Sec. 470.306. - Septic tank capacity.

(a) Every septic tank shall have the capacity required in this Section, depending upon the use to which the septic tank system is to be put and upon the daily sewage waste flow. If the septic tank has more than one compartment, the first compartment shall have the required capacity. The required capacities are based upon a 24-hour detention time interval for efficient sedimentation, plus sludge storage volume. The Director may vary the capacity requirements of the Section to take into account actual detention time intervals in individual cases. (b) The effective capacity for a residence and a multiple dwelling shall be based on the number of bedrooms and determined by reference to Table 470-1. This capacity standard contemplates a single system serving the combined household wastes from all flowing fixtures and appliances commonly used in residences, including a food waste grinder, a dishwasher and an automatic clothes washer. (c) The effective capacity for any other building shall be determined by the applicable estimated daily sewage waste flow listed in Table 470-2 or by the actual maximum daily sewage waste flow if it can be reliably measured by metering, and by reference to the following classifications: (1) If the estimated or, if applicable, the actual, daily sewage waste flow is 450 gallons or less, the minimum effective capacity of the septic tank shall be 750 gallons. (2) If the estimated or, if applicable, the actual, daily sewage waste flow is more than 450 gallons, the minimum effective capacity of the septic tank shall be the estimated or actual daily sewage waste flow plus 300 gallons (for sludge storage volume). Table 470-1 Minimum Effective Capacity By Reference to Bedrooms Number of Bedrooms Minimum Effective Capacity (gallons) 2 or less 750 3 900 4 1,050 5 1,200 Each additional bedroom, add 150   Table 470-2 Estimated Daily Sewage Waste Flow Type of Establishment Gallons Per Day per Person Multiple apartment building (over four units) ..... 75 Rooming house ..... 40 Hotel and motel ..... 50 Restaurant (toilet and kitchen waste per meal served) ..... 10 Bar and cocktail lounge ..... 5 Kitchen wastes—restaurant, hotel, boardinghouse, and similar establishment (per meal served) ..... 3 Tourist camp or trailer park ..... 50 Resort camp (night and day) with limited plumbing ..... 50 Luxury camp ..... 75 Work or construction camp (semi-permanent) ..... 50 Day school with cafeteria, gym and shower [quantity to be estimated from total (100%) enrollment] ..... 11.5* Day school without cafeteria, gym or showers ..... 8.5* Day school with cafeteria but no gym or shower [quantity to be estimated from total (100%) enrollment] ..... 9.5 Boarding schools ..... 75 Day workers at schools and offices ..... 15 Hospitals (per bed) ..... 150—120 Public institution other than hospital ..... 75—125 Factories (gallons per person per shift, exclusive of industrial waste): Showers not provided ..... 15 Showers provided ..... 35 Public picnic park (toilet wastes only) ..... 5 Picnic park, with bathhouse, showers and flush toilet ..... 10 Country club (per resident member) ..... 100 Country club (per member present) ..... 25 Drive-in theaters (per car space) ..... 5 Movie theaters, auditoriums, churches (per seat) ..... 3 Airports (per passenger) ..... 5 Stores, without kitchen wastes (per toilet room) ..... 400 Service stations (per vehicle served) ..... 10 Bowling alley (toilet wastes only, per lane) ..... 100 Stadium, frontons, ball parks (per seat) ..... 3 Self-serve laundries (toilet wastes only, per machine) ..... 40   *The above values are based on 100 percent of students eating meals and 100 percent of students showering. Whenever cafeteria or shower facilities are provided for the general enrollment the above values shall be used. Where physical conditions are known to exist which will increase or decrease the actual 100 percent use of these facilities (i.e., parent cafeteria preparing meals for other schools, or combined elementary and junior high school where only the junior high students are authorized to shower), the following adjustment factors are authorized: Meals Showers For each student in excess of 100% of enrollment, add 1.0 gal. 2.2 gal. For each student less than 100% of enrollment, subtract 0.0 gal. 0.7 gal.   NOTE: The quantities of estimated daily sewage waste flow listed in Table 470-2 do not take into account garbage and laundry wastes. If either garbage or laundry waste is discharged into the septic tank system, the minimum sewage waste flow shall be increased by a reasonable amount determined by the Director, based upon the estimated quantity of garbage and laundry wastes discharged into the system. (Ord. 70-650-526; Ord. 71-397-181; Ord. 75-825-341, § 2; Ord. 83-591-400, § 1) Note— Former § 624.306.