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49 <br /> WSC <br /> WOOD SOIL 620 Lee Fox Lane <br /> Hillsborough NC 27278 <br /> CONSULTANTS (919)417-8027 <br /> March 28, 2023 <br /> Jim Parker <br /> Summit <br /> 320 Executive Court <br /> Hillsborough, NC 27278 <br /> Subject: Lawrence Road Development <br /> Dear Jim: <br /> As you are aware, we performed a Reconnaissance Soil & Site Evaluation of the Subject property <br /> and presented our findings in a report dated November 21, 2021. Based upon the findings in that <br /> report, we considered the site's ability to accommodate an on-site subsurface wastewater system <br /> for a day school with a daily wastewater requirement of 12,000 gallons per day (GPD). Assuming <br /> the septic drainfield would be placed in an area that had soils that were classed as Provisionally <br /> Suitable for Conventional Type systems and assigned a long-term acceptance rate (LTAR) of 0.25 <br /> GPD/ft2, we note the following: <br /> When determining the area needed for the drainfield, the following equation is used to first <br /> determine the amount of drainline: <br /> Drainline = School GPD/ LTAR/3' trench width <br /> 16,000 If= 12,000/0.25/3 <br /> Once the amount of drainline is determined, the area needed for the drainfield is calculated as <br /> follows: <br /> Area = drainline x 9-foot center spacing x buffer x repair system <br /> 345,600 ft2 = 16,000 x 9 x 1.2 x repair system <br /> The area calculation is based on the following assumptions: <br /> • 20% buffer is factored in to allot for diverging drainline and other site factors <br /> • Repair system is using the same drainfield type and parameters as the initial system <br /> As such, 345,600 ft2 or approximately 8.00 acres will be required for the initial and repair systems. <br /> Based on the provided layout of the site, there appears to be a minimum of 8.00 acres that are <br /> available for the drainfield within the area noted to have predominantly soil Provisionally Suitable <br /> for Conventional Type systems. <br /> Sincerely, <br /> W 6- , <br /> Michael G. Wood, LSS <br />