Napa County Municipal Code Ch. 13.32 Subdivision Lot Standards

All proposed subdivisions of land which will receive individual sewage disposal systems must first receive the approval of the administrative authority in relation to such systems.

(Ord. 1109 § 1 (part), 1996: prior code § 5450)

Before such proposed subdivision is approved, evidence may be required to be submitted to the administrative authority by the owner or his agent in the form of site evaluations, percolation tests, soil analysis, as well as depth to groundwater table and temporary and perched water tables, and grading plans, to prove that an individual sewage disposal system can be installed and operated on the proposed lot that will meet the full requirements of Division II of this title with respect to suitability, depth of soil and adequacy of area. Each parcel in the subdivision shall have a site plan approved by the administrative authority showing the areas to be utilized for sewage disposal systems.

(Ord. 1109 § 1 (part), 1996: prior code § 5451)

A. Prior to the approval of any proposed subdivision, the administrative authority may require that a site evaluation or percolation tests be performed on each parcel. On proposed subdivisions of more than four parcels, the report required by Section 13.32.020 must be accomplished by a registered engineer.

B. On parcels of record on which site evaluations or percolation tests have not previously been made, or for which standards have not been established, such tests must be performed prior to the issuance of a permit to install an individual sewage disposal system.

(Ord. 1109 § 1 (part), 1996: prior code § 5457)

A. Where a parcel is to utilize an individual sewage disposal system, the minimum parcel size shall be determined by the following table:

Table 13.32.040 Slope Density Table

Showing Relationship of Average Ground Slope of Parcel to the Required Minimum Area Unless Otherwise Specified

Average ground slope is calculated by the following formula:

S = .00229 IL

___________

A

B. The administrative authority may permit construction of an individual sewage disposal system on a parcel containing less than one acre, providing the parcel contains at least one-half acre and all of the following conditions are met:

1. Water is available from a public entity;

2. The average slope of the parcel is not greater than twenty percent;

3. Suitable soil conditions are determined to exist by a satisfactory site evaluation or percolation test in an approved location, in conformance with Sections 13.28.020, 13.32.030 and 13.32.040 of this title;

4. The parcel contains a minimum of one quarter acre available for sewage disposal purposes, which area is unencumbered by any permanent improvements, and satisfying the clearance requirements of Section 13.28.040;

5. There are no wells existing on the parcel, or any existing wells thereon are properly destroyed under permit as required by Section 13.12.480;

6. The proposed system will not have a significant cumulative effect on surface water or groundwater quality in the vicinity;

7. The proposed system will not have a significant effect on the other sewage disposal systems in the area.

(Ord. 1109 § 1 (part), 1996: Ord. 648 § 1, 1980: prior code § 5454)

Unless otherwise specified by the administrative authority, the minimum size of the disposal system reserve area is one-quarter acre, for any lot. This area is to remain unencumbered by permanent improvements.

(Ord. 1109 § 1 (part), 1996: prior code § 5456)

Unless otherwise specified by the administrative authority, the slope of the disposal system reserve area in relation to such lot should be no greater than the average ground slope of the lot or parcel (see Table 13.32.040). A parcel smaller than one acre may be approved if the provisions of Section 13.32.100 apply.

(Ord. 1109 § 1 (part), 1996: prior code § 5455)

Subject to Section 13.32.080, on such parcels where a high water table or other condition which would prohibit the installation of an individual sewage disposal system is found to exist, a registered engineer shall submit plans for making such corrections as would remedy these conditions, including, if necessary, plans for a special design sewage disposal system.

(Ord. 1109 § 1 (part), 1996: prior code § 5458)

Where in the opinion of the administrative authority conditions for individual sewage disposal are marginal, connection to a public or private sewage disposal system may be required by the administrative authority.

(Ord. 1109 § 1 (part), 1996: prior code § 5461)

The establishment of a private sewage disposal system will be permitted in an urbanizing area only if it is within the boundaries of the service area of an existing public sewage entity, and only if such public entity has agreed to assume responsibility for the maintenance and operation of the proposed private sewage system and to the ultimate annexation and incorporation of the proposed private sewage system into such public system.

(Ord. 1109 § 1 (part), 1996: prior code § 5460)

A. If the administrative authority determines that the proposed subdivision is within an urbanizing area and that there is a reasonable probability that the subdivision will, within a period of five years, be within one thousand feet of a public or private sewage disposal system of sufficient capacity, then the administrative authority may require in-tract street sewers to be installed as part of the subdivision development and, if so, the administrative authority may approve parcel sizes of less than one acre if otherwise permitted by this code.

B. Sewer lines so required shall be installed to such elevations, grades and specifications as may be required by the appropriate sewage entity.

C. Assurance of satisfactory construction of in-tract sewers, as by bonding or other means satisfactory to the administrative authority, shall be a condition of approval of the final subdivision map.

(Ord. 1109 § 1 (part), 1996: prior code § 5452)

For every subdivision in an urbanizing area, when the administrative authority determines that a public or private sewage disposal system of adequate size and capacity is not, within a period of five years, likely to be within one thousand feet of such subdivision, and that conditions in the subdivision will be such that all parcels cannot be served by in-street sewers, the subdivider shall dedicate easements into the lots or along the property lines or in private streets, as necessary, so that all parcels may be ultimately served by sewer lines through such easements. Dedication shall be irrevocably offered by the subdivider to such public agency as may be directed by the administrative authority.

(Ord. 1109 § 1 (part), 1996: prior code § 5453)

The development of a subdivision using individual sewage disposal systems in an urbanizing area, after May 8, 1969, is prohibited where such subdivision could be included in and connected to an existing public sewer system with the installation of not more than one thousand five hundred feet of sewer line. The fact that the subdivision is outside the current legal boundaries of such public system shall not alter the application of this provision.

(Ord. 1109 § 1 (part), 1996: prior code § 5459)