Hi Everyone, I am building a new mini storage facility in my area and my engineer and I are getting down to the last stages of drainage. Since my property is in the county (not city) and I will have my own ponding basin on site I asked my engineer if he could do the drainage specs based on dual wall corrugated pipe instead of SDR 35 (PVC). The main reason I would like to use this pipe is because of the the overall reduction price. I need about 1500' of pipe ranging from 12" to 21". From what I have heard corrugated pipe is much cheaper then traditional PVC pipe and concrete pipe. Is this true considering all aspects (material price, labor price, base material/sand, etc.)? Unfortunately because my engineer is not so familiar with these types of products and I can't get a straight from underground contractors, I am left in the dark. Any info. on this topic is much appreciated, thanks!