Materials
All sanitary piping below grade shall be cast iron, hub and spigot construction. Sanitary piping above grade shall be the same, or Type “L” copper with soldered joints and fittings.
Sizing and Slope
Piping shall be sized and sloped to maintain a minimum effluent velocity of 2 feet per second. The minimum pipe slopes shall be ¼” per foot for piping 3” and smaller, and ⅛” per foot for piping larger than 3”. All pipe sizing shall meet applicable Codes and standards. If considerations are being made for future demand, notes shall be provided on plans and estimates of future demand shall be added to the calculations for the entire system. All underground piping shall be a minimum of 4” diameter.
Distribution
Sanitary piping shall be routed in accessible areas where possible. All plans shall include sanitary piping invert depths at the beginning of the main pipe run and at the point of connection to the exterior piping. Piping cleanouts shall be provided at the following locations:
- 5 feet outside or inside the building at the point of exit
- At every change of direction greater than 45 degrees
- At every change of direction
- Every 50 feet for underground sanitary piping 4” and smaller
- Every 100 feet for underground sanitary piping 5” and larger
Floor Drains
Floor drains shall be provided in all spaces where there is a sink or other plumbing fixture present with the probability of a floor water hazard. These spaces include but are not limited to:
- Toilet Rooms (Refer to CPS Standard ADA Detail Sheets for location)
- Janitor’s Closets
- Mechanical Rooms
- Trash Rooms
- Locker Rooms/Showers
- Science Classrooms that include Emergency Showers
- Shop Area: Service/hand sink
- Makerspace: Service/hand sink
Interceptors
Interceptors shall be used to remove any waste which cannot be discharged directly to the Sanitary system. All interceptors shall be properly vented to the exterior. Interceptor basins shall be placed so that they can be easily maintained. The types of Interceptors include:
- Grease Interceptor - Shall be used in all spaces where cooking and dishwashing (in Food Hall Kitchen only) takes place. All floor drains, floor sinks, and trench drains in these spaces shall be routed through the grease interceptor. All grease interceptors shall be vented. Disposals and Dishwashers (in Food Hall Kitchen) shall not be routed to the grease interceptor. Large grease interceptors serving Kitchens shall be located outdoors in locations easily accessible by pumper trucks. Small, point-of-use grease interceptors serving pantry sinks in Staff Lounges, shall be located in a cabinet adjacent to the sink and installed in a manner that will allow for servicing and maintenance.
- Solids Interceptor - Shall be used at the hand/service sink in all Pre-K/K Classrooms, Visual Art Classrooms, Makerspace and Shop Areas. Interceptors shall include signage to prevent the disposal of organic waste through this fixture.
- Acid Neutralization Basin - Shall be provided in all Science Classrooms where the use of chemicals is anticipated or may be used in the future. Acid Waste venting shall be required from each unit to the exterior through a dedicated acid vent piping system.
- Oil Interceptor - Shall be used in Automotive Shop areas or Parking Garages for collection of oil for proper disposal. Vent directly to the exterior.
- Triple Basin - An exterior triple basin may be used in special circumstances when required by the size of the required basin or building layout. This basin may be used for oil separation.
Kitchen
Sanitary piping within a Kitchen shall be coordinated with the layout of the Kitchen equipment. This layout, including connection locations, sizes and flow rates, shall be provided by CPS Nutrition Support Services. These areas requiring the use of special drain fixtures which include: floor sinks, trench drains, and open site drains for discharge of elevated systems. All kitchen floor drains shall be routed through the Grease Interceptor prior to being discharged to the sanitary system.
Special Systems
For all specialty plumbing systems, all fixtures, piping, materials and installation shall meet all applicable Codes. Any special systems not listed in these Design Guidelines shall be reviewed and approved for use by CPS. There are some alternate systems which may apply to some projects. These include:
- Acid/Chemical Waste Piping - This system shall be used in lieu of individual Acid Neutralization Basins in Science Classrooms. This piping shall extend to a central Acid Neutralizing system, typically located in a Mechanical space.
- Fire Suppression Water Drainage - These shall be required at all zone valve locations outside of the Fire Pump Room to allow for drainage of that zone for maintenance and modifications. These drains may be tied together in a riser arrangement, and shall be routed to a holding basin for analysis prior to discharge to the environment.