© Presby Environmental, Inc., Maine Design & Installation Manual, June 2019 Edition -17-
26.0 Trench Systems
AES and ES pipe may be installed in trench configurations on level or sloping terrain and may utilize serial,
combination or D-box distribution. A minimum of 3 in. of System Sand are required above and 6 in. below, between
and around the perimeter of all pipes. Consult state rules for required trench separation.
27.0 Curved Beds
Curved configurations work well around structures, setbacks, and slopes. Multiple curves can be used within a
system to accommodate various contours of the site.
28.0 Non-Conventional System Configurations
Non-conventional system configurations may have irregular shapes to accommodate site constraints. A site-specific
waiver from the state may be required for non-conventional configurations.
29.0 H-20 Loading
If a system is to be installed below an area that will be subjected to vehicular traffic, it must be designed and
constructed as depicted below in order to protect the system from compaction and/or damage. Note that a layer of
stabilization fabric is added between the System Sand and the cover material. All H-20 systems require venting.
Illustration of H-20 system:
30.0 Pumped System Requirements
Pumped systems supply effluent to the field by using a pump and distribution box when site conditions do not allow
for a gravity system. Dosing siphons are also an acceptable means of delivering effluent to the system.
30.1 Alarm
Maine requires all pump systems to have a high-water alarm float or sensor installed inside the pump chamber.
30.2 Differential Venting
All pump systems must use differential venting (see illustration, para. 32.4, pg. 20).
30.3 Distribution Box
All
pump systems require a distribution box with some means of velocity reduction, see para. 30.5, for the effluent
entering the D-box.
30.4 Distribution Box Manifold
If a distribution box manifold is utilized to divide
large flows, velocity reduction (see para. 30.5)
of the incoming effluent is necessary. Flow
equalizers are installed on all used outlets.
Manifolded D-box:
PRESBY PIPE WITH DOUBLE
OFFSET ADAPTER
INSTALL STABILIZATION FABRIC ON TOP OF THE
6" OF SYSTEM SAND OVER THE PRESBY PIPES.
FABRIC TO HAVE A "GRAB TENSILE STRENGTH
OF 315 LBS PER ASTM D 4632"
EXTEND FABRIC 3' MIN BEYOND EDGE
OF PIPE (ALL EDGES)
BANK RUN GRAVEL
(NO STONES OVER 2"Ø)
12" MIN (BELOW PAVEMENT)
6" SYSTEM SAND
VENT MANIFOLD
(IF REQ'D)
SYSTEM SAND 6" MIN ABOVE AND BELOW PRESBY
PIPES. NO SAND VOIDS ALLOWED. WALK BETWEEN
ROWS TO ENSURE SAND FILLS ALL VOIDS AROUND
PRESBY PIPES (REPEAT IF NECESSARY).
BOTTOM DRAINS
RECOMMENDED WHEN PRESBY
PIPE ENDS ARE INACCESSIBLE
VENTING REQ'D FOR
ALL H-20 SYSTEMS
NOTE:
THE ONLY SOIL COMPACTION THAT SHOULD TAKE PLACE IS AT THE POINT OF PREPARATION FOR PAVEMENT.
PAVEMENT OR OTHER
HARDSCAPE
FABRIC
INLET
OUTLET
D-BOX
OUTLET
UNUSED
OUTLET
4" Ø PVC
TYPICAL
NOTE: UTILIZING EVERY OTHER
OUTLET WILL PROVIDE ROOM FOR
REQUIRED PIPING AND ALLOW
FOR EASIER INSTALLATION