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FFsurprn as retrieved from the bottom of the perc test boring at 42 inches for chemical dering this area has been an open corral for the last 50 years,the results indicate w nitrate-nitrogen and organic matter concentrations of 6 ppm and 0.9%, oluble salts concentration was medium in concentration at 0.8 mmhos. Percolation testing was performed in accordance with San Joaquin County Department of Environmental Health regulations. The attached Site Plan denotes the location of the percolation test and the FIELD PERCOLATION TESTING REPORT illustrates the perc test results. As will be discussed in the following Section,the water table is located approximately 9 feet below grade in the area of the leachfield. Therefore,the perc test was conducted at the maximum leachline depth of 42 inches. The perc test results reveal a steady water infiltration and percolation rate over the four-hour test period. As is normally the case with percolation tests, the greater the hydraulic head, the faster the percolation rate. This was evident at three hours into the test when 10 inches of head water was introduced instead of the typical six inches which corresponded to an increase in the perc rate over the next half-hour test period. The last half- hour decreased to the perc rate observed prior to the increase in hydraulic head. The water drop for the last half-hour of the four-hour test period was 1.6 inches, which translates to a perc rate of 18.8 minutes/inch (min/in). This can be considered a comparatively rapid perc rate, with 60 min/in recognized as failure. The groundwater table is too shallow for traditional sumps and seepage pits since there must be a five-foot minimum distance between the bottom of the leachline trench or pit/sump and the depth to groundwater. Traditional sumps are considered to be 4 ft wide, 8 ft long and 10 ft deep. However, a shallow"sump" (16 ft x 2 ft x 4 ft) was apparently installed at the dairy in 1964. Information obtained from the Environmental Health Department regarding the number of permits for repairs/additions also indicates the septic systems have a definite lifespan and consideration must be given to eventual replacement. The following calculations show leachline requirements for the proposed Milk Barn restroom: 1200 Base Tank Capacity (BTC)+ 15 gal/person/shift x 2 shifts x 6 people= 180 gals average daily flow(ADF) = 1200 + 180= 1380 Calculated Tank Capacity (CTC). 1380 x 0.225 soil factor=310 lineal feet of leachline. Therefore, three-one hundred foot leachlines may be used. If there will be leachfield area constraints, a filter bed should be considered since a shallow sump as described above would not be allowed by the Environmental Health Department. The calculations for a filter bed area are as follows: 310 lineal ft x 3 for sandier soils=900 square ft. LLarea efore, a filter bed 30 ft square may be used as a leachfield if there will be area constraints. imperative that a 100%replacement area be set-aside for eventual repair. This replacement may be used while the primary leachfield area"rests and rehabilitates." Effluent agement can then be converted back to the primary field. This cycle can continue finitely. 3 Vaffey Ag Research