§ 18C-5. New system standards.  


Latest version.
  • The following requirements shall be met to ensure that all new onsite wastewater treatment systems are installed at locations that have been adequately evaluated and that methods used to conduct those evaluations meet specified minimum standards.

    (A)

    General Site Evaluation.

    (1)

    The administrative authority shall require the submission of all information necessary to thoroughly evaluate the suitability of a site for wastewater treatment and dispersal and to asses any limiting conditions. At a minimum, the site evaluation information shall include but is not limited to:

    a)

    The administrative authority may require a geologic report, prepared by a certified engineering geologist, describing any soil or bedrock formations encountered and addressing slope stability when the proposed dispersal field is located on a slope greater than thirty percent.

    b)

    The minimum separation from the bottom of the dispersal field to groundwater shall be confirmed by soil borings pursuant to section 18C-5(B) and section 18C-5(C) of this article. Where fluctuations in groundwater levels may impact the dispersal field, the highest recorded depth shall be utilized.

    c)

    Minimum site requirements shall be those provided in the California Plumbing Code as amended and adopted by the county and/or the OWTS policy, whichever are more stringent.

    (B)

    Soil Evaluation for Leach Lines and Seepage Pits.

    (1)

    Leach Lines:

    a)

    At least one deep soil boring or trench shall be required within the primary dispersal area and expansion area. Deep borings or trenches shall be a minimum of ten feet beneath the proposed maximum depth of the dispersal field.

    b)

    When using percolation tests to determine site suitability, not less than three percolation tests shall be conducted in the primary dispersal field and expansion areas. Percolation tests shall be completed with adequate separation to characterize the primary dispersal field and the expansion area. The tests shall be performed at a depth corresponding to the bottom of the subsurface dispersal field.

    c)

    Percolation tests shall be valid for five years after completion. A professional engineer or soils engineer may recertify the tests for an additional term of five years. After ten years, the original percolation tests are no longer valid and must be repeated.

    (2)

    Seepage Pits:

    a)

    Maximum absorptive capacity of each seepage pit shall be determined using a slug test such as a constant head type test after initial presaturation. Only the sidewall may be used for the purpose of calculating the absorption area using the following criteria:

    Absorptive Capacity (gpd) Application Rate
    (gpd/square foot)
    <500 gallons per day Discharge prohibited
    500—1,000 gallons per day .4
    (treatment required)
    1,000—8,000 gallons per day .8
    >8,000 gallons per day 1.2
    (treatment required)

     

    b)

    Seepage pit testing shall be valid for five years. A qualified professional may recertify the test once for an additional term of five years.

    (3)

    Seepage pits may be utilized only if limiting conditions make leach lines infeasible, as determined by a qualified professional or registered geotechnical engineer with the concurrence of the administrative authority. A determination of leach line infeasibility must be provided and shall include a written statement that has been signed and stamped by the qualified professional or registered geotechnical engineer that specifies the unfavorable conditions, which render effluent dispersal using leach lines infeasible. A determination of leach line infeasibility shall be based on poor absorptive capacity or a lack of separation to a required setback. The encroachment of proposed accessory structures on otherwise suitable dispersal areas shall not be used to determine infeasibility for purposes of this article.

    (4)

    Leach beds may be installed only if leaching trenches are not feasible, as determined by a qualified professional or registered geotechnical engineer with concurrence from the administrative authority. A determination of leach line infeasibility must be provided and shall include a certified written statement by the qualified professional or registered geotechnical engineer, which specifies the unfavorable conditions that render leach lines infeasible.

    (5)

    Alternative systems may be utilized only if limiting conditions make leach lines infeasible, as determined by a qualified professional or registered geotechnical engineer with the concurrence of the administrative authority. A determination of leach line infeasibility must be provided and shall include a written statement that has been signed and stamped by the qualified professional or registered geotechnical engineer that specifies the unfavorable conditions, which render effluent dispersal using leach lines infeasible.

    (C)

    Wet Weather Borings.

    (1)

    Wet weather borings may be required by the administrative authority when available information indicates that variations in groundwater levels occur that may result in a failure to maintain the minimum separation required between the bottom of the dispersal field and groundwater. Wet weather borings may also be required when there is reasonable cause to believe that groundwater is less than sixty feet below the natural ground surface for seepage pits and twenty feet for leach lines and such information is required to confirm adequate separation to groundwater during wet seasons.

    (2)

    Additional requirements for wet weather borings:

    a)

    The depth to groundwater shall be measured from the first encounter of water in the boring. A subsequent measurement shall be made within three days to determine if the water level is static or dynamic.

    b)

    The boring shall be performed after seventy-five percent of the average annual rainfall has occurred as determined by the county water agency.

    c)

    In the event of a drought or the project is constructed in the dry times of the year, the administrative authority may accept additional hydrologic or geologic information provided by a professional engineer experienced in soil mechanics, a registered geotechnical engineer, a professional geologist, a certified engineering geologist, or a certified hydrogeologist that estimates the highest anticipated elevation of groundwater based on soil or historic data.

    (D)

    Tank Requirements.

    (1)

    Septic tanks and treatment tanks must be watertight. Water tightness shall be ensured prior to backfilling the excavation around the tank.

    (2)

    Septic tanks and treatment tanks shall be constructed of reinforced concrete, fiberglass, or other durable, corrosion resistant, synthetic material and shall conform to IAPMO, NSF or ASTM standards or similar criteria.

    (3)

    Septic tanks and treatment tanks installed beneath surfaces subject to vehicular traffic (e.g., driveways and vehicle turnarounds) shall be traffic rated or engineered to support the additional load. Septic tanks and treatment tanks placed in areas subject to vehicular traffic shall be provided with lids or risers that are rated for traffic loading.

    (4)

    Septic tanks shall have a minimum capacity of three times the peak daily flow.

    (5)

    All septic tanks for new systems and replacement tanks for existing systems shall be equipped with an effluent filter that is an American National Standards Institute (ANSI) listed. The filter must be accessible for cleaning, replacement and maintenance.

    (6)

    Septic tanks and treatment tanks shall be installed by a qualified contractor according to the manufacturer's specifications. Earth cover over the tank shall be clean fill material, free of debris and rock.

    (7)

    Septic tanks shall have a minimum of two compartments with access to each compartment and a lid with a minimum of twenty inches in diameter for each compartment. Access lids shall have a maximum separation of ten feet. Treatment tanks may consist of a single tank if required by the manufacturer of the approved supplemental treatment system.

    (8)

    Septic tanks and treatment tanks shall be installed so as to be accessible for servicing, inspection, maintenance, upgrades or replacement.

    (9)

    Septic tanks shall be installed with the top of the tank no deeper than twelve inches below finish grade. If it is demonstrated that the top of a septic tank must be deeper than twelve inches below grade, each compartment of a septic tank shall be provided with a watertight riser, capable of withstanding anticipated structural loads and extending to within twelve inches of finish grade. Septic tanks and treatment tanks shall be installed as shallow as practical and in no case at a depth greater than factory recommendations.

    (10)

    The qualified professional responsible for the approved design shall provide written certification that the installation has been completed per the approved plans.

    (11)

    Risers shall be installed within twelve inches of grade to enhance access for maintenance.

    (12)

    Distribution boxes, drop boxes, pump chambers and stilling chambers shall be watertight and commercially manufactured with corrosion resistant materials.

    (13)

    When necessary to extend septic tank risers to finish grade, access lids shall be gas-tight, securely fastened with stainless steel or other corrosion resistant fasteners and be resistant to vandals, tampering, and access by children.

    (14)

    Surface water shall be diverted away from the riser cover or septic tank lid by providing a sloping surface away from the riser, or extending the riser at least six inches above grade.

    (E)

    Dual Dispersal Area Requirements for Onsite Wastewater Treatment Systems.

    (1)

    For new onsite wastewater treatment systems serving commercial projects installation of dual dispersal fields connected with a diverter valve is required. A third area of adequate size shall be set aside for future expansion of the onsite wastewater treatment system.

    (2)

    Residential OWTS shall have dual fields installed with a one hundred percent set aside if the project is located on a parcel equal to or less than 2.5 gross acres. If the project is located within the AG-I, AG-II, RR, 3-E-1, 5-E-1,10-E-1, or 3.5-EX-1 zone district, and on a parcel equal to or greater than 2.5 gross acres the OWTS will need to meet minimum state and county standards but will not be required to install dual fields. The administrative authority may require that dual fields be installed and have a one hundred percent expansion area set aside if the dispersal field area is found to be severely constrained irrespective of parcel size or zoning designation.

    (F)

    Seepage Pit Construction.

    (1)

    Seepage pits shall be cylindrical in shape with a diameter of not less than four feet or more than six feet. Construction of a seepage pit with a diameter less than four feet or greater than six feet may be permitted with written approval of the administrative authority.

    (2)

    Seepage pits shall have a centrally located four-inch diameter perforated pipe which extends from the inlet to the bottom of the pit and the space around the pipe shall be filled with washed gravel which may vary in size from three-fourths-inch to two and one-half inches. A smaller gravel size may be used if the design engineer can provide justification for its use and written approval is obtained from the administrative authority. When necessary to meet minimum slope setback requirements, the upper portion of the central pipe shall be unperforated.

    (3)

    Rock fill in seepage pits shall be covered with building paper or equivalent, and backfilled with a minimum of eighteen inches of clean earth cover, free of debris and rock.

    (4)

    Seepage pits shall have an effective dispersal depth of at least ten feet. Effective dispersal depth is defined as total depth minus the distance below the grade to the uppermost dispersal pipe perforation.

    (5)

    The maximum depth of a seepage pit shall be sixty feet, unless the administrative authority provides written approval for a greater depth.

    (6)

    Multiple seepage pit installations shall receive septic tank effluent via an approved distribution method.

    (G)

    Leach Line Construction.

    (1)

    Four square feet of absorption area per lineal foot of trench shall be the maximum allowable absorption area for systems without supplemental treatment. Seven square feet per lineal foot of trench may be allowed for systems using supplemental treatment and the dispersal fields are constructed using pipe and rock.

    (2)

    Application rates shall be in conformity with Table 3 in State Water Resources Control Board OWTS Policy.

    (3)

    Inspection ports shall be installed at the end of each trench and at other locations if required by the administrative authority. Inspection ports shall extend to the bottom of the trench or bed and must be anchored to prevent disturbance or removal. The portion of the inspection port within the rock filter material shall be perforated to permit the free flow of liquid. The inspection ports shall have removable caps and may either extend above grade or set to grade if enclosed in a service box with removable lid. The boxes shall be made of non-degradable material such as PVC, fiberglass or concrete.

    (H)

    Low Pressure Distribution.

    (1)

    When required by site conditions, onsite wastewater treatment system effluent may be distributed to a dispersal field under pressure. Dispersal utilizing pressure distribution shall meet the following requirements:

    a)

    Pressure distribution systems shall be fully engineered. A qualified professional shall submit a stamped and signed letter to the administrative authority stating that the pressure distribution system has been constructed per the previously submitted plans.

    b)

    The pump chamber shall include a visual and audible high water alarm.

    c)

    Emergency storage capacity shall be required equal to six hours of peak flow or three hundred seventy-five gallons whichever is greater.

    d)

    The dispersal field shall be dosed in compliance with design requirements.

    e)

    The distribution network shall be accessible for inspection, testing, flushing and adjustment.

    (I)

    Shallow Drip Systems.

    (1)

    Shallow drip systems shall conform to the following requirements:

    a)

    Drip lines shall be installed in native soil. The minimum depth to a limiting soil condition shall be in conformity with state standards.

    b)

    Up to twelve inches of fill may be placed above the drip line to satisfy minimum soil cover requirements. The soil cover may be reduced to six inches when the wastewater has been treated to a tertiary level.

    c)

    Measures shall be taken to avoid collection or ponding of rainfall or runoff in the dispersal field area. Soil erosion in the drip field shall be minimized.

    d)

    All subsurface drip system dispersal fields shall be preceded by a supplemental treatment system that meets the requirements of section 18C-5(K) of this article.

    e)

    Drip lines shall be installed as level as possible and parallel to elevation contours.

    f)

    Drip field design shall be fully engineered and in accordance with manufacturer recommendations. Within thirty days of the completion of the construction of the subsurface drip irrigation system, a qualified professional shall submit a stamped and signed letter to the administrative authority stating that the system was installed per the previously approved plans.

    (J)

    Alternative Wastewater Treatment Systems.

    (1)

    Onsite wastewater treatment systems utilizing an alternative dispersal field that may be approved for installation include mound, evapotranspiration and at-grade systems. The administrative authority may approve other types of systems.

    (2)

    The administrative authority may adopt design standards for alternative systems after consultation with the regional water quality control board.

    (3)

    Alternative dispersal fields shall be engineered in conformance with the Guidelines for Evapotranspiration Systems published by the State Water Resources Control Board. Upon completion of the installation and prior to final approval, a qualified professional shall submit a stamped and signed letter to the administrative authority stating that the alternative dispersal field has been constructed per the previously approved plans.

    (4)

    Operation, maintenance and monitoring specifications shall be provided for review and approval for any alternative dispersal system

    (5)

    A notice of the installation of an alternative onsite sewage dispersal field shall be recorded with the Santa Barbara County Clerk-Recorder's office. Said notice shall run with the land and serve as constructive notice to any future owner, heirs, executors, administrators or successors that the onsite wastewater treatment system serving the subject property has an alternative dispersal field for wastewater dispersal and is subject to an operating permit, regular monitoring, maintenance and reporting requirements.

    (6)

    The property owner shall ensure that a qualified inspector, acceptable to the administrative authority, conducts a visual and operational inspection of the system once every year to ensure that the system is functioning properly.

    (7)

    The property owner shall submit a report a minimum of once a year, prepared by a qualified contractor or qualified professional in a form prescribed by the administrative authority. The report shall include the results of any inspections, a check of the high water alarm, and any other requirements specified by the administrative authority. Reports shall be submitted within thirty days of the completion of the inspection.

    (K)

    Supplemental Treatment Systems.

    (1)

    The administrative authority shall review and approve the method of supplemental treatment proposed prior to construction. Treatment systems and their components shall be tested and certified by an independent testing agency, such as IAPMO, ANSI or NSF or similar, and shall be tested for the removal of total suspended solids, bio-chemical oxygen demand (BOD) and total nitrogen.

    (2)

    A notice of the installation of a supplemental treatment system shall be recorded with the Santa Barbara County Clerk-Recorder office. Said notice shall run with the land and serve as constructive notice to any future owner, heirs, executors, administrators or successors that the onsite wastewater treatment system serving the subject property has supplemental treatment and is subject to an operating permit with monitoring, reporting and maintenance requirements.

    (3)

    A maintenance contract between the property owner and the supplier of the supplemental treatment system or their representative shall be in force for the supplemental treatment unit and dispersal field prior to installation. The maintenance agreement shall be in force for the life of the supplemental treatment system.

    (L)

    Operating Permits.

    (1)

    An operating permit issued by the administrative authority is required for the operation of alternative and supplemental treatment systems. All onsite wastewater treatment systems requiring operating permits shall be operated, maintained and monitored pursuant to the requirements of this article and the permit. The operating permit shall be renewed every five years following the review of satisfactory annual reports submitted to the administrative authority. The administrative authority may suspend or revoke an operating permit for failure to comply with any monitoring, maintenance or other requirements of the permit. If a permit is suspended or revoked, operation of the system shall cease until the suspension or revocation is lifted or a new permit issued. Continued use of an OWTS where the operating permit has expired or has been suspended may cause the responsible party be subject to administrative fines as provided in chapter 24A of the Santa Barbara County Code.

    (2)

    Operation, maintenance and monitoring specifications shall be provided for review and approval for any supplemental treatment.

    (3)

    The property owner shall ensure that a qualified contractor, qualified professional, registered environmental health specialist or manufacturer's representative conducts a visual and operational inspection of the system at the frequency specified by the manufacturer or a minimum of once per year to determine if the system is functioning properly.

    (4)

    The property owner shall submit a report for every inspection or a minimum of once a year, within thirty days of inspection, prepared by a qualified contractor, qualified professional, registered environmental health specialist or manufacturer's representative in a form prescribed by the administrative authority. The report shall include the inspection results, analysis of the wastewater from the inspection ports for total suspended solids, biochemical oxygen demand and nitrogen series, and any other requirements specified by the administrative authority.

(Ord. No. 4909, § 2, 1-6-2015)