Poway Municipal Code Art. V Specifications

A. Any subsurface sewage disposal unit or system or part thereof hereafter constructed or installed in the City shall be so situated as determined by the Director. In determining what is a “safe distance” the Director shall consider the source of possible pollution, the type of soil, surface and subsurface, the type and source of water supply, the geological formation of the ground, the direction of surface drainage, and the depth and direction of groundwater flow.

B. Under no circumstances shall any part of such subsurface sewage disposal unit or system, except the house sewer line, be located closer than 50 feet from any groundwater supply.

C. No part of such subsurface sewage disposal unit or system except the house sewer line, shall be located less than five feet from every building or structure or less than five feet from every property line.

(CC § 68.340; Ord. 29 § 1, 1981)

Any house sewer line or part thereof hereafter constructed or installed in the City shall be constructed of bell and spigot cast iron pipe with leaded joints when located less than 50 feet from any well used as a domestic water supply.

(CC § 68.341; Ord. 29 § 1, 1981)

Any subsurface sewage disposal unit or system hereafter constructed or installed in the City shall consist of a septic tank with effluent discharging into either:

A. A serial distribution system; or

B. A distribution box connected to a subsurface tile system consisting of at least two lateral absorption lines, each of which lines shall not exceed 100 feet in length; provided, that with the approval of the Director such distribution box may be connected to a seepage pit or pits each having at least four feet inside diameter.

(CC § 68.342; Ord. 29 § 1, 1981)

Any septic tank hereafter constructed or installed in the City shall meet the following minimum specifications:

A. Such tank shall have an inside diameter of at least five feet with a liquid depth of at least four feet. The length of the tank shall not exceed three times the width of such tank. Such tank shall have a liquid capacity of not less than 1,000 gallons. Such tank shall have at least two compartments, and a manhole with a minimum diameter or width of 22 inches shall be installed in each compartment, over the inlet and outlet pipe.

B. The inlet and the outlet of such tank shall each be a vertical four-inch diameter “T” extending such a distance below the liquid level that 40 percent of the liquid depth is below it, and extending a minimum of six inches above the liquid level of the tank. The outlet shall be two inches below the inlet.

C. Such tank shall be watertight and shall be constructed of concrete, concrete block, brick or tile. The top of such tank shall be constructed of reinforced concrete at least four inches thick. When such tank is constructed, the walls and bottom of the tank shall be at least six inches thick and shall be adequately reinforced with steel or other approved material. The concrete used for such tanks shall contain one part cement, two parts sharp sand and four parts crushed rock or gravel. Where brick, concrete block, or tile is used in the construction of such tank, the inside shall be plastered with Portland cement mortar composed of one part cement and three parts sand. The side walls of such tank shall be adequately reinforced with steel or other approved material so as to withstand any inside or outside pressure.

D. The line from such septic tank to the distribution box shall be constructed of watertight bell and spigot pipe, or such other pipe with watertight joints that the Director may approve.

(CC § 68.343; Ord. 29 § 1, 1981)

Any distribution box hereafter constructed or installed in the City shall meet the following minimum specifications:

A. Such distribution box shall be watertight and shall be constructed of the same materials authorized for construction of a septic tank. The inner surface of the distribution box shall have a protective coating of Hunt’s Emulsion, or some other protective coating equal thereto in the opinion of the Director.

B. The outlets from such distribution box shall have exactly the same elevation and shall be located at least two inches above the bottom of the box. The inlet to such distribution box shall be one inch above the elevation of the outlets.

C. Such distribution box shall be connected to a subsurface tile system consisting of at least two lateral absorption lines; provided, that one or more seepage pits may be substituted for or used in conjunction with lateral absorption lines when approved by the Director.

D. All lines leading from the distribution box to the lateral absorption lines or to seepage pits shall be constructed with watertight joints.

(CC § 68.344; Ord. 29 § 1, 1981)

Any subsurface tile system hereafter constructed or installed in the City for the purpose of disposing of the effluent from a septic tank shall meet the following minimum specifications:

A. Such tile system shall consist of at least two lateral absorption lines totaling at least 200 feet in length; provided, however, that no line shall exceed 100 feet in length. The lines shall be approximately equal in length, with a maximum variation of 10 percent between the longest line and the shortest.

B. Lateral absorption lines shall be constructed of tile pipe spaced one-quarter inch apart so as to provide open joints. The upper one-half of each open joint shall be covered with tar paper or copper screen.

C. Each lateral absorption line shall be placed in a trench 36 inches deep and 18 inches wide, which trench shall contain at least 21 inches of rock or gravel grading one to one and one-half inches. At least 12 inches of such rock or gravel shall be beneath the bottom of the line, and four inches of such rock and gravel shall be over the top of the line.

D. Lateral absorption lines shall have a grade of two inches per 100 feet with not more than 50 percent variation either way.

E. Lateral absorption lines shall not be more than 36 inches below the surface of the ground, without the prior approval of the Director.

F. Every lateral absorption line shall be at least 10 feet from every other lateral absorption line. All bends used in the disposal field shall have one tight joint to each end of the bend.

(CC § 68.345; Ord. 29 § 1, 1981)

A seepage pit or series of seepage pits may be substituted for or used in conjunction with a subsurface tile system, when such substitution or use is approved by the Director; provided, however, no seepage pit shall be permitted where the Director determines that its use might contaminate or pollute an underground water supply.

(CC § 68.346; Ord. 29 § 1, 1981)

Any seepage pit hereafter constructed or installed in the City shall meet the following minimum specifications:

A. Such seepage pit shall be not less than four feet inside diameter and shall be constructed to a depth where the side wall area of the seepage pit will have sufficient porosity to provide adequate drainage as determined by the Director.

B. Such seepage pit shall be either rectangular or round. In the case of a rectangular shape, such seepage pit shall be constructed of brick, concrete block, and/or two-inch redwood plank securely braced with four-inch by four-inch redwood timber. In the case of a round shape, such seepage pit shall be constructed of brick, concrete block, and/or one-inch redwood boards of full thickness with supporting two-inch by three-inch redwood timbers placed every five feet so as to form a securely braced octagon shape.

C. The top of such seepage pit shall be covered with a concrete slab or cover constructed of concrete reinforced with steel or other approved material, which slab or cover shall extend not less than 18 inches beyond the outside of the side walls of the seepage pit.

(CC § 68.347; Ord. 29 § 1, 1981)

The minimum standards for septic tanks, distribution boxes, tile lines and seepage pits as set forth in this chapter are the minimum standards for a subsurface sewage disposal system or unit serving a one-family or two-family residence or small institution or industry having sanitary facilities used by not more than 10 persons.

(CC § 68.348; Ord. 29 § 1, 1981)

Every applicant for a permit to install or construct a subsurface sewage disposal system or unit to serve residences, institutions or industries, other than a one-family or two-family residence or a small institution or industry having sanitary facilities used by more than 10 persons, shall submit to the Director for approval the detailed plans and specifications of the proposed subsurface sewage disposal system. Upon the filing of the required application, accompanied by such detailed plans and specifications, the payment of the fee hereinbefore prescribed and the approval of such plans and specifications by the Director, the Director shall issue a permit for the construction of such subsurface sewage disposal system.

(CC § 68.349; Ord. 29 § 1, 1981)

Nothing contained in this chapter shall be construed to prevent the Director from requiring compliance with higher or more stringent requirements or specifications than those contained in this chapter where compliance with such higher or more stringent requirements or specifications is necessary to maintain a sanitary condition.

(CC § 68.350; Ord. 29 § 1, 1981)

Nothing contained in this chapter shall be construed to prevent the Director from establishing lower or less stringent requirements or specifications than those contained in this chapter in such cases where a subsurface sewage disposal unit or system may be maintained at such lower or less stringent requirements or specifications in a sanitary condition without detriment to the public health or safety.

(CC § 68.351; Ord. 29 § 1, 1981)