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CONCLUSIONS AND RECOMMENDATIONS <br /> In summary, the soil conditions examined near the proposed septic system drain fields <br /> appear to be suitable. Satisfactory soil percolation rates of 4.5, 8.1, and 13.9 minutes <br /> per inch were observed. <br /> The depth of ground water based on recent aquifer levels is approximately 25 to 31 feet <br /> below the ground surface, depending on the season and location on the Site. The <br /> ground-water flow direction is to the southeast or east-southeast at a rate of <br /> approximately five to eight feet per mile in the vicinity of the Site. <br /> The on-site domestic water well near the office was tested for nitrate and DBCP. Nitrate <br /> was detected at a concentration of 14.0 mg/L-NO3 (3.1 mg/L-N) in the water sample. <br /> DBCP was not detected in the sample. The US EPA has set the Maximum Contaminant <br /> Level (MCL) for nitrate as NO3 at 45 mg/L (10 mg/L-N) and the MCL for DBCP at 0.2 <br /> ppb (equivalent to µg/L). <br /> Based on the current project, the use of on-site septic tanks and drain field systems on <br /> the Site is not expected to cause a buildup of nitrate in the aquifer above 6.69 mg/L-N. <br /> This level falls below the US EPA drinking water recommendation of 10 mg/L-N. In fact, <br /> the actual impact to the aquifer will be much less since the nitrate loading equation is <br /> conservative and overestimates impacts. <br /> �-' We believe the Site suitable for development with the use of standard septic systems <br /> utilizing leach lines and sumps or filter beds. Based on the satisfactory result of the <br /> nitrate loading calculation, no nitrate mitigation is recommended. <br /> �' LOGE 1508 Page 16 <br />