TITLE IV ONSITE WASTEWATER
MANAGEMENT CODE
CHAPTER 4.12 LAND DIVISION STANDARDS
Return to Title IV Table of ContentsSections:
4.12.010 Requirements4.12.020 Field Testing
4.12.030 Documentation
4.12.040 Monumentation of Dispersal Area
4.12.050 Certification
4.12.060 Land Division Plan - Tentative Map
4.12.010 Requirements
Requirements for processing information necessary for approval of a septic system for a
tentative map or a new subdivision (two or more parcels) shall be the same as the general
requirements for wastewater systems. All subdivision submittals shall include a report of
localized groundwater mounding and of generalized and localized nitrate accumulations for
each parcel and for the subdivision as a whole to insure that no septic system will affect other
parcels. No parcels shall cause a nitrate concentration higher than 10 mg/l to any adjoining
property.
4.12.020 Field Testing
All soil exploration holes, groundwater determination holes, and percolation test holes shall be
clearly identified in the field and on a plan as to hole number and lot number.
4.12.030 Documentation
Percolation test information shall be submitted in a separate format for each proposed lot. The
lot-by-lot information may be bound into an overall septic system site assessment for the entire
subdivision. The lot-by-lot information shall include percolation tests for that lot using the same
numbering as in the field and on a wastewater plan. Soil profiles logs and site plans for each of
the proposed sewage treatment areas shall show information as specified in Section 4.07.130.
4.12.040 Monumentation of Dispersal Area
The area tested shall be marked by placing a six foot minimum steel fence post at least four feet
into the ground at the two (or more) profile holes for each percolation test site. The fence posts
shall be located with distances from at least two prominent, permanent, and readily identifiable
property features. Areas tested for sewage treatment shall be delineated on the final map or
parcel map. These areas shall be accurately tied to the fence posts marking the leach field area.
4.12.050 Certification
The individual certifying the test shall indicate the boundaries of the acceptable dispersal field site
and shall certify that each lot has sufficient area to accommodate dispersal for at least a 1,400
square foot home, plus a 100% built secondary area, and a 100% fail safe area.
4.12.060 Land Division Plan - Tentative Map
The plans of the proposed site development shall show all road cuts, driveway cuts, grading,
structures, drainages, and drainage improvements along with the dispersal fields. An overall map
of the subdivision shall be submitted with submittal of the percolation test data. This map shall
clearly indicate location of field tests, proposed building site, proposed individual or mutual lot
configuration, and all proposed and existing improvements. All items listed as requiring setbacks
in this code shall be shown on this plan.