For a geomembrane to function properly and protect the environment from contamination, long-term stability is crucial. With a multitude of options and varieties of geomembranes available, it can be difficult to make an accurate, direct comparison. For example, when filtering by specification, geomembranes may be similar in physical attributes but have unique performance characteristics.
Wastewater treatment plants often utilize geomembranes to help protect the environment and maximize resources. In San Diego County, the Olivenhain Municipal Water District (OMWD) treats up to 34 million gallons of wastewater each day. The treated water is provided to the community through 45-plus miles of recycled water pipelines. With a seasonal increase in rain, the demand for recycled water drops off and the treated water is stored in a wet weather pond.
You may be wondering why you need to worry about installing a chemical/hydrocarbon-resistant liner to catch spills. After all, if you already have a permanent, above-ground tank or a portable spill unit, the chances of the geomembrane receiving a large spill are very low. Further, the spill may be cleaned up within a short period of time.
Government agencies, utilities, and industrial customers are increasingly relying on geomembrane solutions for projects that could potentially threaten the environment. Cost-effective due to their ease of installation and proven to be reliable for decades, geomembranes have become a popular front line in protecting natural settings.
Water reclamation is a vital part of the services provided by government and water agencies. The public demands it be done correctly.
When specifying a geomembrane, engineers have two high-level options: reinforced or unreinforced geomembranes. Both types of geomembranes have unique properties that make them the best solutions for certain applications and projects. In order to assist you with the specification process, we’ve broken down some of the key components for both geomembranes below.
Nearly all geomembrane installations are fixed at the perimeter of the containment by burying the liner in an anchor trench or by attaching it to concrete (i.e., a collar wall, foundation wall, etc.). The standard approach for connecting the geomembrane liner to concrete is to use a batten.
In this technique, concrete lags are set (i.e., drilled) into the concrete. These are placed on 6" or 12" centers at an engineer’s discretion. A compressible material such as Neoprene or butyl tape is then placed between the liner and concrete, and stainless steel, like 316 SS, or aluminum batten strip, is placed over the liner, and the lag bolts are driven through the batten, liner, and anchored into the lag. The top of the detail is then sealed with a waterproof caulk (see Figure 1).
Typically there are two types of geomembranes: flexible membrane liners and rigid geomembranes. With flexible geomembrane liners, large panels can be prefabricated in a factory prior to being delivered to a job site. Rigid membranes, on the other hand, need to be shipped to job sites before their geomembrane seams are joined together. So what difference does it make?
Every year, more and more roads and highways are constructed to meet growing demands. However, this new construction or expansion of infrastructure may end up being built over loose or soft soil that does not have the ability to support the associated loads. So how do you reduce the vertical stress of these projects on the soil below? One solution is by using expanded polystyrene (EPS) geofoam.
The geomembrane industry has been buzzing lately with a new interest in geomembrane covers which are left uncovered. It’s advantageous in some situations to leave a rain-shedding cover, over a closed waste or another site, uncovered, at least for some extended period of time. This allows the owner/engineers to perform various in-situ treatment of the underlying material, make modifications to the geomembrane cover, and/or leave the site available for new or anticipated technological advances for long-term site management.