Imperial County Municipal Code Ch. 8.80 Onsite Wastewater Treatment Systems (owts)

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Editor's note— Ord. No. 1604, adopted February 25, 2025, amended Ch. 8.80 in its entirety to read as herein set out. Former Ch. 8.80 pertained to the same subject matter, consisted of §§ 8.80.010—8.80.230, and derived from Ord. No. 1516, adopted April 26, 2016.

A. This chapter is established pursuant to Section 101000, et seq. of the California Health and Safety Code, the Porter-Cologne Water Quality Control Act, Water Code Section 13000 et seq., State Water Resources Control Board Water Quality Control Policy for Siting, Design, Operation, and Maintenance of Onsite Wastewater Treatment Systems, and the Colorado River Region Basin Plan. This chapter shall apply to all territory embraced within the unincorporated limits of the county of Imperial, state of California.

B. The purpose of this chapter is to protect public health by minimizing:

(1) The potential for public exposure to sewage from onsite wastewater treatment systems; and

(2) Adverse effects to public health that discharges from onsite wastewater treatment systems may have on ground and surface waters.

C. This chapter regulates the location, design, installation, operation, maintenance, repair, and monitoring of onsite wastewater treatment systems. This chapter seeks to:

(1) Achieve long-term sewage treatment and effluent disposal; and

(2) Limit the discharge of contaminants to waters of the State.

D. This chapter implements local alternative minimum standards for new and replacement OWTS consistent with the Local Agency Management Program authorized by the Water Quality Control Policy adopted by the State Water Resources Control Board on June 19, 2012, and in compliance with the Colorado River Region Basin Plan.

E. This chapter incorporates by reference the California Plumbing Code, 2013 Edition, and as amended, including the appendices, as adopted into state law in Title 24 of the California Code of Regulations.

(Ord. No. 1604, § 2, 2-25-25)

A. The administrative officer shall be the administrator of this chapter and shall be responsible for administrating the provisions and requirements of this chapter.

B. The health officer shall act under the direction of the board of supervisors. The health officer shall have the powers and duties enumerated in the California Health and Safety Code, and as may be delegated by the Regional Water Quality Control Board.

C. The health officer is hereby authorized and directed to adopt administrative rules or technical standards that are consistent with and effectuate the purpose of this chapter. Any activity pertaining to onsite wastewater treatment and disposal shall conform to any such administrative rules or technical standards adopted pursuant to the following procedures:

(1) Notice of intent to adopt, amend, suspend, or repeal an administrative rule or technical standard shall be given to the board of supervisors, and any trade, industry, professional interest group or regional publication that the department deems effective in reaching affected persons at least thirty (30) days before the deadline for comments;

(2) Adoption of a proposed administrative rule or technical standard shall be by official action of the health officer, who shall duly consider all relevant matter presented during the comment period; and

(3) Nothing shall prohibit the health officer from adopting emergency administrative rules to the minimum extent necessary without notice to avoid an immediate threat to public health.

D. The administrative officer is hereby authorized to develop a fee schedule to cover all of the activities delineated in this chapter. Any proposed fees shall become effective upon approval by resolution of the board of supervisors. The health officer shall not accept for review any application, nor issue any permit, nor in any manner take any official action until the appropriate fees are paid.

E. Where the provisions of any local, state, or federal regulation conflicts with this chapter, the stricter regulation shall apply.

F. Where waste discharge requirements are also required by the Regional Water Quality Control Board, Colorado River Region, any OWTS construction permit or annual health permit issued by the local health officer shall be consistent with the waste discharge requirements issued by the regional water board.

G. Nothing in this chapter shall be construed as imposing upon the county of Imperial any liability or responsibility for damage resulting from the defective construction, alteration, or relocation of any sewage disposal system, nor shall the county of Imperial, or any official or employee thereof, be held as assuming any such liability or responsibility by reason of any inspection authorized or permit issued hereunder.

(Ord. No. 1604, § 2, 2-25-25)

"Abandoned excavation" means any abandoned mining shaft, pit, well, septic tank, cesspool or other excavation dangerous to persons legally on the premises where the abandoned excavation is located or to minors under the age of twelve (12) years.

"Administrative officer" means the director of the public health department.

"Administrative rule" means a standard, statement of policy, or other statement of general applicability, that is intended to be judicially enforceable and implements, interprets or makes specific the requirements of this chapter, or describes the procedures or practices of the department.

"Alteration" means any change in an OWTS component without a change in the design capacity.

"Alternative system" means any onsite wastewater treatment system designed to include supplemental treatment prior to dispersal or that includes a dispersal field design consisting of components other than conventional gravity or pressure distribution within standard rock and pipe trench disposal configurations.

"Approved" means a written statement of acceptability, in terms of the requirements in this chapter, issued by the health officer or the Regional Water Quality Control Board.

"Approved list" means the document titled list of approved systems and products which is adopted by administrative rule and updated as necessary by the department. This document contains:

(1) A list of proprietary devices approved by the state water board and/or department; and

(2) A list of specific systems meeting Treatment Standard 1 and Treatment Standard 2.

"Area of special concern" means an area of definite boundaries delineated by the health officer, after consultation with the Regional Water Quality Control Board, where additional requirements for onsite wastewater treatment systems may be necessary to reduce potential failures, to minimize negative impacts of onsite wastewater treatment systems upon public health, or to protect an impaired water body due to nitrogen or pathogens pursuant to Section 303(d) of the Clean Water Act.

"Basin plan" means the same as "water quality control plan" as defined in Division 7 (commencing with Section 13000) of the Water Code. The basin plan applicable to Imperial County is adopted by the Regional Water Quality Control Board for the Colorado River Region of the State of California.

"Bedroom" means any room in a dwelling unit with a floor area equal to or greater than seventy (70) square feet that could reasonably be used as a bedroom. Kitchens, bathrooms, laundry rooms, and other rooms such as family rooms and living rooms with large [forty-eight-inch] (48") arched doorways or half walls opening onto living areas shall not be considered as bedrooms.

"Board of supervisors" means the Imperial County Board of Supervisors.

"Building sewer" means that part of the system of drainage piping which conveys sewage into the septic tank or other treatment facility outside the building or structure within which the sewage originates.

"Cesspool" means a pit that receives untreated sewage and allows liquid to seep into the surrounding soil or rock.

"Commercial installer" means a person licensed by the California Contractor State License Board in accordance with the California Business and Professions Code and meeting the requirements of this chapter to install and/or repair onsite wastewater treatment systems.

"Conforming system" means any onsite wastewater treatment system that meets any of the following criteria:

(1) A system in full compliance with the new construction requirements of this chapter or the State Water Quality Control Policy;

(2) A system approved, installed, and operating in accordance with previous regulations pertaining to onsite wastewater treatment systems, unless considered a failing system under Section 8.80.180 of this chapter or the State Water Quality Control Policy; or

(3) A system (including a repaired system) that has been granted a waiver by the health officer or the RWQCB.

"Cover" means soil material that is used to overlay the treatment and disposal area.

"Cuts and/or banks" means any naturally occurring or man-formed slope which is greater than one hundred percent (100%) (or forty-five degrees (45°)) and extends vertically at least five (5) feet from the toe of the slope to the top of the slope.

"Department" means the Imperial County Public Health Department.

"Design flow" means the daily sewage flow in gallons per day that a single family dwelling, multiple dwelling unit, or non-residential facility is expected to produce during peak operating flows and from which the drainfield is sized.

"Designer" means the same as a "Qualified Professional."

"Development" means the creation of a residence, structure, facility, mobile home park, subdivision, planned unit development, site, area, or activity resulting in the production of sewage.

"Discharge" means the discharge or deposition of sewage or other liquid wastes associated with human habitation or from animal origin, or the effluent of treated sewage or other liquid wastes, onto land, into groundwater, or in or on any waters of the state.

"Dispersal system" means a leachfield, seepage pit, mound, at-grade, subsurface dripfield, evapotranspiration and infiltration bed, or other type of system for final wastewater treatment and subsurface discharge.

"Domestic sewage" means the same as domestic wastewater or residential sewage, which is wastewater with a measured strength less than high-strength wastewater and is the type of wastewater normally discharged from, or similar to, that discharged from plumbing fixtures, appliances and other household devices. Domestic sewage does not include wastewater from industrial processes or RV holding tank wastewater.

"Drainage ditch" means a natural or man-made open depression created and maintained to collect and transport surface water runoff and subsurface drainage from agricultural fields, tile lines, surrounding property, structures and/or encumbrances.

"Drainage system" means and includes all the piping within public or private premises which conveys sewage or other liquid waste to a point of disposal, but does not include the mains or laterals of a public sewer system.

"Drainfield" or "Dispersal system" means the treatment and disposal component of an OWTS receiving effluent from a septic tank or other pretreatment device and transmitting it into native soil.

"Dripfield" means a type of drainfield where effluent is applied directly into the soil through driplines.

"Dripline" means the distribution piping used with a subsurface drip system to discharge effluent into the soil. A dripline consists of small diameter, flexible polyethylene tubing with small in-line emitters.

"Dump station" means a facility intended to receive the discharge of wastewater from a holding tank installed on a recreational vehicle. A dump station does not include a full sewer hook-up sewer connection similar to those used at a recreational vehicle park.

"Effective soil depth" means the depth of suitable native soil above a restrictive layer.

"Effluent" means liquid discharged from a septic tank or other onsite wastewater treatment system component.

"Effluent sewer" means that part of the system drainage piping that conveys partially treated effluent from the septic tank or other treatment facility into a distribution unit or drainfield.

"Emergency repair" means the repair of a failing septic system where immediate action is necessary to prevent sewage from backing up into a dwelling or building or to fix a broken pressurized sewer pipe.

"Equivalent dwelling unit" means:

(1) A single-family residence usually occupied by just one household or family; or

(2) Two hundred fifty (250) gallons of sewage per day where the proposed development is a non-residential facility.

"Existing OWTS" means an OWTS that was constructed and operating prior to the effective date of the adopted State Water Quality Control Policy or this chapter, and for which a permit has been issued by the department authorizing its construction and operation.

"Expansion" means a change in a residence, facility, site, or use that:

(1) Causes the waste strength or flows to exceed the existing treatment or disposal capability of an onsite wastewater treatment system; or

(2) Reduces the treatment or disposal capability of the existing onsite wastewater treatment system or the replacement area. For example, a shop, building addition, pool, or impervious area that encroaches into the primary or replacement area, or any other activity reducing the capability of the soil to maintain design acceptance rates.

"Failing system" means the presence of any of the conditions delineated in Section 8.80.180(C), or a system or system component listed under Section 8.80.180(D) of this chapter.

"Fixture unit" means a quantity design factor in the California Plumbing Code expressed in terms of the load-producing effects on the plumbing system of different kinds of plumbing fixtures. Fixture units may be used for the design of sewage flows.

"Gravity system" means a conventional onsite wastewater treatment system consisting of a septic tank and a drainfield with gravity dispersal of the effluent.

"Gray water" means untreated household wastewater that has not come into contact with toilet waste. Gray water includes used water from bathtubs, showers, bathroom wash basins, and water from clothes-washers or laundry tubes. It shall not include wastewater from kitchen sinks, dishwashers, or laundry water from soiled diapers.

"Gray water system" means a system designed to collect gray water and transport it out of the structure for distribution in an irrigation or disposal field. A gray water system may include tanks, valves, filters, pumps or other appurtenances along with piping and receiving landscape.

"Grease interceptor" means a passive interceptor that has a rate of flow exceeding fifty (50) gallons/minute (gpm) and that is located outside of a building. Grease interceptors are used for separating and collecting fats, oils, and greases (FOG) from wastewater.

"Groundwater" means subsurface water occupying the zone of saturation, either permanently, or seasonally. Indication may be demonstrated by one or both of the following methods:

(1) Water seeping into or standing in an open excavation, boring, or monitoring well from the surrounding soil; and/or

(2) The presence of redoximorphic soil features (or soil mottles) caused by intermittent periods of saturation and drying that may be indicative of poor aeration and impeded drainage.

"Health hazard" means a condition or situation where disease potential exists, and if left unabated, the disease potential may increase leading to a public health emergency.

"Health officer" means the health officer appointed by the board of supervisors, or a representative authorized by and under the direct supervision of the appointed health officer or the administrative officer.

"Hearing officer" means an administrative hearing officer designated by the health officer or administrative officer to conduct any hearing required by this chapter.

"High-strength wastewater" means wastewater having a thirty-day average concentration of biochemical oxygen demand (BOD) greater than three hundred (300) milligrams per liter (mg/L) or of total suspended solids (TSS) greater than three hundred thirty (330) milligrams per liter (mg/L) or a fats, oils, and grease (FOG) concentration greater than one hundred (100) milligrams per liter (mg/L) prior to the septic tank or other OWTS treatment component.

"Holding tank sewage system" means an onsite wastewater treatment system which incorporates a holding tank and tank capacity alarm, is designed and constructed to receive and retain sewage, and requires the services of a registered septage pumper hauler for off-site treatment and disposal of the sewage generated.

"Impaired water bodies" means those surface water bodies or segments thereof that are identified by the state water board pursuant to Section 303(d) of the Federal Clean Water Act as being impaired or threatened by either pathogens or nitrogen that may be associated with OWTS installations.

"Large onsite sewage system" means an OWTS that has design flows, at any common point, greater than five thousand (5,000) gallons per day up to ten thousand (10,000) gallons per day, and that is operated in accordance with waste discharge requirements by the regional water board and a local health operational permit. LOSS may include effluent disposal of treated and/or recycled wastewater that discharges on or above the post installation ground surface such as sprinklers, exposed drip lines, evaporative ponds, or lagoons as may be authorized by the state waste discharge permit.

"Listed" means equipment or materials included in a list of approved products published by the department that have been accredited by an approved third-party certifying body.

"Local agency" means the Imperial County Department of Public Health.

"Lot" or "parcel" means a unit or portion of land separate from other units or portions by description as on a final map, parcel map, or certificate of compliance, or by such other map approved by the county under the provisions of the Subdivision Map Act and county ordinance.

"Major repair" means the restoration or replacement of a failed onsite wastewater treatment system, or septic tank replacement due to a failure of its structural integrity or compartmental baffle.

"Minor repair" means any alteration, repair, or replacement of solid or perforated piping, tank baffles, distribution box, pumps, or electrical and mechanical components that may affect the performance and integrity of the OWTS.

"Native soil" means undisturbed soil that exhibits the same structure, texture, and permeability as the area in question.

"Net land area" means the total parcel area excluding surface water, road easements, rights-of-way, and drainage and utility easements.

"New OWTS" means the installation of any permitted system not defined as a repair, expansion, or alteration that occurs after the effective date of the adopted State Water Quality Control Policy or this chapter.

"Non-conforming repair" means a repair or replacement of an existing onsite wastewater treatment system that cannot meet the new installation requirements of this chapter due to soil or site limitations.

"Non-residential facilities" means any facility that is constructed or used for commercial, industrial, institutional, agricultural, public use, or recreational purposes.

"Nuisance" shall mean any nuisance as defined in the Health and Safety Code Section 17920(1), including an inadequate or unsafe onsite wastewater treatment system.

"Onsite wastewater treatment system" means an integrated arrangement of components for a residence, non-residential facility, or other place not connected to a public sewer system consistent with section 13290 of the California Water Code which:

(1) Conveys, stores, treats, and/or provides subsurface soil treatment and disposal of sewage on the property where it originates, or upon adjacent or nearby property; and

(2) Includes piping, treatment devices, other accessories, and soil underlying the drainfield and replacement area.

"Ordinary high-water mark" means the mark on all lakes, reservoirs, rivers, streams, drains, and ponds where the presence and action of waters are so common and usual, and so long continued in all ordinary years, as to mark upon the soil and vegetation a character distinct from that of the abutting upland. The OHWM adjoining canals or rivers shall be the natural or levied edge of the bank.

"Operational permit" means a permit issued by the department for a specified period of time for the operation and/or use of a large onsite sewage system or other alternative wastewater treatment system utilizing supplemental treatment with special operational or maintenance needs.

"Owner of record" means the owner of real property as shown in the records of the Imperial County Assessor's Office.

"Percolation test" means an approved method of testing water absorption of the soil, which can be used to establish the dispersal system design.

"Permit" means a written certificate issued by the department allowing an activity under the provisions of this chapter and the State Water Quality Control Policy.

"Person" means an individual, firm, association, company, organization, partnership, corporation, governmental entity, or any other entity of any kind. "Person" also includes an applicant, a permit holder, an authorized agent of any entity, or any third party acting on behalf of any entity.

"Pressure distribution system" means a system designed to uniformly distribute septic tank or other treatment unit effluent under pressure and described in department standards for pressure distribution systems.

"Prior approval" means any valid written approval or permit pertaining to a specific septic system application that was issued before the effective date of this chapter.

"Privy" means a structure used as a toilet under a part or all of which is a vault or pit intended or used for the reception of sewage.

"Proprietary device" means any device classified as an alternative system or a component thereof that is held under a patent, trademark, or copyright and is listed in the department's list of approved systems and products.

"Public sewer system" means a community sewage system under permit from the regional water board, which is owned or operated by a city, town, municipal corporation, county, political subdivision of the state, or other approved ownership consisting of a collection system and necessary trunks, pumping facilities, and a means of final treatment and disposal.

"Public water system" means a water system regulated by the California Department of Public Health or the Local Primacy Agency pursuant to Chapter 12, Part 4, California Safe Drinking Water Act, and as defined by Section 116275(h) of the California Health and Safety Code.

"Qualified professional" means an individual licensed or certified by the State of California to design an OWTS. This may include an individual who possesses a registered environmental health specialist certificate or is currently licensed as a professional engineer consistent with the requirements of Chapter 7, Division 3, Business and Professions Code of the State of California. A professional geologist may perform soil and site evaluations as required by Chapter 8.80 and Section 8.80.120 of this chapter.

"Recycled water" means non-potable water derived in any part from wastewater with a domestic sewage component that has been adequately and reliably treated and disinfected, so that it can be used for beneficial purposes. Recycled water is not considered a wastewater.

"Redoximorphic soil features" means the presence of soil mottles, or low-chroma colors, manganese and/or iron nodules, concretions, masses; depletions of iron and/or clay; and/or reduced matrices which may indicate the presence of groundwater.

"Regional water board" is the Regional Water Quality Control Board (RWQCB), Colorado River Basin Region, or its Executive Officer.

"Regulation" means a statute, administrative rule, or adjudicatory decision that is adopted under the authority of the Imperial County Board of Supervisors, the State of California, or the Federal Government.

"Replacement area" means an area of land equivalent to not less than one hundred percent (100%) of the required drainfield area that is approved for the installation of an onsite wastewater treatment system and dedicated for replacement of the OWTS in the event of its failure

"Replacement OWTS" means an OWTS that has its treatment capacity expanded, or any portion of its dispersal system replaced or added onto, after the effective date of the adopted State Water Quality Control Policy or this chapter.

"Restrictive layer" means a layer that impedes the movement of water, air, and growth of plant roots; including, but not limited to, groundwater tables, hardpans, claypans, fragipans, compacted soils, bedrock, unstructured clay soils or unsuitable soils.

"RWQCB" means the Regional Water Quality Control Board, Colorado River Basin Region.

"Seepage pit" means a drilled or dug excavation or pit, either lined or gravel filled, designed to dispose the effluent discharge from a septic tank or other OWTS treatment unit to underlying soils that are more permeable without receiving treatment in the upper soil horizons.

"Septage" means the mixture of solid wastes, sewn, sludge, and liquids pumped from septic tanks, pump tanks, holding tanks, chemical toilets, cesspools or seepage pits, or any other OWTS component.

"Septage pumper hauler" means a person registered by the department who cleans and pumps septic tanks, pump tanks, holding tanks, chemical toilets, or other sewage and transports the cleanings thereof to a public sewer system consistent with the California Health and Safety Code Section 117405 et seq.

"Septic tank" means a watertight receptacle which receives the discharge of sewage from a building sewer; and is designed and constructed to permit the separation of settleable and floating solids from the liquid, and detention and digestion of the organic matter, prior to discharge of the liquid portion.

"Service provider" means a person licensed to operate, monitor, and maintain an OWTS in accordance with this chapter. A wastewater treatment plant operator certified pursuant to the California Water Code, Section 3670 et seq. is required for large onsite sewage systems, as established by the Regional Water Board.

"Sewage" means urine, feces, and the water carrying human wastes, or any waste substance that contains or may be contaminated with human or animal excreta or excrement, offal, or any feculent matter, including kitchen, bath, and laundry wastes from residences, buildings, or other facilities. Sewage does not include wastewater from industrial processes.

"Single-family dwelling" means any structure occupied, intended or designed for occupancy by one family for living or sleeping purposes as its principal use. The minimum design flow for OWTS sizing shall be two hundred fifty (250) gallons per day of wastewater, with each additional bedroom at one hundred twenty-five (125) gallons per day.

"Site evaluation" means an evaluation of the soil profile and landscape features of a specific parcel or location for the purpose of determining whether the site complies with the requirements of this chapter for the installation of an onsite wastewater treatment system.

"Soil log" means a detailed description of the soil profile or mantle, and other soil characteristics such as color, texture, structure, and density to provide information on the soil's capacity to act as an acceptable treatment and disposal medium for sewage.

"Soil type" means a textural classification of fine earth particles (i.e. various percents of sand, clay, and silt) and coarse fragments in their various combinations as identified in the soil textural triangle developed by the United States Department of Agriculture, Soil Conservation Service, and as described in Table II of Section 8.80.110(B) of this chapter.

"Special wastes" means liquid wastes or brines that require some special method of handling, such as the use of indirect waste piping and receptors, corrosion-resistant piping, sand, oil or grease interceptors, condensers, or other pretreatment facilities.

"Sump" means an approved tank or pit that receives sewage or liquid waste and which is located below the normal grade of the gravity system and which must be emptied by mechanical means.

"State water board" is the State Water Resources Control Board.

"Statute" means any ordinance of the Imperial County Board of Supervisors, or any state or federal law.

"Subdivision" means any division of land, as defined in Section 90801.04 of the Imperial County Codified Ordinances, as now or as hereafter amended.

"Supplemental treatment" means any OWTS or component of an OWTS, except a septic tank or dosing tank, which performs additional sewage treatment so that the effluent meets specified treatment performance standards (Treatment Standard 1 or 2) prior to discharge of the effluent to the dispersal field.

"Surface water" means any body of water that either flows or is contained in natural or artificial depressions for continuous periods of thirty (30) days or more. Such bodies include, but are not limited to, natural and artificial lakes, ponds, rivers, streams, marshes, and water supply canals; but shall exclude surface water contained by drainage ditches, irrigation supply laterals, flood-irrigated crops, or detention basins.

"Swimming pool" means any constructed or prefabricated structure intended for swimming or recreational bathing that contains water over eighteen (18) inches deep. Swimming pools may be in-ground or above-ground structures, and shall include doughboys, spa pools, and any other special purpose pools.

"Treatment Standard 1" means supplemental treatment requirements for pathogens. Supplemental treatment for pathogens shall provide sufficient pretreatment of the wastewater so that effluent from the supplemental treatment components does not exceed a thirty-day average TSS of thirty (30) mg/L and shall further achieve an effluent fecal coliform bacteria concentration less than or equal to two hundred (200) Most Probable Number (MPN) per one hundred (100) milliliters.

"Treatment Standard 2" means supplemental treatment requirements for nitrogen. Effluent from the supplemental treatment components designed to reduce nitrogen shall be certified by NSF, or other approved third party tester, to meet a fifty-percent reduction in total nitrogen when comparing the thirty-day average influent to the thirty-day average effluent.

"Undocumented onsite sewage disposal system" means an installed onsite wastewater treatment system for which no permit is on file with the department.

"Unsuitable soils" means soils that are not capable of adequate treatment and/or disposal of sewage effluent and include:

(1) Weak or structureless sandy clays, clays, or silty clays, silt, and strongly cemented, compacted, or massive soils;

(2) Very gravelly sands having greater than or equal to thirty-five percent (35%) and less than sixty percent (60%) gravel and coarse fragments by volume;

(3) All extremely gravelly soils having greater than or equal to sixty percent (60%) gravel and coarse fragments by volume;

(4) Soils that have a clay content of fifty (50%) or more as determined by particle size analysis; and

(5) Soils having a percolation rate of less than one minutes per inch (mpi) or greater than two hundred forty (240) mpi.

"Vertical separation" means the depth of unsaturated native soil between the bottom of a leaching trench and the highest seasonal water table, restrictive layer, or unsuitable soils.

"Waste discharge requirement (WDR)" means an operation and discharge permit issued for the discharge of waste pursuant to Section 13260 of the California Water Code.

"Water Quality Control Policy" means the OWTS Policy adopted by the State Water Resources Control Board for the Siting, Design, Operation and Management of Onsite Wastewater Treatment Systems, effective May 13, 2013.

(Ord. No. 1604, § 2, 2-25-25)

A. Every residence, place of business, or other building or place where persons congregate, reside, or are employed in which sewage is generated that is not connected to a public sewer system shall be connected to an onsite wastewater treatment system (OWTS) meeting the requirements of this chapter.

B. An approved OWTS permit issued prior to the effective date of this chapter shall be valid for the period of time that is stated on the permit.

C. The Regional Water Quality Control Board (RWQCB) has authority and approval over:

(1) Public sewer systems;

(2) Industrial wastewater treatment facilities;

(3) Wastewater treatment facilities utilizing sewage lagoons or surface discharge for disposal; and

(4) Onsite wastewater treatment systems with design flows through any common point above five thousand (5,000) gallons per day.

D. The department has authority and approval over:

(1) Onsite wastewater treatment systems with design flows through any common point up to five thousand (5,000) gallons per day;

(2) Any large onsite sewage system with a design flow greater than five thousand (5,000) gallons per day up to ten thousand (10,000) gallons per day for which waste discharge requirements have been issued by the RWQCB, but that ongoing primary administrative authority has been granted by written agreement from the RWQCB to the department.

E. Sewage that is not treated through a public sewer system shall not be discharged to surface water, to the surface of the ground, or underground unless the discharge conforms to the requirements of this chapter.

F. When a public sewer system is available within two hundred (200) feet of the nearest property line as measured along the usual or most feasible route of access, the owner of record must connect the residence or facility to the public sewer system if:

(1) The residence or facility is served by an OWTS which has failed or that requires a major repair; or

(1) The proposed residence or facility does not have an existing OWTS.

G. The health officer may issue a permit to construct and/or repair any OWTS within the incorporated limits of a city-provided public sewer system is not available within two hundred (200) feet of the nearest property line as measured along the usual or most feasible route of access, and the city has requested such action of the health officer in writing.

(Ord. No. 1604, § 2, 2-25-25)

A. Alternative systems and proprietary devices shall comply with the requirements of this chapter and technical standards adopted by the department under Section 8.80.020(C).

B. The health officer shall only permit the installation of alternative systems for which there are technical standards adopted by the department, or a proprietary treatment device if it appears on the list of approved systems or devices maintained by the department. Alternative OWTS shall be designed by a qualified professional.

C. The health officer:

(1) May require performance monitoring or sampling of any alternative system; and

(2) Shall submit copies of evaluation reports to the RWQCB, if required, when alternative system performance is evaluated.

D. No person shall operate or discharge to an alternative system with supplemental treatment without a valid operational permit issued by the department.

E. An owner of record who receives an alternative OWTS permit from the health officer shall:

(1) Record a notice with the Imperial County Clerk Recorder of the presence of an alternative OWTS on the property. The notice shall specify operation and maintenance requirements and any limitations on the use of the property that are related to the presence of an alternative system; and

(2) Monitor the performance of the OWTS according to any requirements stipulated on the annual operational permit.

(Ord. No. 1604, § 2, 2-25-25)

A. Gray water systems shall comply with the requirements of the California Plumbing Code, Chapter 16, or as may be amended, and technical standards adopted by the department.

B. It shall be unlawful for a person to construct, install, alter, or cause to be constructed, installed, or altered, an alternate water source system in a building or on a premise without first obtaining a permit to do such work.

C. A qualified professional shall design gray water systems and shall certify that the proposed gray water system and OWTS together meet the requirements of this chapter and will adequately serve the total amount of estimated gray water and sewage from a proposed facility or residence on a daily basis.

D. The following provisions and limitations apply to the design, construction, alteration, repair, or use of gray water systems:

(1) Gray water shall only be used for subsurface and/or subsoil irrigation, or to be dispersed within a disposal field. Discharges to a mulch basin or to above the ground surface are prohibited;

(2) Unless the OWTS is otherwise designed to accommodate the total combined design flow of gray water and sewage, the diversion of gray water to the OWTS shall be prevented;

(3) Gray water systems shall have no unprotected connections to a potable water supply, private water cistern, fire protection tank, or non-potable irrigation service lines; and

(4) The indoor use of onsite treated gray water is prohibited until such time that standards have been adopted by the health officer pursuant to Section 8.80.020(C).

E. An operation and maintenance manual for gray water systems shall be supplied to the building owner by the qualified professional, and include the minimum items of Section 1601.6 of the California Plumbing Code.

F. The discharge of gray water from a clothes washer to the surface of the ground is considered a nuisance and is prohibited.

(Ord. No. 1604, § 2, 2-25-25)

A. A qualified professional shall design onsite wastewater treatment systems for non-residential facilities and shall certify that the proposed onsite wastewater treatment system meets the requirements of this chapter and will adequately serve a proposed facility.

B. For non-residential facilities, the design flow rate shall be based on estimated wastewater flow rates specified in the California Plumbing Code or EPA OWTS Manual, or based on the number of plumbing fixture units, whichever is greater for the type of building occupancy.

(1) Any deviations shall be supported by appropriate water usage information and/or the use of low water use fixtures or gray water system.

(2) The minimum design flow for a non-residential OWTS shall be two hundred fifty (250) gallons per day.

C. When an OWTS is proposed to treat and dispose of special wastes that are not classified as domestic sewage, the applicant shall have an authorized professional submit to the health officer, and the rwqcb as necessary:

(1) Information which shows that the waste is not industrial or high-strength wastewater;

(2) Information that establishes the waste strength and identifies chemicals present that are not found in residential sewage;

(3) A design that provides treatment equal to that required for residential sewage; and

(4) An approved operation and maintenance contract between the system owner and qualified service provider (certified by the proprietor of the treatment unit), if applicable.

(Ord. No. 1604, § 2, 2-25-25)

A. No person shall construct, repair, replace, alter, expand, relocate, or destroy an OWTS or gray water system without a valid permit.

B. Persons applying for a building permit for the construction of a building that will necessitate an onsite wastewater treatment system shall obtain a permit from the department prior to commencement of construction of such new building.

C. Any persons desiring to modify or construct a building or structure, or modify the existing use on any lot or site that is served by an onsite wastewater treatment system, shall file a building plan review with the department and obtain approval for any such proposed addition or alteration prior to the issuance of the building permit.

(1) The application shall contain a detailed site plan and description of the proposed modifications.

(2) No building or land use permit shall be issued by the county where there is insufficient lot area or improper site conditions for adequate sewage disposal and replacement area consistent with this chapter.

D. Every cesspool, septic tank, and seepage pit that has been abandoned or has been discontinued otherwise from further use shall be filled in accordance with Section 722.0 of the California Plumbing Code. A permit shall be obtained prior to the completion of such work.

E. If a person fails to comply with the terms of a permit issued under this chapter, or engages in activities regulated under this chapter without the appropriate permit(s) or approval, the health officer may issue a written order to immediately stop or suspend all work, except that which is necessary to bring the project into compliance with this chapter.

(Ord. No. 1604, § 2, 2-25-25)

A. Every new onsite wastewater treatment system shall meet the minimum horizontal separations shown in Table I, Minimum Horizontal Separations:

Table I. Minimum Horizontal Separations (Setbacks)

Notes:

1

Prior to any disposal field being placed within one hundred (100) feet of a well the owner of record shall obtain a well destruction permit from the county and have the well destroyed by a licensed well driller.

2

See Section 720.0 of the California Plumbing Code.

3

Measured from the ordinary high water mark. If surface water is used as a public drinking water supply, the designer shall locate the OWTS outside of the required sanitary control area.

4

Including porches and steps, whether covered or uncovered, breezeways, roofed porte cocheres, roofed patios, carports, covered walks, covered driveways, hay storage sheds, and similar structures or appurtenances. The minimum setback from building structures to a drip field may be reduced to two feet.

5

See also Section 307.0 of the California Plumbing Code. The health officer may require a fifty-foot setback to property lines from the OWTS when individual wells are to be installed and the minimum distance between the drainfield and wells cannot be assured.

6

Tile lines within ten (10) feet of the disposal field shall be cut and capped.

7

The item is down-gradient when liquid will flow toward it upon encountering a water table or a restrictive layer. The item is up-gradient when liquid will flow away from it upon encountering a water table or restrictive layer. The health officer may increase the setback to down-gradient cuts or banks with less than five feet of undisturbed soil above a restrictive layer due to a structural or textural change.

B. OWTS design and/or installation shall only occur where:

(1) The slope is less than thirty percent (30%);

(2) The area of the proposed OWTS and the replacement area is not subject to:

(a) Encroachment by buildings or construction such as placement of swimming pools, patios, stormwater drainage systems or facilities, interceptor drains, drainage courses, and/or underground utilities;

(b) Cover by impervious material;

(c) Vehicular or animal traffic; or

(d) Other activities adversely affecting the soil or OWTS performance; and

(3) Sufficient replacement area exists to treat and dispose one hundred percent (100%) of the design flow.

C. Except as otherwise provided in this chapter, no private sewage disposal system, or parts thereof shall be located in any lot other than the lot that is the site of the building, structure, or premises served by such facilities.

D. Any new or replacement OWTS discharge shall be located a minimum of two hundred (200) feet from a water body listed as impaired unless the discharge meets the performance standard of Treatment Standard 1 or 2 for the applicable impairment of pathogens or nitrogen.

(Ord. No. 1604, § 2, 2-25-25)

A. A qualified professional shall perform all necessary soil and site evaluations for all new OWTS and for existing OWTS where the dispersal system will be replaced or expanded.

B. In performing soil and site evaluations, the qualified professional shall:

(1) Record a minimum of three soil percolation tests in locations representative of the primary and replacement drainfield areas at a depth that sufficiently characterizes the receiving soils present below the proposed disposal field. Percolation testing shall be performed in a manner consistent with the Department's Policy for Soils Evaluation, Testing, and Reporting;

(2) Record the static groundwater elevation, the date of the observation, and the probable maximum height;

(3) Record the topography and drainage characteristics of the site;

(4) Record a minimum of one representative soil boring log in close proximity to the proposed dispersal area. The description shall include:

(a) The location and depth of restrictive layers, and effective soil depth; and

(b) Classification of soils according to Table II, Soil Textural Classification.

Table II Soil Textural Classification

C. Site Approval.

(1) The Health Officer:

(a) May require additional soil testing as outlined in Section 8.80.120, Extended Site Evaluation;

(b) May waive the required number of soil percolation tests if adequate soil information has previously been developed for the site.

(2) The results of a soil evaluation report prepared by a qualified professional shall be valid for a period of five years from the date of the report, provided that no grading or disturbance of the soil has significantly modified site conditions.

(3) Site approval and a permit for the installation of a new or replacement OWTS may be granted by the department provided that the soil application rates proposed do not exceed the maximum hydraulic loading rates for the soil type listed in Section 8.80.170, Table III.

D. The health officer shall render a decision or notify the applicant of the reason for delay on all permit applications within twenty (20) working days of submittal of a complete application by an authorized professional and/or property owner.

(Ord. No. 1604, § 2, 2-25-25)

A. The health officer shall require additional soil testing prior to owts permit issuance if soil percolation data indicate the presence of soils with a percolation rate slower than sixty minutes per inch (<60 mpi) or exceeding five minutes per inch (>5 mpi), or in very gravelly soils, or as otherwise necessary to determine if the site meets the minimum requirements of this chapter. Additional soil testing may include:

(1) Particle size analysis (hydrometer testing) and plasticity index (PI) testing; and

(2) Preparation of a minimum of one representative soil profile excavation within the primary drainfield area and a minimum of one representative soil profile excavation within the replacement area (additional soil excavations may be required) to a depth of five feet:

(a) To allow examination of the soil profile in its original position by:

i. Excavating pits of sufficient dimensions to enable observation of soil characteristics by visual and tactile means to a depth of five feet deeper than the anticipated bottom of the drainfield; or

ii. Stopping at a shallower depth if a water table or restrictive layer is encountered; and

(b) To allow determination of the soil texture, structure, color, compaction, water absorption capabilities or permeability, and elevation of the maximum groundwater level.

B. All testing shall be done by a qualified professional and in accordance with testing standards adopted by administrative rules under Section 8.80.020(C). All soils analysis shall be completed at a commercial engineering testing laboratory.

(Ord. No. 1604, § 2, 2-25-25)

A. When an application for an onsite wastewater treatment system conforms to the provisions of this chapter and requirements of other pertinent regulations, the health officer shall issue a permit to the applicant. No permit, unless it is for a minor repair or septic tank replacement, shall be issued without a signed application accompanied by a site evaluation report prepared by a qualified professional, a detailed system design, and the payment of permit fees as established by ordinance.

B. The applicant shall submit a detailed system design for any new or replacement OWTS that is approved by the health officer and satisfies the requirements of Section 8.80.170. The detailed system design must include:

(a) A scaled, dimensional drawing showing the proposed location of all OWTS components and replacement area;

(b) Vertical cross-section drawing showing the depth of the drainfield, the vertical separation to groundwater, the depth of soil cover, and any other OWTS components to be constructed or installed at the site;

(c) Calculations and assumptions supporting the proposed design, including:

i. The soil type;

ii. The hydraulic loading rate in the drainfield;

iii. The design flow of the OWTS; and

(d) Such additional information as required by adopted technical standards.

C. The OWTS design shall be prepared by a qualified professional for all sites where soils have a percolation rate slower than sixty minutes per inch (<60 mpi) or faster than five minutes per inch (>5 mpi), or where gravity dispersal cannot be utilized due to insufficient depth to groundwater.

D. When the health officer issues a permit, he/she shall:

(1) Identify the permit as a new installation, replacement, repair, alteration, abandonment, or operational permit;

(2) Specify the expiration date on the permit; and

(3) State the period of validity for operational permits, the date by which an operational permit must be renewed, and the conditions of renewal.

E. The health officer may amend, suspend, revoke, or deny a permit for reasonable cause. Reasonable cause may include, but is not limited to:

(1) Installation of an OWTS that creates a health hazard;

(2) Misrepresentation or concealment of material fact in information submitted to the health officer; or

(3) Failure to meet conditions of the permit or the requirements of this chapter.

F. The health officer may stipulate additional requirements for a particular permit if a health hazard would otherwise occur.

G. New installation, alteration, or replacement permits shall be valid for a period of two years from the date of issuance. Such permits are not transferable or renewable.

H. Minor repair, abandonment, and tank replacement permits shall be valid for a period of one year from the date of issuance and shall not be transferable.

I. Operational permits for alternative OWTS utilizing supplemental treatment shall be valid for the calendar year for which they are issued. All operational permits are transferable and shall be renewed each year subject to conditions specified by the health officer.

(Ord. No. 1604, § 2, 2-25-25)

A. All recreational vehicle dump stations shall discharge into a public sewer system or private OWTS operating under an individual waste discharge requirement issued by the regional water board, or a wastewater holding tank system approved by the health officer.

B. Recreational vehicle dump stations shall be provided in an accessible location for all special occupancy parks or RV storage facilities without permitted sewer utility connections. Recreational vehicle dump stations are not required in tent camps or incidental camping areas, but if provided, they shall comply with the requirements of this chapter.

C. Each recreational vehicle dump station shall be constructed and maintained to meet the specifications of Sections 2270 and 2271 of Title 25 of the California Code of Regulations, or as amended, including cross-connection protection to the potable water supply and the provision of a warning sign immediately adjacent to the hose connection warning users to use the hose only to flush holding tanks and the drain receptor.

(Ord. No. 1604, § 2, 2-25-25)

A. All proposed major subdivisions shall provide for the extension or development of public sewer systems permitted by the regional water board. Any proposed subdivision within a designated urban area of the unincorporated county shall also connect to a public sewer system.

B. The use of OWTS on newly created individual lots is restricted to minor subdivisions where access to a public sewer system is otherwise unavailable.

C. Where an OWTS is existing or being proposed, the minimum net land area per dwelling unit shall be:

(1) One acre for areas designated as limited agriculture within urban boundaries (A-1) or other community areas;

(2) Two and one-half acres for areas designated as general agriculture (A-2) or heavy agriculture (A-3) with a lot reduction exception;

(3) Two and one-half acres within a designated area of special concern; or

(4) Two and one-half acres within open space, recreation, or preservation areas.

(5) The minimum net land area per dwelling unit requirements of Ssection 8.80.150(C) are waived for non-conforming lots, created prior to June 30, 2016, that are undeveloped. These non-conforming lots are commonly located in, but not limited to, the communities of Vista Del Mar, Salton Sea Beach, and Ocotillo.

D. The health officer may waive the minimum net land area requirements of this chapter for lot reduction exceptions, or for lot line adjustments on nonconforming lots created prior to June 30, 2016.

E. A maximum allowable density of OWTS for new land developments on existing parcels shall be one dwelling unit per acre.

F. Prior to the submittal of a tentative map for a minor subdivision, a site evaluation by a qualified professional shall be made and site approval received for each parcel within a proposed subdivision, unless parcels in the proposed subdivision will be connected to a public sewer system or a parcel is not designated for land development.

G. Site evaluations for subdivisions and lot line adjustments utilizing OWTS shall include a minimum of two representative soil percolation tests for each proposed or adjusted parcel designated for land development. The test holes shall be prepared in accordance with Section 8.80.110. The health officer may waive this requirement for lot line adjustments if the existing OWTS and replacement area will not be impacted by the adjustment.

H. If alternative systems are proposed for a subdivision, sufficient design information that includes the specific site location for both primary and replacement systems shall be provided to the health officer for review to determine if the minimum requirements of this chapter can be met. A minimum of five feet to groundwater must be maintained for any new parcels within an area of special concern.

I. The health officer may require specific language to be recorded on or with the parcel map or final map addressing OWTS design or operational permit requirements.

(Ord. No. 1604, § 2, 2-25-25)

A. The health officer, after consultation with the rwqcb, may designate the following areas as areas of special concern. This designation shall not be made unless a minimum of one public hearing is held by the health officer.

(1) Sole source aquifers designated by the U.S. Environmental Protection Agency;

(2) Areas with a critical recharging effect on aquifers used for potable water;

(3) Designated public water supply wellhead protection areas;

(4) Areas designated as special protection areas for impaired surface and ground waters of the state of California;

(5) Drainage and flooding problem areas; and

(6) Areas identified and delineated by the department in consultation with the RWQCB which constitute a health hazard due to the presence of failing onsite wastewater treatment systems.

B. The health officer may impose more stringent requirements on new developments and take corrective measures to protect public health upon existing developments in areas of special concern, including:

(1) Additional design and/or performance standards for OWTS;

(2) Larger land areas for new development;

(3) Mitigation for the impacts of development;

(4) Additional operation procedures and maintenance/monitoring protocols for OWTS;

(5) Upgrades to existing OWTS;

(6) Abandonment of undocumented and failing OWTS; and

(7) Monitoring of ground water or surface water quality.

C. The health officer has designated the Townsite of Palo Verde (Zoning Map 57A), Bard Area (Zoning Maps 25-26), and the Ocotillo/Nomirage Community Area as defined by Title 9, Division 25 of Imperial County Ordinance as Areas of Special Concern for purposes of implementing this chapter.

D. Any new or replacement OWTS within the Bard Area or Ocotillo/Nomirage Community Area shall maintain the minimum vertical separation depth of five feet to groundwater, unless supplemental treatment meeting Treatment Standard 1 is provided prior to discharge.

E. Any new or replacement OWTS discharge within six hundred (600) feet of the Palo Verde Lagoon shall meet the performance standard of Treatment Standard 1 for the impairment of pathogens, unless:

(1) The owner has committed by way of a legally recorded document with the county recorder's office to connect any existing or proposed building structure with plumbing to a wastewater collection and treatment system operated under waste discharge requirements from the regional water board when said system is developed; or

(2) The OWTS discharge is otherwise permitted under an individual waste discharge by the Regional Water Board.

F. Any person operating an OWTS requiring supplemental treatment to meet a treatment standard within an area of concern shall maintain a contract with a licensed service provider to perform scheduled maintenance and testing in accordance with the terms of the annual operational permit. No person shall operate an alternative OWTS without a valid operational permit issued by the health officer.

G. When the health officer intends to designate an area of special concern, the health officer shall notify the board of supervisors of the definite boundaries of such designation, and the additional requirements for OWTS to be applied within the delineated area of special concern.

(Ord. No. 1604, § 2, 2-25-25)

A. The detailed design and construction of all OWTS shall conform to this chapter and technical standards adopted by the department. All pressure distribution, alternative OWTS, non-residential systems, and OWTS discharging to clayey soils with percolation rates slower than sixty minutes per inch (<60 mpi) shall be designed by an authorized professional.

B. The OWTS shall be designed to receive all sewage from the residence or facility served unless otherwise approved by the health officer. The design flow shall be established as follows:

(1) For individual residences, and accessory dwelling units connected to the same OWTS, flows of one hundred twenty-five (125) gallons/day/bedroom shall be used for design purposes;

(2) For non-residential facilities, the design flow rate shall be based on typical values noted in the California Plumbing Code, EPA OWTS Manual, or the number of plumbing fixture units, whichever is greater for the type of building occupancy. Any deviations shall be supported by appropriate water usage information and/or the use of low water use fixtures or gray water system; and

(3) The minimum design flow for an OWTS shall be two hundred fifty (250) gallons per day.

C. Gravity systems and pressure distribution systems shall have the calculation of drainfield area based upon the design flows in Section 8.80.170(B) and loading rates equal to or less than those in Table III, Maximum Hydraulic Loading Rate for Residential Sewage, and applied only to the bottom of the excavated trench.

Table III Maximum Hydraulic Loading Rate For Residential Sewage 1,2

1 Compacted soils, cemented soils, and/or poor soil structure may require a reduction of the loading rate or make the soil unsuitable for the installation of an onsite wastewater treatment system.

2 The maximum hydraulic loading rate for the soil type listed is to be used for calculating the drainfield area required.

(1) If more than one suitable soil horizon is encountered in the soil profile, drainfield trench sizing shall be based on the most restrictive soil within twenty-four (24) inches beneath the bottom of the trench.

(2) The minimum total length of drainfield lines for all residential OWTS within the irrigated farm areas of Imperial Valley shall be one hundred and ninety-five (195) feet. No reductions may be applied such that the minimum total length is not met.

(3) The health officer may allow the drainfield area calculated from Table III to be reduced by a maximum of twenty percent (20%) to account for trench sidewall infiltration if at least eighteen (18) inches of drain rock is used under the distribution pipe.

(4) The Health Officer may allow a maximum reduction of thirty percent (30%) for IAPMO certified gravel-less chamber products if designed in accordance with the Department's Chambered Leach Fields policy.

D. Effluent Treatment and Distribution.

(1) The standard of effluent treatment prior to discharge and/or method of distribution in all cases shall meet or exceed the requirements contained in Table IV. Effluent Treatment and Distribution for Soil Types and Vertical Separation.

Table IV Effluent Treatment and Distribution for Soil Types and Vertical Separation

1 Depth to groundwater must be greater than or equal to twenty (20) feet for gravity distribution.

(2) A minimum effective soil depth of twenty-four (24) inches is required to utilize an onsite wastewater treatment system for wastewater treatment and disposal.

(3) Onsite wastewater treatment systems requiring more than five hundred (500) lineal feet of drainfield trench shall utilize pressure distribution.

E. Holding Tanks.

(1) Persons shall not install or use holding tank sewage systems for residential or non-residential development whether seasonal or year-round. This prohibition may be waived by the health officer:

(a) For temporary office construction trailers;

(b) For recreational vehicle dump stations; and

(c) For limited, seasonal use where it is not practicable to install an OWTS system as permitted under this chapter.

(2) A person proposing to use a holding tank sewage system shall submit a design by a qualified professional, which includes:

(a) A description of the intended use and duration of use;

(b) A site plan indicating the proposed location of the holding tank sewage system;

(c) A pumping contract with a licensed septage hauler to pump and remove the contents of the tank at a minimum frequency of once per week;

(d) Details for a tank capacity alarm to notify the owner that the sewage has reached three-quarters (¾) of the tank capacity; and

(e) The specifications of the proposed holding tank to be utilized and any installation details necessary to meet the requirements of this chapter.

F. Septic Tanks.

(1) Must be watertight and constructed in accordance with the California Plumbing Code;

(2) Must be certified as compliant with the Uniform Plumbing Code by the International Association of Plumbing and Mechanical Officials (IAPMO) if the tank is prefabricated or manufactured;

(3) Shall have the following minimum liquid capacities for a single-family residence:

(4) Shall have at least two and one-half (2.5) times the daily design flow with a minimum of one thousand (1,000) gallons for non-residential facilities where waste/sewage flow rates are available;

(5) Shall have a minimum capacity based on the maximum fixture units served per Table 702.1 of the California Plumbing Code for non-residential facilities if estimated waste/sewage flow rates are not available;

(6) Shall have clean-out and inspection accesses at or above grade;

(7) Shall have access risers and covers that are watertight, constructed of a durable material, and secured with a lockable lid or otherwise secured to prevent unauthorized entry;

(8) Must be designed with protection against flotation and groundwater intrusion in high groundwater areas;

(9) Must be equipped with an NSF/ANSI Standard 46 certified or department approved effluent filter designed to prevent solids in excess of three-sixteenths of an inch in diameter from passing to the drainfield; and

(10) In multi-compartment tanks or when two or more tanks are used in series, the primary compartment or tank shall not have a liquid capacity of less than five hundred (500) gallons or less than two-thirds of the total liquid capacity, whichever is greater.

G. Pump Tanks.

(1) Must be watertight and constructed in accordance with the California Plumbing Code;

(2) Must be certified as compliant with the Uniform Plumbing Code by the International Association of Plumbing and Mechanical Officials (IAPMO) if the tank is prefabricated or manufactured;

(3) Shall have a liquid capacity of at least two times the daily design flow with a minimum capacity of five hundred (500) gallons;

(4) Shall have cleanout and inspection accesses at or above finished grade;

(5) Shall have access risers and covers which are watertight, constructed of a durable material, and secured with a lockable lid or otherwise secured to prevent unauthorized entry; and

(6) Must be designed with protection against flotation, ground water intrusion, and surface water inflow.

H. Location of Septic Tanks and Pump Tanks.

(1) Septic tanks and pump tanks shall be located in an accessible location for pumping and maintenance.

(2) Septic tanks and pump tanks located under paving or in areas subject to vehicular traffic must be reinforced to withstand the additional loading caused by potential vehicular traffic. A California registered civil engineer shall determine the appropriate specifications for the reinforced tank.

I. Building Sewer and Gravity Effluent Pipe.

(1) Pipe used for the construction of a building sewer and gravity effluent line, beginning two feet from any building or structure shall be a minimum of three inches inside diameter and of plastic that shall be PVC ASTM D3034/SDR 35, or ABS Schedule 40, or an equivalent material as specified by the California Plumbing Code. Effluent gravity sewer pipe shall be of the same material and size as the building sewer pipe.

(2) Construction of the building sewer line shall be run in practical alignment and at a uniform slope of not less than one-quarter inch per foot, or not less than one-eighth inch per foot when utilizing piping four inches or larger in diameter.

(3) Construction of the effluent sewer line to the distribution box shall be in such manner as to maintain watertight joints and shall be on a grade of not less than one-eighth inch per foot on natural ground or compacted fill. All laterals from the distribution box to the disposal field shall be approved pipe with watertight joints.

(4) No tees or ells exceeding forty-five degrees (45°) shall be permitted in the building sewer line except for plastic long bend ninety degree (90°) elbows or sanitary tees.

(5) Building sewers shall have accessible cleanouts installed at intervals of not more than one hundred (100) feet and for each aggregate horizontal change in direction exceeding one hundred thirty-five degrees (135°).

J. Distribution Boxes.

(1) Shall be required on all conventional gravity trench systems;

(2) Shall be constructed and installed to provide equal flow of effluent to all outlets;

(3) Shall be set on a level concrete slab, unless a concrete distribution box of the minimum dimension of twenty (20) inches in both length and width is utilized;

(4) Shall be installed in natural or compacted soil to prevent misalignment;

(5) Shall be durable, watertight, and equipped with an adequate removable cover;

(6) Shall not be constructed or installed where the invert of the inlet pipe is less than one inch above the level of the invert of the outlet pipes, nor shall the invert of the outlet pipes be less than two inches above the floor of the distribution box; and

(7) Shall not be installed within five feet of the drainfield trenches to prevent settling.

K. Drainfield.

(1) All drainfields shall be installed or located to comply with the following design criteria:

Trench Design Criteria

1 Without pressure distribution. 2 The minimum trench depth for alternative OWTS may be less than twelve (12) inches provided sewage effluent is dispersed at or below grade. 3 For existing structures only, the bottom of the drainfield shall not be deeper than forty-eight (48) inches below the finished grade, unless written approval is given by the health officer. Gravel-filled excavated pits shall not be designed or constructed in drainfield trenches.

(a) The length of all drainfield trenches in conventional gravity systems shall be the same length with a maximum variance of fifteen percent (15%);

(b) The grade of the bottom of drainfield trenches and drainfield lines shall be level with a maximum grade of two inches per one hundred (100) feet;

(c) The minimum depth of drain rock under gravity drainfield lines shall not be less than twelve (12) inches;

(d) The amount of drain rock over drainfield lines shall not be less than two inches; and

(e) The drain rock in the drainfield shall terminate at the intersection of the drainfield trench sidewall and the effluent sewer line, and such intersection shall be at least five feet from the distribution box and the septic tank or pump tank.

(2) Drainfield trenches shall not be excavated during wet soil conditions to prevent smearing and/or compaction of the soil interface. All smeared or compacted soil surfaces in the trench shall be scarified and the loose material removed.

(3) All distribution piping for gravity drainfields shall be a minimum three-inch diameter Polyethylene (PE), ABS, or PVC perforated sewer pipe. Diameter of pressure laterals shall be as specified in the engineering design and must meet those specifications listed in the department's standards and guidance for pressure distribution.

(4) Drain Rock.

(a) Shall be one-half to two inches in diameter, with no less than one hundred percent (100%) passing a two-inch sieve by weight and no more than five percent passing a one-half inch sieve by weight; and

(b) Must be durable, clean, washed, non-deteriorating gravel, free of organic materials and fines, and having a cleanliness value of eighty-five (85) or higher.

(5) Drainfield trenches shall have an approved barrier material consisting of untreated building paper (forty pounds (40 lbs.) to sixty pounds (60 lbs.)) or a geotextile filter fabric placed between the gravel or gravel substitute and soil cover. This requirement may be waived by the health officer when gravel-less chambers are used.

(6) Gravel-less chambers or gravel substitutes may be used if shown on the department's list of approved systems and products, and installed in accordance with the manufacturers' specifications and standards established by the department.

L. Cover of the Drainfield.

(1) The minimum depth of soil cover over the drainfield shall not be less than twelve (12) inches unless otherwise authorized by the health officer;

(2) The maximum depth of soil cover over the drainfield shall not exceed twenty-four (24) inches except by special permission of the health officer;

(3) The soil cover shall extend at least five feet beyond the limits of the drainfield trenches and graded at a maximum slope of three-to-one (3:1). On sloping sites, a downslope correction factor shall be used to maintain the required maximum slope of three-to-one (3:1);

(4) The required grade of the drainfield trenches must be maintained while backfilling;

(5) The soil cover shall be graded to prevent ponding and covered with an approved erosion control material if necessary;

(6) Disposal fields shall not be paved over or covered by concrete, base, asphalt, or other material that can reduce or inhibit any possible evaporation of sewer effluent; and

(7) Barriers, fencing, or other means as approved by the health officer shall be constructed as to restrict vehicles access on or over the drainfield or replacement area.

(Ord. No. 1604, § 2, 2-25-25)

A. No person shall knowingly cause, permit, or allow an OWTS failure to occur.

B. All sewer wells, failing OWTS and cesspools are declared a public nuisance. It is unlawful to drill, construct, maintain, or to operate a cesspool, failing OWTS, or a sewer well, and such an offence shall constitute as a misdemeanor and/or infraction pursuant to Section 8.80.270.

C. An onsite wastewater treatment system failure occurs when:

(1) Sewage and/or sewage effluent or untreated gray water is present upon the surface of the ground;

(2) Sewage and/or sewage effluent or untreated gray water is discharging to surface water directly or by means of a ditch or depression;

(3) Sewage and/or sewage effluent that has affected, or will affect, groundwater or surface water to a degree that makes it unfit for drinking or other uses, or is causing a human health or public nuisance condition;

(4) Sewage is backing up into a residence, business, or facility;

(5) Sewage is leaking from a septic tank, pump tank, holding tank, or collection system; or

(6) Non-domestic sewage is being discharged from an OWTS to waters of the state that is not authorized by ordinance or waste discharge requirements issued pursuant to the California Water Code.

D. The following systems or system components shall also be considered a failing system and shall be repaired or replaced:

(1) Pit privies;

(2) Cesspools or seepage pits;

(3) Deep trenches or gravel pits that discharge effluent directly to groundwater within a designated area of special concern under Section 8.80.160 of this chapter;

(4) Metal or wood septic tanks;

(5) Concrete septic tanks that may be considered a potential safety hazard (i.e. wood lid or otherwise structurally unsound);

(6) Any dispersal system that is located within fifty (50) feet of surface water or a water supply well; and

(7) Any dispersal systems within one hundred fifty (150) feet of a public water supply well.

(Ord. No. 1604, § 2, 2-25-25)

A. A permit shall be required for all OWTS repairs or replacements, including major or minor repairs, unless such repair is to stop leaks in drain or sewer pipes, remove clogs in existing drain or sewer pipes, or to install maintenance and monitoring components to the septic tank or drainfield that do not otherwise affect the performance or integrity of the system.

B. When an OWTS failure occurs that cannot be readily repaired without the replacement of the drainfield or an owner of record submits an application to use an undocumented system which does not comply with this chapter, the OWTS owner shall, in order of priority:

(1) Connect the residence or facility to a public sewer system;

(2) Repair or replace the OWTS with a conforming system, either on the property served, or on nearby or adjacent property if the necessary easement(s) is/are obtained.

(3) Perform one of the following when the requirements in subdivision (1) or (2) are not feasible:

(a) Repair or replace the OWTS with a non-conforming repair;

(b) Obtain a National Pollution Discharge Elimination System or an individual waste discharge permit from the Regional Water Quality Control Board issued to a public entity or to the system owner; or

(c) Abandon uses of the property which generate sewage.

C. Prior to replacing or repairing the drainfield, the OWTS owner shall develop and submit information required under Section 8.80.110 and obtain a permit.

D. The health officer shall permit a non-conforming repair only when:

(1) Installation of a conforming system is not possible; and

(2) Connection to a public sewer system is not feasible.

E. An owner of record who receives a non-conforming repair permit from the health officer shall:

(3) Record a notice with the Imperial County Clerk Recorder of the presence of a non-conforming repair on the property. The notice shall specify operation and maintenance requirements and any limitations on the use of the property that are related to the presence of a non-conforming repair;

(4) Monitor the performance of the OWTS according to any requirements stipulated on the permit; and

(5) Immediately report any failure to the health officer.

(Ord. No. 1604, § 2, 2-25-25)

A. An expansion of a residence or other facility not served by a public sewer system shall not occur unless the onsite wastewater treatment system and replacement area comply with the new system construction standards specified in this chapter.

B. The owner of record may replace an existing residence or structure ("like for like") served by a conforming OWTS with record of approval provided that:

(1) The replacement residence or structure does not cause the waste strength or flows to exceed the design flow of the existing system;

(2) The replacement area fully complies with this chapter; and

(3) The existing OWTS is not considered a failing system under Section 8.80.180 of this chapter.

(Ord. No. 1604, § 2, 2-25-25)

A. No person shall permanently abandon any septic tank or other tank, seepage pit, or cesspool without first obtaining a permit from the health officer.

B. Any septic tank or other tank, seepage pit, or cesspool, which is no longer in use or has been discontinued otherwise from further use, shall be abandoned by:

(1) Having the septage removed by a registered pumper;

(2) Removing or destroying the lid; and

(3) Filling the void with soil, concrete, or other approved material after the health officer has inspected the tank, seepage pit, or cesspool.

C. Pre-fabricated tanks to be abandoned, such as fiberglass or polyethylene septic tanks, shall be removed from the site for disposal after the septage has been removed by a registered pumper.

(Ord. No. 1604, § 2, 2-25-25)

A. All construction and materials used in an OWTS shall be subject to inspection by the health officer at any reasonable time. Using an OWTS prior to final inspection and approval is unlawful. At the time of final inspection, the OWTS shall meet the following conditions:

(1) The septic tank and pump tank (if applicable) installation shall be completed and the access covers shall be removable so that the inside of the tank(s) may be inspected;

(2) An open trench inspection or any other required inspections shall have been conducted by the health officer;

(3) The drainfield trenches shall be completed except for backfilling with cover material. A pressure test of the laterals is required prior to covering the laterals on pressure distribution systems;

(4) There shall be an unobstructed view of all outlets within the distribution box;

(5) All electrical work including the installation of system control panels and float switches shall be installed and operating; and

(6) All required OWTS components shall be installed.

B. The owner of record or commercial installer making such installation or modification shall be responsible for notifying the health officer that the installation is ready for inspection. Notification shall be made at least one working day prior to the anticipated date that the system will be ready for inspection.

C. If, upon inspection, the health officer finds that the work, material, design, or location of the OWTS does not comply with the requirements of this chapter, he/she shall notify the owner of record and/or commercial installer by written notice. If non-conformance with the provisions of this chapter is not corrected, the OWTS shall not be approved and its use shall be prohibited.

D. OWTS shall not be approved by the health officer until the designer and/or commercial installer has submitted a scaled "as-built" drawing of the installed system.

E. As-Built Drawings.

(1) All "as-built" drawings shall include measurements to existing site features enabling all OWTS components to be easily located.

(2) All "as-built" drawings for new OWTS shall delineate the dimensions of the replacement area.

(3) All "as-built" drawings for repaired or altered OWTS shall include the new, repaired, or altered components with their relationship to the existing system.

(4) All "as-built" drawings for designed systems must include the minimum information specified in the adopted technical standards.

(Ord. No. 1604, § 2, 2-25-25)

A. It shall be unlawful for any person to engage in the cleaning or pumping of any septic tank, pump tank, holding tank, or chemical toilet, or to dispose of the cleanings therefrom without first obtaining registration from the health officer.

B. Only disposal sites with a valid discharge permit from the RWQCB shall be used for the disposal of septage. The transfer of septage from one container to another is prohibited, unless conducted:

(1) At a publicly owned treatment works pursuant to waste discharge requirements issued by the RWQCB; or

(2) At a permitted temporary septage storage facility. Septage that is transferred at a permitted temporary septage storage facility shall be stored in licensed septage pumper hauler(s) as authorized under the temporary septage storage facility permit. Septage that is transferred and stored at a permitted temporary septage storage facility may only be stored temporarily for no more than seven calendar days. A temporary septage storage facility shall not exceed twelve thousand (12,000) gallons of cumulatively stored septage onsite at any given time.

C. An applicant for registration as a septage pumper hauler must furnish his/her equipment for inspection by the health officer prior to the issuance or renewal of registration. The equipment must meet the following minimum requirements:

(1) All equipment, pumps, valves, and hoses must be in good repair, leak proof, and easily cleanable. Vehicles shall be kept clean of splashing and waste accumulation;

(2) Truck equipment must be designed to adequately control effluent disposal from the truck into receiving stations without spilling or splashing;

(3) The tank discharge valve must be equipped with a leak proof cap fitted over the outlet pipe at all times, and the cap chained to the truck;

(4) A sighting gauge or other reliable tank content level indicator must be installed on the exterior of the tank adjacent to a manual vacuum shut-off device and must be calibrated to measure capacity to the quarter tank;

(5) A properly functioning automatic vacuum shut-off system shall be provided;

(6) Each vehicle shall carry a hose of at least twenty-five (25) feet in length, a minimum of one gallon of disinfectant material, and at least five gallons of potable water for sanitary cleanup; and

(7) The name of the operating firm, address, phone number, and tank capacity shall be conspicuously displayed on both sides of the truck or on the rear of the tank in bold letters not less than three inches high.

D. Septic tank pumper registration expires on December 31 of each year. This registration is renewable if the registrant continues to meet the requirements of this chapter.

F. Septic tank pumpers shall submit the following minimum information in writing on forms provided by the health officer no later than the tenth of each calendar month for the previous month:

(1) Gallons pumped according to location and site address;

(2) Date of pumping, type of waste, and reason for pumping, if applicable; and

(3) Gallons disposed of at each authorized dumping site.

G. Any septage pumper hauler registration issued pursuant to this chapter may be revoked by the health officer for incompetence, negligence, misrepresentation, or failure to comply with the requirements of this chapter on the part of the septage pumper hauler.

(Ord. No. 1604, § 2, 2-25-25)

A. The owner of record is responsible for properly operating and maintaining the OWTS, and shall:

(1) Employ a registered septic tank pumper to remove septage from the tank when the level of solids and scum indicates that removal is necessary;

(2) Protect the OWTS and the replacement area from:

(a) Cover by impervious material or additional overburden;

(b) Surface or stormwater drainage;

(c) Soil compaction by vehicular traffic; and

(d) Damage by soil removal and grade alteration;

(3) Keep the quantity and waste strength of sewage entering the OWTS at or below the approved design; and

(4) Operate and maintain alternative systems as directed by the health officer.

B. All OWTS designs prepared by a qualified professional shall include operation and maintenance information for the owner of record prior to approval of any new installation, repair, or alteration of the OWTS.

C. The administrative officer, in consultation with the health officer, shall develop and implement plans to:

(1) Monitor all OWTS performance within areas of special concern;

(2) Ensure that each owner of record of an alternative OWTS and/or OWTS with supplemental treatment properly maintain and operates the OWTS in accordance with this chapter and with periodic monitoring requirements as specified in the annual operational permit; and

(3) Disseminate relevant operation and maintenance information to the OWTS owner of record.

D. Persons shall not:

(1) Use or introduce strong bases, acids, or chlorinated organic solvents into an OWTS for the purpose of system cleaning; or

(2) Use an OWTS to dispose of waste components atypical of residential sewage.

E. Operating Permits. When required by this chapter, an owner of record is responsible for maintaining a valid annual operational permit issued by the health officer. Renewal shall be completed prior to the expiration date of the operating permit (December 31 of each year) on a form or manner as required by the department, and shall include:

(1) An annual inspection and evaluation report prepared by a qualified service provider. Quarterly maintenance inspections are required where supplemental treatment components are not equipped with a telemetric alarm and monitoring system;

(2) Quarterly treated effluent sampling results demonstrating continued compliance with Treatment Standard 1, if applicable;

(3) Proof of repairs, pumping, or maintenance conducted on the alternative OWTS when such repairs have been required by the department or otherwise recommended by the qualified service provider; and

(4) An approved ongoing operation and maintenance contract between the system owner and qualified service provider (certified by the proprietor of the treatment unit).

F. Bacteriological sampling results for disinfection treatment shall be submitted to the department by the tenth day of the following month of the sampling event. All effluent samples shall be taken by a qualified service provider and analyzed by a California certified laboratory for the most probable number of total coliform bacteria.

G. No person shall operate or discharge to an alternative system with supplemental treatment without a valid operational permit issued by the department.

H. Within sixty (60) days of a change of ownership, the new owner or owners must transfer the operational permit into his, her or their names, using forms provided by the department.

(Ord. No. 1604, § 2, 2-25-25)

A. A technical advisory committee shall be established to review and recommend revisions to adopted technical standards in response to changes in regulation and/or technology.

B. The technical advisory committee shall review the technical standards documents at a minimum frequency of once every five years and submit any recommended changes to the department.

C. The technical advisory committee shall be appointed by the administrative officer based on experience, training, and knowledge of onsite wastewater treatment system technology; and

D. The technical advisory committee shall be comprised of the health officer, and authorized professionals and commercial installers as appointed by the administrative officer.

(Ord. No. 1604, § 2, 2-25-25)

A. This section only applies to:

(1) The processing of applications for permits;

(2) The issuance of permits;

(3) The suspension of permits;

(4) The revocation of permits; and

(5) The issuance of stop work orders.

B. Notwithstanding Section 8.80.260(A), any action which is taken that requires a valid permit when no such permit has been issued, or when the permit has expired, or when the permit is suspended or revoked, is subject to the sanctions listed in Section 8.80.270. In addition, any violation of a stop work order is subject to the sanctions listed in Section 8.80.270.

C. A person aggrieved by any action taken by the health officer pertaining to the activities listed in Section 8.80.260(A) may request an administrative hearing before a hearing officer.

(1) A request for an administrative hearing shall be filed in writing with the department within twenty (20) working days of the date of the action being challenged.

(2) Upon receipt of a request for administrative hearing, the department shall notify the person aggrieved of the time and place of such hearing, which shall be set not less than ten (10) working days nor more than twenty (20) working days from the date the request was received, unless a later date is agreed to in writing by the person aggrieved.

(3) The department shall, if possible, set the hearing at a mutually convenient time.

D. The administrative hearing delineated in Section 8.80.260(C) shall be conducted in an informal manner. All relevant evidence is admissible and the strict rules of evidence shall not apply. The person aggrieved may be represented by a lawyer.

E. The hearing officer shall determine whether the explanation of the events by the person aggrieved justifies modifying or reversing the initial decision.

(1) The decision of the hearing officer to affirm, reverse, or modify the initial decision shall be in writing and shall be issued within twenty (20) working days after the close of the hearing.

(2) The decision shall be accompanied by written findings of fact and shall be promptly sent to the person aggrieved.

(Ord. No. 1604, § 2, 2-25-25)

A. Any person who violates any of the provisions of this chapter or fails to comply with any of its requirements is guilty of an infraction or a misdemeanor, and each day or portion thereof during which a violation is committed, continued, or not permitted shall constitute a separate offense. The penalty for each violation determined to be a misdemeanor is punishable by a fine of not more than one thousand dollars ($1,000.00) and/or by imprisonment for not more than six months, unless otherwise prescribed.

B. The health officer or designee(s) have authority pursuant to Section 1.12.020 of the Codified Ordinances of the county by Imperial to issue citations against any person, firm or corporation that is in violation of any provision of this division and/or any section, article, or regulation of the adopted codes.

C. Any disposition of a violation pursuant to this chapter shall not absolve a person from correcting or abating a violation and shall not prevent the prosecuting authority from pursuing criminal prosecution, other civil action including, but not limited to, injunctive relief, registration revocation, and abatement, or all of the above. If the county prevails in a separate civil action, the court may award the county reasonable costs including, but not limited to, the costs of the responsible officials' time, witness fees, attorney fees, court costs, and the costs to the county of abatement or of enforcement of an injunction, or both.

D. Nothing contained in this chapter shall prevent the administrative officer, by and through the prosecuting authority, from taking such other lawful action as is necessary to prevent or remedy any violation of this chapter.

(Ord. No. 1604, § 2, 2-25-25)

A. For individual, site-by-site waiver requests, the health officer may grant a waiver from specific requirements in this chapter for OWTS if:

(1) The applicant submits a waiver application to the health officer which justifies how the requested waiver is consistent with the purpose of this chapter; and

(2) The health officer determines that the waiver is consistent with the purpose and intent of this chapter and would not result in a violation of mandatory state laws and regulations.

B. A person aggrieved by a decision of the health officer pertaining to a waiver request may appeal the decision to the administrative hearing officer. The hearing officer shall process waiver appeals according to the procedural rules delineated in Section 8.80.260.

C. If an applicant desires to modify and resubmit a previously denied waiver request, the process described in Section 8.80.280(A) shall be followed again.

D. The health officer may grant special permits allowing for variances from the provisions of this chapter in the case of natural disasters (i.e. fires, floods) and/or unnecessary hardships provided that:

(1) An expansion of the original structure does not occur; and

(2) The special permit does not create a potential health hazard and is consistent with the purpose of this chapter.

(Ord. No. 1604, § 2, 2-25-25)

If any section, subsection, sentence, clause, phrase, or portion of this chapter is for any reason held invalid or unconstitutional by a court of competent jurisdiction, such portion shall be deemed a separate, distinct, and independent provision, and such holding shall not affect the validity of the remaining portions thereof.

(Ord. No. 1604, § 2, 2-25-25)