Infiltrator Presby Advanced Enviro-Septic User manual

© Presby Environmental, Inc., Missouri Design & Installation Manual, September 2020 Edition
Design and Installation Manual
for Advanced Enviro-Septic®(AES)
Wastewater Systems
Missouri
Table of Contents
1.0 INTRODUCTION
3
1.1 State-Specific
Information
3
1.2 Background
4
1.3 System Components
5
2.0 SYSTEM DESIGN
6
2.1 System Sizing
6
2.2 Design Procedure
6
2.3 Design Examples
7
2.4 Design Specifications
8
2.5 System
Configurations
11
2.6 Pump Systems
13
2.7 Venting
17
2.8 Site Selection
18
3.0 INSTALLATION
19
4.0 REJUVENATION AND
EXPANSION
22
5.0 OPERATION AND
MAINTENANCE
23
6.0 WARRANTY
24
SEPTEMBER 2020
For more detailed design and installation information on AES, please contact Infiltrator
Water Technologies at [phone] or Presby Environmental, Inc. at [phone].
www.infiltratorwater.com • www.presbyeco.com

© Presby Environmental, Inc., Missouri Design & Installation Manual, September 2020 Edition
The information in this Manual is subject to change without notice. We recommend that you check your state’s
page on our website on a regular basis for updated information. Your suggestions and comments are welcome.
Please contact us at:
Presby Environmental, Inc.
143 Airport Road
Whitefield, NH 03598
Phone: [phone] Fax: [phone]
Website: www.presbyenvironmental.com
The products and methods depicted in this Manual are protected by one or more patents.
Advanced Enviro-Septic®is a registered trademark of Presby Environmental, Inc.
IMPORTANT NOTICE: This Manual is intended ONLY for use in designing and installing Presby Environmental’s
Advanced Enviro-Septic®Wastewater Treatment Systems. The processes and design criteria contained herein are
based solely on our experience with and testing of Advanced Enviro-Septic®. Substitution of any product is
prohibited.
© Presby Environmental, Inc. September 2020
All Rights Reserved

1.0 INTRODUCTION
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 3
NEW FOR 2020
IMPORTANT CHANGES TO THE USE OF ADVANCED ENVIRO-SEPTIC IN MISSOURI
The Missouri Department of Health and Senior Services (DHSS) has approved a number of critical changes to the
way in which the Advanced Enviro-Septic System (AES) is to be designed, permitted and installed in Missouri. The
changes are effective September 1, 2020 and will remain in effect until further notice.
ALL OF THESE CHANGES ARE INCORPORATED INTO THIS MANUAL.
PLEASE READ, UNDERSTAND AND INCORPORATE/PRACTICE THESE CHANGES BEFORE DESIGNING
AND/OR INSTALLING AN AES SYSTEM
1.1 Missouri State-Specific Information
System Type
The AES is approved for use as an experimental system. In every instance the property owner(s) must:
•be made aware of this fact before purchasing an AES system;
•sign a form acknowledging that they understand this fact; and
•allow DHSS and Presby Environmental (PEI) or Infiltrator Water Technologies (Infiltrator) personnel onto
their property to investigate system function.
The AES is a combined treatment and dispersal system (CTDS), a system type which is not specifically addressed in
19 CSR 20-3.060 (the Rules). It shall be designed, permitted, and installed in accordance with the requirements
and exceptions listed below. If there are questions about design specifications, please contact your local health
department or Presby Environmental (PEI) for assistance at [phone].
System Design
Design of the AES shall comply with the following:
•the soil type and soil loading rate (SLR) must be established by a soil morphology evaluation;
othe AES system shall not be permitted for installation and use in IVb soils.
•the minimum total absorption area is determined by utilizing the soil loading rates in Table A in Section
2.1 below, which are based on Tables 13 and 14 in the Rules;
•a minimum vertical separation distance of 1 foot (ft) is required:
othere must be a minimum of 12 inches (in) of naturally occurring suitable or provisionally suitable
soil below grade at the location of the system on the site for the AES to be permitted; and
•AES pipe rows in a given bed shall be designed and installed at the same elevation (level to one another);
•serial distribution is not allowed;
•a Missouri-licensed engineer is required for design if either:
othe SLR is less than or equal to (≤) 0.29 gallons per day per square foot (gpd/ft2); or
oany aspect of the AES (18 in tall –6 in of system sand plus the 12 in diameter pipe) is at grade or
above grade.

1.0 INTRODUCTION
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 4
System Installation
Installation shall be undertaken and completed only by an advanced registered onsite wastewater treatment
system installer.
Variances
No variances shall be issued with use of the AES system while approved as an experimental system.
1.2 Background
The Advanced Enviro-Septic®(AES) Wastewater
Treatment System utilizes a unique combination of
components that work together to treat effluent and
prevent suspended solids from sealing the
underlying soil. Comprised of a patented corrugated,
perforated plastic pipe with interior skimmer tabs
and cooling ridges, the large-diameter pipe retains
solids while the Bio-Accelerator®fabric, coarse
fibers, and geo-textile fabric provide multiple
bacterial surfaces to treat effluent prior to its
contact with the receiving soils. The continual cycling
of effluent (the rising and falling of liquid inside the
pipe) enhances bacterial growth. The AES system is
completely passive, and yet provides increased
aeration and a greater bacterial treatment area than
traditional systems. The result is a system that is
more efficient, lasts longer, and has a virtually no
negative environmental impact.
The AES system has been successfully tested and
certified to NSF/ANSI 40, Class I (a certification
typically given to mechanical aeration devices) and
BNQ Class I, II, III standards.
Additional system benefits include:
•requires a smaller area
•installs easily and quickly
•eliminates the need for environmentally impactful washed stone
•adapts easily to residential, commercial and difficult sites
•prevents formation of organic material at the receiving soil interface
•safely recharges groundwater
Environmental Standards and Technical Support
All AES systems shall be designed and installed in compliance with the procedures and specifications detailed in
this Manual and in the product’s state approval. In the event of contradictions between this Manual and DHSS
regulations (the Rules), PEI should be contacted for technical assistance at [phone].
Certification Requirements
Designers and installers who have not previously attended a PEI certification course are required to obtain
certification. Certification is obtained by attending a certification course presented by PEI or its sanctioned
representative or by viewing tutorial videos on our website and then successfully passing a short assessment test.
PEI recommends professionals involved in the inspection or review of AES systems also become PEI certified.

1.0 INTRODUCTION
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 5
1.3 System Components
AES Pipe:
•nominal exterior diameter of 12 in
•holding capacity of 5.8 gallons per foot
•10 ft length of AES pipe is flexible enough
to bend up to 90° and can be cut to any
length
•made with a significant amount recycled
material
Offset Adapter - A 12 in plastic fitting with a single
inlet hole oriented in the 12 o’clock position and designed to accept a 4 in sewer line, raised connection or vent
pipe.
Double Offset Adapter - A 12 in plastic fitting with two 4 in holes designed to accept a 4 in inlet pipe, raised
connection, vent or vent manifold, and/or bottom drain, depending upon the requirements of the design
configuration.
Coupling - A plastic fitting used to create a connection between two pieces of AES pipe.
System Sand - The system sand that surrounds the AES pipes is an essential component of the system. It is critical
that the correct type and amount of system sand is used during construction. System sand shall be coarse to very
coarse, clean, granular sand, free of organic matter. System sand is placed a minimum of 3 in above and 6 in
below, between, and around the outer perimeter of the AES pipes. It shall adhere to all of the following
percentage and quality restrictions:
System Sand Specification
Sieve Size
Percent Retained on Sieve (by weight)
3/4 in (19 mm)
0
#10 (2 mm)
0 - 35
#35 (0.50 mm)
40 - 90
Note: not more than 3% allowed to pass the #200 sieve (verified by washing
sample per requirements of ASTM C-117)
System Sand Bed Height Dimension
The height of an AES system measures 21 in minimum (not including cover material):
•minimum of 6 in of system sand below the AES pipe;
•12 in diameter of the pipe;
•minimum of 3 in of system sand above the AES pipe; and
•when a system sand extension is required it shall be a minimum of 6 in thick.
Note: the 3 in of system sand is not considered as “part of the AES” when determining if the system is at grade or
above grade.
System Sand Acceptable Alternative - ASTM C-33 (concrete sand), natural or manufactured sand, with not
more than 3% passing the #200 sieve (verified by washing the sample per the requirements of ASTM C-117 as
noted in the ASTM C-33 specification) may be used as an acceptable alternate material for use as system sand.
Fill Material - Fill material or system sand may be used in side slope tapers. Fill material shall meet the
requirements of the Rules.

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 6
2.1 System Sizing
All residential AES systems require the use of 70 linear feet (lf) of AES pipe per bedroom (br). In non-residential or
commercial applications, divide the DDF by 2.14 gal to calculate the minimum amount of AES pipe required.
In accordance with the Rules, daily design flow (DDF) is calculated as follows: the minimum flow rate shall be one
hundred twenty gallons (120 gals.) per day per bedroom. When the occupancy of a single family dwelling exceeds
two (2) persons per bedroom, the volume of sewage shall be determined by the maximum occupancy at a rate of
sixty gallons (60 gals.) per person per day.
The minimum absorption area (known as the system sand bed area or SSBA) for the AES system is determined
using the formulas provided in Table A below and is based on the soil loading rate (SLR) as established by a soil
morphology evaluation.
Table A: AES Minimum Pipe Requirements and System Sizing Formulas for Residential Systems
Actual Soil Loading
Rate at Site
(gpd/ft2)
Minimum
AES Pipe
per Bedroom
(ft)
System Sand Bed Area
(SSBA) Formula
Soil Loading Rate
Rule Reference
1.20 –0.30
70
SSBA = DDF/SLR * 0.90
Table 13
0.29 –0.10
70
SSBA = DDF/SLR
Table 14
2.2 Design Procedure
Step #1: Determine System Sand Bed Area (SSBA) Required
Based upon the SLR on the site as established by a soil morphology evaluation, use the formulas from
Table A above to calculate the minimum SSBA required.
Step #2: Calculate the Minimum Amount of AES Pipe Needed
Residential systems: multiply the number of bedrooms in the design by 70 ft.
Non-residential or commercial applications: divide the DDF by 2.14.
This results in the minimum amount of AES pipe that must be used in the system.
Step #3: Determine Row Length and Quantity Needed
Select a row length suitable for the site and calculate the number of rows needed (round up to whole
number).
Step #4: Determine Pipe Layout Width (PLW)
Calculate the PLW using a 1.5 ft minimum center-to-center row spacing (larger spacing allowed).
Formula for PLW = [(# of rows –1) * spacing (1.5)] + 1.
Step #5: Determine Minimum System Sand Bed Width (SSBW)
Calculate the minimum SSBW by dividing the SSBA from Step #1 by the selected row length from Step #3
+ 1 ft (1 ft allows for 6 inches of sand on each end of the AES rows).
Step #6: Verify Final Bed Width Requirements
a) Beds sloping 5% or less: If the minimum SSBW is less than the PLW + 1 ft, use (PLW + 1 ft) as the new
minimum SSBW.
b) Beds sloping > 5%: If the minimum SSBW is less than the PLW + 3.5 ft, use PLW + 3.5 ft as the new
minimum SSBW. Adding 3.5 ft to the pipe layout width accounts for the minimum required 2.5 ft

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 7
system sand extension on the down slope side of the AES system. [Please see sections titled “System
Sand Extensions (SSE)”on page 9 and “Elevated Bed Systems” on page 10].
Step #7: Calculate System Sand Extension (SSE):
a) Beds sloping 5% or less: SSE is divided in half and placed evenly on each side of AES pipes. Formula for
SSE on level sites [SSBW –(PLW + 1)] ÷ 2. There will be no SSEs if the SSBW ≤PLW +1 ft.
b) Beds sloping > 5%: SSE placed entirely on the down slope side of the bed. Formula for SSE = SSBW –
(PLW + 1) and must be at least 2.5 ft (3 ft from the edge of the AES Pipe).
2.3 Design Examples
Design Example #1:
Single family residence, 4 bedrooms (480 gpd), SLR = 1.00 gpd/ft², level site, vertical separation greater than 2
feet.
Step #1: Determine System Sand Bed Area (SSBA) Required
SSBA: 480 gpd ÷ 1.00 gpd/ft² = 480 ft². 480 ft² * 0.90 = 432 ft².
Step #2: Calculate the Minimum Amount of AES Pipe Needed
AES pipe required: 70 ft/br * 4 br = 280 ft minimum.
Step #3: Determine Row Length and Quantity Needed
Using a row length of 70 ft requires 4 rows (280 ft ÷ 70 ft = 4 rows).
Step #4: Determine Pipe Layout Width (PLW)
PLW = [(4 –1) * (1.5)] + 1 = 5.5 ft.
Step #5: Determine Minimum System Sand Bed Width (SSBW)
Minimum SSBW = 432 ft² ÷ (70 ft + 1 ft) = 6.08 ft (round up to 6.5 ft for ease of construction).
Step #6: Verify Final Bed Width Requirements
a) Beds sloping 5% or less: Minimum SSBW of 6.5 ft is equal to PLW +1 (5.5 ft + 1 ft.). Use Minimum
SSBW for design.
b) Not Applicable.
Step #7: Calculate System Sand Extension (SSE):
a) Beds sloping 5% or less: SSE is divided in half and placed evenly on each side of AES pipes. SSE = [6.5 ft
–(5.5 + 1)] ÷ 2 = 0.0 ft. No system sand extensions are needed for this design.
b) Not Applicable
Illustration of Example #1:

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 8
Design Example #2:
Single family residence, 3 bedrooms (360 gpd), SLR = 0.25 gpd/ft², 12% site slope, limiting layer at 14 in. The SLR
of 0.25 gpd/ft and the fact that the system will be above grade both require that the system be designed by a
licensed professional engineer.
Step #1: Determine System Sand Bed Area (SSBA) Required
SSBA = (360 gpd ÷ 0.25 gpd/ft²) = 1440 ft² minimum.
Step #2: Calculate the Minimum Amount of AES Pipe Needed
AES pipe required: 70 ft/br * 3 br = 210 ft minimum.
Step #3: Determine Row Length and Quantity Needed
Using a row length of 70 ft requires 3 rows (210 ft ÷ 70 ft = 3 rows).
Step #4: Determine Pipe Layout Width (PLW)
PLW = [(3 –1) * (1.5)] + 1 = 4.0 ft.
Step #5: Determine Minimum System Sand Bed Width (SSBW)
Minimum SSBW = 1,440 ft² ÷ (70 ft + 1 ft) = 20.28 ft (round up to 20.5 ft).
Step #6: Verify Final Bed Width Requirements
a) Beds sloping 5% or less: not applicable.
b) Beds sloping > 5%: Minimum SSBW 20.5 ft is greater than the (4.0 + 3.5 ft), use 20.5 as the SSBW.
Step #7: Calculate System Sand Extension (SSE):
a) Beds sloping 5% or less: not applicable.
b) Beds sloping > 5%: SSE placed entirely on the down slope side of the bed. SSE = 20.5 –(4.0 + 1) = 15.5
which meets the 2.5 ft minimum extension for this slope.
Illustration of Example #2:
2.4 Design Specifications
The AES system shall be designed in accordance with this Manual and the Rules and can be installed using either
bed or trench design utilizing any of the design configurations outlined in this Manual.
Daily Design Flow (DDF)
In accordance with the Rules, daily design flow (DDF) is calculated as follows: the minimum flow rate shall be one
hundred twenty gallons (120 gals.) per day per bedroom. The minimum volume of sewage from each single family
dwelling shall be two hundred forty gallons (240 gals.) per day. When the occupancy of a single family dwelling
exceeds two (2) persons per bedroom, the volume of sewage shall be determined by the maximum occupancy at a
rate of sixty gallons (60 gals.) per person per day.

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 9
Septic Tank
The AES system is designed to treat effluent that has received “primary treatment” in a standard septic tank.
Septic tanks shall be sized according to the Rules.
Pressure Distribution
The use of pressure distribution lines in AES systems is prohibited. Pumps may be utilized when necessary only to
gain elevation and to feed a distribution box which then distributes effluent by gravity to the AES field. Siphon
dosing is permitted; adequate venting is required in a siphon-dosed system or pumped system, which may require
an additional high vent (referred to as “differential venting”).
Effluent (Wastewater) Strength
The AES pipe requirement for bed or trench systems is based on residential strength effluent, which has received
primary treatment in a septic tank. Use of the AES in non-residential or commercial applications requires that a
treatment train be included in the design which reduces effluent to residential strength prior to release into the
AES. Industrial (processed) waste shall not be discharged into the AES system. Our Technical Advisors may be
consulted for recommendations at [phone].
Effluent Filters
•Effluent filters are not recommended for use with AES systems.
•If used, effluent filters shall be maintained on at least an annual basis. Follow manufacturer’s instructions
regarding required inspections, cleaning and maintenance of the effluent filter.
•Effluent filters must allow the free passage of air to ensure the proper functioning of the system.
•Charcoal filters in vent stacks (for odor control) are not recommended by PEI. They can block air flow and
potentially shorten system life.
Flow Equalizers Required
All distribution boxes (D-box) used to divide effluent flow require flow equalizers
in their outlets. A flow equalizer is an adjustable plastic insert installed in the
outlet holes of a D-box to equalize effluent distribution to each outlet whenever
flow is divided. Each row is limited to a maximum of 15 gallons per minute
(gpm), due to the flow constraints of the equalizers. Example: pumping to a D-
box with 4 outlets. The maximum delivery rate is (4 x 15) = 60 gpm. Always
provide a means of velocity reduction when needed.
Two Inch Rule
The outlet of a septic tank or D-box shall be set at least 2 in above the highest inlet of the AES row, with the
connecting pipe slope not less than 1% (approximately 1/8in per foot). Illustration of 2 in rule:
AES Pipe Requirement
AES systems use the bed sizing tables, pipe and installation requirements noted in this Manual.
•Residential systems: 70 ft/br.
•Non-residential or commercial systems comprised of residential strength effluent: 2.14 gpd/ft2.
Water Purification Systems
•Water purification systems and water softeners should not discharge into any AES system.

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 10
•If there is no alternative means of disposing of this backwash other than in the system, the system will
need to be “oversized.” Calculate the total amount of backwash in gpd, multiply by 2, and add this
amount to the daily design flow when determining the field and septic tank sizing.
•Water purification systems and water softeners require regular routine maintenance; consult and follow
the manufacturer’s maintenance recommendations.
Sloping Sites and Sloping Mound Systems
•On sloping sites (>5%) the AES pipe rows and surrounding system sand shall be level.
•Any system sand extension may follow the slope of the site.
•Maximum site slope is 25%.
Row Requirements
•All beds shall have at least 2 rows.
•Maximum row length for any system is 100 ft of pipe.
•Recommended minimum row length is 30 ft of pipe.
•A minimum of two D-box outlets must be used and the field must be vented. Minimum center-to-center
spacing is 1.5 ft for all systems. Spacing may be increased at the discretion of the system designer or as
needed to meet the required SSBA.
•Sewn seam must be oriented in the 12 o'clock position. This correctly orients the Bio-Accelerator®fabric in
the 6 o'clock position.
•For level beds the AES rows shall be centered in the middle of the system sand bed area (SSBA) and any
system sand extensions (SSE) divided evenly on both sides.
•For sloping beds (>5%): the elevation for the AES rows must be provided on the drawing. All rows shall be
grouped 6 in from the up-slope edge of the SSBA with any system sand extensions placed entirely on the
downslope side. Systems sloping greater than 5% require a 2.5 ft SSE on the downslope side of the bed (3
ft when measured from the pipe).
•Each row must be laid level to within +/- ½ in (total of 1 in) of the specified elevation and shall be parallel
to the contour of the site.
•It is most convenient if row lengths are designed in exact 10 ft increments to accommodate the length of
the AES pipe as manufactured. However, AES pipe lengths can be cut to any length.
System Sand Extensions (SSE)
System sand extensions (SSE) are placed on the down slope side of sloping systems and equally divided on each
side of level systems. The SSE is measured from the tall portion of the system sand bed. In systems sloping more
than 5%, a 2.5 ft minimum SSE is required. The SSE area is a minimum of 6 in deep.
Separation Distances (Horizontal and Vertical)
Horizontal separation distances are measured from the outermost edge of the system sand bed area. Vertical
separation distances are measured from the bottom of the 6 in-deep basal system sand layer to the naturally
occurring suitable or provisionally suitable receiving soil interface.
Design of the AES requires a minimum vertical separation of 12 in. There must be a minimum of 12 in of naturally
occurring suitable or provisionally suitable soil below grade at the location of the system on the site for the AES to
be permitted.
No variances will be issued until the AES system is no longer considered by DHSS to be experimental.
Barrier Materials over System Sand
No barrier materials (hay, straw, tarps, etc.) are to be placed between the system sand and cover material. The
only exception is the placement of the specified fabric to achieve H-20 loading requirements.

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 11
2.5 System Configurations
Elevated Bed Systems
Elevated beds are designed for sites with soil, depth to groundwater or restrictive feature constraints that do not
allow for in-ground bed systems. An elevated bed system is a soil absorption field with any part of the AES system
(6 in basal system sand layer and 12 in tall AES pipe rows) is located above original grade. Side-slope tapering is
used to blend the raised portion of the system with the existing grade. Elevated bed systems require 6 in fill
extensions on each side (measured from the pipe), after which side-slope tapering is to be a maximum of 3
horizontal feet for each 1 ft of vertical drop until it meets existing grade. In systems sloping greater than 5%, there
must be a minimum of 2.5 ft of system sand extension (3 ft measured from the pipe) beyond the last down-slope
row of pipe. There must be a minimum of 12 in of cover material over the ends of all system sand extensions (if
present).
Illustration of an elevated level bed: Illustration of an elevated sloping bed:
In-Ground Bed Systems
Systems are installed at or below existing grade for sites with no soil restrictive features within 30 in of grade. In-
ground systems that slope over 5% require a 2.5 ft system sand extension on the downhill side of the field. In-
ground on level site:
Trench Systems
AES pipe may be installed in trench configurations on level or sloping terrain. Trench systems incorporate one or
more rows of AES pipe per trench. A minimum of 3 in of system sand is required above and 6 in below, between,
and around the perimeter of the AES pipe. Consult the Rules for acceptable trench width and/or required trench
separation.

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 12
Butterfly Configuration
•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.
•Butterfly configurations are generally used to accommodate bed lengths longer than the maximum row
length of 100 ft.
•Rows shall meet requirements outlined in the design criteria above.
Illustration of a butterfly configuration bed design:
D-box (Parallel) Distribution
•All pipe rows shall be the same length.
•Flow equalizers must be used in the D-box.
•Use a manifold to connect the ends of all rows. Manifold shall be sloped toward AES pipes.
•D-box placement shall be installed on level, firmly compacted soil.
•All rows shall be laid level end-to-end.
•A 2 in min. drop is required between the D-box outlets and the AES pipe inlets.
•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.
•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.
•All pipe rows to be the same length.
•End-to-end configurations are preferred to side-to-side configurations.
•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.

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 13
Illustration of multiple beds at same elevation: Illustration of multiple beds at different elevations:
Angled and Curving Beds
Angled and curving beds are used to avoid obstacles and work well around structures, setbacks, and slopes.
Multiple curves can be used within a system to accommodate various contours of the site.
•Rows are angled by bending pipes up to 90 degrees or through the use of offset adapters
•Rows shall meet requirements outlined in the design criteria above.
Illustrations of angled and curving beds:
2.6 Pump Systems
Pumped systems supply effluent to the system using a pump and D-box when site conditions do not allow for a
gravity system. Dosing siphons are also an acceptable means of delivering effluent to the system.
•Pump volume per dose shall be no greater than 1-gallon times the total linear feet of AES pipe.
•Pump dosing should be designed for a minimum of 6 cycles per day; 6-8 cycles per day are recommended.
•If possible, the dosing cycle should provide one hour of drying time between doses.
•Pump systems must have a high-water alarm float or sensor installed inside the pump chamber. Follow
state, local and national code requirements.
•All pump systems require differential venting.
•All pumped systems require a D-box with baffles, a velocity reducing tee or other means to be used for
velocity reduction.

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 14
•All systems with multiple bed distribution shall use flow equalizers in each D-box outlet with each bed or
section limited to a maximum of 15 gpm, due to the flow constraints of the equalizers.
oExample: pumping to a system using 3 D-box outlets, the maximum delivery rate is (3 x 15) = 45
gpm. Higher flow rates can be accommodated by connecting multiple D-box outlets to each line.
•The rate at which effluent enters the AES pipe shall be controlled. Excessive effluent velocity can disrupt
solids that settle in the pipes.
•Effluent shall never be pumped directly into AES pipes.
•A D-box or tank shall be installed between the pumping chamber and the AES pipe to reduce
effluent velocity.
•Force mains shall discharge into a D-box (or equivalent) with velocity reducer such as a baffle, 90°
bend, tee or equivalent.
•Velocity reducers are also needed for gravity systems when there is excessive slope between the septic
tank and the AES system.
Two methods of velocity reduction:
2.7Venting
An adequate air supply is essential to the proper functioning of AES systems. Venting is always required. All
systems shall utilize differential venting.
General Rules
•Differential venting is the use of high and low vents in a system.
•In a gravity system, the roof stack acts as the high vent.
•High and low vent openings shall be separated by a minimum of 10 vertical ft.
•If possible, the high and low vents should be of the same capacity.
•Roof vent diameter must be a minimum of 3 in, 4 in diameter is recommended. If the roof vent is less
than 3 in, an additional high vent is recommended.
•Vent openings shall be located to ensure the unobstructed flow of air through the entire system.
•The low vent inlet shall be a minimum of 1 ft above final grade or anticipated snow level. Vents extending
more than 3 ft above grade must be anchored.
•Sch. 40 or SDR 35 PVC (or equivalent) should be used for all vent stacks.
•One 4 in vent is required for every 1,000 ft of AES pipe.
•A single 6 in vent may be installed in place of up to three 4 in vents.
•If a vent manifold is used, it shall be at least the same diameter as the vent(s).
•Vent piping should slope downward toward the system to prevent moisture from collecting in the pipe
and blocking the passage of air.
•Remote venting may be utilized to minimize the visibility of vent stacks.
•When venting multiple beds, it is preferred that each bed be vented separately rather than connecting
bed vents together. Multiple vents can be remotely located to the same location if desired.

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 15
Vent Manifolds
A vent manifold may be incorporated to connect the ends of a number of
sections or rows of AES pipe to a single vent opening. Slope the lines
connecting the manifold to the AES pipes to drain condensation.
Gravity Systems Vent Location
•A vent manifold shall be used to connect the distal ends of the rows within a bed (or each section in a
multiple bed system).
•The vent manifold shall include use of offset adapters.
•A low vent shall be installed into any aspect of the vent manifold of the bed (or each section in a multiple
bed system).
•The house (roof) vent functions as the high vent as long as there are no restrictions or other vents
between the low vent and the house (roof) vent.
•When the house (roof) vent functions as the high vent, there shall be a minimum of a 10 ft vertical
differential between the low and high (roof) vent openings.
Illustration of gravity system air flow:
LOW VENT
(AIR INLET)
VENTING IS ESTABLISHED THROUGH SUCTION (CHIMNEY EFFECT) CREATED BY THE DRAW OF AIR
FROM THE HIGH VENT, WHICH DRAWS AIR INTO THE LOW VENT AT THE LEACH FIELD THEN
THROUGH THE SEPTIC TANK AND EXHAUSTED THROUGH THE (HIGH) ROOF VENT.
ROOF VENT (HIGH VENT,
EXHAUST - CREATES SUCTION)
PVC SANITARY TEE
INLET BAFFLE
WITH OPEN TOP
PVC BAFFLE
NOTES:
1. EFFLUENT FILTER (IF USED) MUST BE PROPERLY
MAINTAINED TO ENSURE ADEQUATE AIR FLOW.
2. DO NOT USE CHARCOAL FILTERS ON VENTS. THEY
CAN RESTRICT AIR FLOW.
GRAVITY SYSTEM AIR FLOW
PVC SANITARY TEE OUTLET
BAFFLE WITH OPEN TOP

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 16
Pump System Vent Locations
•A low vent shall be installed into any aspect
of the vent manifold on the distal end of the
bed (or each section in a multiple bed
system).
•The vent manifold shall include use of offset
adapters.
•A high vent is attached to an unused D-box
outlet.
•The low and high vents may be swapped,
provided the D-box is insulated against
freezing in cold climates.
•For options to relocate the high vent, see
Remote Venting.
•For options to eliminate the high vent, see
Bypass Venting.
Remote Venting
If site conditions do not allow the vent pipe to slope toward the system, or the owner chooses to utilize remote
venting for aesthetic reasons (causing the vent pipe not to slope toward the system), the low point of the vent line
must be drilled creating several ¼ in holes to allow drainage of condensation. This procedure may only be used if
the vent pipe connecting to the system has:
•A high point that is above the highest point of all AES pipes or the D-box (2 in minimum for each); and,
•A low point opened for drainage which is above the SHWT (see diagram below).
By-Pass Venting
When a field is fed using pumping or dosing, it is necessary to provide air flow through the system by using either
an independent high vent at the field or “by-pass venting”. For by-pass venting, the system is plumbed by
attaching Sch. 40 or SDR 35 PVC from the D-box back to the septic tank or pump chamber if no effluent filter is
present. This process “by-passes” the pump line and allows air to flow from the low vent to the roof vent which
functions as the high vent. The bypass vent line invert must rise 2 in above the D-box before dropping to pump
chamber or septic tank.

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 17
Illustration of by-pass venting:
2.8Site Selection
Determining Site Suitability
Refer to DHSS regulations and local rules regarding site suitability requirements.
Topographic Position Requirement
AES systems shall not be located where surface or ground waters will converge, causing surface water flow to
become concentrated or restricted within the soil absorption field. The system shall be located in an area that does
not concentrate water, both surface and subsurface. If allowed by state and local authorities, altering the terrain
upslope of a system may alleviate this requirement if the waters are sufficiently altered to redirect flows away
from the field.
•Locate systems on convex, hill, slope or level locations. Avoid swales, low areas, or toe-of-slope areas that
may not provide sufficient drainage away from the system.
•No onsite system may be located on concave slopes that concentrate surface or ground water flows
unless up-slope terrain is sufficiently altered or interceptor drains are used to redirect water away from
the system.
•Systems should not be located where lawn irrigation, roof drains, or natural flows increase water loading
to the soils around the system. Divert surface water away from the system.
•Interceptor drains, if used, must be upslope of the AES system and a minimum of 10 ft away from all AES
pipe.
•Systems should not be located where structures such as curbs, walls or foundations might adversely
restrict the soil’s ability to transport water away from the system.

2.0 SYSTEM DESIGN
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 18
•Systems should be located to allow access for septic tank maintenance and to at least one end of all AES
rows.
•Avoid locating systems in rocky or wooded areas that require additional site work, since this may alter the
soil’s ability to accept water.
•No trees or shrubs should be located within 10 ft of the system to prevent root infiltration.
AES as a Replacement System
If an AES system is being installed in the same location where another onsite system has previously been installed:
•Remove the existing components and contaminated sand and soil.
•If the soils under and around the system have not been compromised, it is permissible to install the AES
system in the same excavated location using new system sand.
Note: Permits are required for system replacement.

3.0 INSTALLATION
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 19
3.1 Installation Requirements
Component Handling
•Keep mud, grease, oil, etc. away from all components. Avoid dragging pipe through wet or muddy areas.
Store pipe on high and dry areas to prevent surface water and soil from entering the pipes or
contaminating the fabric prior to installation.
•The outer fabric of the AES pipe is ultra-violet stabilized; however, this protection breaks down after a
period of time in direct sunlight. To prevent damage to the fabric, cover the pipe with an opaque tarp if
stored outdoors.
Site Preparation Prior to Excavation
1. Locate and stake out the system sand bed, extension areas and soil material cover extensions on the site
according to the approved plan.
2. Install sediment/erosion control barriers prior to beginning excavation to protect the system from surface
water flows during construction.
3. Do not stockpile materials or equipment within the portion of the site receiving system sand.
Critical Reminder to Prevent Soil Compaction
It is critical to keep excavators, backhoes, and other equipment off the excavated or tilled surface of a bed. Before
installing the system sand, excavation equipment should be operated around the bed perimeter; not on the bed
itself. It is especially important to avoid using construction equipment down slope of the system to prevent soil
compaction.
When to Excavate
•Do not work wet or frozen soils. If a fragment of soil from about 9 in below the surface can easily be rolled
into a wire, the soil moisture content is too high for construction.
•Do not excavate the system area immediately after, during or before precipitation.
Tree Stumps
Before tilling, remove all grass, leaves, sticks, brush and other organic matter or debris from the excavated system
site. Removal of all tree stumps and the central root system below grade is recommended (see note below). Use a
backhoe or excavator with a mechanical “thumb” or similar extrication equipment to lift or leverage the stump in a
manner that minimizes soil disturbance. It is not necessary for the soil of the system site to be smooth when the
site is prepared.
•Avoid soil disturbance, relocation, or compaction.
•Avoid mechanical leveling or tamping of dislodged soil.
Fill all voids created by stump or root removal with system sand.
NOTE: If removal of a tree stump will result in disturbance of the suitable or provisionally suitable soils which
comprise part of the minimum vertical separation distance, then the stump should not be removed. Disturbance
of the materials which comprise the minimum vertical separation will render the site unacceptable.
Raking and Tilling Procedures
All areas receiving system sand, sand fill, side-slope tapering and fill extensions shall be raked or tilled to remove
the organic layer (grass, leaves, forest litter, etc.). If a backhoe/excavator is used to till the site, fit it with chisel
teeth and till the site. The backhoe/excavator shall remain outside of the proposed system sand area and all areas
that will be impacted by side-slope tapering. While tilling, remove all stones larger than 6 in, stumps roots, grass,
brush and other organic matter or debris from the excavated system site.
•For in-ground bed systems, excavate the system bed as necessary below original grade. Using an
excavator or backhoe, tilt the bucket teeth perpendicular to the bed and use the teeth to rake furrows
2 in –6 in deep into the bottom of the entire area receiving system sand or sand fill.
•For elevated bed systems, remove all organics and topsoil (O & A soil horizons) in the footprint of the
dispersal area prior to installing system sand; for percolation rates of 61 –120 MPI, remove the organics,

3.0 INSTALLATION
© Presby Environmental, Inc., Design & Installation Manual, September 2020 Edition 20
the topsoil may be left in-place and tilled. Next, use an excavator or backhoe to rake furrows 2 in –6 in
deep into the receiving area.
Note: It is not necessary for the soil of the system site to be smooth when the site is prepared.
Install System Sand and/or Sand Fill Immediately After Excavation
•To protect the tilled area from damage by precipitation, system sand should be installed immediately
after tilling.
•Work off either end or the uphill side of the system to avoid compacting soil.
•Keep at least 6 in of sand between the vehicle tracks and the tilled soil of the site if equipment must work
on receiving soil.
•Track construction equipment should not travel over the installed system area until at least 12 in of cover
material is placed over the AES pipes.
•Heavy equipment with tires shall never enter the receiving area due to likely wheel compaction of
underlying soil structures.
Distribution Box Installation
It is essential that the D-box remain level after installation in order to ensure even distribution to all rows within
the system. To prevent movement, D-box shall be set on a layer of level compacted soil, sand, pea gravel base or a
concrete footing. Take care when backfilling that the D-box remains level.
Row Installation Sequence
1. Install a minimum of 6 in of system sand to the elevation where the bottom of AES pipes will be and install
the sand for side-slope tapering to allow machinery movement around the perimeter of the system. Rake
the system sand where the AES pipes will be installed so it is as level as possible before placing pipes on
the system sand. This will make it easier to level the pipe rows.
2. Locate AES rows horizontally.
3. Locate AES rows vertically using a laser level or transit. Lift or lower the pipes at couplings using a hand
shovel and adding or removing system sand as necessary.
4. Drop system sand along each row of couplings being careful to avoid moving the rows.
5. Add or remove system sand along rows to level. The rows may be raised by pushing additional system
sand below the pipes. A hand shovel may be scraped along the system sand below the pipes to remove a
small amount if needed.
6. Re-check horizontal and vertical locations. Re-check that pipes are level to within 1 in end-to-end.
7. Add system sand between and around the AES pipes, leaving the uppermost surface of the pipe exposed
to allow for system inspection (if required by local approving authority).
Level Row Tolerances
Use a laser level or transit to install rows level. Variations beyond 1 in (±½ in) may affect system performance and
are not acceptable.
Correct Alignment of AES Bio-Accelerator®Fabric
The Bio-Accelerator (white geo-textile fabric) is to be positioned centered along the bottom of the pipe rows (sewn
seam up).
Row Spacers
System sand may be used to keep
pipe in place while covering, but
simple tools may also be constructed
for this purpose. Two examples are
shown. One is made from rebar, the
other from wood. Caution: Remove
all tools used as row spacers before
final covering.