Offsite odors, foresight in sizing infrastructure and lack of comprehensive leachate monitoring rank as top concerns.
Three, mission-critical issues threaten the operational efficiency of solid waste landfills and even endanger business continuity. Foremost among the issues is controlling odor, the telltale sign of a landfill’s gas emissions. As four-letter words go, odor can run afoul of a landfill’s community goodwill, eventually souring operations.
Another issue is poorly sizing landfill infrastructure for future growth. This creates expensive redesign and rework to re-achieve efficient operation and ensure regulatory compliance.
The third issue—inadequate leachate trending and monitoring—can fail to accurately identify surface and subsurface changes, and ultimately, require significant, costly remedial action.
The Nose Knows
Offsite odor is the most critical issue affecting a landfill’s good community relations. Not methane or other gases, but smelly sulfides and acid ammonia that offend the nearby neighborhood residents. Today, a landfill’s future is directly impacted by its ability to control odor.
Releasing odors is one of the quickest ways a landfill can make headline news, and lose control of its destiny. Hyperbole? Hardly. Communities near a landfill in the Midwest filed and won a class-action lawsuit complaining about odors. Regulators assessed a $2 million fine and required more than $500,000 in odor misting and suppressant systems be installed. They denied the landfill operator’s request for permit changes regarding sludges and bio-solids. The fatal blow to business continuity, though, was ordering the operator to stop accepting waste and to close and cap the landfill. Regulators made clear a key factor in their decision was the communities’ concerns about odor.
Unfortunately, the above outcome is not an isolated incident. Another landfill had to install $1.3 million in odor control equipment to quell community complaints about smelly air. It was not completely successful, as nearby residents continued to oppose the landfill operator’s request to expand capacity for fear of additional stink.
More landfills could be on the precipice of a public relations nightmare. While they were originally sited in rural, undeveloped areas, more and more landfill operators find their facilities now surrounded by new housing. There is literally little room for error in odor control.
Most operators, of course, see the value of being a good neighbor. Some, however, pay less attention to odor control, which can increase pressure and scrutiny on all operators. The stakes then become even higher. Responsible operators often consult with an engineering firm, making certain they consider short and long-term solutions and strategies.
The preemptive solution is to proactively capture and collect gas byproducts of decaying waste. Managing a landfill’s cover to prevent gas from escaping is one of the easiest ways to accomplish this. Soil, soil-like matter or an odor-control blanket (tarp) make effective covers. Shrinking the working face and adopting more efficient compaction techniques complement effective cover management. These measures not only help contain gases, but they also minimize stormwater infiltration. Rain entering the landfill can substantially augment gas production.
Optimally, good odor control begins with good, active gas extraction design that prevents odor emissions in the first place. Front-end design costs represent a fraction of redesign and rework costs to install expensive collection systems for an existing facility. It is critical to stay ahead of the curve by designing with the future in mind to accommodate growing waste volume and consequent odorous gas production, especially since landfills are generating gas quicker today—now taking only one and a half years, rather than the traditional four to five years. Otherwise, when a landfill unleashes odors, operators should expect mandatory changes in operations, or installation of expensive gas management systems like the ones mandated for the landfills in Pennsylvania and Virginia.
Long-Term Performance
Good front-end design with an eye on future requirements not only helps prevent onerous odor issues, but it also helps ensure facility infrastructure is right sized for the life of the landfill. Poorly sized infrastructure impairs efficient operation and regulatory compliance long term, and encompasses expensive redesign and rework for continued landfill operation.
The key is to prevent problems in the first place. Following accepted engineering standards in designing landfills is one approach, although they tend to be rigid and set a low bar for minimum performance requirements.
Another approach is to focus on long-term landfill performance that recognizes landfill growth, increasing gas and leachate generation, and the evolving performance requirements needed to satisfy those demands. This approach can actually surpass regulatory requirements because it is forward thinking. It also provides a measure of protection for landfill operators since the facility is better prepared to handle unforeseen issues and the resulting liability. Going above and beyond minimum standards also helps assure skeptical communities that the landfill will be a good neighbor.
An example of going above and beyond is specifying robust control infrastructure capable of managing quantities of gas and leachate that exceed the facility’s initial design standards. Right sizing infrastructure also means accommodating wear and tear from operations. I’ve seen leachate drainage pipes crushed by the weight of waste that exceeded the landfill’s original engineering design criteria. Traffic from large waste trailers has collapsed drainage pipes that ran under road crossings.
Although seemingly mundane, these issues obviously can cripple a landfill’s environmental compliance. The front-end solution would be to install thicker-walled pipes or pipes made of PVC rather than HDPE. Although HDPE is stronger than PVC, PVC has superior pressure and temperature capacity for design stress. For a given pressure rating, HDPE pipe walls must be 2.5 times thicker than PVC pipes. So material selection, in addition to proper sizing, can help ensure long-term performance when performance has priority.
During day-to-day operation, landfill operators can monitor infrastructure systems to identify potential issues and correct them when planning future phases of landfill operation. Critical systems demanding close attention include control of odor and gas emissions, leachate management and surface water. Onsite traffic patterns, structures and utilities also should be monitored.
All’s Well That is Monitored—Hopefully
The problem with leachate monitoring, however, is that not all landfills are studying or trending quality as well as quantity. Operators run the risk of failing to accurately identify changing characteristics/chemistry, which could ultimately require significant, costly remedial action. Not to mention the negative appearance to the community.
From the simplest approach, knowing that the makeup of the leachate is starting to change will allow time for conversations with the local publicly owned treatment works (POTW) where the leachate is being disposed. These early conversations may result in a joint upgrade to the POTW instead of the facility being forced into building a costly pre-treatment plant. Not only is that better for the landfill, but it is also usually beneficial to the community where the landfill is located.
From a complicated approach, many of the “reaction landfills” we read about in the press showed signs in their leachate prior to the “breaking news.” Hindsight is always 20/20, but maybe a little more time and effort trending quality could have saved a lot of effort after the fact.
In addition, new clean water legislation in the last five years further restricts what wastewater treatment plants can discharge and in turn affects landfill discharge limits. Meeting nitrogen-phosphorous limits, for example, make it difficult to remain in compliance. So it is more than housing developments that are closing in on landfill operators. It is also stricter regulatory limits and tighter operational processes.
Liability Aversion
The common thread weaving through the three issues of controlling odor, right sizing landfill infrastructure and comprehensive leachate trending is liability aversion. Incurring liability is expensive—more expensive than effective odor control, building for long-term performance and thoroughly monitoring leachate.
Landfill operators will never make more money than what they spend recuperating from a PR nightmare, paying million-dollar attorneys’ fees or remedial activities. It is less expensive to do it right the first time.
But problems do happen. Operators are best advised to attack them early and proactively. The purpose of this article is to remind operators to strike preemptively. Otherwise, they will be scrambling, taken out of the driver’s seat by events, never to sit back in it, with their facility grinding to a halt.
Chris Jaquet, PE, leads the T&M Associates (Middletown, NJ) national solid waste services business. He has overseen the operation of Republic’s Eastern Ohio and Western Pennsylvania territories. At T&M, he provides expertise in operations, financial risk management and technical services to help both public and private clients address their transfer, disposal, recycling, composting and recovery challenges through economical and reliable solutions that will improve operational efficiency. He is based in T&M’s Cleveland, OH office. Chris can be reached at [email protected].