In lieu of calculating the wastewater flow capacity required pursuant to ARSD § 74:53:01:20, Table 4 may be used to determine wastewater flow capacity for public parks and marinas when the usage cannot be accurately determined. Flow projections, expressed as gallons per fixture per hour, are based on the related statistical flow figures per unit of plumbing fixture. To determine the flow capacity of the system, multiply the number of hours the facility is open by the flow figure for each fixture available as given in Table 4.