(A)   General requirements.
      (1)   Scope.
         (a)   The design and construction of sanitary sewers, sewer pump stations, sewer treatment plants and sewer systems, in the unincorporated area of San Benito County subject to control or permit requirements of the county, shall be in accordance with these minimum design standards. The work shall comply with these standards except where specific modifications have been approved by the County Engineer in writing.
         (b)   These requirements are applicable only when sanitary sewers do not fall within the jurisdiction of other special districts or agencies. In the event that such sewers are within the jurisdiction of another agency, then all sanitary sewer improvements shall be designed and constructed in accordance with the requirements of that agency.
         (c)   Whenever sewerage systems are to be installed in an area that has a master sewerage plan, the facilities shall be designed as much as possible to conform with the various elements of this plan.
      (2)   Interpretation. The County Engineer shall decide all questions of interpretation of these design standards.
      (3)   Plumbing Code. All work on house laterals, house sewers, building sewers, outside of public rights-of-way or sewer easements will be governed by the provisions of the Uniform Plumbing Code as amended by these standards and other applicable ordinances of the local sewerage agency.
      (4)   Other standards.
         (a)   Where the sections of this design manual do not cover fully, the following additional references (latest edition) can be used, subject to approval by the County Engineer:
            1.   “Design and construction of Sanitary and Storm Sewers” (ASCE Manual of Engineering Practice No. 37 or WPCF Manual of Practice No. 9).
            2.   “Sewage Treatment Plant Design” (ASCE Manual of Engineering Practice No. 36 or WPCF Manual of Practice No. 8).
            3.   “Gravity Sanitary Sewer Design and Construction” (ASCE Manual of Engineering Practice No. 60 or WPCF Manual of Practice No. FD-5).
            4.   The Vitrified Clay Pipe Institute Engineering Handbook.
            5.   The State of California, Standard Specifications. Further reference is made to the Health and Safety Code and Cal. Administrative Code Title 17 relating to sewers and sewer districts. Ali work contemplated in the county shall comply with the applicable regulations of these codes.
         (b)   In case of conflict, these county standards shall have precedence.
   (B)   Enforcement. Provisions of these design standards shall be enforced by the County Engineer.
      (1)   Deviations. Requests for deviations from the standards contained in this manual should be submitted to the County Engineer. The county staff shall make a recommendation to the County Engineer on the deviation. The final decision on deviations from the standards will be decided by the County Engineer.
      (2)   Waiver. The requirement for review by, and approval of, the County Engineer for sewer plans may be waived when all of the following conditions exists:
         (a)   The facilities are to be accepted and maintained by an established public district or agency.
         (b)   The agency or district has adopted standards that are equivalent to, or more restrictive than, the adopted county standards.
         (c)   The plans are prepared by the developer’s engineer and approved by the agency’s or district’s engineer.
         (d)   The agency’s or district’s engineer is independent of the developer and the developer’s engineer and no organizational conflicts of interest exist.
         (e)   The agency or district’s engineer shall state by certificate that the plans meet or exceed the minimum county standards.
         (f)   The district or agency has received written approval of the County Engineer for waiver of the requirement by the County Engineer’s review and approval of the plans.
   (C)   Definitions. Wherever any of the following words, or expressions or pronouns in place of them, are used in these specifications, they shall be understood to have the meanings given as follows.
      ADWF. Average dry weather flow.
      AWWF. Average wet weather flow = ADWF.
      INFILTRATION. The quantity of groundwater on surface water that leaks into a pipe through joints or breaks.
      PDWF. Peak dry weather flow = ADWF x Peak Factor (PF).
      PWWF. Peak Wet Weather Flow = [ADWF x PF].
      SEWER. Sanitary sewer main.
      SEWERAGE AGENCY. The public agency or private company who owns and operates the sewerage system.
      SEWERAGE AGENCY’S ENGINEER. Civil Engineer registered in California employed by the sewerage agency.