SU0004527 SSNL - Laserfiche WebLink

Home Browse Search

Engineered Septic System The proposed leach field area on Parcel l failed passing acceptable percolation rates. The results were mixed during the deep percolation test but based on Neil O Anderson &Associates report (enclosed in appendix), I will use 125 minutes per inch to design the engineered system The 125 minutes per inch is considerably higher than the County minimum of 60 minutes per inch. All of the surrounding parcels were able to find a permeable membrane within 25 feet deep. I would expect with further exploration, this property would support a conventional leach line and pit system. Since a strata was not encountered, this report will design a theoretical system for a future home. The theoretical home this strata will consider is a four bedroom house. The percolation rate is 125 min/in which equals 0.008 in/min or 11.5 in/day. Utilizing a 4% factor(which is very conservative), the actual amount of percolation per day is 0.46 in/day or 0.038 ft/day. My design will utilize a filter bed with leach lines on 5 foot centers. The bed will consist of a 12" gravel bed, overlaid with perforated pipe, overlaid with 6" gravel, overlaid with paper, overlaid with native soil. The filter I am designing is a 60 foot by 60 foot effective bed. The amount of percolation by this bed is: 60x60=3,600 sq ft x (0.038ft/day) =136 cft/day =1017 gal/day This is more than sufficient for a four bedroom house. If a future home builder encounters sufficient strata with acceptable percolation rate, a conventional system may be utilized and this theoretical system can be ignored. Based on depth to groundwater in the area and the size of the proposed parcels, it is our opinion that the installation of any new proposed septic system, if properly installed, should not adversely affect the quality of groundwater in the area. 7.0 CONCLUSION SECTION The conclusions of this report are based on the information provided regarding the proposed development, the use of the subject property, and the site conditions as they existed at the time we excavated our test holes and performed the percolation tests. It was assumed that the test holes and percolation tests results are representative of the subsurface conditions in the general area. Our services were performed, our findings obtained, and our conclusions proposed in accordance with generally accepted engine les and practices. This warranty is in lieu of all other warranties either expressed i dings and statements of professional opinion do not constitute a guarante y, F or implied. CID CD z 2 No. 61041 ,�I * Exp. 12-31-06 Brian Gorbet �T. 0��1L o��P R.C.E. 61041 c: 5 --- 00423\Soil Report