1. (a) A pressure sewer system shall have at least one grinder pump at each building or residence that is connected to the system.
2. (b) The minimum capacity requirements for a pressure sewer system and each grinder pump connected to a pressure sewer system shall be determined based on hydraulic modeling of the entire pressure sewer system and the main sewer to which the pressure sewer is proposed to be connected.
3. (c) A design report for a pressure sewer system shall be prepared by the engineer and submitted in accordance with Env-Wq 703.01.
4. (d) Pressure sewer design shall provide a minimum cleansing velocity of 2 feet per second.
5. (e) Pressure sewers shall be constructed with force main materials as specified in Env-Wq 704.08 and tested as specified in Env-Wq 704.09.

6. (f) Grinder pumps for pressure sewer systems shall be:

   1. (1) Wet well type;
   2. (2) Readily removable without manual disconnection of piping;
   3. (3) Rotating type with a stationary hardened and ground stainless steel shredding ring with stainless steel cutters;
   4. (4) Capable of reducing all components in typical domestic sewage, including a reasonable number of foreign objects, including but not limited to wood, paper, plastic, glass, and rubber, to a size that will pass through pump passages and a 1.25-inch nominal diameter pipe;
   5. (5) Positioned so solids are fed into pump from the bottom in an upward flow;
   6. (6) Capable of processing foreign objects without jamming, stalling, or overloading;
   7. (7) Accessible for maintenance and replacement; and

   8. (8) Equipped with:

      1. a. Non-fouling sensing devices for high level alarms;
      2. b. A visible alarm light;
      3. c. An audible alarm;
      4. d. A gravity-operated, integral anti-siphon valve with corrosion-resistant moving parts; and
      5. e. A suitable receptacle and transfer switch in the electric supply panel for connection to a portable generator.

7. (g) A grinder pump tank shall be designed to withstand HS-20 loading if installed in a location where traffic loads are anticipated and consist of:

   1. (1) A manhole meeting the requirements of Env-Wq 704.12 through Env-Wq 704.17;
   2. (2) A reinforced concrete tank;
   3. (3) A high density polyethylene tank; or
   4. (4) A fiberglass-reinforced polyester resin using a filament wound process, layup, and spray technique.

Source. (See Revision Note at chapter heading for Env-Wq 700) #8590, eff 3-25-06; ss by #10693, eff 10-15-14; ss by #14258, eff 7-1-25, EXPIRES: 7-1-35