Engineered Steel Containment System
LOCATION: Southern Ontario
TIMEFRAME: 3-4 Day Install
SCOPE OF WORK: Supply & install new secondary containment system to replace current substandard earthen berm
Owners: Liquid Nitrogen Fertilizer Manufacturer
Background Information and Challenges
Liquid fertilizer manufacturer chooses steel walled secondary containment system
After years of service, a solution was required for the replacement of an eroding earthen dyke containing an 88,000 imperial gallon steel walled tank, for a liquid nitrogen fertilizer manufacturer in Southern Ontario.
The task was to supply and install a new secondary containment system to replace the current substandard earthen berm. This project required a lining system to be sealed around the existing concrete pad while providing chemical resistance to the fertilizer. design criteria and job constraints included: speed of installation, ability to withstand a catastrophic tank failure, and a 10ft x 10ft x 1ft sump area also had to be built. Down time of the tank had to be kept to a minimum with the approaching growing season, plus attention to design detail and shape of the containment system had to be adhered to in order to allow easy access to the tank with deliver trucks
All existing pipe penetrations were removed and the berms demolished. A 6 inch compacted sand base was constructed while allowing for a low-lying are for the sump. The site had good access and the project was to go ahead during dry weather conditions in February 2002. an irregular shaped 12 gauge, galvanized, 50ft x 120ft x 46in high containment system was chosen, manufactured by GRIT Industries Inc. and supplied by Layfield Geosynthetics and Industrial Fabrics Ltd.
The G-55 system from Grit, is a free standing system which does not require support posts so the entire wall system was installed in a matter of days. The unique foot print, de to the flexible nature of the G-55 wall panels, allowed space for delivery trucks to drive up close to the rounded end of the system and the square end provided the 110% required capacity. The narrow walls allowed for a tighter design radius of the system while maintaining capacity as compared to the wide base of an earthen berm. By choosing this system the owner has the option of altering the tank farm size, thus capacity, by adding or removing wall panels as the tank grows in size.
The geomembane containment liner was prefabricated and shipped to site in tow large panels premeasured to fit this system thus minimizing waste. Supplied by Layfield, the Enviro Liner 30 was chosen for its low cost, UV and chemical resistance. The largest panel, roughly 60ft x 132ft, was deployed and a relief cut was made on site to fit around the concrete pad that supports the tank and then seamed in the field extending to the G-55 wall. The goemembrane was then mechanically attached to the concrete pad using concrete bolts, flat bar, neoprene gasket and finally caulked. The second liner, roughly 15ft x 15ft, was seamed on site for the sump area, and the perimeter of the overall liner was attached to the top of the G-55 system and trimmed to fit.
Prefabrication of the liner reduced 90% of field welding and allowed the entire 5,049 square foot area (does not include the tank area) to be lined and tested for seaming integrity and the walls assembled by Layfield in about three days with a crew of four.
As there are several geomembrane liners available with varying chemical resistance properties, this system can be used in numerous secondary or primary containment applications.