[Ord. 146, 2/18/1992, § 200; as amended by Ord. 167, 12/17/1996]
1. 
All sewer pipe shall be SDR 35 PVC conforming to requirements of ASTM Specification B 3034 (unless otherwise noted). Heavier pipe may be required for sewers with a depth greater than eight feet, measured from invert to finish grade.
2. 
The minimum sanitary sewer main diameter shall be eight inches. Pipe sizes shall be increased as directed by the Township Engineer to accommodate for potential future design flow.
3. 
The minimum lateral diameters within rights-of-way or Township easements shall be six inches.
4. 
A minimum flow velocity of three feet per second shall be provided when specified.
5. 
No sewer main or lateral may be located closer than 10 feet to a property line or easement line. Main end laterals must be designed to cross existing and proposed utilities at 90° angles.
6. 
All PVC sewer pipe shall be manufactured with integral bell elastomeric sealed joint and smooth inner walls.
7. 
Grade.
A. 
The minimum slope for a sanitary sewer main shall be 0.4%, except for terminal manhole runs, which shall be a minimum of 1/8 inch per foot.
B. 
The minimum slope for sanitary laterals shall be 1/4 inch per foot.
8. 
The minimum cover for mains and laterals shall be four feet zero inches from the top of the pipe to finished grade within rights-of-way and easements. Cover may be reduced to three feet zero inches only as approved by the Township. The minimum cover for laterals on lot shall not be less than three feet zero inches approved by the Township.
9. 
Sewer mains or laterals that are located within or pass through flood-plains/wetlands shall be ductile iron pipe.
10. 
No radii are permitted in design or installation of gravity sewer mains or laterals. Mains and laterals shall be centered within easements unless otherwise directed by the Township.
11. 
Laterals.
A. 
Connection of laterals directly to manholes is prohibited.
B. 
Connection of laterals to the main shall be accomplished by a 45° wye fitting. The wye branch shall be sufficiently tilted to a 45° angle at installation. A 45° bend shall be provided as connection between the lateral and wye branch.
C. 
Laterals shall be extended to a point of at least one foot beyond the right-of-way line. The free end of all laterals shall be fitted with a 45° wye branch and six-inch diameter riser pipe. Connection between the riser pipe and wye branch shall be a 45° elbow fitting.
D. 
Risers shall be extended to a point at least five feet above existing grade.
E. 
Riser pipe and the end of the lateral shall be plugged with an approved push-on-type plug. All plugs must be capable of withstanding the required air test and must be watertight. Upon completion of finished grading, the riser pipe shall be cut to a height six inches above finished grade and provided with a watertight screw cap.
F. 
Laterals shall run straight. No radii are permitted.
G. 
Cleanouts shall be placed every 50 linear feet or immediately upgrade of any change in lateral direction as required by the Township. All cleanouts shall be provided with watertight screw caps.
H. 
Laterals located beneath driveways shall be ductile iron pipe.
I. 
Cleanouts located within driveways, sidewalks or aprons shall be sleeved with a ductile iron valve box and cap.
J. 
Minimum cover over laterals on lot shall be 30 inches from top of pipe to finished grade.
K. 
A cleanout/trap shall be provided at a point not less than five feet nor more than 20 feet from the structure which the lateral serves. The cleanout/trap shall be provided with a standard vent (mushroom) type cap.
L. 
Ninety-degree elbows are not permitted along sewer laterals. Ninety-degree turns must be accomplished utilizing two 45° elbows.
[Ord. 146, 2/18/1992, § 201; as amended by Ord. 167, 12/17/1996]
1. 
Manholes shall be spaced at distances no greater than 350 feet unless permitted by the Township. All manholes shall be precast. Cast-in-place manholes are only permitted when approved by the Township.
2. 
Invert drops shall be provided as follows:
A. 
One-tenth foot for flow-through manholes.
B. 
Two-tenths foot with two incoming pipes at a junction manhole.
C. 
Three-tenths foot with three incoming pipes at a junction manhole.
3. 
Drop manholes shall be provided when the difference in invert elevations between an incoming line and an outgoing line is greater than 12 inches.
4. 
Manhole Lids.
A. 
All manholes outside of cartways located in swales, easements, lawn/field area and within floodplain/wetland areas shall be provided with watertight lids. Bolt-down lids shall only be provided when approved by the Township.
B. 
Whenever practical, rim elevations shall be set above the one-hundred-year flood elevation within the floodplain.
C. 
Whenever practical (outside of maintained law area), manhole rim elevations shall be set six inches above finished grade.
D. 
Rim elevations within cartways shall be set at an elevation 1/2 inch below final paving grade.
5. 
All manholes shall be precast unless otherwise specified.
6. 
Manholes shall have a minimum internal diameter of 48 inches. The top section shall be an eccentric (cone) type top with a minimum clear opening of 24 inches.
7. 
Precast bases, risers and top sections shall be reinforced with steel as required in ASTM C 478 (latest revision).
8. 
Manhole numbering shall be consistent with the numbering system as presented on the East Rockhill Township Wastewater Facilities Plan as prepared by C. Robert Wynn Associates, Inc., dated June 10, 1991, as revised.
9. 
Entry and exit angles between sewer lines shall not be less than 90° unless approved by the Township Engineer.
10. 
All new manholes shall be designed and constructed with external manhole chimney seals in accordance with requirements of § 13-343.
[Ord. 146, 2/18/1992, § 202]
1. 
Approval must be received in writing from the authority/owner of any existing utility line which will be located less than 10 feet horizontally from the proposed sewer installation.
2. 
Vertical Separation.
A. 
Approval must be received in writing for any sewer/utility crossing regardless of depth or vertical separation. This includes crossings over/under existing or proposed utility lines.
B. 
A minimum eighteen-inch vertical separation shall be provided unless reduced separation is approved by the Township. Vertical separations shall be measured from the outer surface of pipe.
3. 
Whenever possible, sewer shall be designed and laid to cross under a proposed or existing utility so it is placed on undisturbed subgrade. If a PVC sewer main must cross over an existing or proposed utility, the sewer main shall be provided with a concrete encasement when there is less than a thirty-inch vertical separation. Concrete encasements and cradles shall be provided in accordance with the requirements of § 18-314.
4. 
Whenever the minimum vertical separation of 18 inches cannot be provided, and either the sewer or utility cannot be relocated, new sewer shall be cast iron pipe for a minimum distance determined when center lines of the sewer and utility are at a ten-foot horizontal separation. Concrete encasement and cradle shall be provided in accordance with requirements of § 18-341.
5. 
Utility lines may not be placed within the same trench as sewer line installation unless otherwise permitted by the Township. Utility service lines must maintain horizontal separation of 10 feet from sewer main or laterals.
6. 
All utility lines within 10 feet of a sewer main or lateral must be provided with a minimum cover of 18 inches of grit.
7. 
When a new utility line is being installed in conjunction with installation of a sewer main or lateral, work shall be coordinated so that full-depth compacted 2A stone backfill is provided within the entire limits of the trench between the two lines (at the crossing location), regardless of vertical separation and regardless of which pipe is on top or on the bottom. Full-depth 2A backfill between a utility and a new sewer line shall extend horizontally to a point where the sewer main/lateral is a minimum of five feet from any point of the utility crossed.
[Ord. 146, 2/18/1992, § 203; as amended by Ord. 167, 12/17/1996]
1. 
General.
A. 
All concrete shall be specified as Class C (2,000 psi) mix unless otherwise specified by the Township.
B. 
All concrete and materials shall conform to PennDOT Form 408 specifications.
Refer to all applicable detail sheets of Part 31 of this Part.
2. 
Stream Crossing Encasements.
A. 
Concrete encasements shall conform to requirements of PADEP BDWW General Permit 5 specifications (Drawing 1).
B. 
Concrete easement shall extend horizontally a minimum of 10 feet beyond the top of bank location.
C. 
Encasement shall extend below, over and adjacent to sewer pipe, a depth equivalent to the pipe diameter. Pipe shall be supported laterally with brick or concrete block spaced at 1/4 points. Use of rocks or soil to support line shall be prohibited.
3. 
Utility Crossings.
A. 
General.
(1) 
Concrete encasements are required when vertical separation between a utility and sewer main is less than 18 inches and around a sanitary sewer main when the main crosses over an existing or proposed utility with separation of 30 inches or less.
(2) 
Concrete encasement shall extend horizontally to a point where the sewer main/lateral is a minimum of 10 feet from any point of the utility crossed.
(3) 
Concrete encasement shall be provided whether the sewer line crosses over or beneath the utility line. Concrete encasements shall be provided around existing utilities as directed by the utility.
(4) 
Encasement shall extend below, over and adjacent to sewer pipe, a depth equivalent to the pipe diameter. Pipe shall be supported laterally with brick or concrete block spaced 1/4 points. Use of rocks or soil to support line shall be prohibited.
B. 
When a concrete encasement is installed for a sanitary crossing over a utility line, four-and-one-half-inch-diameter (Grade 60) No. 4 rebar shall be provided (two top and two bottom).
C. 
No stone bedding is required for concrete encasement.
D. 
When a new utility line is installed crossing over an existing sewer main, and vertical separation is 18 inches or less, said utility line shall be encased. Utilities, such as cable TV, telephone, electric, etc., shall be provided with conduit as approved by the utility prior to encasement. Minimum encasement for conduit less than six inches shall be six inches.