(A) Shaped bottom bedding (NPW-1). Shall be so the pipe bears uniformly upon undisturbed native earth. Soil is then backfilled and tamped by hand around the pipe (and completely under the pipe haunches) in uniform layers not exceeding six inches in depth to ten inches above the top of pipe. Each six-inch layer shall then be placed, then carefully (so as not to disturb or damage the pipe) and uniformly tamped, eliminating the possibility of lateral movement.
(B) Type II - granular material embedment (NPW-3). Shall be when the trench bottom is undercut a minimum of six inches below the pipe barrel grade and filled with an approved stone as shown in the standard details.
(C) Type III - granular material embedment (NPW-4). Shall be when the trench bottom is undercut a minimum of six inches below the pipe barrel grade and filled with an approved stone to an elevation such that the pipe will be completely and uniformly bedded.
(D) Concrete encasement and cradles (NPW-5). Shall be as shown in the Standard Details.
(Ord. passed 6-21-2011)