Waste Management provides solid waste collection services to nearly 20 million customers in North America — from households to public venues to large companies. All told, after recycling or diverting various materials for reuse, we safely manage the disposal of nearly 100 million tons of waste annually, including common municipal trash and highly specialized materials such as medical and industrial waste. To handle this volume, Waste Management operates the largest network of landfills in our industry and works hard to minimize the impact of those facilities on neighbors and the environment.
Modern landfills are the products of sophisticated engineering, providing both secure containment systems for the disposal of waste and the opportunity to capture value through the conversion of waste to energy. Waste Management’s modern landfills in the United States were developed under the federal Resource Conservation and Recovery Act (RCRA), which requires rigorous siting evaluation, site characterization and scientific engineering design, as well as a comprehensive permitting and regulatory approval process that includes public notification and comment. RCRA standards also require a range of measures to prevent environmental contamination, including the use of engineered liners and covers, collection and control systems for landfill gas, and collection and treatment systems for leachate (water that accumulates in and filters through waste).
Our modern sites are designed and operated to go beyond regulatory requirements. We continually monitor and work to improve the safety and environmental security of our disposal facilities and are committed to reporting the results of these efforts. We strive to avoid conditions that cause concern for neighbors and communities, including odors and noise, regardless of whether those conditions are covered in our regulatory obligations. We also work with waste sector experts to understand what happens within landfills after they are closed. Studies have shown that modern municipal solid waste landfills tend to improve predictably over time, steadily producing less gas and less (and cleaner) leachate. Many of our landfills are designed and managed to ensure they can be used after closure for commerce, industry or even conversion into wildlife habitat or public parks.
Surface and Groundwater
Waste Management’s landfills are living laboratories for testing new technologies to help us improve how we manage stormwater and leachate, and how we design and maintain landfill cover and gas collection systems. We test the effectiveness of new technologies at select sites before broadly employing them at all sites to enhance environmental performance and reduce operational costs. Waste Management utilizes extensive engineering controls and practices to protect surface water and groundwater. We maintain a comprehensive network of more than 6,000 groundwater-monitoring wells around our facilities, and every landfill uses monitoring strategies — many involving sophisticated statistical evaluations — to ensure that water quality in adjacent surface water and groundwater bodies is not impacted.
Our modern municipal solid waste landfill liners contain all liquids, which are then managed according to applicable regulations and design standards. We employ a staff of nearly 200 professional engineers, environmental scientists, regulatory experts and technicians who ensure that every facility works to protect surface water, stormwater and groundwater from any potential operational impacts.
We use managed basins, tanks, containment structures and separators to redirect liquids for proper disposal and treatment. We also monitor on-site wastewater treatment plants to optimize efficiency and utilize a toolkit of best management practices for our field operations.
Waste Management landfills collect and discharge millions of gallons of stormwater each year. The water must be managed to ensure it is clean enough to meet strict state requirements before being released to water bodies or public treatment plants. One new technology, called Terra-Tubes, has been successfully deployed at several landfills to reduce suspended solids in the stormwater. Terra-Tubes are made of engineered wood and man-made fibers encased in a heavy-duty, knitted cylindrical tube. The tubes are installed at stormwater outfalls and have been successful in slowing water flow to allow for settling and enhanced filtration of the water prior to discharging it off site.
Natural & Enhanced Leachate Evaporation
Landfills naturally produce leachate from a combination of the breakdown of waste materials and precipitation falling on the landfill. Leachate is typically stored on site in lined impoundments or tanks before it is treated and eventually discharged. Waste Management has been developing and testing technologies to reduce both the volume of water and disposal costs. One technology harnesses nature. By constructing wetlands and planting grasslands and poplar groves to naturally filter and clean leachate, Waste Management has made use of natural ecological systems to treat water, while also increasing natural habitat for native plants.
We have also used a simple technology that recirculates and evaporates leachate using the side slopes of leachate ponds. An electric pump pulls water from the pond and circulates it through lateral pipes that are equipped with sprinkler heads. Water that is not evaporated filters through gravel placed on the side slopes to return to the pond. The system can evaporate as much as 20,000 gallons of liquid per day, reducing the volume of water that must be handled at publicly owned wastewater treatment plants by as much as 30 percent.
Another new technology deployed at several western Waste Management landfills uses a solar-powered floating recirculation device that draws leachate from deep within the pond and disperses it at the surface to help maintain warmer surface temperatures that enhance evaporation. Called the SolarBee, the device also eliminates pond scum on the surface that can interfere with evaporation.
Waste Management engineers have developed a pilot evaporation system that uses waste heat from the landfill’s engine plant that is used to produce renewable electricity. The waste heat warms the leachate to facilitate evaporation and enhance treatment. Data from the pilot will be used to evaluate other locations where the technology can be deployed.
Innovation in Landfill Cover
A closed landfill’s final cap or cover is one of its most important environmental protection features. It must be constructed in accordance with federal and state requirements and properly maintained for years into the future. A typical final cap comprises several layers of plastic membrane, a drainage system and a covering of soil. These covers are engineered to prevent precipitation from percolating through the landfilled waste.
With approval from U.S. EPA, Waste Management has permitted over 40 sites for the design and construction of innovative final covers known as evapotranspiration covers. These covers are constructed of soil and selected vegetation and are specifically designed to store water and release it to plants through evaporation. By working with nature rather than resisting it, evapotranspiration covers provide long-term, sustainable protection, are easy to maintain and provide a natural habitat of native plants and grasses.
The responsible parties at this Superfund site are finding opportunities for “green remediation” consistent with EPA Region 2’s Clean and Green Policy. The group will purchase renewable energy credits equivalent to the electrical power usage at the site in lieu of on-site renewable energy generation inconsistent with local conditions. 100 percent of electricity used at the site comes from renewable sources. Where consistent with regulations, material at the site, for example, construction material for wells and piping, is reused or recycled. Also, equipment used at the site is evaluated for incorporation of energy efficiency and recycled material.