Written By: Michael Dickey, P.E., Director of Presto Geosystems Like many other industries, geosynthetics manufacturers are navigating the rapidly evolving landscape of new per- and polyfluoroalkyl substances (PFAS) regulations. However, in the case of geosynthetic products, an interesting and seemingly paradoxical question emerges: Is it possible that the same products that have been designed to solve complex environmental problems, and even contain pollutants, could also be a possible contributing source of PFAS? In this article, we explore this question and discuss the historic role of polymer processing aids (PPAs) in the production of geosynthetics. What Does Intentionally vs Unintentionally Added PFAS Mean? Since the discovery of PFAS in the 1930s, these compounds have been widely used in manufacturing operations worldwide—both intentionally and unintentionally. In a recent article published by the American Bar Association, the concept of intentional versus unintentional use of PFAS is discussed, and in the case of the latter, the use of fluorinated PPAS used in thermoplastics processing is highlighted as a well-known unintentional PFAS source. How this concept relates to traditional geosynthetics manufacturing is discussed further below. Eliminating Polymer Processing Aids (PPAs) from Geosynthetics Production of geosynthetic products such as geogrids, geomembranes, and geocells commonly involves sheet… Read more »
Posts Categorized: GEOWEB Geocells Soil Stabilization System
Advancing Rail Resilience: How Geosynthetics Help Achieve CRISI Objectives for Robust and Stable Infrastructure
The U.S. Department of Transportation, under the Consolidated Rail Infrastructure and Safety Improvements (CRISI) program, has allocated over $1.4 billion to upgrade and safeguard rail infrastructure across 35 states and the District of Columbia. This initiative, enriched by the Infrastructure Investment and Jobs Act (IIJA), focuses on ensuring more resilient, efficient, and safe rail infrastructure, mitigating the impacts of severe weather and climate change. It seeks to enhance community safety and expedite the transportation of goods and people through improved and robust rail services. The demand for these grants is significantly high, highlighting the pressing need for enhancements in rail infrastructure across the nation. CRISI Key Takeaways: Grant Allocation: Over $1.4 billion has been allocated for 70 rail projects to enhance and protect rail infrastructure. CRISI Program & IIJA: The program, supercharged by the Infrastructure Investment and Jobs Act, focuses on improving rail infrastructure standards and resilience. High Demand: The overwhelming requests for grants underscore the pressing need for improvements and innovations in rail infrastructure. Community Impact: The projects funded are crucial for ensuring community safety and promoting efficient transportation of goods and people. The GEOWEB® Soil Stabilization System (Geocells): A Proven Solution for Rail Infrastructure Mainline Ballast Reinforcement The… Read more »
Are material shortages delaying your road construction projects? Here is how to stay on schedule and within budget.
Written by: Bryan Wedin, P.E., Chief Design Engineer Road construction is booming, and this trend is expected to remain strong due to high demand and the Infrastructure Investment and Jobs Act (IIJA), which includes investments across many sectors, including public infrastructure. Along with this boom, the road construction industry has been dealing with inflation-related cost increases and limited availability of construction materials. The industry has been impacted by supply-chain interruptions and shortages for many roadway materials including lime, cement, and even aggregate. These materials are typically used for roadway base construction, which means road construction projects that use these materials may be subject to delays. Due to these shortages and delays, on-site material or sand-filled GEOWEB® geocells can provide a cost-effective, readily available substitute for base materials–especially where native subgrade conditions consist of weak or soft soils. GEOWEB® Geocells for Roadway Base Stabilization The GEOWEB geocells have been used for load support and foundation applications worldwide for more than 40 years. Developed in collaboration with the U.S. Army Corps of Engineers (USACE) in the late 1970s, Presto co-invented the technology now known as geocells or a cellular confinement system (CCS). The early applications of geocells consisted primarily of stabilized, expedient… Read more »
How Geosynthetics Are Uniquely Poised to Help Alleviate Congestion at U.S. Ports
Written by: Michael J. Dickey, PE, Director and Bryan Wedin, PE, Chief Design Engineer On May 6, 2022, the Maritime Administration (MARAD) released an amended Notice of Funding Opportunity (NOFO), allocating over $234 million for port infrastructure development in 2022. Adding to the previously appropriated amount of $450 million from the Infrastructure Investment and Jobs Act (IIJA, or Bipartisan Infrastructure Law), this will bring the total amount available for port improvement projects to $684 million for FY2022. The significance of this investment comes at a crucial time. According to the American Association of Port Authorities, the pandemic has laid bare the need for a transport system that is able to surge and stretch across all links—from sea, to land, to rail, to warehouse, to consumer. The question is, how can this funding be used to meet this need quickly and cost-effectively? The answer may lie in a strategy implemented in 2021 in the state of Georgia to alleviate congestion at the Port of Savannah. The Georgia Port Authority, in partnership with Norfolk Southern, implemented a solution that has caught the attention of other U.S. port authorities and Class I railroads using what is being referred to as “pop-up container yards”…. Read more »
Protecting Environmental Geomembrane Covers With Suspended GEOWEB Geocells
Economic pressure, the desire for green solutions, and the intensification of climate extremes have converged to create a need for better methods to effect soil stabilization. Fortunately, a proven technology exists that addresses issues associated with these conditions and provides a more stable cover solution for landfill covers, lagoons, stormwater containment basins, and other geomembrane-covered systems. Soil, aggregate, and concrete protective covers over geomembranes can be secured against known gravitational, hydrodynamic, and seismic forces using the GEOWEB® Soil Confinement System. Soil and aggregate are commonly used as a protective cover over liners on slopes of 3H:1V or less. However, when slope gradients are greater, unconfined soil and aggregate covers are typically unstable and not used. In arid areas, cover depth may range from 75 mm (3 in) to 150 mm (6 in). Where conditions support vegetation, cover depth may range from 100 (4) to 600 mm (24 in) or greater where the final depth is a function of the characteristics of the desired vegetation. Regardless of cover depth, if an extreme rainfall event occurs that is 10%, or greater than what would typically be expected, soil mass increases, assumed friction angles decrease, and factors of safety for soil stability drop to… Read more »
Solar Installations on Closed Landfills: Using Geosynthetics to Overcome Redevelopment Challenges
Written by: Michael Dickey, P.E. (WI, FL, GA, NC), Director Redevelopment of closed landfills and capped solid waste sites represent a unique opportunity for landfill owners, solar developers, and communities to work together to put underutilized properties back into productive use. Moreover, many such sites are conveniently located near existing transmission infrastructure and may be easier and more economical from an interconnection standpoint than rural greenfield sites. However, building over a closed landfill poses unique challenges because most landfills are covered by an engineered cap not typically designed to support loads from permanent foundations or heavy equipment. Additionally, state and federal regulations generally prohibit any activity that could potentially breach or damage the cap. Therefore, retrofitting a closed landfill for utility-scale or community solar projects requires careful planning. Ultimately, the project must not jeopardize the intent of the original cap design; that is, to protect human health and the environment. Selecting a Suitable Foundation Concrete slabs and pre-cast ballast footings are both foundation options for solar system installations on landfill caps. In general, concrete slab foundations are heavier than ballast footings and pose a higher risk of creating landfill settlement and side-slope stability issues. Ballasted footings are a lighter-weight option… Read more »
The History of Geocells
Geocell technology has come a long way over the past four decades. In its early days of development, the geocellular soil confinement system consisted of wax-coated craft paper; a plastic drainage pipe matrix fastened with staples; paper-thin, hexagon-shaped, glued aluminum; low- and medium-density recycled materials; pure polyethylene without UV stabilization; and square cells similar to old-fashioned egg carton separators. The Invention of Modern Geocell Technology In the late 1970s, the U.S. Army Corps of Engineers (USACE) contacted Presto Products Company—a private-label consumer packaging manufacturer—to develop a more robust honeycomb-shaped confinement system that would maintain load-bearing strength under heavy vehicle loads. Working with Steve Webster at the Waterways Experiment Station (WES), Presto’s Gary Bach devised a method to weld polyethylene strips to form a cellular structure. This innovative system became known as Sandgrid and was used by the military primarily for road applications. After the development of Sandgrid, Presto Products created a new business unit to focus solely on the geosynthetics business. With this expansion, Presto Geosystems® was established. Presto Geosystems and the USACE tested various resin blends and concluded that virgin high-density polyethylene (HDPE) provided superior weld consistency and structural strength. Presto Geosystems introduced the GEOWEB® Cellular Confinement System (CCS)… Read more »
Advancing the Mining Industry’s Transition to Sustainable Practices with Geosynthetics
Written by: Michael Dickey, P.E. (WI, FL, GA, NC) Mined materials are essential to our everyday lives. We use these valuable minerals in nearly every sector of the economy—they are necessary to construct roads and buildings, manufacture vehicles, build computers, and generate electricity. Additionally, the mining industry stimulates economic growth by providing employment opportunities and generating tax revenue that helps fund vital public services, such as hospitals and schools. As the mining industry navigates environmental, social, and governance (ESG) issues, there is a sense of urgency to adopt sustainable or “green” mining practices. Green mining can be defined as technologies, best practices, and mine processes that are implemented to reduce the environmental impacts associated with the extraction and processing of metals and minerals. The Mining Industry Faces Unique Challenges When it comes to sustainable development, operation, and closure of mines, the industry faces myriad challenges—not the least of which are poor soil conditions, weak subgrades, and other geotechnical challenges that can complicate miners’ efforts to meet ESG goals. In this regard, some of the more common geotechnical challenges that mine operators must contend with include: Constructing and maintaining heavy-duty haul roads. Stabilizing and protecting slopes. Tailings management and site reclamation…. Read more »
Innovative Design of Sludge Drying Beds Using 3D GEOWEB® Geocells
Wastewater treatment facilities have long had to contend with the challenge of dewatering sludge to minimize waste and achieve overall cost efficiency for disposal. Large-scale facilities commonly use mechanical filter presses or centrifuges to dewater sludge. This equipment is often too cumbersome and expensive for many smaller facilities, so they rely on sand filter drying beds for sludge dewatering. Because small tractors or loaders cannot be operated on the loose sands of a conventional drying bed, a system must be implemented to stabilize the sand and improve load distribution for routine cleanout operations. Transforming Infill Material with the GEOWEB® Geocells Through an interconnected honeycomb-like network, 3D geocells confine and stabilize soils that would otherwise be unstable under loading conditions. Geocells are efficient and economical for fast-built unpaved roadways and retaining walls, erosion control of slopes, and stormwater channel protection. The GEOWEB® 3D Stabilization System is the industry’s most complete geocell system, designed with fully engineered components to withstand the most challenging site problems. Made from robust high-density polyethylene (HDPE) since conception, GEOWEB geocells offer the highest, longest-lasting, and most proven performance of any geocell system in civil applications. The GEOWEB® System Improves Clean-Up System for Solid Waste Treatment Facility A solid… Read more »
Building Energy Roads in Harsh Conditions With the GEOWEB® System
Energy sites are often located in remote and difficult-to-access sites in environments with poor soils, limited road-building resources, and extreme weather conditions. Site Challenges in Western Canada In Western Canada’s Oil Sands region, transporting construction equipment, drilling rigs, and completions apparatus – all with heavy wheel loads (typical loads exceeding 125,000 lbs.) is the challenge. It can be extremely difficult to accomplish this over the soft, wet ground (thick muskeg and saturated clays) typical of this region. Add the challenge of working in the dead of winter in below-zero temperatures and on frozen ground, with limited road building materials, and the scenario makes accessing the sites extremely difficult. In the wettest months, muddy conditions can make access by heavy trucks and equipment nearly impossible. So, energy companies typically wait for the ground to freeze before ramping back up construction. Even in winter, access to remote oil sites creates challenges including undeveloped roads, soft ground, and scarce materials suitable for constructing roads. A Road Solution Built for Extreme Conditions The GEOWEB® 3D Soil Confinement System is built for these challenges. The all-weather HDPE material is fast to install and isn’t hindered by soft ground or extreme temperatures. GEOWEB® 3D technology allows… Read more »