N.J. Admin. Code § 7:9A-5.5

Current through Register Vol. 56, No. 12, June 17, 2024

Section 7:9A-5.5 - Rock substrata

(a) Criteria for recognition of rock substrata shall include but not be limited to the following:

1. Any solid and continuous body of rock, with or without fractures, or any weathered or broken body of rock fragments overlying a solid body of rock, in which more than 50 percent by volume of the rock fragments are greater than two-millimeters in diameter or large enough to be retained on a two millimeter sieve shall be considered to be a rock substratum. In cases where the content of coarse fragments increases downward in a soil profile underlain by a rock substratum, the upper limit of the limiting zone shall be taken as the depth above which 50 percent or more of the soil material consists of particles less than two millimeters in diameter or small enough to pass through a two millimeter sieve.

2. A rock substratum shall be considered as a fractured rock substratum if, based upon the judgment and experience of the soil evaluator, the rock substratum in question is determined to contain an adequate number of open and inter-connected fractures to allow unimpeded absorption of applied wastewater and transmission of this wastewater away from the disposal area. Any rock substratum which does not contain an adequate number of open and inter-connected fractures shall be considered a massive rock substratum. When doubt exists as to whether the limiting zone should be considered a fractured rock substratum or a massive rock substratum, the administrative authority may require a pit-bailing test or a basin flooding test to be performed as prescribed in N.J.A.C. 7:9A-6.

3. Whenever the presence of a perched zone of saturation, immediately above the rock substratum, is inferred based upon observation of soil morphology, as prescribed in 7:9A-5.8, or confined, by direct observation or by testing, as prescribed in 7:9A-5.9, the rock substratum shall be considered massive.

N.J. Admin. Code § 7:9A-5.5