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An analysis was completed of the indigenous soils in the proposed effluent disposal area to determine the acceptance of the anticipated wastewater flows, along with an assessment of the characteristics of the soil to mitigate nitrate impact. Discussions are presented on the operational parameters to achieve these two goals of proper wastewater management and nitrate loading mitigation from the mound disposal system, and were accomplished by the referenced testing, physical/chemical analyses and operational parameters incorporated into the design of the OWTS. The two proposed primary mound system disposal areas can be situated to the east of the existing raised building pads. However, due to the fact that the basal areas of both mound systems are large, there is insufficient reserve/replacement area for the construction of new mound systems in the event of failure of the primary systems. Consequently, the only alternative is to remove the mounds upon failure and construct new mound systems over the original mound footprint. The soils testing and investigation has found the soils under the proposed wastewater effluent disposal area to contain a predominately clay material with exceedingly slow percolation. Under EHD requirements and regulations, a mound system for effluent disposal is required in this locale and for this project due to these clay soils, slow percolation, anticipated and comparatively high wastewater flow volumes, and a shallow groundwater table. A duplex pump arrangement will alternate pumping to pressure and time dose effluent and distribute it equally through the mound basal area. The mound system design is described in detail on Page 8 of this Report. II. SOIL SUITABILITY STUDY FINDINGS A. SUBJECT PROPERTY AND SURROUNDING STUDY AREA INFORMATION SSS§ 1.1. As noted on the Google aerial map, surrounding land use to the south, east and west is, and has been, in agricultural production and dairies for many decades. To the north is the southern boundary of the Delta. The subject property is zoned AG-40. SSS§ 3.1, 3.2, 3.3, 3.4, 3.5, 3.6. EHD Application files for repairs/replacements/ additions to septic systems within this locale only reveal two permits. This is due to the sparse rural residential structures in this area. Two miles to the southeast, in the actual Larch-Clover area, there are more than 12 permits issued for repairs/replacements/ additions to existing systems. This area has always had a significantly high number of repair permits due to the clayey soil and high groundwater, and may also be due to inadequately sized systems initially installed. The project site has relatively level terrain with a slight decline to the north. There will be no need to incorporate design considerations for slopes within the mound system area. Mound systems are sensitive to sloping, and changes in design must be taken into consideration when natural ground sloping is present. This is typically taken to be a ground surface decline greater than 2%. 2 Chesney Consulting