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Fobtained ER BED SOIL WASTEWATER DISPOSAL SYSTEM d disposal system dimensions and operations are dependent upon the testing data , and referenced in, the Phase I Report, and flow volumes determined in this Report.disposal area is proposed to be installed in the northwest corner of the property, adjacent to Newton Road. It is anticipated that approximately one ft of top soil will be removed from the entire project area. Considering the filter bed is to be approximately 33 inches deep,this places the soil-effluent interface approximately 3.5 to 4 ft below existing grade. A percolation rate of 20.8 min/inch was obtained at this depth, with a corresponding application rate of 0.643 gallons/ft'/day. To determine the filter bed disposal area by the Hydraulic Loading Rate (HLR) method, we take the projected ADF from both the Restaurant and ARCO Station(1,360 + 1,000)=2,360 gpd and find the calculated filter bed size to be: 2,360 -0.643 = 3,670 sq. ft. As noted on the Site Plans, the primary filter bed area is to be 36 ft x 100 ft= 3,600 sq. ft. This 3,600 sq. ft area also applies to the secondary 100%reserve/replacement area, designated adjacent to the northeast of the primary disposal field. If the filter bed design is based on the Organic Loading Rate (OLR), the highest measured BODS strength of 3,663 mg/L from the grease interceptor tank will be used as the starting point. Due to new tank upgrades and sizing, a 75% reduction in BODS concentration is anticipated. This reduction places the BODS concentration at 916 mg/L. If this concentration is equally commingled with the BODS of the conventional septic tank at 150 mg/L BODS, we find an average BODS concentration of: 916(Restaurant grease tank)+ 150(Restaurant conv. tank)+ 150 (ARCO tank)-3 =403 mg/L BODS: Organic loading/day=403 mg/L x 0.643 gallons/ft2/day x 8.34 lbs/mg/L x 10'=2.16 x 10' BOD5/ft2/day Assume 2.16 x 10` lbs BOD5/ft2/day as design organic loading rate: Area=403 m BOD,x 2.360 god x 8.34 lbs/mg/L,x 10-6 gals 2.16 x 10` lbs BOD,/ft-day Area= 7.9 BODS/d 2.16 x 10` lbs BOD,/ft'-day Area=3,672 ft? In addition to the primary filter bed, a series of three, 36-inch dia., 25 ft deep seepage pits to be installed in-between the primary and secondary disposal area filter beds as illustrated on the Site Plans. An innovative effluent conveyance system will drain potential standing effluent from within the primary filter bed and convey it to the seepage pits through drop boxes and a piping network. It is anticipated that this "overflow safety design"will manage effluent when the primary filter bed begins to mature and the infiltration and permeability rates slow due to biomat formation and/or when extreme hydraulic stress occurs from heavy rainfall. The installation of these three seepage pits adds an additional: 196 sq. ft/pit x 3 pits= 588 sq. ft of absorption area for a total primary disposal area of 3,600 + 588 =4,188 sq. ft. The secondary reserve area will not be constructed until failure occurs within the primary disposal field and seepage pits. Page 6 of 8 Chesney Consulting