SCS Engineers

December 14, 2020

environmental compliance firm

SCS Engineers’ SCSeTools® platform and applications help facilities and companies operate more efficiently by continually gauging operational health and identify trends critical to operations and the environment.

 

SCS Technology Services®, the technology development practice within SCS Engineers, announces a new application for tracking and analyzing environmental data. The application expands the firm’s SCSeTools® platform, demonstrating its commitment to developing the most advanced data-driven technology in the environmental services industry.

Groundwater monitoring and compliance services are long-term and expensive responsibilities that generate enormous amounts of monitoring and laboratory data. SCS Groundwater™ is a tool to monitor and manage the data associated with operations and reporting requirements for various sites. Sites include active or closed landfills, plants, and impact sites such as former dry cleaners or industrial facilities.

The application also monitors and manages data effectively for clean groundwater applications such as groundwater basin management projects consistent with standard protocol under state and federal environmental compliance rules. SCS Groundwater™ collects and efficiently organizes groundwater monitoring and maintenance data providing those responsible for environmental compliance with a reliable, consistent, and cost-effective way to manage the large volume of information.

The application’s primary value is enabling users to set up a detailed monitoring plan for any number of events, including the sampling points to include and what analyses to perform at each point. Once the information upload is finished, the application checks incoming data against the plan to confirm all work is complete.

SCS Groundwater™ generates reporting components such as data tables, charts, graphs, and maps for compliance, reporting, and finding trends. For example, on a brownfield site, the compliance manager could upload historical monitoring data results, view the data trends over time, and then produce report tables and figures. Operators can also use the data in other applications for additional analysis or visualization.


 

SCS Engineers’ environmental solutions and technology directly result from our experience and dedication to industries responsible for safeguarding the environment as they deliver services and products. For information about SCS, visit the SCS eTools pages or enjoy our 50th Anniversary video to see the technology in action.

The SCSeTools® platform and applications help facilities operate more efficiently by continually gauging operational health and spot trends that help determine when and how to invest in infrastructure. Field staff, environmental compliance experts, brownfields, developers, and clients in the waste industry guide the technology designs. For additional information and demonstrations of these productivity-enhancing tools, please contact .

 

 

 

 

Posted by Diane Samuels at 6:00 am

December 9, 2020

groundwater monitoring well cost

The events of 2020 have affected the economy, the way we conduct business, and even our social interactions. Now, more than ever, streamlining costs is key for public and private sector clients across the country. Enter groundwater monitoring projects.

Often overlooked as an opportunity to reduce costs, it’s an excellent place to start when examining the costly operational processes of a solid waste facility. Groundwater monitoring is often thought of as necessary for compliance requirements and overlooked when considering ways to reduce spending. However, the proactive review of all monitoring projects may offer monitoring reduction or even cessation opportunities.

Consider the following questions:  

  • When you evaluate monitoring data, are you also evaluating the adequacy of your monitoring program? Are the well locations, number of samples, sampling frequency, and the monitored constituents approved during the site closure appropriate for current conditions (possibly 10 to 15 years into post-closure monitoring)? Ask yourself if it still makes sense.
  • Have you completed a deep dive into the data to look at trends? Have you looked at naturally occurring conditions as potentially skewing constituent concentrations in groundwater? Have you completed statistical analyses of monitoring data to justify reducing the frequency or scope of monitoring?
  • Compare how many years you are into post-closure care with the original required monitoring period. Is there a way to shorten this? Can the zone of discharge or point of compliance be modified? Are there receptors nearby? Can you demonstrate either waste mass stability or stable/shrinking groundwater contamination? 

SCS Engineers has successfully employed these strategies at several Florida landfills. For instance, in Marion County, the SCS team worked to get a cessation in landfill gas and groundwater monitoring at the Martel Closed Landfill. Hired to conduct routine post-closure monitoring, the team observed obvious trends in the data that were favorable to the County. If you consider that monitoring costs average $10,000 to $50,000 per year, the potential cost savings over ten years is $100,000 to 500,000.

Is it worthwhile to take a fresh look at your monitoring program? Absolutely. 

  • Potentially significant cost savings can be recognized by the early cessation of monitoring. If you have a contaminated site, you could potentially reduce your environmental liability and decrease environmental reserves. For sites requiring financial assurance, the cost estimates that are the basis for the amount of financial assurance required could be decreased, thus decreasing the costs to maintain financial assurance.
  • Ending/closing out a consent order requirement also allows for redevelopment of a site, thus turning a liability into an asset, and who wouldn’t want that?
  • By investing a relatively small amount in evaluating your monitoring programs, you could realize a return on investment within 1 to 2 years by reducing or ceasing monitoring.

Bottom line: you should take the initiative to ask a few simple questions to see if further examination is warranted. What if contaminants are naturally occurring? Is the data in the technical reports supporting conclusions that include reduction or cessation when appropriate? Are you simply meeting the minimum requirements of the permit without an eye on the future?

 

So, what’s in your groundwater monitoring plan?

 

About the Author: SCS Project Director David Atteberry puts his 20+ years of environmental consulting and management experience to work for his clients. His technical experience includes geologic and hydrogeologic investigations involving hazardous waste, solid waste, environmental, and water supply. Dave’s technical areas of expertise include contamination assessments, remediation, site characterization, aquifer characterization, RCRA compliance, waste characterization, environmental due diligence, reserve budgeting, and field sampling techniques.

 

SCS Groundwater™

SCS Groundwater™ collects and efficiently organizes groundwater monitoring and maintenance data providing those responsible for environmental compliance with a reliable, consistent, and cost-effective way to manage, view, and assess large volumes of information.

The application’s primary value is enabling users to set up a detailed monitoring plan for any number of events, including the sampling points to include and what analyses to perform at each point. Once the information upload is complete, the application checks incoming data against the plan to determine if all work is completed.

Efficient and consistent data collection means better quality control, fewer violations, and less costly operations. The application is a relational data management system specifically designed for groundwater management. Learn about more benefits here.

 

 

 

 

 

Posted by Diane Samuels at 6:00 am

December 7, 2020

Tracie Bills and Mauricio Cordova
SCS Engineers’ Tracie Bills and Mauricio Cordova of Loaves & Fishes’ are creating a distribution network diverting unsold safe, healthy food from businesses to food-insecure communities. Volunteer groups play an important role in these efforts, bridging the gap between resource-recovery-distribution.

California’s SB 1383, the Short-Lived Climate Pollutants Act, sets a statewide goal for reducing organic waste to landfills of 50 percent by 2020, and 75 percent by 2025. Included in SB 1383 is a goal to recover 20 percent of edible food waste for human consumption.

Meeting these requirements, particularly the recovery of edible food, is not as straightforward as it might seem. For example, it is difficult to accurately identify edible food from other waste once it’s in the waste stream.

“We can estimate the amount of edible food during waste characterizations, but we find working directly with businesses to identify the edible food they can make available and in what quantities is a more holistic approach,” said Tracie Bills, SMM Northern California Director. “We assist businesses with identifying edible food recovery partners with reputable community programs to distribute food to people in need.”

SCS Engineers partners with Loaves & Fishes Family Kitchen in San Jose to create a sustainable solution that could become a model for how municipalities can meet the 20-percent food recovery requirement.

Loaves & Fishes is a non-profit organization with roots going back 40 years. It’s grown from a simple soup kitchen to one of the leading providers of meals in Santa Clara and San Mateo Counties. The organization recently opened its new location in San Jose.

“Last year, we served more than 1 million meals, almost twice as many as just a couple of years ago,” said Mauricio Cordova, Loaves & Fishes’ COO. “With the help of local restaurants, grocery stores, and others, we’re able to use the food they can’t use to feed residents in need. In our new building, we expect to increase capacity to 10,000 meals per day.”

“Creating these partnerships isn’t part of our typical scope of work,” adds Bills. “But it’s important to go beyond simply identifying edible food. As we work with potential contributors and partners, we’re able to create a sustainable network that achieves a common goal.”

Says Cordova, “Through our A La Carte Food Recovery program, we can help companies divert perfectly safe and usable food away from composting and landfills, and re-distribute them in the form of meals to our most vulnerable neighbors.  The all-around win is that people in dire need of food assistance – compounded by the impact of Covid-19 – can receive healthy, nutritious food, and companies lessen their food waste levels and greenhouse gas emissions.”

Loaves & Fishes has recovered more than 1 million pounds of edible groceries and reduced greenhouse gas emissions by 1,058 metric tons.

 

Learn more about sustainable materials management.

 

 

 

 

 

Posted by Diane Samuels at 6:00 am

December 2, 2020

landfill leachate treatment plant

Across the industry, stakeholders agree the next few years will be critical in shaping how landfills deal with PFAS and how the public perceives it. Waste trade associations, scientists, and a host of organizations are in the midst of conducting a number of studies looking closely at the issue, PFAS treatment options, the positive impact of recycling, and regulatory policies.

While there are sites noted in the article, there’s no practical way for most companies and landfills to respond at this time responsibly. Additionally, landfills are unique; no two are alike. Most human exposure to PFAS occurs through contaminated food. The majority of landfill leachate is pre-treated at the landfill before going to a wastewater treatment plant, where additional treatment occurs before discharge.

According to EREF President Dr. Bryan Staley, in the article, “The relative impact of leachate as a human exposure pathway needs further evaluation to understand its relative degree of importance as it relates to health implications.”

 

Gomathy Radhakrishna Iyer
Dr. Gomathy Radhakrishna Iyer presenting at GWMS.

Dr. Gomathy Radhakrishna Iyer, landfill leachate and design expert for SCS Engineers, said some operators are waiting to see what regulations may come even as they work on accounting for potential compliance issues and seeking solutions. “When the clients are thinking of upgrading their treatment plans, some are definitely taking into consideration PFAS treatment,” Radhakrishna Iyer said.

“You’re spending millions of dollars, you need to do your due diligence, right? At this point, consideration should be given to PFAS treatment during the feasibility stages,” she said.

 

Read the Waste Dive article Toxic PFAS waste that lasts ‘forever’ poses financial, logistical challenges for landfills, Waste Dive, Oct. 19, 2020

 

 

 

 

 

 

 

Posted by Diane Samuels at 6:00 am

December 1, 2020

FAST-41 permitting SCS Engineers

SCS Engineers is 100% employee-owned electing its Board of Directors. Following our November Board Meeting, we are pleased to announce the promotion of several key professionals, including Robert Dick in Virginia and Michelle Leonard in California, as Senior Vice Presidents.  

These professionals inform our business strategies and technical directives while providing the personal service clients expect from SCS. Every executive remains in the field listening to and serving clients – that’s the benefit of employee-ownership – no desk jockeys here.

Senior Vice Presidents

Bob Dick
Bob Dick

Bob Dick supports landfills throughout the eastern seaboard and Mid-Atlantic, including over 150 landfill gas projects. He helps SCS clients to meet their Clean Air Act compliance goals and use methane gas for energy, reducing emissions. Bob is a civil and environmental engineer with expertise in solid and hazardous waste management. He manages SCS’s landfill and landfill gas engineering solutions for clients in more than 15 states and several foreign countries. “Bob plays a key role in our success,” said Jim Walsh. “His work and dedication to his clients help them implement environmental solutions that can be employed in other parts of the U.S. and globally.”

 

Michelle Leonard
Michelle Leonard

As a sustainable materials management leader, Michelle Leonard, well known throughout the waste industry, is also SCS’s National Expert in Solid Waste Planning, Recycling, and Sustainability. She has over 30 years of environmental consulting and project management experience, including solid waste management planning and facilities focusing on reducing, reusing, and recycling waste materials. Michelle is a long-time proponent of integrating the principles of a circular economy into the waste industry. “Michelle informs some of the largest cities and waste company programs in the country,” said Jim Walsh. “Her knowledge and dedication to her clients, industry, and within SCS earn her the position of Senior Vice President and our respect.

Vice Presidents

SCS announces the promotion of Garold (Tony) A. Cartee and Luke T. Montague, PG, to Vice President.

Tony Cartee
Tony Cartee

Tony is a Regional Manager for Filed Services OM&M in Charlotte, North Carolina. He has over two decades of experience in landfill gas system operations monitoring, maintenance, migration control, and recovery, plus New Source Performance Standards compliance and construction expertise.

 

 

Luke Montague
Luke Montague

Luke is a Project Director in San Diego, California. He is a Professional Geologist and licensed contractor with nearly two decades of experience providing environmental consulting and geotechnical support to general contractors, commercial and residential developers, and property and asset managers. His focus is site remediation activities that bring contaminated properties back to pristine condition.

National Experts

Our National Experts play an important role as industry leaders who are deeply involved in professional associations related to their expertise. These professionals organize and participate in workshops and conferences, author and present technical papers, conduct research, and participate in national and state-level legislative and rule-making processes and regulatory policy.


Michael Schmidt
Dana Blumberg

The SCS Board announces new National Experts, Michael Schmidt – Environmental Insurance Claims and Underwriting, and Dana Blumberg, PE, who, in addition to her responsibilities as SCS’s International Expert, serves the Federal Services Experts.

 

We’re very proud of our colleagues and grateful to our clients who entrust SCS to support their businesses, communities, and agencies.

 

 

 

 

 

 

Posted by Diane Samuels at 6:00 am

November 30, 2020

Jeff Phillips

SCS Engineers welcomes Project Manager Jeff Phillips to the Clive, Iowa office. Jeff works with a growing number of solid waste management clients interested in integrating sustainable materials management into their solid waste master plans. The practice is widely known as Integrated Solid Waste Management, ISWM.

Jeff Phillips comes to SCS with over two decades of designing and implementing ISWM programs. His expertise includes a comprehensive list of individual tasks and services, including facilitating strategic planning and consensus-building sessions, performing waste and recycling industry market analyses, developing and presenting comprehensive financial plans to solid waste agencies, identifying, authoring, and managing federal and state grants. He also designs, performs, manages waste characterization analyses, authors and produces videos for training and education purposes, and is involved in community outreach events for solid waste agencies, city councils, and the public.

“Jeff provides innovative approaches to develop and strengthen programs and operations in Iowa,” said Christine Collier, senior project manager. “He fits right into our SCS philosophy of ensuring client success.”

Jeff is an active member of the Solid Waste Association of North America and the Iowa Society of Solid Waste Operations, where he previously served on the Board of Directors and Conference Planning Committee. He earned a Bachelor of Arts, Geography, and Environmental Studies from the University of Iowa.

 

 

 

 

 

 

 

Posted by Diane Samuels at 4:49 pm

November 30, 2020

graphic by Samuels of SCS Engineers

Landfill engineers rely heavily on topographic maps in their design work. Topographic maps present elevation contours, known as contour lines, for changes in the ground surface. Surveying companies create contour lines by performing land surveys, Light Detection and Ranging (Lidar) surveys, or aerial mapping. In all cases, the topographic maps are generated based on a standard coordinate system.

Basing horizontal systems on geodetic coordinates worldwide, they may be updated every few years or decades. An example of the horizontal coordinate system is the North American Datum (NAD). A datum is a formal description of the Earth’s shape and an anchor point for the coordinate system. Using the NAD system, engineers can make horizontal measurements in consideration of the anchor point information.

NAD 27 and NAD 83 are two versions of the NAD system with slightly different assumptions and measurements. A point with specific latitude and longitude in NAD 27 Datum may be tens of feet away from a point with similar latitude and longitude in NAD 83 Datum.

The latitude and longitude of an initial point (Meads Ranch Triangulation Station in Kansas) define the NAD 27 Datum. The direction of a line between this point and a specified second point and two dimensions define the spheroid. Conversely, NAD 83 Datum uses a newer defined spheroid, the Geodetic Reference System of 1980 (GRS 80). GRS 80 is an Earth-centered or geocentric datum having no initial point or initial direction.

Similarly, vertical systems provide surveyors the means to measure vertical measurements based on a standard system. Examples of the vertical datum are the National Geodetic Vertical Datum 1929 (NGVD 29) and North American Vertical Datum 1988 (NAVD 88).

Using topographic maps, solid waste engineers pay special attention to the standard coordinate system used for generating the topographic map made available to them for their design work. Engineers will want to check for additional topographic maps using another Datum for the same site. Checking eliminates the possibility of discrepancies in the design documents.

Typically, the standard system set for a landfill site remains unchanged for consistency among topographic maps generated over the years. If the standard system must change, document the conversion making it available to the solid waste engineers working at the site. The conversion information is valuable for converting engineering plans to prevent the older plans from becoming obsolete and unusable for practical engineering work.

A solid waste engineer that begins work for the first time at an existing landfill site pays special attention to the standard system (horizontal or vertical). The engineer wants to ensure the time spent producing design documents and plans aren’t wasted. For optimum efficiency, landfill owners contracting with new solid waste engineers should provide conversion information from the old to the new system upon the contract’s commencement.

The United States National Spatial Reference System NAD 83(2011/MA11/PA11) epoch 2010.00, is a refinement of the NAD 83 datum using data from a network of very accurate GPS receivers at Continuously Operating Reference Stations (CORS). A new Global Navigation Satellite System (GNSS) will replace the National Spatial Reference System NAD 83 and the NAVD 88 in 2022, according to the National Geodetic Survey Strategic Plan 2019-2023. The GNSS will rely on the global positioning system and a gravimetric geoid model resulting from the Gravity for the Redefinition of the American Vertical Datum (GRAV-D) Project. The new systems’ intention is easier access and maintenance than NAD 83 and NAVD 88, which rely on physical survey targets that deteriorate over time.

Solid waste engineers should be aware of the upcoming changes to adapt site designs as necessary and to check with landfill owners and operators to check for any implementations at their facilities.


 

About the Authors:

Ali KhatamiAli Khatami, Ph.D., PE, LEP, CGC, is a Project Director and a Vice President of SCS Engineers. He is also our National Expert for Landfill Design, Construction Quality Assurance, and Elevated Temperature Landfills. He has over 40 years of research and professional experience in mechanical, structural, and civil engineering. Dr. Khatami has been involved for more than 30 years in the design and permitting of civil/solid waste/environmental projects such as surface water management systems, drainage structures, municipal solid waste landfills, hazardous solid waste landfills, low-level radioactive waste landfills, leachate and wastewater conveyance and treatment systems, gas management systems, hazardous waste impoundments, storage tank systems, waste tire processing facilities, composting facilities, material recovery facilities, landfill gas collection and disposal systems, leachate evaporator systems, and liquid impoundment floating covers. Dr. Khatami has acquired extensive experience and knowledge in the areas of geology, hydrogeology, hydrology, hydraulics, construction methods, material science, construction quality assurance (CQA), and stability of earth systems. Dr. Khatami has applied this experience in the siting of numerous landfills.

William RichardsonWilliam Richardson, EIT is Project Professional at SCS, and part of our Young Professionals organization. Will has two years of experience with landfill design projects, including permit modifications and siting requirements. He is currently working in Virginia Beach under the tutelage of Dr. Khatami.

 

 

 

 

 

Posted by Diane Samuels at 6:00 am

November 23, 2020

what are some concerns that engineers need to keep in mind while building a landfill?

Landfills are large and dynamic systems that can take several decades to develop. Unlike many other infrastructure projects that have a beginning and an end to the construction of the project, landfills constantly grow and change due to many factors, including but not limited to:

  • The type of waste stream delivered to the site;
  • Type of operations carried on at the site;
  • Operator’s experience and operational preferences;
  • Capital flow into the site;
  • State and local regulatory changes;
  • Engineer’s recommendations;
  • The rate of development around the site;
  • Interactions with local communities around the site;
  • Agreements with environmental groups; and
  • Political will and the extent of support by politicians.

From an engineering perspective, it is very common to see changes to the engineering team over time. Each team brings about their ideas and preferences to the operator, and if they present technically competent and economically solid ideas, they can change the course of the landfill development. The course change could be shaped by what will get constructed, how it will get constructed, when it will get constructed, and what sequence it will get constructed. In most cases, the owner is in the loop, but the owner may not be intimately familiar with the nuances that such designs and modifications entail. Therefore, the owner may not necessarily realize hidden problems or mishaps that may happen in the future, which could be prevented by the engineer at an earlier stage of work.

Competent engineers starting work at an existing landfill site for the first time need to review years of data to become familiar with the history of the site before they can begin design work. The history of the site involves, but is not limited to, land use approvals, permitting, designs, modifications, environmental impacts, subsurface conditions, environmental improvements, leachate and gas collection and disposal, existing and future planned developments, operation requirements, and many other features that vary from site to site. Without such knowledge, the engineer is working in the dark without the owner’s knowledge that the engineer’s path lacks familiarity with details. Work products generated by an engineer with limited familiarity with the site are, at best, not reliable. Even potentially having significant impacts on the owner to fix issues that otherwise are preventable with sufficient due diligence.

For example, tasking an engineer to close a portion of the landfill, the engineer must investigate any plans set for landfill development, in the area planned to close. The engineer and owner can discuss any problems discovered by the engineer’s early due diligence, and solutions will be developed and adopted to address issues during the design. This level of due diligence provides the opportunity to generate sound designs and develops a level of confidence in the engineer in the mind of the owner.

SCS landfill design professionals train regularly to be thorough and comprehensive in their familiarization with a site. They spend significant effort to foresee potential problems that might arise many years down the road and find solutions for them now.


 

About the Authors:

Ali KhatamiAli Khatami, Ph.D., PE, LEP, CGC, is a Project Director and a Vice President of SCS Engineers. He is also our National Expert for Landfill Design, Construction Quality Assurance, and Elevated Temperature Landfills. He has over 40 years of research and professional experience in mechanical, structural, and civil engineering. Dr. Khatami has been involved for more than 30 years in the design and permitting of civil/solid waste/environmental projects such as surface water management systems, drainage structures, municipal solid waste landfills, hazardous solid waste landfills, low-level radioactive waste landfills, leachate and wastewater conveyance and treatment systems, gas management systems, hazardous waste impoundments, storage tank systems, waste tire processing facilities, composting facilities, material recovery facilities, landfill gas collection and disposal systems, leachate evaporator systems, and liquid impoundment floating covers. Dr. Khatami has acquired extensive experience and knowledge in the areas of geology, hydrogeology, hydrology, hydraulics, construction methods, material science, construction quality assurance (CQA), and stability of earth systems. Dr. Khatami has applied this experience in the siting of numerous landfills.

William RichardsonWilliam Richardson, EIT is Project Professional at SCS, and part of our Young Professionals organization. Will has two years of experience with landfill design projects, including permit modifications and siting requirements. He is currently working in Virginia Beach under the tutelage of Dr. Khatami.

 

 

 

Posted by Diane Samuels at 6:00 am

November 19, 2020

Sandy Ripplinger

 

On Tuesday, November 10th, SCS Engineers announced the promotion of Sandra Ripplinger to Director of Health & Safety. Sandy will oversee all industrial health and safety guidance and training for the SCS employee-owners in her expanded role, reporting to the Board of Directors and Chief Financial Officer Curtis Jang.

Ms. Ripplinger is a Board Certified Industrial Hygienist (CIH) and Safety Professional (CSP) with three decades of experience providing occupational and environmental health and safety services. She is currently also a Project Director with SCS’s Environmental Health Services Practice in Henderson, Nevada.

Her experience includes providing industrial hygiene expertise for industrial facility health and safety audits, process safety management audits, training, environmental evaluations preventing worker exposure. “Sandy has done a great job strengthening our clients’ safety programs and evaluating the risks to prevent accidents,” said Curtis Jang. “She is a strong leader, and I’m confident she will guide our employees with ever-smarter Industrial Health and Safety (IHS) protocols.”

“I am looking forward to working with our team of business unit directors and IHS professionals, continuing to make improvements that benefit our staff and clients,” Ripplinger said. “Safety and industrial safety are an important part of people’s lives, and SCS is committed to continuing delivery of our services in line with legal compliance, industry guidelines, and our clients’ business needs.”

Sensational, Sandy! 

 

 

 

 

 

Posted by Diane Samuels at 6:00 am

November 16, 2020

landfill closure
With the proper design and planning, partial final covers can provide multiple benefits and long-term performance from the active life and well beyond.

About the Author: Ali Khatami, Ph.D., P.E.

There are several hundreds of Municipal Solid Waste (MSW) landfills in the United States. Many of these landfills are anticipated to remain active for decades to come, and Federal and state rules require slopes reaching permitted final elevations to be closed within 180 days. This means partial closure of slopes is part of the operational requirements of MSW landfills.

Federal and State Rules

Subtitle D of the Resource Conservation and Recovery Act (RCRA), enacted on October 21, 1976, requires the final cover of MSW landfills to include a barrier layer with hydraulic conductivity that is substantially equivalent to or less than the hydraulic conductivity of the bottom liner. State-level regulations developed following the enactment of the federal law also required similar standards for MSW landfills. Many states, pursuing the federal guidelines, require at a minimum, the bottom lining system of MSW landfills include at least one primary barrier layer consisting of Polyvinyl chloride (PVC), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE). Naturally, the final cover barrier layer should also be PVC, HDPE, LLDPE as well.

According to the Federal and state regulations, following the completion and closure of a MSW landfill, the facility owner maintains the landfill for a minimum of 30 years beyond the final closing date. Extension of the long-term care period beyond the 30-year post-closure period is a hot subject among solid waste professionals. Some states have already implemented matrices for such time extensions; it is anticipated that the remaining states will require similar extensions for MSW landfills over the next several years. Even if regulatory agencies approve completion of the post-closure period for a specific landfill, the landfill’s final cover system is expected to perform for many more years to come. Otherwise, environmental issues associated with a lack of performance may force the regulatory agency to spend money for repairs no longer available through a financial instrument.

Long-Term Performance Designs

For the past few decades, SCS has specifically designed and permitted final cover systems with special features to prolong the final cover system’s performance beyond the post-closure period of the landfill. The final cover system designs:

  • Maximize available airspace in the landfill,
  • Simplify waste placement in the vicinity of the exterior landfill slopes,
  • Simplify stormwater management components over landfill slopes,
  • Effectively collect and remove rainwater percolating through the final cover soils,
  • Collect lateral leachate seeps below the final cover barrier layer, and
  • Effectively encapsulate landfill gas at the landfill perimeter.

Less Maintenance

The first partial final cover with these features was constructed in 1998, and since then, many more partial closures with these types of features have been constructed. All partial closures are performing satisfactorily without failure. Regular maintenance of the final cover vegetation and occasional cleaning of drainage swales, which are common maintenance activities, have been the only measures taken by the operators of the facilities with these final cover systems.

The features incorporated into the final cover systems were:

  • Straight 3H:1V slopes to the top of the landfill with no benches or terraces, providing benefits such as maximizing airspace; eliminating complications during filling of the landfill near exterior slopes; allowing final surface water drainage swales to be constructed during the construction of the final cover which provides flexibility for the swale locations, swale slopes, drainage points of swales on the slopes; and downchute pipes that do not require complicated geometric features at the point of connection to drainage swales on the slope;
  • A leachate toe drain system (LTDS) collecting and disposing of leachate seeps below the final cover geomembrane reaching the bottom of the landfill slope; and
  • A rainwater toe drain system (RTDS) collecting and draining out of the final cover the rainwater that percolates through the final cover reaching the cover system geocomposite drainage layer.

The features above have financial, performance, and stability benefits for the facility for many years to come. So far, such final covers have been constructed on 3H:1V slopes as long as 550 ft. in length with no terraces. Several of the completed final covers were partial closures on a 3H:1V slope, where the next phase was constructed directly above a previous phase with the two phases tied together at the phase boundary.

Proper design and planning for the construction of partial final covers are significantly important for the long-term performance of landfills during the active life, post-closure period, and beyond.

 


 

Want more advice from our designers? Select articles and blogs for further reading:

 

 

 

 

 

Posted by Diane Samuels at 6:00 am
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