409.1 Circulation systems for pools shall comply with Section 311 of the 2012 International Swimming Pool and Spa Code (ISPSC) and this section.

409.2 Circulation equipment shall be sized to turn over the entire water capacity of the pool as specified in Table 407.2 of the 2012 International Swimming Pool and Spa Code (ISPSC). The system shall be designed to provide the required turnover rate based on the maximum pressure and flow rate recommended by the manufacturer for the filter and clean filter media.

TABLE 407.2 TURNOVER RATE

Swimming Pool Category	Turnover rate In hours
Class A, B, and C pools	Hours equal 1-1/2 times the average depth of pool in feet not to exceed 6 hours
Wading pools	1

SOURCE: Final Rulemaking published at 64 DCR 5359 (June 9, 2017).