(A) Location.
(1) New sanitary sewers.
(a) All sanitary sewers are to be located within the public right-of-way, unless otherwise approved by the Department. The pipe must be located to allow for a minimum of ten feet of right-of-way on each side.
(b) If due to development constraints the right-of-way is not able to accommodate the proposed sewer, then a separate sanitary sewer easement is to be granted. The easement is to be a minimum of 20 feet, dedicated as an exclusive sanitary sewer easement to the Town of Clarksville and recorded in the Office of the Clark County Recorder. Other utilities may locate within the easement upon prior written approval of the Utility Director or their designee on a case-by-case basis.
(c) Sanitary sewers shall not be located in rear yards or inaccessible areas as determined by the Utility Director or their designee.
(2) Existing sanitary sewers.
(a) All proposed developments shall be configured to allow for adequate access to existing sanitary sewers. This includes placement of facilities within common areas, proposed or current rights-of-way, or easements.
(b) No redevelopment shall allow for the placement of sanitary sewers in rear yard or inaccessible areas without the prior written consent of the Utility Director, which consent shall be granted or denied in the exercise of their sole discretion.
(B) Pipe slope and grade.
(1) All proposed sanitary sewers must be sized to accommodate the anticipated flows. The Department shall determine if the flows used for design are adequate.
(2) Gravity sewers shall be a minimum of eight inches in diameter.
(3) Service laterals for residential homes shall be a minimum of four inches in diameter from the home to the right-of-way, and six inches in diameter from the right-of-way to the main.
(4) Commercial laterals shall be a minimum of six inches in diameter.
(C) Slopes.
(1) Gravity sewer lines eight inches or more in diameter shall have a slope no less than as shown on the following table:
Pipe Diameter | Slope |
Pipe Diameter | Slope |
8-inch | 0.40% |
10-inch | 0.28% |
12-inch | 0.22% |
15-inch | 0.15% |
18-inch | 0.12% |
21-inch | 0.10% |
24-inch | 0.08% |
(2) Design slopes above the minimum are encouraged.
(D) Alignment.
(1) There shall be a minimum of ten feet of separation between sanitary sewer facilities and water mains. Exceptions to this may be granted on a case-by-case basis with approval by both the water company and the town.
(2) All gravity sewers shall be installed on a straight line and grade. Any error in horizontal alignment of one-half inch or more in anyone joint of pipe shall require removal and proper reinstallation. Any error in vertical alignment of more than one-quarter inch or more in any single joint of pipe shall require removal and proper reinstallation.
(E) Minimum cover. All gravity sewers shall have a minimum depth of 36 inches. If this depth cannot be maintained, than ductile iron pipe may be substituted; however, there still must be a minimum depth of 24 inches.
(F) Special requirements.
(1) No footer drains, sump pumps, downspouts, area drains, or any other such drains for rainwater shall be discharged into any public sanitary sewer.
(2) In no case in which a floor drain or low-level plumbing is to be connected to a sanitary sewer shall it be allowable for the floor grade of a basement or lower level of a house or building to be less than three feet above the crown of the sanitary sewer in the street or easement.
(3) A back flow preventer must be installed by the property owner where a floor drain or other low-level plumbing fixture is to be connected to the sanitary sewer. A back flow preventer must be installed in the basement or in an accessible vault or pit for maintenance.
(4) When any lateral is accessed for repair or replacement, or when a floor drain or low-level plumbing fixture is to be connected to the sanitary sewer, a check valve conforming to clean check extendable backwater valve standards must be installed.
(5) The top of castings of all manhole structures shall be at least one foot above the 100-year flood elevation. In areas where this requirement cannot be met, bolt down castings shall be installed.
(6) No portion of any home or permanent structure shall be built within ten feet of any main sewer.
(G) Manholes.
(1) Manholes shall be placed no further than 350 feet apart.
(2) Manholes shall be placed where pipe alignment, slope, materials, and/or size changes.
(3) The angle, between any inlet pipe and the outlet pipe, must be equal to or greater than 90 degrees.
(4) Minimum manhole diameter is 48 inches.
(5) Outside drop manholes shall be provided in cases where the invert of any incoming sanitary sewer enters the manhole at elevations greater than 24 inches. Inside drop manholes are permitted only with the prior written approval of the Utility Director or their designee.
(Ord. 2020-SW-02, passed 3-3-20) Penalty, see § 51.999