Dedicated to advancing the use of fabricated geomembranes through education, research, and technology transfer.

Factory fabrication reduces field welding, reduces installation time and costs, allows modular construction and provides consistent seam and liner quality.

Geomembrane Test Method Videos Now Available

FGI has created FIELD AND FACTORY VIDEOS for the following
Test Methods:

ASTM D1239 Chemical Resistance, ASTM D1203 Volatile Loss, D5641 Vacuum Chamber, ASTM D4437 Air Lance Test,
ASTM D5994 Thickness (Textured), D5119 Procedure B Thickness (Smooth), ASTM D7408 Seam Peel Strength, ASTM D882 Tensile Properties & D7408 Seam Shear Strength, ASTM D1204 Dimensional Stability, ASTM D1790 Brittleness Temperature.


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Join Tim Stark (Professor of Civil Engineering and Technical Director of the FGI) and Jen Miller (Coordinator of the FGI) as they discuss the latest emerging geosythetics industry trends and news.


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Cutting edge topics presented by industry experts & scholars.


View Our Latest Webinar:
A Panel Discussion on Geosynthetics CQC & CQA

Recorded July 22, 2021


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NEW! Spanish Webinars

Check out our latest Spanish webinar: Ingenio en el Diseño de Obras Geotécnicas con el Uso de Geosintéticos
Presented by Jorge G. Zornberg of the University of Texas, Austin

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Design and Installation Detail Drawings Available

Details available for constructing a containment facility including pipe boots, concrete attachments, penetrations, and vent details.  Both PDF and DWG available.

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Columbus UpGround Reservoir (2011-2013)

Geosynthetic bottom liner system to prevent water migration into solutioned limestone bedrock underlying reservoir
37 million square feet (3.4 million sq m) of 40 mil (1.0 mm) fPP geomembrane and 43 million square feet (4.0 million sq m) of 10 oz (283 g) nonwoven cushion geotextile

The John R. Doutt Upground Reservoir is a 9.2 billion gallon (27.6billion liter) off-stream raw water storage containment reservoir for Columbus, Ohio. The reservoir covers a plan area of 785 acres (314 hectares) and covers primarily farmland. The reservoir area is underlain by glacial till that contains large pockets of high hydraulic conductivity sands and gravels. These permeable materials are about 6 m (20 ft) thick in some areas, which essentially brings the underlying fractured limestone bedrock in close proximity to the bottom of the reservoir. Therefore, reservoir water could seep into the underlying soil and bedrock and increase solutioning of the limestone and possibly destabilize the reservoir. As a result, the designers decided to install a geosynthetic bottom liner system across the reservoir to minimize leakage and connection with the underlying limestone bedrock. The geosynthetic liner system did not extend up to near the embankment crest because the upstream portion of the embankment consists of low hydraulic conductivity soil and could be exposed to ultraviolet light and wave action.


The use of factory fabrication allowed the project to move at a much faster rate and resulted in higher quality seams than what would have been possible with field fabrication, i.e., onsite welding. Because the geomembrane was primarily factory fabricated, 78% of all seams were performed under controlled factory conditions so only 12% of the seams were field welded. One of the biggest project challenges was the shear size of the project and the compacted clayey subgrade when it rained. The relatively flat site simply did not drain surface water, which resulted in ponding and softening of the clayey subgrade. This necessitated re-working of the subgrade and other challenges for the earthwork contractor. Luckily, most of the geosynthetics were installed during dry summer conditions so the factory fabricated geomembrane panels were able to cover a lot of prepared subgrade every day to reduce damage due to rainfall. The fine-grained particles of the clayey subgrade did create issues with the field seaming of the large fabricated panels. The clay particles were so fine that they actually embedded into the geomembrane surface and could not be physically cleaned off before field seaming. This resulted in a 25% of the field seams failing project specifications. Conversely, 100% of all of the factory seams exceeded project seam strength requirements. Therefore, having large factory fabricated geomembranes panels allowed the project to be completed on budget and well ahead of schedule. The Electric Leak Location Survey (ELLS) was also highly effective in locating hidden damage to the geomembrane.


Factory fabricated panels allowed the project to be completed at a much faster rate than was possible if all seaming was performed in the field, i.e., field fabrication. In the summer of 2012, factory fabricated geomembrane panels were being placed at an average rate of 12 panels per day (125’ x 250’ each, 31,250 sq ft or 38.1 m x76.3 m each, 2,907 sq m). That is an average is 375,000 square feet (34,884 sqm) per day in place, tested, and covered with a 10 ounce (283 g) nonwoven cushion geotextile every day for protection. The factory fabricated seams were higher quality, approximately 9% stronger in peel strength and over 9% stronger in shear strength, than what was possible in the field due to onsite contamination of fine-grained subgrade clay particles. For more information on this important project, please see the attached article: Stark, T.D., Hernandez, M.A., and Rohe, D.S.(2020). "Geomembrane Factory and Field Thermally Welded Geomembrane Seams Comparison,” Geotextiles and Geomembranes Journal, 48(4), August, 2020, 454-467,

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Tim Stark, FGI Technical Director

Tim Stark, Ph.D., P.E., D.GE., F.ASCE


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Geomembrane Guide

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

Pond Leakage Calculator - Fabricated Geomembranes
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.
Temporary Landfill Covers - Design & Construction

Panel Discussion onGeosynthetics CQC & CQA
Brian Queen ofOhio Environmental Protection Agency; Shannon Goodrich of GO2CQA;
TonyaSwitalski of Titan Environmental; Ryan Kamp of Chesapeake Containment Systems
Recorded on July 22, 2021

Earn PDH Credit for viewing this webinar!


FGI Welcomes Alphard Group

The Fabricated Geomembrane Institute (FGI) is pleased to welcome its newest Associate Member, Alphard Group (Alphard).  Alphard is a Canadian consulting engineering firm specializing in industrial projects, construction management, and environmental performance. Incorporated in 2010,Alphard has built a team of engineers, environmental technicians and specialists, as well as a network of collaborators and strategic partners in the industry to offer a wide range of solutions and specialized services.

Alphard is also known for its leak location expertise participating in projects all over the world, and it has developed its own technology in-house for the past 10 years.

Their FGI liaison is Marina Villarroel, Director of International Projects, who can be reached at Please help us welcome Alphard Group to the FGI!!!!

FGI Newsletter - Spring 2021 Now Available

Highlights include:

FGI Elects New Board of Directors

2021 Webinar Series

Project Spotlight: Below Ground Double Lined Brine Storage Pond

Top Trending Podcasts

Spanish Speaking Webinar Series

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Pond Leakage Calculator

Use our Excel calculator to learn what measurements are needed to properly plan for your pond liner project.



Frequently asked questions from members, customers and industry professionals answered.


Specifications & Guides

FGI, ASTM and IAGI material specifications in one place for your reference and convenience


Geomembrane Guide

A comprehensive guide to industry and our member material offerings for fabricated geomembranes.