Infiltrator Presby Advanced Enviro-Septic Design And Installation Manual page 12

2.0 SYSTEM DESIGN
Butterfly Configuration
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A "butterfly configuration," is considered a single bed system with two or more sections extending in
opposite directions from the D-box along the contour.
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Butterfly configurations are generally used to accommodate bed lengths longer than the maximum row
length of 100 ft.
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Rows shall meet requirements outlined in the design criteria above.
Illustration of a butterfly configuration bed design:
D-box (Parallel) Distribution
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All pipe rows shall be the same length.
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Flow equalizers must be used in the D-box.
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Use a manifold to connect the ends of all rows. Manifold shall be sloped toward AES pipes.
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D-box placement shall be installed on level, firmly compacted soil.
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All rows shall be laid level end-to-end.
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A 2 in min. drop is required between the D-box outlets and the AES pipe inlets.
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Rows shall meet requirements outlined in the design criteria above.
Illustrations for D-box (parallel) distribution bed design:
Multiple Bed Distribution
Incorporates two or more beds, each bed receiving an equal amount of effluent from a D-box. Multiple beds may
be oriented along the contour of the site or along the slope of the site.
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Each bed shall have the same minimum linear feet of pipe. The minimum linear feet of pipe per bed is
determined by dividing the total linear feet required in the system by the number of beds.
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All pipe rows to be the same length.
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End-to-end configurations are preferred to side-to-side configurations.
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Bed separation distance is measured from the edge of the SSBA. Multiple beds located at the same
elevation shall be separated bv a minimum of 10 ft. Multiple beds located upslope and downslope of one
another shall be separated by a minimum of 25 ft.
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 12