Have you ever considered rainwater harvesting for irrigation, non-potable uses or just for LEED credits? Did you know that corrugated steel pipe (CSP) can be fabricated to function as a durable, inexpensive and water tight cistern system? The adaptability of CSP allows for a variety of design options to fit any site or scenario. The recycled steel in CSP allows the manufacturer to offer LEED credit. CSP can be manufactured in long lengths for ease of laying and in large diameters for volume considerations. In today’s construction market aimed at sustainability, CSP is the ideal option.
The University System of Georgia has their eyes on sustainability in part for economic reasons but also because of periods of lengthy drought. The University of Georgia recently expanded and added a Special Collections Library to the campus. This project called for a large cistern system for rainwater collection to water the surrounding landscape.
Engineer of record, Breedlove Land Planning Inc., designed three large tanks, 37 feet, 50 feet and 58 feet in length, to be fabricated from 144 inch diameter, 10 gauge CSP. The cistern’s Aluminized Steel Type 2 coating offers a 100 year service life.
Breedlove specified that these CSP tanks be fabricated as single pieces with bulkheads welded to each end, on the interior and exterior for water tightness. The lockseams were sealed during the manufacturing process to eliminate leakage. Lockseams may be sealed by a full seam weld or by the addition of a gasket during the manufacturing process.
The tanks were joined by 12 inch flanged CSP to eliminate leaks at pipe joints. Further, control gates were welded to the interior of the tanks to control flow between tanks. The ease of fabrication of CSP pipes meant that the tanks were quickly manufactured and delivered to the job on time. The pipes were taken off the trucks, set in place and backfilled quickly. It is recommended to perform a leakage test before backfilling.
Corrugated steel pipe is a viable option for any specifier considering a rainwater harvesting system. A local pipe manufacturer can offer valuable expertise for fabrication ideas. Before designing another cistern, consider the merits that CSP can impart to your project.
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