§ 19-10. Minimum requirements for creation of all new parcels and for existing parcels within a Watershed Protection Overlay Zone.

A.

An applicant initiating a parcel or subdivision map shall utilize a certified designer to perform the site evaluation. The soil suitability investigation shall be performed jointly by the certified designer and the LEA, using the site evaluation process as described in this chapter and the On-Site Wastewater Manual.

B.

No parcel or subdivision map shall be recorded and no on-site wastewater system shall be approved for existing parcels within a Watershed Protection Overlay Zone unless all proposed lots or parcels which rely on on-site wastewater systems have an approved site evaluation report that verifies, at a minimum, the following site characteristics:

1.

Vertical separation will be not less than thirty-six (36) inches. The required depth of effective soil for the creation of new parcels and for parcels within Watershed Protection Overlay Zones may be reduced by the LEA when all of the following conditions are met:

a.

Wastewater system designs are provided by a certified designer demonstrating that a supplemental treatment and dispersal alternative meeting the provisions of this chapter and the On-Site Wastewater Manual will maintain a vertical separation of twenty-four (24) inches and include the use of pressure distribution or subsurface drip dispersal of the treated effluent; and

b.

Primary and repair dispersal areas are designated on the parcel map to assure subsequent construction activities do not take place that would adversely impact the soil in those areas.

2.

Slope is no greater than thirty percent (30%).

3.

Receiving soils are in Soil Groups A-E, as identified in Table One, Subsection C of this section.

4.

When percolation testing is required, percolation rate is one (1) to one hundred twenty (120) minutes per inch (mpi). Percolation testing shall be required by the LEA as shown in Table One in Subsection C of this section, and shall be conducted by a certified designer and verified by the LEA. Soils that percolate at a rate of one (1) to five (5) mpi shall require pressure distribution and shall demonstrate adequate filtration capacity. Designs for on-site wastewater systems that will be installed in soils that percolate at a rate of one (1) to five (5) mpi shall demonstrate adequate filtration capacity by consideration of design factors identified in the On-Site Wastewater Manual for rapidly drained soils.

C.

Minimum Useable Wastewater Area.

1.

No parcel or subdivision map shall be recorded, and no on-site wastewater system shall be approved for existing parcels within a Watershed Protection Overlay Zone, unless all parcels, which rely on wastewater systems, have an approved site evaluation, that specifies whether the parcel has the required minimum useable wastewater area (MUWA) in accordance with the area requirements shown on Table One for each residence, or for each Residential Equivalent (three hundred sixty (360) gallons per day) in the case of non-residential development.

Table One
MUWA Requirements Per Residence or Residential Equivalent

Soil Group	USDA Soil Texture Classifcation	Rate of Percolation (Minutes/Inch)	MUWA (Total Square Feet for Primary and Repair Areas)
			Gravity Distribution	Pressure Distribution
	Gravel, coarse sand, fractured rock	<1	Not suitable for parcel creation
A 1, 2	Medium to coarse sand	1—5	Not allowed	6,000
B	Fine sand, loamy sand	>5—15	9,000	6,000
C	Sand loam, loam, sandy clay loam	>15—30	12,000	8,000
D	Silt loam	>30—60	15,000	10,000
E	Clay loam, silty clay loam, sandy clay	>60—120	Not allowed	15,000
	Clay, highly compacted soil	>120	Not suitable for parcel creation

 

Subject to percolation test in addition to using soil textural determination.

Must demonstrate adequate filtration capacity.

Subject to percolation test in addition to soil textural determination if thirty-five percent (35%) or more (by volume) coarse fragments (defined as > 2 mm size).

Clay shall be nonexpansive.

2.

Usable parcel area shall not include areas contained in the following:

a.

Wastewater system setbacks to buildings as specified in the On-Site Wastewater Manual.

b.

Easements dedicated or reserved for surface or underground improvements unless dedicated or reserved for sewage disposal purposes.

c.

Easements for access for roadway purposes.

d.

Areas within five (5) feet of the property line.

e.

Areas that are within minimum setbacks as specified in the On-Site Wastewater Manual.

f.

Paved areas.

g.

Areas with a slope in excess of thirty percent (30%).

h.

Areas where the percolation rate is slower than one hundred twenty (120) mpi or faster than one (1) mpi.

i.

Areas that would provide less vertical separation than specified in Subsection B of this section.

D.

Minimum Parcel Size. Until such time that Butte County General Plan 2030 is completed and the Butte County Zoning Code is amended, as may be necessary to implement the General Plan, and with the exception of development approved pursuant to Butte County Code Section 24-210, Planned Unit Development, no parcel or subdivision map shall be recorded unless the minimum parcel size meets the requirements for each residence, or for each Residential Equivalent (three hundred sixty (360) gallons per day) in the case of nonresidential development, as specified in Table Two. For Planned Unit Development, the minimum parcel sizes specified in Table Two shall be minimum average parcel size. This requirement shall be reevaluated when the General Plan and Zoning Code have been updated as specified herein.

Table Two
Minimum Parcel Size

Effective Soil Depth	Minimum Parcel Size Per Residence or Residential Equivalent (360 gpd)
	Public Water System	Individual Well
More than 5 ft	0.5 acre	1.0 acre
4—5 ft	1.0 acre
3—<4 ft	2.0 acres
<3 ft	5.0 acres Not allowed unless consultant can show that 2 ft vertical separation can be maintained with supplemental treatment

 

E.

No parcel or subdivision map shall be recorded where any parcel relies on an on-site wastewater system that cannot be sited within the boundaries of the proposed parcels, except where the LEA authorizes use of a Community Wastewater System, as approved by the Central Valley Regional Water Quality Control Board, meeting the provisions of this chapter and the On-Site Wastewater Manual.

F.

No parcel or subdivision map shall be recorded where any parcel relies on a seepage pit for disposal of sewage.

G.

When a proposed parcel or subdivision map is located within a reasonable distance of an existing public sewer system and it is practicable and feasible for the proposed parcels to be connected to, and be served by the same, the LEA may require that the parcel or subdivision map be conditioned to connect to the public sewer system.

H.

Actions taken by the Planning Commission, based upon recommendations made by the LEA, through the discretionary land use permitting processes may be appealed pursuant to the procedures set forth in Butte County Code Chapters 20 or 24, as applicable.

I.

This chapter and/or the On-Site Wastewater Manual are intended to be consistent with and implement the Butte County General Plan, any applicable Community Plan, or any other applicable plan of any agency having jurisdiction.

(Ord. No. 4018, § 1, 3-16-10)