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An interactive list of geomembrane products for various applications. Read more
The FGI Equipment Guide
An interactive list of welding equipment and products for fabricated geomembranes. Read more
The FGI Pond Leakage Calculator Geomembranes v. Compacted Clay Liners
Fresh water is a precious resource with demands rising daily and supply greatly fluctuating. Only two (2) percent of all water on Earth is fresh water with the other 98% being salt water. This 2% of fresh water is comprised of: 87% ice, 12% groundwater, and 1% rivers and lakes. Thus, only 13% of the available freshwater is readily accessible. Therefore, it is imperative that we capture and hold these limited water resources for agriculture, domestic use, and industry and also protect valuable groundwater from surface or subsurface contamination.
The FGI’s Pond Leakage Calculator is a Microsoft EXCEL spreadsheet based on Darcy's Law of Seepage and provides a comparison between leakage rates from a canal, pond, or reservoir constructed with compacted fine-grained soils and a geomembrane liner system. The Leakage Calculator allows the user to input the size of the containment basin (including length, width, depth, side slope angle and freeboard), the anticipated level of hydraulic conductivity of the compacted soil or geomembrane liner, and the relative cost of water in dollars per acre-foot of water.
The Calculator then calculates the volume of the basin in gallons, a comparison of leakage rates between the compacted soil and geomembrane liner systems in gallons, and the cost of the leakage based on the cost of water per acre-foot to replace it. This Calculator is designed to help consultants, engineers, architects, and end users decide how to line their canals, ponds, reservoirs, and basins to capture and/or protect valuable fresh water. The Calculator does not consider variances in construction quality and operational techniques on the long-term effectiveness of the chosen liner system. The FGI has additional research and publications to help with other aspects of successful water containment applications.
Types of Geomembranes Four (4) popular types of geomembranes are available for pond liner systems. These four (4) geomembranes in ALPHABETICAL order are: (1) EPDM, (2) reinforced polyethylene (RPE), (3) Polypropylene (PP), and (4) Polyvinyl Chloride (PVC). EPDM (Ethylene Propylene Diene Monomer) geomembranes are unreinforced and have been used for the construction of ponds of varying kinds. EPDM geomembranes are made from rubber and can be welded together with tape and primer. EPDM can be reinforced or unreinforced. RPE geomembranes have a high tensile strength and puncture resistance because they are reinforced. RPE geomembranes also can be welded with heat. PP geomembranes can be unreinforced or reinforced depending on the application. Reinforced PP geomembranes also have a high tensile strength and puncture resistance because they are reinforced. PVC geomembranes are also unreinforced and have been used successfully for decades in water canals, ponds, and reservoirs. PVC geomembranes can be welded with heat and/or solvents.
Please click below to access FGI’s Pond Leakage Calculator.
The Fabricated Geomembrane Institute (FGI) updated its Material Specification for New PVC Geomembranes, previously referred to as PGI 1104 and FGI 1117. The new specification, FGI 9119, addresses camber or layflat, film gloss, shore hardness, and color deviation within a manufactured lot. The new specification introduces the FGI Circumference Test which measures the roll circumference at the ends and several points along the roll to maintain roll straightness or decrease camber. FGI 9119 also includes requirements for film gloss to reduce blocking or sticking of the geomembrane upon unrolling. A Shore Hardness requirement was also added to improve handling and welding of the geomembrane.
The new specification can be downloaded for free by clicking here.
About the FGI:
The FGI is dedicated to advancing the use of fabricatedgeomembranes through education, research, and technology transfer. The FGI is a non-profit consortium of manufacturers,fabricators/installers, designers, regulators, and material suppliers offabricated geomembranes.
FGI Summer 2019 Newsletter - Now Available
Check out the FGI's Summer Newsletter with information on Safety, the new Online PDH Program, Upcoming Webinar on Temporary Landfill Covers, Coal Combustion Residuals Short Course, Women in Geosynthetics, and more.