The irrigation system shall be sized in accordance with the gallons-per-day-per-occupant number based on the type of fixtures connected to the
gray water system. The discharge shall be calculated by the following equation:
| C = (A × B) - D | (Equation 7-1) |
where:
Residential—For dwelling units regulated by this code in accordance with Section 101.3, the number of occupants shall be determined by the actual number of occupants, but not less than two occupants for one bedroom and one occupant for each additional bedroom.
Commercial—Number of occupants for buildings without dwelling units shall be determined by the International Building Code.
| B | = | Estimated flow demands for each occupant: |
Residential— For dwelling units regulated by this code in accordance with Section 101.2, 25 gallons per day (94.6 Lpd) per occupant for showers, bathtubs and lavatories and 15 gallons per day (56.7 Lpd) per occupant for clothes washers or laundry trays.
Commercial—For buildings, without dwelling units, based on type of fixture or water use records minus the discharge of fixtures other than those discharging gray water.
| C | = | Estimated gallons (L) of gray water discharge based on the total number of occupants. |
| D | = | Estimated gallons (L) of gray water to be used within the interior of the building. |
