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Our Lady of Sorrows Chapel Page 2 between the elevation contours indicates "high"ground water is 7.5 to 8.5 feet in depth at the site (Figure I). Regarding Item No. 3, our initial estimation for nitrate loading was 16.49 mg/l as N. This value was determined from the maximum building capacity noted on the site plan of 50 persons. We understand from you that 50 people per day is incorrect and the following table indicates the correct use of the Chapel: Maximum Expected Use of Chapel Project Use Daily Monthly For Yearly Interval 1" Saturday each month 100 100 people/day * 12 days= 1200 people 100 persons. Maximum other days 8 (365-12) days * 8 people/day=2824 people is 8 per day. Average: 4024 people per year(or 11.02 people/day) The nitrate loading worksheet (Worksheet No. 2) is attached with the revised estimate of nitrate load is 5.56 mg/L as N using 1 I.02 persons per day(based on yearly average of 4024 person use) and 15 % denitrification. If soils containing organic material are used in the design, the nitrate load will be 4.93 mg/L as N using 11.02 persons per day and 25% denitrification. Conclusions and Recommendations Because of the anticipated high ground water known to occur at the site, maintaining a 5- foot separation between the static water table and the bottom of the leach line may be a limiting factor in designing the septic system. We estimate the"high"ground water depth at the site is between 8.5 and 7.5 feet. Therefore, if the depth to ground water is 7.5 feet at the site, the bottom of the leach line cannot be set deeper than 2.5 feet to maintain this 5-foot separation per County requirements. If raising the leach field or mounded septic system design is determined to be necessary, importation of organic soils preferred over sandy soils. These soils will promote greater denitrification(about 25%) and slower percolation rates. We believe the site is suitable for an on-site septic system providing the proposed septic a �jtOG