All About Geomembrane Covers

Take the temporary tarp to the next level by installing a permanent geomembrane cover that can handle UV exposure, heavy rain or snow loads, and even employees walking over the surface for maintenance. Only a geomembrane cover can offer all these benefits in one package with many different applications. The majority of geomembrane covers are designed for use over some kind of fluid. Whether you’re keeping something in or out, you’ll need a truly fluid and gas impermeable cover. BTL Liner’s laminated geomembrane materials, including ArmorCover and ArmorPro, definitely qualify as an ideal material for making a custom cover.

Protecting Water from Contamination

One of the most important uses for permanent geomembrane covers is to protect potable water supplies from contamination. When you’re storing hundreds of thousands or millions of gallons of drinking water for humans or animals, the cost of fully enclosed cisterns and storage tanks becomes prohibitive. Open storage ponds are perfectly safe to use when covered by a reliable geomembrane. Since the material is impermeable, rainwater gathers on the surface and doesn’t mingle with the sanitized water below. If a bird flies over and aims its waste right for the pond, the geomembrane will prevent that bacteria from contaminating the entire supply.

Not only will an opaque cover stop debris and bacteria from getting into the water, it also stops contamination from the inside out by blocking light that triggers algae growth. Many types of algae are unsafe to drink, leading to extensive sanitizing processes after even a small amount grows in a storage pond. Finally, geomembrane covers trap vapors as well, so that water sanitizing chemicals don’t evaporate too quickly. Chlorine is highly volatile and can evaporate so quickly that the water doesn’t undergo the planned amount of processing. Covers control the rate of evaporation and vapor loss so that there’s no changing variables to consider when sanitizing potable water.

Controlling Vapors and Fumes

On the opposite end of potable water, facilities used for storing and processing sewage, wastewater and manure sludge all require vapor-proof covers as well. These geomembrane covers are designed to keep gases and liquids in rather than out, but they’re used in similar ways as potable water protection. Even fracking and oil refinery residues, stored in open tanks, usually require some kind of gas-tight cover to keep fumes and exhaust under control. Covers for sewage and wastewater treatment tanks also help prevent contamination of the surrounding area by keeping the waste from splashing up and out as a result of rainfall or falling debris.

Keeping Wildlife Away

Open bodies of water are highly appealing to animals and insects of all kind looking for a drink or a place to lay eggs. Potable water is easily contaminated by an animal’s saliva or its body if it falls in, while open chemicals and sewage can be spread far and wide by a single exposed squirrel or bird. Covers both protect animals from the contained liquids and keep the liquid safe as well. Loose, tarp-style covers, are easily pushed aside by small and insistent visitors, but tightly sealed geomembrane covers are basically impervious to wildlife. These visitors can even include humans in some instances, so a truly secure cover will even resist a person’s attempt to remove it.

Pairing Geomembranes with Floating Ball Cover

Most geomembrane covers float along the surface with the help of buoyant foam blocks or stretch across the open space thanks to underwater supports and tension plates along the edges. This allows water to accumulate on the taut surface, necessitating the use of a sump pump to keep the cover from sinking under the water’s weight. For a geomembrane cover system that doesn’t need any pumps, consider a hybrid cover that combines floating ball technology with a stable geomembrane. Floating balls cover the surface to reduce evaporation and block light that leads to algae growth, but they aren’t impermeable like a geomembrane. By pairing the two types of covers for a single pond or storage tank, you get the best of both systems with fewer drawbacks. For example, ball ballasted floating covers don’t need pumps since channels formed into the geomembrane direct rainwater to the edges for capture and removal.

Capping a Landfill Permanently

Once a landfill has reached capacity, it can’t simply sit open to the elements and release methane to the atmosphere as millions of pounds of waste breaks down. Proper capping procedures involve sealing the top of the pile with an impermeable layer, such as a geomembrane and then covering it with soil and grass so it resembles a natural environment again. The impermeable layer must not only keep water from running down into the layers of trash and leaching out chemicals, it must also keep methane gas trapped inside so it only escapes through the designated vents. With many capped landfills located near homes and schools, improper venting or leaching could cause serious health problems. Materials approved for buried use, including ArmorPro from BTL Liners, must be used since the landfill cover is intended to be permanent.

The membranes that seal landfills must stay flexible for years, and even decades to come, because the surface below the material continuously changes. As waste breaks down and collapses, the material must conform to each new configuration to prevent gaps from forming so that gas does not build up. Soft and flexible LDPE layers are ideal for ensuring the geomembrane moves with each change of the landfill’s surface, while a strong interior HDPE layer provides the durability necessary to help the geomembrane last for decades when properly buried.

Fully Sealed Geomembrane Cover Systems

The most advanced geomembrane covers are sealed directly to the liner for a complete liquid and gas-proof enclosure. For this to work successfully, obviously both the liner and cover materials must either be identical or compatible for seam sealing. Most geomembrane materials only seal securely to the same material, limiting your options for mixing and matching. All of BTL Liner’s geomembrane products work well together so you can pair the right liner with the perfect cover. If you need help determining which of our products seal together with no additional interface, contact a member of our team for assistance.

Selecting the Right Material for a Geomembrane Cover

Permanent landfill covers require a geomembrane that is at least 40 mil thick, while covers for water, waste lagoons and ponds can be as thin as 10 mil for small applications. HDPE is the most widely used material for both landfill and open water covers because of its UV and chemical resistance. It’s also highly abrasion resistant, which is essential when it’s being installed over a rough layer of soil with landfill waste and potential puncture hazards. Yet, getting a purely HDPE geomembrane to conform to the shape of a landfill or to drape evenly over open water can be tricky and it’s also not the most cold-weather resistant material. BTL Liner’s cover materials include bonded lamination of LDPE layers on both sides to ensure our geomembranes are flexible enough to fit any application. Combine that with easy seaming processes that create durable and trustworthy seals and you’ve found the ideal geomembrane cover material.


Liners by BTL

AquaArmor Pond Liner

The most versatile liner on the market today, AquaArmor maximizes protection from harmful UV rays, tear resistance and punctures that cause leaks. Simply the best liner on the market.

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