© Presby Environmental, Inc., Maine Design & Installation Manual, June 2019 Edition -9-
13.0 Certification Requirements
Any designers and installers who have not previously attended a Presby Environmental, Inc. Certification Course are
strongly encouraged to obtain Presby Certification. Certification is obtained by attending a Certification Course
presented by Presby Environmental, Inc. or its sanctioned representative. Certification can also be obtained by
viewing tutorial videos on our website (high speed connection required) and then successfully passing a short
assessment test, which is also available over the internet. All professionals involved in the inspection, review or
certification of Presby Systems should also become Presby Certified. Professionals involved in the design or
installation of Multi-Level™ systems
must
be Presby Certified.
14.0 Design Criteria
14.1 Advanced Enviro-Septic Requirements
a) Sewn seam must be oriented in the 12 o'clock position. This correctly orients the Bio-Accelerator
®
fabric
in the 6 o'clock position.
b) Venting is always required regardless of vertical separation to restrictive features.
c) AES may be substituted for ES or SS. ES may be substituted for SS. However, ES may not be
substituted for AES without the approval of the designer and Licensed Plumbing Inspector. The design
must be revised to show this change.
14.2 Barrier Materials over System Sand
No barrier materials (hay, straw, tarps, etc.) are to be placed between the System Sand and cover material; such
materials may cut off necessary oxygen supply to the system. The only exception is the placement of the specified
fabric to achieve H-20 loading requirements. See para. 29.0, pg. 17.
14.3 Converging Flows Restriction
AES and ES systems must not be located where surface or ground waters will converge, causing surface water flow
to become concentrated or restricted within the soil absorption field.
14.4 Daily Design Flow
Residential daily design flow for AES and ES Systems is calculated in accordance with Maine rules. Systems
servicing more than two residences shall use the Commercial portions of all sizing tables. The minimum daily design
flow for any single-family residential system is two bedrooms and 300 GPD for any commercial system.
a) Certain fixtures, such as jetted tubs, may require an increase in the size of the septic tank.
b) Daily design flow for a single bedroom apartment with a kitchen connected to a residence (also
sometimes referred to as a “studio” or “in-law apartment”) shall be calculated by adding two additional
bedrooms.
c) When daily design flow is determined by water meter use for commercial systems, refer to the Maine
Rules.
d) PEI recommends taking the average daily use from a peak month and multiply it by a peaking factor of 2
to 3 times.
e) Note that “daily design flows” are calculated to assume occasional “peak” usage and a factor of safety;
Systems are not expected to receive continuous dosing at full daily design load.
14.5 End-to-End Preferred Over Side-to-Side
If site conditions permit, End-to-End multiple bed configurations are preferable to Side-to-Side configurations (see
para. 22.0, pg. 15).
14.6 Fill Extensions for Elevated (Mound) Systems
If any portion of the bed extends above the original grade, the fill covering the field cannot begin the 4:1 side slope
taper for a distance of 3 ft. minimum from the outmost edge of any AES or ES pipe and for systems sloping greater
than 10%, the downhill fill extension is increased to 5 ft. (see ill. in para. 39.0, pg. 29).
14.7 Filters, Alarms & Baffles
a) Effluent Filters are not required in Maine and are not recommended for use with our systems.
b) If used, effluent filters must be maintained on at least an annual basis. Follow manufacturer’s instructions
regarding required inspections, cleaning and maintenance of the effluent filter.
c) Effluent Filters must allow the free passage of air to ensure the proper functioning of the system. A
blocked filter in any on-site septic system could interfere with venting, causing the system to convert to an
anaerobic state and result in a shortened life.
d) All pump systems to have a high-water alarm float or sensor installed inside the pump chamber.
e) All septic tanks must be equipped with baffles to prevent excess solids from entering the system.
f) Charcoal filters in vent stacks (for odor control) are not recommended by PEI. They can block air flow and
potentially shorten system life. Contact PEI for recommendations to correct odor problems.
