Conductor casing shall be set to a minimum depth of 40 feet below ground level or to bedrock, whichever is less.  The conductor hole shall be drilled with fresh water and native mud or air.  No chemicals or foreign substances are to be added to the drilling fluid.  The conductor casing shall be cemented to the surface by circulating cement or by using the grout method.  After cementing the conductor casing, drilling shall not be resumed until the cement has set for 24 hours.
(Ord. 2991, passed 7-19-94)