SU0011922 - Laserfiche WebLink

Home Browse Search

�Y April. 13,2000 - Job Number.L000-714 .• 'Page 6 ' Borings 13-2 aLd B-3 Are dissimilar to BA •in composition in that a hard pan zone was found to exist between 2.5 to 8 feet'in depth(Plates'9 and .10). No moist zones were.encountered �. . `in B-2 or.B73: A one�foot thick medium sand was encountered at 16:5 feet in B-2 and 14.$ in B-. •3. The percolation capacity ofthis sand:was tested in the percolation test at B-3. ` One(1) percolation test was performed within B-3 at a depthof 15 feet. The percolation . . test casing was 2 ihchidiameter PVC pipe with slots and it,open end on the bottom. Two inches of"pea gravel"was placed in the bottom of the hole;the casing was instaped,_and one(l)foot of 'pea g-ravel'wakbacl filled-in the annular space. ,' �A one(1)hour percolation test was;conducted on April 6,2000 in accordance with the �— requirements ofSan Joaquin County Environmental Health Division. The entire test was observed by Adieene Ellsaesser:ofthat office A satisfactory' peculation rate of 0.31 min/in was measured;for thepercolation test(Plate 11) L .. ' v l VII. " NITRATE LADING STUDY A.build tip of citrates in the upper ground-water zones can cause'a temporary blood ' disorder in infants called methemoglobinemia(blue baby.)'.',Serious and occasionally fatal. poisonings of infants Piave occurred following the ingestion of water containing nitrate concentrations greater than 10 mgti nitrate as N or 45 mg/l nitrate as.NO,: Because of the concern of nitrate leaching into ground water;a nitrate loading analysis.is required to estimate the average nitrate concentration of percolating water for the subject parcel.' o- .. The nitrate sources include the septic effluentt-and deep percolation of rain water. .The nitrate concentration of the heated septic effluent mixed-with the:deep percolating rain water is estimated before it mixes with ground water and dilutes, The nitrate balance method assumes 100%mixing ' with rain water over an average-yearly period for the acreage of the subJect parcel: The method is based on a sunple mass balance formula which takes into-account soil denitrification factor,fain M amount, rain fall nitrate concentration,' the waste.effluent quantity, ' and waste eluent nitiate,concentration The formula,assumptions and'calculations,for the', analysis are shown oJPlates:11 and 12.1he units of nitrate used in the,mass balance equation is . ' nitrate-N whose maximum drinking water'contaminate level,is 10 mg/1:.