introduCtion Underground construction is an industry that involves a number of key stakeholders and a variety of alternatives that can change from project to project. It is especially important in light of federal, provincial, and municipal specifications and codes that our industry remain well informed and technically knowledgeable concerning underground infrastructure. The purpose of this manual is to accomplish this goal. We hope you find this manual an asset in designing and constructing quality underground projects. Lafarge has been an industry leader in the development, manufacture and promotion of concrete pipe and precast concrete drainage structures for many years. We supply concrete pipe, manholes, catch basins, box sections, culverts, and oil/grit separators to the underground construction industry. We trust the information contained in this manual will be helpful to you and that you will consider specifying Lafarge Concrete Pipe in your projects. If you require additional information related to these of any other Lafarge products, please do not hesitate to let us know. Lafarge would like to specially acknowledge the American Concrete Pipe Association (ACPA) for granting permission to use their literature in this manual, particularly content from the Concrete Design Handbook. For more information on the ACPA, please visit Lafarge would also like to acknowledge contributions from the Canadian Concrete Pipe Association and the Ontario Concrete Pipe Association. We hope the material contained in this resource serves you well in your efforts to design and specify precast concrete drainage structures. ConCrete pipe stormwater treatment teChnologies Lafarge Pipe box seCtions manhole and CatCh basin material