The past few decades of advancements in developing new drainage media have led to the use of geocomposites as the primary drainage layer above the bottom lining system geomembrane. However, you need to be watchful for the free flow of leachate through the thin layer of geocomposite under high gas pressures near the bottom lining system.
Short of investigations and clear guidelines for addressing high gas pressure near the bottom lining system, you can use a gas pressure relief system near the bottom in future new disposal cells. The pressure relief system can simply include a few perforated high-density polyethylene pipes laid in parallel directly above the soil layer placed above the bottom lining system drainage layer, as shown in the schematic.
About the author: Dr. Ali Khatami
Landfill Leachate Management Services
In this day and age, a back office customer information software system is a “must” for solid waste agencies managing inventories, work orders, and large numbers of customers.
However, many solid waste agencies have inadequate computer hardware and software systems to enable tracking of work productivity and customer service. Oftentimes, many use a combination of an Excel-based software system and manual card systems to track residential and commercial accounts. To the world of business operations, these manual systems are analogous to a stone and chisel versus a typewriter.
There are a wide variety of management information and software products used by solid waste agencies across the U.S. Each has its particular advocates and uses in the solid waste management practice. This article will provide an overview of the major trends in software development.
About the authors: Marc J Rogoff, Ph.D. and Laurel C. Urena, M.S.
As authorized by the WIIN Act, the U.S. Environmental Protection Agency (EPA) issued interim final guidance to help states develop their own permitting programs to manage coal combustion residuals – also known as coal ash.
The guidance instructs states on how they can apply to EPA to implement the federal CCR rule and outlines what thresholds states must meet to demonstrate their programs are as protective as federal requirements. The guidance also offers examples of regulatory flexibilities that could meet EPA approval and indicates that states can propose other flexibilities in addition to those specifically identified.
EPA will accept public comments on the guidance through September 14, 2017. To submit your comments, go to Regulations.gov, search for docket number EPA-HQ-OLEM-2017-0458 and follow the online instructions for submitting comments. EPA anticipates that this guidance is likely to be updated as informed by comments received on this interim final guidance and will respond to these comments as appropriate.
For questions and help managing your coal ash in compliance with CCR regulations contact:
Mike McLaughlin, PE, Senior Vice President
Eric Nelson, PE, Vice President
Steve Lamb, PE, Vice President
Kevin Yard, PE, Vice President
Or, contact your local SCS Engineers office .
Landfill odors have impacts beyond landfill boundaries and are a nuisance to people in the landfill vicinity. Landfills located near or adjacent to residential and commercial neighborhoods, including those near industrial areas, get complaints from citizens, businesses, and regulatory agencies no matter how vigilant the operator is about controlling odors. Properly controlling odors at municipal solid waste landfills is a challenge that landfill operators deal with on a daily basis.
We are keenly aware that the means of masking, neutralizing, controlling, or eliminating odors are cumbersome and expensive. A privately operated regional landfill located in a high-profile urban area found an effective and cost-efficient solution to their odor problem. The term pin wells was coined by the landfill engineers who created and used the methodology. The pin wells proved their usefulness, resulting in dramatic, positive results with respect to effectively controlling odors from newly-placed waste.
As many as 20 wells can be installed in one day at a minimal cost. A 20-ft long, 3-inch diameter solid rod, which is similar to carpet poles or the poles used by geosynthetics installers to move rolls of materials, is pushed into the fresh waste placed in the disposal cell to open a vertical, narrow opening in waste. A 1-inch diameter, perforated PVC pipe is inserted into the hole and sand is placed in the annulus space between the pipe and the boring walls. The top of the pipe is connected via temporary laterals to a vacuum source, typically the existing landfill gas collection system. Care is needed to place just enough suction on the pin wells to control odors but not create significant air intrusion into the gas collection system, which could impact the flare or end-use, if in place. The spacing of the pin wells is decided by the operator and depends on what level of effort is needed to control off-site odors.
Pin wells may be installed at the top surface of a new waste lift until the next lift is placed. When the time comes to cover the previous lift with a new lift, the temporary pin wells are removed, and waste is pushed over. New temporary pin wells go in after the next lift is formed. Pin wells may be considered exempt from routine monitoring; the operator will need to check with the local state regulatory agency to obtain confirmation of state and local policy.
Pin wells may be the innovative and inexpensive odor control solution that could work for you too.
Ask the author a question: Dr. Ali Khatami
More about stopping landfill odors.
Removing biological growth in landfill leachate collection pipes is an important maintenance measure to keep the pipes in operable condition. High-pressure jet cleaning of the pipes on a regular schedule is performed in accordance with best practices and regulatory policy. For example, in Florida, solid waste rules require leachate collection pipes to be either jet cleaned every five years or videoed to confirm that the pipes are in operational condition. Of course, if the video shows that cleaning is necessary, the operator performs the maintenance and submits a report to the appropriate agency.
The spent jetting liquids contain a mix of calcite and microorganisms that have been removed from pipe walls and perforations. The liquid mixture flows to the lowest point in the pipe and enters the sump medium, which is typically composed of one to three-inch size rock. A drawback of jet cleaning is that when the pipes are cleaned, the spent jetting liquids enter the sump medium, thereby using essential leachate storage space in the sump. The calcite and microorganisms that were removed from the leachate piping are now present in the sump and will reduce the sump capacity and cause bottlenecks within the perforations in the riser pipe(s). Over time, this buildup will prevent the flow of leachate in the sump into the riser pipe. Without flow into the riser pipe, leachate removal from the sump becomes impossible, causing expensive operations and compliance issues for the landfill operator.
Clogging of the sump medium is a slow process; many sumps do not show indication of the impact of buildup for years. Landfill operators typically don’t use jet cleaning equipment equipped with vacuum features to remove the spent liquids from the pipe during cleaning. SCS recommends that this potential issue is discussed with the cleaning contractor in advance to account for the problems that can occur. For shallow landfills, contractors could provide a vacuum line inserted into the cleanout riser to remove the spent liquids as the pipe is cleaned. For deep landfills, the cleaning contractor can provide a temporary pump inserted inside the riser to remove the spent liquids.
To prevent excessive biological growth, jet cleaning of the riser pipes every time the leachate collection pipes are cleaned will significantly reduce clogging of the riser pipe perforations. Unmaintained riser pipes block leachate from entering the riser, preventing liquid removal and causing compliance issues when found.
Ask the author a question: Dr. Ali Khatama
The local SCS Engineers staff participated in United Way’s Seasons of Caring Community Kickoff. It was a “power hour” of volunteering at the Mallards Duck Pond. The event brought together more than 750 people from across the Madison community to help community members in need. Our staff
SCSers labeled and stuffed emergency medical information packets that are delivered to the elderly and homebound to help them get quick access to medical support when they are in need. Brian Meister’s team held the night’s record stuffing 2,000 informational packets in one hour with SCSers Chris Jimieson and Sherren Clark pacing them.
The primary role of gas collection system laterals is conveying landfill gas to the final destination in the system; however, lateral pipes are also used to convey condensate in the system to a collection point such as a condensate sump. Between the gas collection laterals and the condensate sump, there are gas headers that provide vacuum to the laterals. Condensate sumps are primarily connected to gas headers for effective management of condensate in the system.
On many occasions, gas headers are installed over the landfill surface, where condensate sumps have to be constructed as well. This type design could potentially create issues during construction of the final cover system in the area. On numerous occasions, the condensate sump sticking up above the surface is too short causing the sump to be extended during the final cover construction.
The gas system in the area must be taken out of service to extend the condensate sump. Such interruptions are never welcome because odors or lack of gas productivity can cause serious issues for operators. Also, waste settlements at or around the condensate sump can cause other issues that must then be addressed during construction of the final cover. Furthermore, if the gas header connected to the condensate sump ends up in the middle of the waste column with tens of feet of waste above the gas header, there is the risk of the gas header collapsing under the waste surcharge load and causing issues in the flow of gas and condensate in the system.
Avoid problems by allowing for constructing the gas header and condensate sumps in the landfill perimeter berm.
There are major benefits when the gas headers and condensate sumps are located outside of the waste. First, settlement issues are avoided and secondly potential gas header collapse is averted because they are not situated below many tons of waste. Construction of the condensate sumps to the correct and final height is accomplished while avoiding any final cover construction delays because of issues with the condensate sump locations. In addition to these benefits, the condensate sumps are readily accessible for maintenance.
Under certain conditions construction of the perimeter, berm needs to be carried out in advance of construction of certain disposal cells to position the gas header and condensate sumps in the berm. The design adds to the planning time and requires close coordination with a landfill engineer, but the return is worth every penny.
Contact Dr. Khatami to learn more about the specific conditions that can increase your ROI.
MasterMold, LLC makes component parts for manufacturers of recreational vehicles, utility equipment, and agricultural equipment who use the components in their end products. Because of the wide variety of industries and customers it serves, MasterMold must be poised to respond to its customers’ growth by increasing production levels on demand.
Executive Vice President Jon Butts manages environmental compliance at three production facilities. “Environmental management is just one of the many hats I wear,” says Butts. MasterMold has multiple environmental needs. Permitting is high on Butts’ list, and so is passing routine inspections.
To help MasterMold meet its environmental compliance needs, the SCS Engineers team assessed the company’s air permitting needs with an eye toward future increases in customer demand. The team helped turn around a permit application quickly so MasterMold could continue to meet its customers’ production expectations without interruption and remain compliant with environmental rules and regulations. Butts stated:
Then SCS Engineers helped me collect and organize data for emission calculations in one place. They created an easy-to-use tool that my staff updates monthly so we’re prepared for an on-site inspection anytime. I can demonstrate compliance, pass inspections quickly, and get back to focusing on my customers.
Butts got the opportunity to test the new tool during the company’s latest inspections. MasterMold has undergone routine inspections by the Wisconsin Department of Natural Resources (WDNR) and the U.S. Environmental Protection Agency (USEPA). Both agencies checked the company’s compliance status with its air permit at its largest plants. “I had everything organized right at my fingertips,” Butts says. “I was ready for the inspections. I now know exactly where all of our emissions come from and exactly how they change over time.”
Thanks to the tool SCS Engineers helped me build, MasterMold passed its latest inspections in just a few hours with no citations. I’m confident I will pass on-site inspections and gain and grow inspectors’ trust in MasterMold’s business practices. Now I’m in a position to influence the process, take proactive steps, and partner with my inspector instead of responding reactively.
—Jon Butts, Executive Vice President, MasterMold, LLC | Johnson Creek, WI
In February Dane County opened their expanded C&D Recycling Facility with its adjacent 4,800 sq. ft. Clean Sweep building. The facility accepts materials in segregated or mixed loads from home demolition projects, new residential and commercial construction, and large quantities of shipping materials such as pallets and cardboard. See coverage of the opening on the local news station.
According to an article in WMW County Executive, Joe Parisi is quoted as saying:
This new facility will extend the life of our landfill, recycle more materials, save millions for taxpayers and create jobs. This facility will be run on waste heat from our landfill and continues our efforts to increase our renewable energy for all of our county facilities.
This is a win for taxpayers and a win for our environment. Dane County will continue to be a leader in our efforts to protect our environment.
In addition to the environmental benefits of landfill diversion, the County is proud of the many new jobs created and the $600,000 taxpayer dollars saved. Months later, are the results still as good as projected? As a matter of fact, they are.
Congratulations to Dane County and the Department of Public Works.
Read about this award-winning project and the County’s waste screening process by clicking here.
