This L.A I know mentioned that a P.E can actually desgn and sign a set of Landscape Plans. Keep in mind this is Florida so the statutes may allow this.
Well then 2+6 doesn't equal 60% either.
Nicole, why the America Water Works Association? If that will give you guidance than more power to you. I would simply refer to either a county or city public works department for thier input. Stick to the specs....
This is the part where you go to the city/county specifications and see for your self if this infact is correct. Never have other people make assumptions for you.
Besides....they add up to 14'' and I don't think that pipe is manufactured in 14''. It depends.