*'''Void-forming structures:''' Includes chambers, vaults, crates or perforated pipes that provide large water storage volume per unit area, reduce required facility footprint area and conserve aggregate. Plastic chamber systems should be compliant with CSA B184 SERIES 11 (R2015) or ASTM F2418-16A. Maximum allowable load for plastic chambers must be determined in accordance with ASTM F2787-13. Concrete vault systems should be compliant with CSA A23.3-14 and CSA A23.1-09/A23.2-09 (R2014) or ASTM C858-10e1. See manufacturer for product specific specifications regarding maximum load, minimum cover depth and porosity or water storage per unit area. | *'''Void-forming structures:''' Includes chambers, vaults, crates or perforated pipes that provide large water storage volume per unit area, reduce required facility footprint area and conserve aggregate. Plastic chamber systems should be compliant with CSA B184 SERIES 11 (R2015) or ASTM F2418-16A. Maximum allowable load for plastic chambers must be determined in accordance with ASTM F2787-13. Concrete vault systems should be compliant with CSA A23.3-14 and CSA A23.1-09/A23.2-09 (R2014) or ASTM C858-10e1. See manufacturer for product specific specifications regarding maximum load, minimum cover depth and porosity or water storage per unit area. |