Section 58.01.16.470 - FACILITY AND DESIGN STANDARDS FOR MUNICIPAL WASTEWATER TREATMENT OR DISPOSAL FACILITIES: SETTLING01.General.a. Where settling is being used, a minimum of two (2) units capable of independent operation are desirable and shall be provided in all plants where design average flows exceed one hundred thousand (100,000) gallons/day. Plants not having multiple units shall include other provisions to assure continuity of treatment.b. The design of settling facilities shall include a minimum of two (2) units with flow splitting. Sizing shall be calculated for both design average and design peak hourly flow conditions, and the larger surface area determined shall be used.c. The plant design shall allow for isolation of each unit. The plant design shall allow for sludge and scum removal.d. Baffling shall be designed to control solids carry-over.e. The minimum side depth for primary settling facilities shall be ten (10) feet.f. The minimum side depth for secondary settling facilities shall be twelve (12) feet.Idaho Admin. Code r. 58.01.16.470