Section 3105 - Proof of rock cover(a) Proof of the existence of thirty-five feet of rock cover shall accompany any plans submitted.(b) Said proof of rock cover is to be ascertained by test holes drilled on intersecting lines forming rectangles or squares where the cover thickness is less than fifty feet. These holes shall be drilled on spacing of not more than thirty-five feet centers.1959, Dec. 22, P.L. 1994, § 5.