Chamber Model = ADS N-12 15" (ADS N-12® Pipe) Inside= 14.8"W x 14.8"H => 1.20 sf x 20.00'L = 24.0 cf Outside= 18.0"W x 18.0"H => 1.60 sf x 20.00'L = 31.9 cf Row Length Adjustment= -7.00' x 1.20 sf x 4 rows 18.0" Wide + 10.9" Spacing = 28.9" C-C Row Spacing 3 Chambers/Row x 20.00' Long -7.00' Row Adjustment +1.50' Header x 2 = 56.00' Row Length +8.0" End Stone x 2 = 57.33' Base Length 4 Rows x 18.0" Wide + 10.9" Spacing x 3 + 8.0" Side Stone x 2 = 10.06' Base Width 4.0" Stone Base + 18.0" Chamber Height + 4.0" Stone Cover = 2.17' Field Height 12 Chambers x 24.0 cf -7.00' Row Adjustment x 1.20 sf x 4 Rows + 8.72' Header x 1.20 sf x 2 = 275.3 cf Chamber Storage 12 Chambers x 31.9 cf -7.00' Row Adjustment x 1.60 sf x 4 Rows + 8.72' Header x 1.60 sf x 2 = 366.2 cf Displacement 1,248.8 cf Field - 366.2 cf Chambers = 882.6 cf Stone x 40.0% Voids = 353.0 cf Stone Storage Chamber Storage + Stone Storage = 628.4 cf = 0.014 af Overall Storage Efficiency = 50.3% Overall System Size = 57.33' x 10.06' x 2.17' 12 Chambers 46.3 cy Field 32.7 cy Stone