N.J. Admin. Code § 7:9A-6.7

Current through Register Vol. 56, No. 23, December 2, 2024

Section 7:9A-6.7 - Basin flooding test

(a) The following equipment is required for basin flooding test:

1. Excavating equipment capable of producing a test basin as prescribed in (b) below;

2. A water supply (minimum of 375 gallons per basin filling); and

3. A means for accurately measuring the water level within the basin as required in (c) below.

(b) A test basin meeting the following requirements shall be excavated within or immediately adjacent to the proposed disposal field.

1. The bottom of the test basin shall be at a depth between six and eight feet below the bottom of the proposed level of infiltration.

2. The bottom area of the basin shall be a minimum of 50 square feet.

3. A soil profile pit excavated as prescribed in 7:9A-5.2 may be utilized for this test provided that the requirements of (b)1 and 2 above are satisfied.

4. The bottom of the basin should be made as level as possible so that high areas of rock do not project above the water level when the basin is flooded as prescribed in (c) below.

5. If ground water is observed within the test basin, the basin flooding test shall not be used.

(c) The following test procedure shall be used for the basin flooding test:

1. Step One: Fill the test basin with exactly 12 inches of water and record the time. Allow the basin to drain completely. If the time required for the basin to drain completely is greater than 24 hours, the test shall be terminated and the limiting zone in question shall be considered to be a massive rock substratum.

2. Step Two: If the basin drains completely within 24 hours after the first flooding, immediately refill the basin to a depth of 12 inches and record the time. If the basin drains completely within 24 hours of the second filling, the limiting zone in question shall be considered to be fractured rock substratum. If water remains in the basin after 24 hours the limiting zone in question shall be considered to be a massive rock substratum.

(d) Due to the potential safety hazards which are posed by the excavation of a large test basin such as that required for this test, adequate safety measures shall be taken including the use of stepped and sloped sidewalls as shown in Figure 2 of Appendix A to permit safe access to the test basin during the test procedure as well as the use of warning signs or a fence to limit access to the basin by the public during periods when the basin is left unattended, or both.

(e) The basin flooding test shall not be conducted in rock strata which have been blasted with explosives.

N.J. Admin. Code § 7:9A-6.7