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Percolation Test Procedure: The San Joaquin County Environmental Health Department (EHD) has adopted the following procedure <br />in order to evaluate and process percolation results uniformly, effectively and quickly. <br />l05 rr7_57- Obtain Application for Percolation Test Permit: <br />Fee is $93:00 per test hole or $465-60 for 5 or more test holes. <br />Indicate the test hole location(s) on the permit application plot plan. <br />Percolation Test Hole(s) shall not be located within 100 feet of any well or violate any other set -back requirements for a septic system. <br />Call (209) 953-7697 to schedule an inspection 48 hours in advance. <br />Preparation of Test Hole (s): <br />Test Hole Dimensions: <br />Diameter= 4 inches to 12 inches. <br />Depth (Consistent with leach rield) = 36" - 42" <br />.Scratch or score sides to remove any smeared soil surfaces. <br />Remove loose material from hole. <br />Add 2 inches of course sand or fine gravel. <br />Saturation: Pre-soak Test Hole 24 hours before test by adding water a <br />minimum of 12 inches over gravel. The EHD is to be notified of start of <br />Percolation Test. <br />PROCEDURE #1 <br />If water remains in the test hole. overnight <br />Add clear water to approximately 6 inches <br />over the gravel. <br />From a fixed reference point, measure the <br />drop in water level over a thirty (30) minute. <br />ep riod. <br />Calculate the percolation. rate in minutes per <br />inch." <br />Preparation of Test Hole (s) for Deep Perc Test: <br />Test Hole Dimensions: <br />Diameter= 4 inches to 12 inches <br />Depth = 42 inches to 25 feet, Minimum 10 ft above water table <br />Pre-soak Test Hole by adding water 6" above selected stratum. <br />Maximum water level allowed 3 ft above selected stratum. <br />Red Zone area required 25' deep or stratum that meets minimum perc for pit <br />testing. <br />PROCEDURE #2 <br />If no water remains in test hole overnight <br />Add clear water to bring depth of water in the <br />hole to approximately 6: inches over the gravel. <br />From a fixed reference point, measure the <br />drop in Water level at thirty (30) minute <br />intervals for four (4) hours, refilling 6 inches <br />overthe gravel as necessary. <br />Use the final reading of the four (4) hour period <br />to calculate percolation rate in minutes per <br />inch. <br />PROCEDURE #3 <br />Sandy soils (or other soils) in which the first 6 <br />inches of water seeps away in less than thirty <br />(30) minutes after the overnight saturation <br />period <br />Refill thehole to approximately 6 inches above <br />the gravel <br />From a fixed reference point, take the readings <br />10 minutes apart over a one (1) hour Deriod. <br />Use the final reading change; calculate <br />percolation rate in minutes per inch. <br />At the time of the percolation test inspection, Environmental Health Staff will: <br />Review application and parcel map for location accuracy and verify appropriate procedure used. <br />Inspect test hole construction and review raw field data recorded prior to arrival. <br />Observe and document the readings during the final 30 minutes of the test on the EHD "Percolation Test Application". <br />Correct any data on the application and sign the percolation record sheets. <br />Source: Manual of Septic Tank Practice, U.S. Dept of H.E.W. (1967), as founded and modified for San Joaquin County. <br />San Joaquin County EHD Policy #02-02 <br />EHD 42-02-002 817102 <br />