§ 9-604

This Chapter specifies the requirements for wastewater treatment and disposal for development projects. The following requirements for wastewater disposal apply to development, unless otherwise specified in

this Title:

(a)

Compliance with Environmental Health Department and Agency Requirements. Public wastewater treatment and disposal systems shall comply with the requirements of the Public Works and Environmental Health Departments and the agency or district providing wastewater treatment and disposal services. Private on-site wastewater disposal shall comply with the requirements in Chapter 9-605, Private On-Site Wastewater Disposal Facilities.

(b)

Wastewater Service by District or Agency. Development projects requiring wastewater service by a public agency or district shall be served by a public wastewater treatment and disposal system.

(c)

Written Confirmation for Building Permits. Applications for building permits shall include written confirmation that the development project meets the requirements of this Chapter. For public systems, this confirmation shall be given by the agency or district providing the services to the Environmental Health Department

(d)

Suitability of an Area for Septic Tank Usage. The suitability of an area proposed for septic tank usage shall be determined prior to submission of a General Plan Amendment or Zone Reclassification application, the approval of a Parcel Map or Final Map, or the issuance of a building permit for development on the site. The suitability shall be determined by the Environmental Health Department based on the following criteria:

(1)

The intensity and extent of the existing and the proposed development project's use of septic tanks on the site, identified in a Nitrate Loading Study or other documentation;

(2)

The suitability of the soil for utilizing septic systems, including percolation rates and soil profiles;

(3)

The depth and gradient of the water table;

(4)

The history of past uses in the project area to assess potential problems;

(5)

Other information as required by the Environmental Health Department to determine the cumulative effect of the existing and the proposed development project on groundwater contamination; and

In non-agricultural zones, septic systems will only be considered for lots two acres or more in size, except in areas zoned Rural Residential, where lots one acre or more in size will be considered if served by a public water system and public storm drainage system.

(e)

Mandatory Connection within Two Hundred Feet. Any expansion of an existing use on an existing lot shall require the project to be served by a public wastewater disposal system if:

(1)

The expanded use generates additional wastewater; and

(2)

The sewer main is within 200 feet of the nearest building.

(3)

Exceptions may be granted if the project site meets the requirement for on-site wastewater disposal and:

(A)

The Director of Public Works determines that the existing public wastewater disposal system has no capacity to accommodate additional sewage; or

(B)

The site cannot be annexed to the existing sewer district at a reasonable cost and no health hazard would be posed by allowing on-site disposal in an area judged by the Director of Environmental Health to be suitable for septic tank use.

(f)

Extension of Sewer Main. When the Director of Public Works determines that extension of the sewer main through a project or along a project parcel frontage is necessary for the orderly provision of wastewater disposal service to an area, the developer shall extend the sewer main in accordance with the serving agency's design standards.

(g)

Capacity of Existing Wastewater Disposal System. If the existing wastewater treatment and disposal system is required to serve a development project but does not have capacity to serve a development project, the developer shall provide for additional capacity either by constructing off-site wastewater treatment and disposal system facilities or contributing funds to the serving agency for system expansion. The serving agency shall determine which option is appropriate. The existing wastewater treatment and disposal system shall have the capacity to serve the development project prior to the certificate of occupancy or final permitting, as determined by the agency or special district providing the service.

(h)

Development Projects Using Existing Structures. Development projects using existing structures only and adding no new structures shall be served by a public wastewater disposal system if there is an existing sewer main within 200 feet of the nearest property line unless the Director of Public Works grants an exception pursuant to Section 9-604.010 (e) above. Otherwise, on-site wastewater disposal may be utilized subject to the provisions of this section.

(i)

Community Sewage Treatment Systems. For community sewage treatment systems, the average dry weather daily sewage flow quantity for residential developments, which is used to design the system, shall be based on the maximum number of allowable dwelling units per the General Plan designation, including accessory dwelling units, and additions. This number may be reduced subject to recorded deed restrictions.

Within urban communities identified in the General Plan, required public wastewater disposal systems shall be provided by an existing public agency or district or, where there is no public agency providing wastewater disposal services in the community, by a new agency or district.

(a)

Development Projects. Development projects within urban communities shall be served by a public wastewater disposal system, except within the following General Plan map designations on-site wastewater treatment and disposal may be used subject to the provisions of Section 9-601.020: Rural Residential (R-R), Commercial (C-N, C-C, C-O, and C-G) adjacent to Rural Residential (R-R), and Warehouse Industrial (I-W) zones.

(b)

Development Projects on Existing Vacant Parcels. Development projects on existing vacant parcels shall be served by a public wastewater disposal system. IF there is no wastewater disposal system within 200 feet, exceptions may be granted subject to the general requirements of the General Plan and Development Title and the approval of the Environmental Health Department.

(Ord. No. 4683, § 26, 12-9-2025)

Within rural communities identified in the General Plan, wastewater treatment and disposal may be provided on-site, subject to the general requirements of Section 9-604.010. Otherwise, the development project must be served by a public wastewater disposal system.

(a)

I-L, I-P, and I-G Industrial Zones. All development must comply with Section 9-604.010. In addition, as required by the General Plan, development projects in the Limited Industrial (I-L), Industrial Park (I-P), and

General Industrial (I-G) zones outside of urban communities or on land rezoned to these zones on or after December 29, 2022, the effective date of the ordinance codified in this Title, shall be served by a public wastewater disposal system planned to serve the entire industrial area. The Environmental Health Department may authorize use of on-site wastewater disposal subject to the general requirements of Section 9-604.010 upon finding that an on-site wastewater treatment and disposal system would meet the State Water Resources Control Board On-site Wastewater Treatment System Policy and the Boardapproved Local Agency Management Plan.

(b)

Warehouse and Truck Terminal Zones. Development projects within Warehouse (I-W) and Truck Terminal (IT) zones may utilize on-site wastewater disposal subject to the general requirements of Section 9-604.010. Otherwise, the development project shall be served by a public wastewater disposal system.

(c)

Freeway Service Commercial Zone. Development projects within a Freeway Service Commercial (C-FS) Zone shall be served by a public wastewater disposal system planned to serve at least each side of the freeway service area.

(d)

Commercial Recreation Zone. Development projects within a Commercial Recreation (C-R) zone that is outside of urban communities shall be served by a public wastewater disposal system planned to serve the entire C-R zone.

Development projects within the General Agriculture (AG), Limited Agriculture (AL), and Agriculture-Urban Reserve (AU) zones may be served by on-site wastewater treatment and disposal systems subject to the general requirements of Section 9-604.010.

(a)

Existing Buildings. Subdivision of parcels with existing County-approved buildings on each new lot are required to meet the general requirements in Section 9-604.010.

(b)

Remainder Parcels. Undeveloped, designated remainder parcels shall meet the requirements of this Chapter prior to any grant of approval for a development project or issuance of a building permit on the remainder parcel.

For existing lots in antiquated subdivisions, service by a public wastewater disposal system shall be required for new residences, except that on-site wastewater disposal may be utilized, subject to the

general requirements of Section 9-604.010, for lots of two acres or more or for lots of one acre or more when served by a public water system.

When a new district is formed or services within an existing district are expanded to include wastewater treatment and a wastewater treatment plant is required, the plant shall be capable of expanding to serve the entire urban or rural community; the entire freeway service area on at least one side of the freeway; or the entire commercial recreation area as designated on the General Plan.

Chapter 9-605 - Private On-Site Wastewater Disposal Facilities