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C r r C ,j r r Deo =ber l6, 3002 Job Number: W02413 Page I I ter► � �•� Table 6. Snlnmttry of Nitrate Mass Balance Analysis. Regan • Acres Avera] a Effluent De WtAfkatkM (et) Deep Pereeladon (W) (A) Daily Conem"do" of Rainfall (R) (ptstt: 9) Flow (t) (NW) (plate 8) (Table 6) 4.0 mgrL N' I6_7 657 W 45 mgll.rh 100/0 3101 in Now Maxienum Contaminate Levet (MCI,) for T wa-te is 10 mg/L-14 and 45 mg/L as NU,. Please nose that N%%,(nitrate wa51e leycl of sewage) of 45 mglL-N is � rtEale;d to the nitraie drinking coulee MCL of 45 mglL w N(I ,, vi11_ CONCLUSIONS AND 1tEC0.41MENDATiONS In conclasiori, a rapid percolation rate oflesfi than 1.7 minlinch was measured within the percolation test boring. Our office cw)untered loose sandy soils to a total depth of 10 feet during our field investigation. The depth to ground water at the.site was 23 feet according to tate most recent ground water depth maps. The nitrate lcvrl measured from the onsite domestic well indicatod high cAmcentrations in the ground water- The nitrate level measured in the well was collected and -tested two (z) different times and was found to be 77 and 120 mg/L as N0_,. The Environmental Protection Agency maximum contarninalt: level for drinking water for nitrate as NO3 is 45 mg!(. (or 10 mgrL as nitrogen N), A nitrate plume in the ground water appears to exist within the local area which probably,originated from the use of septic systems, agricultural fcctilizem or possibly dairy activities or a cotnbination of the uses. be geologic map and sail tuaps of the local area indicate these sandy conditions also exist throughout the area_ The ground water map indicates that shallow ground water exists throughout the area- It is well,known that for sandy seits of high permeability coutbincd Kith the shallow depth to ground water, the shallow aquifer is susceptible to nitrate impacts from human Because of the sandy conditions, the rapid peimlation rate measured, the shallow depth G} ground watts, anti thin pre-existing nitrate condition of the grottttd water, we reonun tc use of an engineered fic s em to reduoe mitral a effluent- Since the nitrate loading balance indicated minimal long tum impacts due mainly to the size of the property. we tin not believe that long term verification monitoring is warrantied for this project. The ,recommendations for the project are as follcm-s: