§ 25-56. Generally.

The subdivider shall make or agree to make all required improvements in accordance with the standards set forth in Section 25-57 and to the satisfaction of the county surveyor and may include, but not be limited to, the following:

(a)

Improvement of streets, installation of curbs and gutters where required, barriers where required and provision for drainage and construction of drainage structures necessary to the health, convenience and safety of the public.

(b)

The subdivider shall make application for an encroachment permit as provided in this code, and shall, under the terms of such permit improve the extension of all subdivision streets, highways or public ways to the intersecting paving line of any county road.

(c)

Provision shall be made for such domestic water supply as may be necessary to protect public health. Such water supply may be by:

(1)

Connection to a public utility, in which case a letter from the public utility shall be submitted showing its ability to serve the proposed subdivision and evidence indicating that a satisfactory agreement has been entered into for such service.

(2)

Establishment of a mutual water system, in which case the divider shall, prior to the filing of the final map, submit evidence that the source of supply is adequate and potable and that the mutual water company has been formed

(3)

(i)

Domestic water supply must be provided from either an approved public water system or from an individual source for each parcel. Any proposal to share a water source with five (5) or more connections requires compliance with the Pure Water Law (Health and Safety Code, Section 4010 et seq.). Any proposal to share a water source with two (2) to four (4) connections requires establishment of an entity which meets the approval of the health officer to operate and maintain the system. Design of water systems of two (2) or more connections shall be in conformance with Sonoma County water systems standards.

(ii)

All subdivision applications within area 4 as shown on that certain map entitled "Groundwater Availability" (on file with the Sonoma County permit and resource management department and available for public inspection) and served by individual wells shall meet the following requirements relating to groundwater prior to recordation of the parcel map:

(a)

That a well or wells on each new undeveloped lot yield a minimum of one (1) gallon per minute for a sustained yield, metered pump test of twelve (12) hours or eight (8) hours in accordance with the Sonoma County permit and resource management department's well pump test guidelines;

(b)

A note shall be indicated on the parcel map or similar document that this minimum shall be accompanied at the time of residential construction with a requirement of a minimum of one thousand (1,000) gallons of storage capacity. Said capacity may be stored in the well hole itself or in storage tanks or in any combination thereof;

(c)

A yield of three (3) gallons per minute will require five hundred (500) gallons of storage under the above testing procedure. A yield of five (5) gallons per minute will require no storage;

(d)

Testing to meet the above yield requirements shall be conducted from July 15th to October 1st. This time may be extended by the project review and advisory committee in the case of successive dry years;

(e)

Pump tests shall be performed by or under the direction of a licensed water well drilling contractor (C57), pumping contractor (C61/D21), a registered civil engineer or a registered geologist. The director of permit and resource management department shall be notified a minimum of twenty-four (24) hours prior to the pump testing of wells or springs;

(f)

Test wells shall be sealed as required by Section 25B-7 or completed immediately upon completion of the test or before the driller leaves the site in order to prevent accidental injury to people and animals. A well log on each test well shall be submitted to the Sonoma County permit and resource management department upon completion of the test;

(g)

On lots greater than twenty-five (25) acres (gross) in size, the project review and advisory committee may waive the requirement of test wells. The parcel map or similar document shall contain a note relating to the lack of evidence of groundwater availability;

(iii)

All subdivision applications within area 4 as shown on that certain map entitled "Groundwater Availability" (on file with the Sonoma County permit and resource management department and available for public inspection) and served by a water system shall meet the following requirements relating to groundwater prior to recordation of the parcel map:

(a)

That the well or wells supplying the water system yield a minimum of one (1) gallon per minute per dwelling unit by a sustained yield, metered pump test of the following duration:

(1)

Each dwelling unit is a connection to the well. Wells with one (1) to two (2) connections: test of twelve (12) hours or eight (8) hours in accordance with the Sonoma county permit and resource management department's well pump test guidelines.

(2)

Wells with three (3) to four (4) connections: test of twenty-four (24) hours or sixteen (16) hours in accordance with the Sonoma County permit and resource management department's well pump test guidelines.

(3)

Wells with five (5) or more connections: test of at least seventy-two (72) hours after the dynamic pumping level has been established. A reduction of the seventy-two (72) hour metered pumping test may be granted by the administrative authority if it is indicated that the sustained yield well production is two (2) or more times greater than required. Under no circumstances shall the test be less than forty-eight (48) hours;

NOTE: Also see Section 64563 of the California Code of Regulations for determination of source capacity for systems with five (5) or more connections

(iv)

In water scarce areas bordering on known groundwater or recharge basins (generally within five hundred feet (500')) the project review and advisory committee may waive the well requirement upon submission of evidence of groundwater availability. Such evidence shall include, but not be limited to, geology reports, well log data, and historical documentation.

(v)

The project review and advisory committee upon reason to believe the existence of salt, bacteriological, mineral or other contamination, shall require a water quality test for such wells to be conducted by a State Department of Health certified laboratory. Test results shall be submitted to the Sonoma County permit and resource management department for approval or disapproval.

(vi)

If springs are to be used as the primary domestic water source, yields from springs and the required storage capacity shall meet the same minimum requirements as for wells. Springs shall be perennial. The water collection facilities from the springs shall be designed to the satisfaction of the Sonoma County permit and resource management department.

(vii)

In areas designated water scarce area 4 or marginal water availability area 3 on the groundwater availability map, a report by a registered geologist shall be prepared as required by general plan policy RC-3h. Test wells may be required in marginal water availability areas 3 and 4 where doubt exists as to the possibility of developing water.

(viii)

An annual review of the groundwater availability map shall be made so that new data and information can be utilized to keep the map up-to-date.

(d)

Provision shall be made for adequate sewage disposal by:

(1)

Connection to sanitary sewer when available, in which case a letter shall be submitted from the governing board of the sewer system showing the ability of the system to handle sewage from the proposed subdivision and evidence that a satisfactory agreement has been entered into for connection to the system. In addition, the subdivider shall give such guaranty or shall post a bond as deemed necessary to ensure the installation or proper sewer facilities within the proposed subdivision. Proper sewer facilities shall be considered as the installation of service laterals to the property line of each lot.

(2)

(i)

Minimum lot size shall be one and one-half acres where individual sewage disposal and water supply systems are necessary, unless the size and shape of the site and surrounding parcels allow for a lesser lot size. Minimum lot size shall be one (1) acre where individual sewage disposal systems are necessary but water is available from an approved public water system. These lot sizes are exclusive of rights-of-way and/or easements. In either case, there shall be sufficient area on the parcel to accommodate a private sewage disposal system for a typical three (3) bedroom house plus unencumbered area to expand or replace this system by two hundred percent (200%).

(ii)

Evidence shall be provided of suitable soil percolation characteristics to meet current criteria of the Sonoma County public health service and the basin plan of the appropriate regional water quality control board. Some parcels require testing during the official "wet-weather" season.

(iii)

Leachfield areas must be located a minimum of one hundred feet (100′) horizontally from the contour of the ten (10) year flood elevation of perennial waterways and fifty feet (50′) horizontally from the top of bank of ephemeral waterways or drainage courses.

(iv)

Leachfield areas shall be a minimum of one hundred feet (100′) from existing or proposed well sites, springs, seepage areas, oceans, lakes, or reservoirs. The presence of springs, seepage areas, or shallow water tables may necessitate approval of the proposal by a registered geologist or certified engineering geologist.

(v)

On parcels where drainage may adversely affect septic field function, an approval by a registered civil engineer and/or provision of drainage easements may be required.

(vi)

Leachfields shall be located to avoid areas of land slippage or instability and shall not be placed in areas where land slippage or instability could be induced or accelerated by leachfield discharge. In areas designated potentially unstable, an analysis by a registered or engineering geologist will be required.

(vii)

Additional conditions necessary to supplement those established for the tentative map to ensure compliance with sewage disposal regulations prior to filing the final map may be required by PRAC.

(viii)

Preliminary percolation testing and soil profile analysis will be required on major subdivisions prior to filing the tentative map in order to determine whether the proposed density and lot design are feasible. Reports on at least one (1) percolation test hole per lot and one (1) soil profile hole per five (5) lots must be submitted. Soil profile holes may be reduced if conformity to a given soils type can be established. Additional testing will be required prior to filing the final map to fully substantiate suitable disposal area.

(ix)

Location of leachfields shall not be on slopes of greater than thirty percent (30%).

(3)

Provision shall be made for any and all railroad crossings necessary to provide access to or circulation within the proposed subdivision, including the preparation of all documents necessary for application to the State Public Utilities Commission for the establishment of a public crossing. All costs necessitated by the establishment and improvement of such crossings shall be assumed by the subdivider.

( Ord. No. 6121, § II(b) , 7-28-2015; Ord. No. 5489 § 3, 2004: Ord. No. 2510 § 24; Ord. No. 965 § 6.)