Laserfiche WebLink
C. CALCULATION OF MOUND DIMENSIONS <br /> BASAL LOADING RATE <br /> t Due to the long-term acceptance rate anticipated, a conservative basal rate will be employed for design <br /> purposes. As referenced above, although the peat soils demonstrated virtually no percolation, there must <br /> have been infiltration and percolation of effluent from the schoolhouse and subsequent labor camp. <br /> Additionally, as referenced in the Introduction,rainwater obviously infiltrates and percolates through this <br /> soil when it rains. rConsequently, a basal loading rate figure of 0.15 gallons/ftZ/day will be;used. This-is <br /> equivalentto.approximately 2 eups of effluentlftz/day. <br /> HYDRAULIC LINEAR LOADING RATE <br /> rFrom-the-percolation tests-and knowledge that the peat soil must infiltrate rainfall,water,.it_is <br /> evident that-there is both vertical and lateral flow of water.:.Con8equently;a'linear loading rate of <br /> 4:5 gallons/lineal:foot/day-will-be used. This4inear.loading'rafe Twill'also allow.for gaseous linear <br /> transfer:.of.oxygen to-meet the oxygen demand: <br /> SAND MEDIA/GRAVEL BED SPECIFICATIONS AND LOADING RATE <br /> The filter media is typically a sand soil material that underlies the gravel bed. The sand media <br /> should be tested by an engineering laboratory, or be certified by the sand supplier before <br /> emplacement. A sieve analysis (ASTM C-33 Specifications) should demonstrate the sand media <br /> material must not have more than 20% (by wt.) of material greater than 2 mm dia. and no more <br /> than 2% (by wt.) passing the No. 200 sieve. Effective Diameter(d10) should be 0.20 to 0.30 mm <br /> with a Uniformity Coefficient (D60/D,o) of approximately <4. The sand media loading rate <br /> complying with the specifications above will be 0.6 gpd/ftZ. ` <br /> The gravel bed on top of the sand media shall also be tested for conformance with the following <br /> size distribution: 318 in. washed pea gravel to 1.5 in. washed drain rock. A geotextile filter fabric <br /> f must be placed over the top of the gravel bed. <br /> AGGREGATE ABSORPTION AREA WIDTH,(A) <br /> A=Linear Loading Rate_Sand Media Loading Rate <br /> =4.5 gals/day/ft+0.6 gal/ft'=10 ft C_,t,> <br /> AGGREGATEABSORPTION'AREA,LENGTH(B) <br /> B=Design Flow Rate_Linear Loading Rate <br /> B =375 gpd_6 gals/day/ft='0-it <br /> BASAL AREA WIDTH (A +I+J) <br /> A+I+J=Linear Loading Rate_Basal Loading Rate(Based on Long-Term Acceptance Rate-LTAR) <br /> f =4.5 gals/My—Kf-=-0.1-5 gallons/ft'/day <br /> =30'ft' <br /> Use A= 10 ft,I= 10 ft and J= loft <br /> MOUND FILL DEPTH <br /> Sand Fill depth north side of Aggregate Absorption Area= 1.5 ft. <br /> Sand Fill depth south side of Aggregate Absorption Area= 1.5 ft. (1Vl6uid must be level). <br /> 15 <br /> Chesney Consulting <br />