Agenda - Council - 06/10/1997 - Laserfiche WebLink

Home

§ 8.30 10. 11. 12. condition. Excavation shall be made only when the soil moisture content is at or less tb_~n the plastic limit. V/hen the soil percolation rate at the bottom of the trench or bed is slower than 15 rn~nutes per inch, no vehicle or excavation equipment shalt be allowed on the trench or bed area. Excavation aha1] be by back hoe or other means that allow the equipment wheels or tracks to remain on the surface soils. Excavation equipment or other vehicles shall not be driven on the soil treatment area. There shall be a layer o£ at least 6 inches, but no more than 24 inches of drainfield rock in the bottom of the trenches and beds. Where disposal trenches are constructed within 10 feet of trees 6 inches or larger in diameter, or dense shrubbery, or where it can reasonab]y be anticipated that such vegetation will be present during the expected life of the system, at least 12 inches of filter materia] shall be placed beneath the distribution pipe. Distribution pipe used in trenches or beds for gravity flow distribution shall be at least 4 inches in diameter and constructed of solid and durable material not subject to corrosion or decay or to loss of strength under continuously wet conditions. a) Agricultural drain tile shall be in 12-inch lengths and laid v~th .25-inch open joints on grade boards. All open joints shall be protected on top by strips of asphalt treated building paper at least 10 inches long and 3 to 6 inches wide or by other acceptable means. b) Other devices may be used to distribute sewage tank effluent over the soil treatment area upon approval of the adru~rdstrator. Distribution pipes used in trenches or beds for pressure distribution shall be at least 1 inch in diameter and constructed of sound and durable material not subject to corrosion or decay or to loss of strength under continuously wet conditions. a) Perforations shall be sized and spaced as sho~vn in Table I. The distribution pipes shall be laid level or on a uniform slope away from the distribution device of no more than 4 inches per 100 feet. The distribution pipes in beds shall be uniformly spaced no more than 5 feet apart and not more than 30 inches from the side walls of the bed. I I I I I I I: I: I I I I I I I I I I Page 252 Printed 12/28/90