Appendix G. SEWERAGE SYSTEMS

SEWERAGE SYSTEMS

1)

Sewerage services shall be provided by the town.

2)

The sewerage system shall be in compliance with the Louisiana State Board of Health, the St. James Parish Health Unit, and the town.

3)

No sewer main or other collection works shall be installed in the town, except in accordance with plans and specifications which have been approved by the town council [board of aldermen].

4)

Minimum pipe size allowed for collector line shall be eight inches in diameter, that for headers shall be six inches in diameter, and that for laterals shall be four inches in diameter.

5)

Gradients, pipe type, location, and type of manholes, and characteristics of lift stations shall be approved by the town. Minimum gradient of a gravity sewer shall be one-eighth-inch per foot and a minimum cover shall be three feet.

6)

Sanitary manholes shall be spaced at intervals not to exceed 350 feet at each junction or change in alignment.

7)

Each lot within the subdivision shall be connected to the system.

8)

All sanitary sewers shall be designed to carry peak rates of flow on 150 gallons per capita per day and/or as prescribed by the Louisiana State Board of Health. Sewer shall be constructed to meet infiltration standard as set forth by the state board of health.

9)

A subdivision developer who connects a subdivision sewerage system to the city sewerage system shall pay to the city a fee to be determined by the city at the time of connection to the sewerage system, which fee will offset the cost to the city of expanding city facilities to adequately handle the increased demand on the city system.

10)

All wye branches, tees and other special fittings shall be installed at locations indicated on plans approved by the town. Each wye shall be provided with a 45-degree bend properly connected to the branch. In cuts of eight feet or more, riser connections shall be provided with a tee having a six-inch branch in a vertical plane. A six-inch riser with double branch fitting set to proper elevation for service connections shall be constructed for the tee branch. Each connection will be recorded by marking its location at the curb. Cleanouts shall be provided at each dead end of the line and at each turn in vertical and horizontal direction in the line.

11)

In unstable soils, the foundations for wyes and tees shall be a timber platform having vertically driven timbers to develop bearing for the masonry, the pipe fitting and the backfill.

12)

Service connection lines shall be installed from the sewer line branches or risers to the property line at a grade of not less than one-eighth inch per foot. Service connection lines will be a minimum of three inches in diameter, and be placed not more than 4½ feet below finished grade. The line shall be true to line and grade, with all future connection openings being sealed tight against the entrance of water, earth or any other material until such time as the permanent connection at the property is made. Cleanout will be molded into 18" × 18" × 4" concrete slabs and clearly marked and shall be to sidewalk grade abutting sidewalk on property side.

13)

Vitrified clay pipe and appurtenances used for gravity sewers must conform to the following:

a)

Pipe and fittings. All clay pipe and fittings for use in sewer mains shall conform to ASTM specification C-200, Specifications for Extra Strength Clay Pipe. Pipe conforming to ASTM Specification C-13, Specifications for Standard Strength Clay Sewer Pipe, may be used for service connections of six inch diameter or less.

b)

Joints and couplings. Vitrified clay pipe and fittings will be joined in accordance with the provision of either ASTM Specification C-425, Specification for Compression Joints for Vitrified Clay Bell and Spigot Pipe, or ASTM Specification C-594, Specification for Compression Couplings for Vitrified Clay Plain-End Pipe.

c)

Installation. Vitrified clay pipe and fittings will be installed in conformity with ASTM Specification C-12. Recommended Practice for Installing Vitrified Clay Sewer Pipe.

14)

Cast and ductile iron pipe and appurtenances may be used for gravity and pressure sewers. Materials and installation must conform to the following:

a)

Pipe and fittings. AWWA C101, Thickness Design of Cast Iron Pipe; AWAA C106, Cast Iron Pipe Centrifugally Cast in Metal Molds, for Water or Other Liquids; AWWA C108, Cast Iron Pipe Centrifugally Cast in Sand-Lined Molds, for Water or Other Liquids; AWWA C110, Gray Iron and Ductile Iron Fittings, 2 inch through 48 inch, for Water and Other Liquids; AWWA C150, Thickness Design of Ductile Iron Pipe; AWWA C150, Ductile Iron Pipe, Centrifugally Cast, in Metal Molds or Sand lined Molds for Water or Other Liquids.

b)

Linings and coatings. All cast and ductile iron pipe used in sewer must have an interior lining and an exterior conforming to the following specifications:

AWWA C104, Cement Mortar Lining for Cast Iron and Ductile Iron Pipe and Fittings for Water AWWA C105, Polyethylene Encasement for Gray and Ductile Cast Iron Piping for Water and Other Liquids.

c)

Joints. Joints shall conform to the provisions of AWWA C111, Rubber Gasket Joints for Cast Iron and Ductile Iron Pressure Pipe and Fittings.

d)

Installation. Installation will be in accordance with the manufacturer's recommendations, the recommendations of the "Handbook of Cast Iron Pipe" (Cast Iron Pipe Research Assn. Chicago, Ill.), and good engineering practice.

15)

Solid wall plastic pipe and appurtenances conforming to the following specifications may be used for gravity and pressure sewers. Truss pipe consisting of inner and outer walls connected by webs and having the voids filled with lightweight concrete or similar filler, is not allowed.

a)

Pipe and fittings. Pipe and fittings shall conform to ASTM Specification 3034, Specification for Type PSM Poly (Vinyl Chloride) (PVC) Sewer Pipe and Fittings, with dimensions conforming to "extra heavy" with a standard diameter ratio (SDR) of 35 as described in that specification, and shall be colored green.

b)

Jointing. Joints on service connections of six inches diameter or less may be solvent-weld using cement conforming to ASTM Specification D2564 and socket dimensions acceptable to the city engineer. All joints on mains and on pipes over six inches in diameter will use elastomeric gaskets conforming to ASTM Specification D1869, C361 or C443.

c)

Installation. Installation will conform to the provisions of ASTM Specification D2321, Underground Installation of Flexible Thermoplastic Sewer Pipe.

16)

Reinforced concrete pipe and appurtenances may be used for gravity and pressure sewers in accordance with the following requirements:

a)

Gravity sewers:

(1)

Concrete pipe conforming to one of the following specifications may be used for gravity sewers:

ASTM Specification C14, Specification for Concrete Sewer, Storm Drain and Culvert Pipe; ASTM Specification C76, Storm Drain and Sewer Pipe; ASTM Specification C506, Specification for Reinforced Concrete Arch Culvert, Storm Drain and Sewer Pipe; ASTM Specification C507, Specification for Reinforced Concrete Elliptical Culvert, Storm Drain and Sewer Pipe; ASTM Specification C655, Specification for Reinforced Concrete D-Load Culvert, Storm Drain and Sewer Pipe.

In addition, pipe permitted for pressure sewers will be permitted for gravity sewers.

(2)

Joints in concrete pipe used for gravity sewers must be packed and sealed with a cement mortar, a preformed mastic gasket, or a trowel applied mastic compound in a procedure acceptable to the city engineer. In addition, any joint sealing method acceptable for pressure sewers may be used for gravity sewer.

b)

Pressure sewers:

(1)

Concrete pipe conforming to ASTM Specification C361, Reinforced Concrete Low-Head Pressure Pipe, may be used for pressure sewers with maximum heads as indicated in the specification.

(2)

Joints in concrete pipe used for pressure sewers will conform to ASTM Specification C443, Joints for Circular Concrete Sewer and Culvert Pipe, with Rubber Gaskets.

17)

Developer shall identify sewer taps by placing approved markings ten feet back of the curb at each location.

18)

Plans prepared by a registered professional engineer shall meet the requirements included in Appendix I of this code.

LIFT STATIONS

1)

The following outlines the type of pumps and electrical controls to be installed at new sewerage lift stations and old lift stations to be renovated. It is beneficial in maintaining the lift stations if the pumps and electrical controls are standardized as much as possible.

Trash pumps—Gorman-Rupp (direct drive)

Electric motors—U.S. Electric

Electric control panel—Healy-Ruff (float switches)

2)

Belt drive pump, compact package units, and air bubbler systems for the electrical controls are not permitted.

3)

The use of submersible pumps is not permitted.

4)

Any control panel exposed to the weather or sewer water will be housed in a weather-proof NEMA 12 enclosure.

5)

Electrical serviced to be overhead, if possible, secured to the pump houses or to a stationary pole. These poles are to be creosoted or pressure treated. Rigid conduit is to be used for the stack. The entire entrance is to be bonded and grounded, including the EMT covering the ground wire. If it is not possible for the service to be overhead, then rigid conduit buried at a minimum of 36 inches from top of the grade is required. The length of the underground service is not to exceed 50 feet.

6)

Rigid conduit is to be used from the motor starter panel to the motor pot head. Watertight flexible conduit (not to exceed 18 inches from the end of the conduit to the motor pot head) can be used. All wiring which controls the float bulbs is to be placed in rigid conduit to a point entering the wet well.

7)

One 110V utility receptacle with a GFJ circuit breaker is required as well as adequate lighting.

8)

All conduit will be bonded and grounded and will be properly anchored.

9)

All wire will be copper, stranded, TW or THW and sized according to the ampere load.

10)

All exposed light bulbs to have guards, if these guards are metal they will be bonded and grounded.

11)

All piping inside lift stations will be flanged cast iron or threaded iron pipe.

12)

On the suction side of the wet well, a combination wye and eighth bend with clean-out plug will be used.

13)

On the discharge side of the wet well, there will be a check valve and a gate valve.

14)

Piping will be long sweep fittings.

15)

All hanging pipe will be properly supported and braced.

16)

Lift station design shall be prepared by a registered professional engineer and approved by the town engineer.

17)

All brackets for float levels and fasteners shall be a minimum type 304 stainless steel.