826 OCEAN BLVD COAB Calcs revised and corrected Rev. 9-22-23Soil porosity = 0.4
SHWT below Ground = 5.080 ft(provided by COAB)
Basin top below grade = 0.500 ft
Basin bottom below grade = 2.500 ft
Basin bottom to SHWT = 2.580 ft
V = (2 x (2.58+.5) x 0.4 = 2.464 ft3 / ft
COAB used incorrect
number in calc
Pipe Vol + Rock Vol + Soil Storage = 4.181 ft3 / ft
storage volume calc
pip unit vol = 0.196 ft3 / ft
#57 unit vol = 1.521 ft3 / ft
soil above basin = 0.4 ft3 / ft
total storage = 2.117 ft3 / ft
13% FOS
COAB does not accept EOR #'s
using COAB numbers below
COAB did not account for volume above
basin, all surfaces above basins are
previous pea gravel, #57 stone, grass
equivalent w/ 0.4 porosity
Pipe length req'd to provide retention vol = 2669 ft3 / 4.181 ft3 / ft = 638.4 ft
PIPE LENGTH PROVIDED = 645 ft
By vangers at 8:54 am, Sep 22, 2023