SU0004969 SSNL - Laserfiche WebLink

Home Browse Search

L January 5, 2005 NOA Project Number: E0162A LThe 25 foot borings and three foot borings on the parcels were used for the percolation tests. Within the boring, about an inch of"pea gravel'was placed in the bottom of the hole to stabilize the side wall from caving and prevent erosion while filling the boring. A 2-inch diameter PVC pipe with open ends and slots was placed in the hole. About 6-inches of pea gravel was placed in the annular space around the pipe. The hole was pre-soaked 24 hours prior to the test with 12 inches of water above the bottom of the hole. Presoaking of the percolation test hole occurred approximately ` 24 hours prior to the percolation tests. The percolation tests were conducted for the borings on December 21,2005 in accordance with the ` requirements of the EHD. A percolation test with a duration of four hours was performed for each hole. The final half-hour of each four-hour percolation test was observed by Mr. David Van Dyne, L Senior Registered Environmental Health Specialist, Environmental Health Department (EHD). Measurement of the water level during the percolation test was from a fixed reference point on the PVC casing using an electric well sounder with an depth accuracy of 1/100th foot. All tabulated values on the field data sheet (attachment) are in decimal feet. After water drop was observed, the holes were checked for refill. The refill level was approximately 0.5 ft (6 inches) of water above the bottom level of the percolation test hole. The readings were taken approximately every 30 minutes for a period of four hours. A shallow percolation test is defined by the EHD as being between 36 and 42 inches in depth;a ` satisfactory percolation rate for a shallow test is less than or equal to 60 minutes per inch drop.A deep percolation test is defined as being between 3.5 and 25 feet in depth;a satisfactory percolation rate for a deep test is 30 minutes per inch or less. A percolation test must demonstrate a satisfactory ` percolation rate within the proposed septic system disposal field of each parcel to be suitable for a standard septic system. Details of the percolation tests are summarized in the following table. Summary of Percolation Tests. ` Test No., Percolation Percolation Rate Test Comment Date Tested Test Depth (ft) (minutes/inch) Duration (see notes) Parcel 1 shallow 3.11 No movement 4-hr Failing percolation rate _ 12-21-05 Parcel 1 deep 22.85 50 4-hr Failing percolation rate 12-21-05 Parcel 2 shallow 3.08 No movement 4-hr Failing percolation rate 12-21-05 Parcel 2 deep 22.11 250 4- hr Failing percolation rate 12-21-05 Parcel 3 shallow 3.12 25 4-hr Satisfactory percolation rate 12-21-05 V r