© Presby Environmental, Inc., Maine Design & Installation Manual, June 2019 Edition -16-
Illustration of an elevated level bed:
23.1 System Sand Extension
In Systems sloping more than 10%, a System Sand extension is required. The System Sand extension area is
additional System Sand added to the down slope side of all systems sloping more than 10%. The System Sand
extension area is a minimum of 6 in. deep and extends a
minimum of 3 ft. beyond the tall portion of the System Sand bed
on the down slope edge of the bed. For multiple slope beds, if
any portion of the bed has a system slope greater than 10% a
system sand extension is required.
Illustration of bed with multiple slopes to the right:
23.2 Total Linear Feet Requirement
a) Maximum row length is 100 ft.
b) Each section or bed must have at least the minimum linear feet of pipe (total feet of pipe required divided
by number of sections equals the minimum number of feet required for each section or bed).
c) A section or bed may exceed the minimum linear length.
d) Rows within a section or bed may vary in length (except D-box configurations) to accommodate site
constraints.
24.0 In-Ground Bed Systems
AES or ES systems are installed below existing grade for
sites with no soil restrictive features to limit placement. In-
Ground systems that slope over 10% require a 3 ft.
system sand extension on the downhill side of the field.
In-ground on level site:
25.0 Angled and Curving Beds
Angled configurations generally have one or more specific bends, but the rows should follow the contour of the site as
much as possible. Rows are angled by bending pipes or through the use of offset adapters. A 10 ft. length of AES or
ES pipe may be bent up to 90°. The angled system shown on the right in the illustration below requires 30 ft.
minimum row lengths. Multi-Level™ systems may use angled bed configurations.
Illustrations of Angled Beds:
