Illinois Administrative Code › Title 77 - PUBLIC HEALTH › Part 906 - PRIVATE SEWAGE MOUND CODE › Section 906.60 - Distribution System (for sewage flows of less than 800 gallons per day)

Current through Register Vol. 48, No. 28, July 12, 2024
a) Piping System.
			 The piping distribution system for the mound shall consist of a manifold pipe
			 and small diameter laterals with perforations. The perforations shall be
			 drilled at 30"-36" intervals along with the invert of the lateral. Perforations
			 shall be installed perpendicular to the pipe axis. Perforation diameters shall
			 be between 3/16" and 1/4". If the distance between the end of the lateral and
			 the nearest perforation is greater than 1/2 the perforation spacing used,
			 another hole shall be installed in or near the end cap of the lateral. A
			 typical distribution system of a mound is shown in Appendix A, Illustration E.
			 For a trench system, one lateral shall be required per trench; for a bed
			 system, up to 3 laterals may be used. Laterals shall extend to within 6 inches
			 of the end of the bed or trench. Lateral spacing shall be a maximum of 3 ft.
			 for beds in small mounds only (1-4 bedroom sized system). Pipe diameter will
			 depend upon the length of bed or trenches. The allowable lateral lengths for
			 various size diameter pipes and various hole spacings are given in Appendix A,
			 Exhibit D. The system shall be designed and placed so that the laterals and
			 manifold drain after every dosing. If the mound is downslope of the pumping
			 chamber, the manifold shall be on top of the laterals so the manifold drains,
			 or cross-to-cross construction used. For systems which are to treat a flow of
			 more than 800 gallons per day, the manifold and lateral network must be
			 designed in accordance with Section
			 906.70.
			 All piping shall be Schedule 40 Polyvinyl Chloride (ASTM Standard D1785/76) or
			 Schedule 40 Acrylonitrile/Butadiene/Styrene (ASTM Standard D1527/77).
b) Pumping System. The components of the
			 pumping system shall consist of the pumping chamber, pump, pump controls and
			 alarm system as shown in Appendix A, Illustration F. The dosing volume shall be
			 ten times the total lateral pipe void volume or one-fourth the estimated daily
			 sewage flow, whichever is greater. Appendix A, Exhibit F lists the void volumes
			 for various sizes of pipe. The daily volume of sewage shall be determined using
			 Appendix A, Illustration A of the Private Sewage Disposal Code (77 Ill. Adm.
			 Code 905).
1) Pumping Chamber Requirements.
A) Pumping Chamber. Appendix A, Illustration
			 F gives a cross-section of a typical pumping chamber. The volume shall be
			 sufficient to provide the desired dosing volume, space for controls, space for
			 setting the pump on a pedestal, and extra volume for a malfunction and
			 flow-back after pump shuts off. Appendix A, Exhibit G establishes pumping
			 chamber sizes for the various sized systems. Larger tanks may be used, but they
			 may limit the flexibility of adjusting the desired dosing quantity. Sufficient
			 volume must be available to provide for the dose volume, pump pedestal and
			 controls.
B) The pumping chamber
			 shall be waterproof. Waterproofing shall consist of sealing all joints and
			 coating the outside of the tanks. The pumping chamber shall be filled with
			 water after being installed and back filled to prevent the pumping chambers
			 from floating out of position due to hydrostatic pressures, unless the tank is
			 installed in dry soil. A riser pipe shall extend at least 6 in. above the
			 ground surface. All electrical controls shall be mounted outside the tank. The
			 pump disconnect shall be accessible for easy pump removal in the event of pump
			 failure.