Unless otherwise indicated herein, all work shall be done in accordance with:
A. The standard specifications for Public Works Construction (SSPWC) latest approved edition.
B. The Regional Supplemental Amendments to the Standard Specifications for Public Works’ Construction.
C. The San Diego Regional Standard Drawings (SDRSD), latest approved edition.
And the following special provisions:
1. Trench width shall be per SDRSD No. SP-02, for pipe up to 15 inches, unless otherwise noted. For pipe 15 inches and over, trench width shall be per specifications for Public Works Construction, 306-1.2.13.
2. Pipe and bedding conditions shall be per SDRSD SP-02, for pipe up to 18 inches. For pipe 18 inches and above, refer to SSPWC Section 306-1.2.13.
3. PVC pipe bedding from the bottom of pipe to 12 inches minimum above the pipe shall be 3/4 –inch crushed rock.
4. After completion of pipe laying, all main line sewers, service laterals and structures shall be tested in the presence of the inspector. Air pressure test, per SSPWC Section 306-188.8.131.52, and Mandrel Test, per Section 306-1.212 shall be used unless otherwise directed by the inspector. Final acceptance of sewer lines will be subject to internal closed circuit television inspection. It will be the permittee’s responsibility to pay for the cost of this work.
5. The construction of PCC sewer manhole per SDRSD SM-01 or SM-02 poured-in-place manhole bases shall be a monolithic pour finished complete at time of pour. Each new manhole shall be vacuum tested prior to back filling. The test shall be conducted immediately after placement of pre-cast units with polymer mortar/butyl sealant. All pipes in the manhole shall be securely plugged. The test head shall be placed at the inside of the top pre-cast unit prior to the installation of the grade ring, and the seal inflated in accordance with the manufacturer’s recommendations.
A vacuum of 10 PSI shall be drawn and the vacuum pump shut off. With the valve closed, the time shall be measured for the vacuum to drop to 9 PSI. The manhole shall pass if the time is greater than 75 seconds for SDRSD SM-2 and 60 seconds for SDRSD SM-1 manhole. If the manhole fails the initial test, necessary repairs shall be made with no shrink grout while vacuum is still being drawn. Retesting shall proceed until a satisfactory test is obtained.
6. The construction of 4-inch sewer laterals shall be per SDRSD SS-01 and SS-02. Laterals shall not discharge directly into manholes. A cleanout shall be installed approximately 2 feet inside the property line.
7. The construction of cut-off walls shall be per SDRSD No. SP-07 on all segments having a slope of 20% to 50%. Construction of concrete anchor walls shall be per S-9 (March 2000).
8. All mains and laterals shall be constructed with 48 inches minimum cover, provided that the invert of the lateral at the property line is above the soffit line of the sewer main.
9. The final location and elevation of sewer and water laterals shall be shown on original plans, prior to acceptance for public use.
10. All design changes of sewer mains shall be approved by the District engineer, in writing, prior to acceptance of work.
11. Fill areas must be compacted to 90% prior to pipe installation.
12. The contractor shall notify the District’s inspection department 48 hours in advance of beginning work to arrange for inspection of the project.
13. The contractor shall obtain a permit from the County Department of Public Works for any excavation within existing County rights-of-way.
14. Contract record drawings must be submitted prior to final acceptance of the work. They must reflect post construction verification of pipe lengths and invert elevations.
15. The contractor shall guarantee all work for a period of 1 year after the date of acceptance of the work by the District and shall repair or replace any or all such work together with any other work that may be displaced in so doing, that may prove defective in workmanship and/or materials within the 1-year period from date of acceptance without expense whatsoever to the District, ordinary wear and tear, unusual abuse or neglect excepted.
16. The contractor shall furnish and install, per specifications, the appropriate buried utility warning and identification tape above all public sewer lines, including sewer laterals, located in the public right-of-way.
17. The contractor must call “Dig-Alert” of Southern California to have underground service utilities located prior to construction. The call will be made at least 48 hours prior to any construction. 1-800-422-4133.
18. At all manholes, the minimum fall across manhole shall be 0.1 feet, at angles larger than 45 degrees, allow 0.2 feet fall.
19. Joint sealant and exterior water proofing (where specified) required on all manholes as identified on each proposed sewer main plan profile.
Polymer mortar shall be used to join pre-cast components on all manholes to create watertight joints to resist infiltration. The mortar shall be mixed in accordance with the manufacturer’s specifications, and shall not exceed five parts sand to one part polymer. Acceptable joint sealant products shall be skidder 31 and 32 hi-mod gel manufactured by Sika Corporation, 490 epoxy putty and 498 underwater epoxy putty manufactured by Engard Coatings, and CS 102 butyl gaskets (rope form) manufactured by concrete sealants or approved equal.
The concrete or other surfaces that are to adhere to polymer mortar shall be free from dust, loose aggregates, oil, grease or other contaminants.
On all manholes, contractor shall apply waterproofing agent consisting of a coal tar emulsion on all exterior surfaces. The emulsion shall be Tnemec 46-465, or approved equal. The emulsion shall be applied in no less than two coats to achieve a total dry thickness of 25 mils minimum. The exterior emulsion coatings shall be applied prior to delivery to the jobsite. In addition, a bitumastic band 6 inches wide shall be applied at all joints on exterior of such manholes that shall be waterproofed. Full compensation for the waterproofing of manholes shall be awarded.
When completed, all manholes shall be watertight with zero infiltration of groundwater.
20. Epoxy lining coating (where specified).
SM-07 constructed manholes as identified on each proposed sewer main profile:
Manhole bottom shall be lined with epoxy. The epoxy product shall be Raven 405 manufactured by Raven Lining Systems, or approved equal.
The primer material shall be 100% solids, moisture tolerant epoxy capable of spray application to 5 mils thickness in one continuous coat.
The lining material shall be 100% solid, high build epoxy capable of spray application to 125 mils thickness in one continuous coat. The material shall meet the requirement of the SSPWC Section 210-2.3.3, “Chemical Resistance Test”, and the SSPWC Section 500-2.4.10, “Applicable Standard”.
Only workers trained by, and qualified as installers by the manufacturer, shall be used on this work. Contractor shall provide manufacturer’s certifications.
The epoxy lining shall be continuous without seams, uniform in color, fully cured, and free of pinholes, surface imperfections, and blisters. The lining must completely bond to the concrete. The color shall be light blue.
Testing of Manhole
The cured epoxy lining shall be spark tested for pinholes at 15,000 volts minimum. All pinholes shall be repaired as specified in Section 500-2.4.9, “Repair Methods” of the “Green Book” Standard Specifications.