N.J. Admin. Code § 7:14A-23.12 - Dry wells and wet wells

(a) The construction of dry wells and wet wells for sewage pumping stations shall meet the following requirements:

1. Dry and wet wells shall be completely separated and have adequate ventilation and drainage;

2. Dry wells and wet wells shall have a means of entrance and exit, preferably by a stairway;

3. Dry wells shall have sufficient accessible space for the repair and removal of pumps;

4. The detention time of a wet well shall not exceed ten minutes when the flow is at the average dry weather rate. The detention time is calculated by dividing the volume of the wet well (volume between the pump on and the pump off switch levels) by the projected flow for the pumping station;

i. Wet well detention times greater than 10 minutes may be approved by the Department for small pump stations that cannot meet this requirement due to the minimum available size of the wet well and an estimated low volume daily wastewater flow. If longer detention times are proposed, additional measures necessary to prevent the development of septic conditions may be required;

ii. To minimize the development of septic conditions during the early phases of pump station operation, the Department may require special operational and/or maintenance procedures particularly when the initial contributory flows will be substantially below the approved design flow;

5. The base of pump station wet wells shall slope at least 45 degrees toward the pump suctions to prevent solids accumulation; and

6. A sump pump or other effective method to drain accumulated water from the dry well to the wet well and to prevent sewage from entering the valve pit during surcharged wet weather conditions shall be provided.

Notes

N.J. Admin. Code § 7:14A-23.12