws require landfills to install, operate and maintain a variety of environment control systems — and adhere to the monitoring and reporting programs for these systems. Dealing with multiple entities responsible for the differing programs can be complicated and time-consuming.

As a result, the interaction and interdependence of the systems often is overlooked. Uncoordinated efforts can lead to environmental problems, regulatory violations or a failure in remedial techniques. If landfills appoint a single manager to supervise and communicate all monitoring activities, they often can avoid unnecessary costs and more efficiently manage their environmental compliance programs.

A Myriad of Players

Today's landfills include numerous environmental control systems and monitoring programs for liquids, gasses, cover maintenance, etc. that are frequently treated by landfill managers as independent systems. Separate departments may be in charge, often resulting in several consultants and contractors at a single site.

Such systems include, but are not limited to:

  • Grass, grounds and final cover maintenance;

  • Ambient air and explosive gas monitoring;

  • Migration probe and barhole monitoring;

  • Surface emissions monitoring;

  • Landfill gas (LFG) collection and flaring system;

  • Leachate collection and treatment system; and

  • Water and leachate sampling, analysis and data management/statistical analysis.

The personnel performing separate environmental tasks at a single site are unlikely to completely understand each other's responsibilities and roles. Workers from one department may lack incentives or instructions to share what could be crucial information with workers responsible for another environmental system.

For example, a consultant performing New Source Performance Standards (NSPS) surface emissions monitoring may not know that the LFG collection operator has shut the system down for routine maintenance or repairs. If NSPS monitoring occurs when the LFG collection system is down, unnecessary compliance issues may arise. Also, if one entity tests LFG migration probes and either delays or fails to transmit the information to the LFG collection system operator, this could result in prolonged offsite LFG migration.

However, if a single technical manager is responsible for all the systems, then the interaction of one system to another can be easily monitored.

Understanding the Puzzle

A single manager is useful in ensuring all environmental compliance programs and personnel are working in tandem. If a problem arises in one system, the manager can more closely watch the effects on other dependent systems. When a manager is acutely aware of all the ways systems interact, then he can more effectively implement optimal solutions while considering the impacts on all systems.

Field technicians also can benefit from knowing the interdependence of environmental systems. If a technician is cross-trained on all environmental systems, decisions made in the field can be more effective. Problems with a leachate recovery system, for example, should prompt the cross-trained technician to pay more attention to the potential negative effects on the LFG collection system. System adjustments could be made, or monitoring events rescheduled, to avoid unnecessary regulatory violations.

Addressing Issues

As a striking example of the interdependence of all landfill control systems, consider the routine maintenance of grass, grounds and final cover. Improperly maintaining these areas can create one or all of the following compliance issues in seemingly unrelated environmental systems:

  • Missing or lost environmental monitoring component (e.g., LFG monitoring probe, LFG extraction well, groundwater monitoring well, etc.) due to overgrown vegetation or soil erosion. A missing monitoring component can cause problems with regulatory reporting requirements, squander expensive field labor in locating components or cause costly misinterpretation of data due to missing information. Replacing or repairing lost or damaged monitoring components is wasteful and expensive.

  • Creating pathways that allow gasses to escape through the landfill surface or air that can intrude into the landfill. Poorly maintained landfill caps (i.e., caps with cracks or fissures) can more easily emit methane gas concentrations above compliance limits and/or create odor complaints. Cracks and fissures also can allow air to be easily drawn into the landfill by active LFG collection systems. In extreme cases, when the landfill cover and LFG collection systems are both improperly maintained and operated, subsurface combustion can occur. This typically results in intense regulatory involvement, severe damage to several environmental compliance systems and costly combustion suppression activities.

  • Creating pathways that allow leachate to escape from the landfill or rainwater to infiltrate the landfill. Leachate escaping from a landfill can result in public nuisances and unwanted regulatory involvement. Rainwater infiltration creates more leachate and potential groundwater contamination problems.

Conversely, a properly maintained landfill cover can have an unwanted effect on LFG monitoring probes by inhibiting LFG emissions through the surface and promoting lateral migration. This also can lead to violations at LFG monitoring probes or safety concerns within onsite or neighboring structures.

Uncollected LFG

If a site's LFG collection system is not properly designed, installed, operated or maintained, there is a high probability that environmental compliance issues will arise, including NSPS violations, “hot” migration probes, etc. Additionally, uncollected LFG can create detrimental conditions in other environmental compliance systems or programs. These conditions can lead to compliance and regulatory headaches, needless expense, and even injury or loss of life. For instance:

  • Protective vegetation may be harmed by displacing oxygen within root zones of site soils.

  • The landfill could be “pressurized,” leading to damage of the final cover (especially synthetic liners) and/or liquids could be forced out side slopes of the landfill.

  • A public nuisance could be created by malodorous gas emissions.

  • Groundwater contamination above regulated limits (commonly with volatile organic compounds) could occur.

Liquid Control Systems

A site's liquid control systems (e.g., leachate recovery, surface runoff, etc.) can affect the performance of other environmental control systems, too. Besides affecting groundwater compliance issues, uncollected liquids within or entering the landfill can:

  • Flood LFG monitoring probes if liquids leave the site by an improperly maintained leachate recovery and containment system. If uncontrolled surface water runoff accumulates near an LFG monitoring probe, flooding also can occur. Missing data from inaccessible LFG monitoring probes can cause costly misinterpretation of data.

  • Flood LFG collection wells if leachate recovery and containment systems are improperly maintained and operated. This can cause a domino effect: First, LFG can migrate offsite and through the surface, resulting in regulations violations. Then, the LFG can contaminate groundwater, pressurize the landfill, damage the cover, etc.

  • Transport particulate material into the gravel/filter pack of LFG collection wells. The continual movement of particulate-laden liquid within the landfill will eventually clog the filter pack surrounding the perforated section of the LFG extraction well. Over time, this will “silt in” the well, reducing LFG collection. Re-drilling new LFG extraction wells is expensive and time-consuming. An inexperienced technical manager may be unaware of what caused this condition and of promising new technologies that could cleanup the silting problem.

Because environmental compliance is complex and requires close supervision and monitoring, it is best left to one entity solely dedicated to the task. This managerial staff person should have first-hand experience of the systems' interdependence. Then, technical staff should be cross-trained to be sensitive to interactions among the control and monitoring systems.

If a landfill outsources management to a contractor, the vendor's qualifications should be checked to ensure that he has access to all necessary specialties and to a staff that is cross-trained in all aspects of landfill monitoring and environmental control as well.

Jim Bier is division vice president of field services for EMCON/OWT Solid Waste Services, San Jose, Calif., a subsidiary of The Shaw Group. E-mail: [email protected]. A version of this article was presented at SWANA's WASTECON 2003.

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