Laserfiche WebLink
PROJECT: Ahern Road Fueling Station February 28, 2022 <br /> Job No: 20-544 Ross P.Shoat Civil Engineer <br /> Nitrate Reduction Calculations <br /> These calculations are being based on an assumed Total Nitrate (TN) loading of 100 m/I rather <br /> than the 85 m/I used in the Nitrate calculations done by Live Oak Geo Environmental, INC.. The <br /> filter sizing is also based on the BOD5 loading (assumed 650 m/1). The sizing will be based on <br /> the larger required area of filter surface. <br /> The system is also being designed to achieve a greater than 50% reduction of Nitrate as <br /> outlined in the State OWTS manual section 10.9. The addition of a Pre-anoxic and post-anoxic <br /> tank with Chemical feeders will be added to accomplish this. <br /> The Formula Used for Nitrate Sizing of the Filter/area is A= (TN/TNLR) <br /> TN in lbs. = 100 X .00000834 X 3225(avg. daily Load) = 2.68965 lbs./day <br /> A= 2.68965/.014 (allowable sf loading rate) = 192 sf of filter area needed <br /> The Formula Used for BOD5 (OLR) Sizing of the filter Area is A = BOD5/ OLR <br /> BOD5 in lbs. = 650 X .00000634 X 3225 = 17.482725 lbs./day <br /> 17.482725/.04=437 sf of filter area needed <br /> The Primary Filter bank will be sized according to the BOD5 loading Rate <br /> Nitrate reduction from the Primary Filter bank coupled with the Pre-Anoxic tank is based on the <br /> anticipated reduction factor of 70%. Therefore, Nitrate output from the first stage of treatment <br /> should be 100mg/I X (1 -.70) = 30 mg/I. The Second stage (Post-Anoxic) of treatment should <br /> reduce that figure by another 70%to a level well below 30%of the original load. <br /> Page 5 Of 11 <br />