Section 3132B Cartridge Filters
In addition to the requirements for all filters as indicated in Section 3128B, the following apply to cartridge filters.
The filtration rate shall not exceed 0.375 gallons per minute per square foot of filter area.
An approved wash down area equipped with potable water shall be provided in the pool equipment area with permanently installed drainage piping discharging to the public sewer or wastewater system approved by the enforcing wastewater agency. The filter vessel shall be capable of being drained and shall be equipped with an indirect drain for the purpose of draining the entire contents of the filter vessel. Drainage and backwash piping shall be considered indirect waste and installed in accordance with the requirements of Chapter 8 of the California Plumbing Code.