There are many uses of geomembrane liners. They can be used for floating baffles, secondary containment, wastewater impoundments, and more. It’s easy to bypass the important items and make blunders when selecting and specifying a geomembrane. Below are the five biggest mistakes in the selection process and how to avoid them:
When designing a pond or lagoon, preventing leaks is a major concern. However, determining the best geomembrane liner for your project can be an extremely daunting task. You have to decide between reinforced and unreinforced geomembranes, which material and thickness is best, and between a myriad of other physical properties that could play a part in the success of your project. As a result, people oftentimes choose a natural clay liner because it is the less complicated choice.
Dr. Robert Koerner, professor emeritus of civil engineering at Drexel University, is a highly respected professional in both the geosynthetic and engineering communities. In his webinar, “Wave (or Wrinkle),” Koerner covers unreinforced geomembranes, such as HDPE, and how geomembrane waves or wrinkles can be somewhat prevented and/or fixed. Here is an overview of the webinar:
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).