AquaShield Bio-Filter Instruction Manual

Bio-FilterTM
Stormwater Biofiltration System
Inspection and Maintenance Manual
March 2017
AquaShield,
TM
Inc.
2733 Kanasita Drive, Suite 111
Chattanooga, TN 37343
Phone: [phone]
Fax: [phone]
Email: [email protected]
© AquaShield
TM
, Inc. 2017

AquaShield,TM Inc. Bio-FilterTM
Table of Contents
 AquaShieldTM Bio-FilterTM Overview
 Bio-FilterTM Operation
 Bio-FilterTM Inspection & Maintenance
 Appendix
2733 Kanasita Drive, Suite 111, Chattanooga, Tennessee 37343
Phone [phone] Fax [phone]
www.AquaShieldInc.com

AquaShield
T
M Bio-Filter
T
M
Overview
The highest priority of AquaShieldTM, Inc. (AquaShield™) is to protect waterways
by providing stormwater treatment solutions to businesses across the world.
These solutions have a reliable foundation based on over 20 years of water
treatment experience. Local regulators, engineers, and contractors have praised
the AquaShieldTM systems for their simple design and ease of installation. All the
systems are fabricated from lightweight, durable materials, and contractors
prefer the quick and simple installation of our structures that saves them money.
The AquaShieldTM line of patented stormwater treatment products provide high
levels of stormwater treatment. AquaShieldTM manufactures the following
integrated product solutions:
 Aqua-Swirl® Stormwater Treatment System
 Aqua-FilterTM Stormwater Filtration System
 Aqua-GuardianTM Catch Basin Insert
 AquaShieldTM Bio-FilterTM Stormwater Biofiltration System
The Bio-Filter
TM
Stormwater Biofiltration System is capable of gross
contaminant removal, coarse- and fine-grained sediment removal, oil removal, as
well as the removal of heavy metals and phosphorus.
This Inspection and Maintenance Manual provides important information for
continued effective operation of the AquaShieldTM Bio-FilterTM system.
The Bio-FilterTM Stormwater Biofiltration System is a modular “tree box” design
that provides an innovative and sustainable green infrastructure solution to meet
the growing challenges of Low Impact Development (LID) practices. The Bio-
FilterTM is a water quality treatment device capable of removing coarse and fine
sediment, trash and debris, heavy metals bound to particulate matter, and oil by
utilizing elements of pretreatment and biofiltration. Biofiltration is accomplished
by a proprietary engineered soil biomedia as well as uptake by the selected tree.
The Bio-FilterTM provides advanced pretreatment for rainwater collection
structures, or can be used as a standalone device for discharges to sensitive
receiving waters. Each system is custom engineered for site-specific needs using
proven lightweight and durable Polymer Coated Steel (PCS). The system
operates under gravitational and hydrodynamic forces with no moving parts
which simplifies the treatment process. The standard Bio-FilterTM system utilizes

an internal bypass design with custom system footprints ranging from 4 x 4 feet
to 8 x 8 feet (16 to 64 square feet). An optional cylindrically shaped Bio-FilterTM
model uses an external bypass structure(s) in lieu of the internal bypass, having
similar surface areas as the standard models.
All Bio-FilterTM systems use a 3 inch top layer of mulch underlain by 18 or 24
inches of engineered biomedia, and an 8 inch gravel base containing an
underdrain pipe. Two 15-inch diameter metal access port covers to the Trash
Shelf, Pretreatment Chamber and Underdrain Pipe are also included for each
unit. A metal tree grate is available in several colors and patterns. A non-skid
surface material is used for the top of the unit and can be applied to the unit’s
sides on request. No heavy lifting equipment is needed for installation. All filter
media is typically shipped separately, and replacement biomedia is available from
AquaShieldTM. AquaShieldTM is not responsible for tree specification, purchase,
delivery, installation or maintenance.
Bio-FilterTM Media Installation
After the Bio-Filter™ is installed and before media installation, ensure that the
filtration chamber is free from debris and that the perforated underdrain pipe is
connected and in place (refer to SHOP drawing).
The first step in media installation is to fill the bottom 8 inches of the filtration
chamber with gravel (contractor furnished). Fill to the one inch flatbar
reinforcements that are attached to the front and back chamber walls at this
elevation. The top of the gravel bed should be smooth and level and the
underdrain pipe should be fully covered.
A layer of geotextile fabric (contractor furnished) is lain on top of the gravel bed.
Fabric should be smooth and cover the entire surface to the filtration chamber
walls.
Next the AquaShield™ Bio-Filter™ media is installed. The soil matrix should be
installed in 6 inch lifts and the surface of each lift smoothed and leveled before
proceeding to the next lift. Media should be filled to the upper 1-inch flatbar
reinforcements on the front and back filtration chamber walls.
At this point a solid cover should be placed over the tree grate opening and the
curb inlet blocked off to minimize construction debris from contaminating the
Bio-Filter™ media bed during the final site construction phases.

After all construction activities are complete, the cover should be removed from
the tree grate opening and the specified vegetation planted in the Bio-Filter™
media. After planting, the 3-inch layer of mulch (contractor furnished) should be
placed on top of the filter media bed. Note that mulch should not extend above
the bottom of the water distribution rails along the walls of the filtration
chamber. Refer to the AquaShield™ Bio-Filter™ Activation Guide to finalize
operation of the bio-filtration system.
Bio-FilterTM Operation
The five internal design elements of the Bio-FilterTM unit include the following:
1. Inlet and Trash Shelf
2. Pretreatment Chamber
3. Biofiltration Chamber
4. Outlet Chamber
5. Internal Bypass
These system components are identified in Figure 1. The five steps of Bio-FilterTM
treatment are described in the sections below.
Step 1: Inlet and Trash Shelf
Operation begins when water enters the Bio-Filter™, such as a curb inlet, and
flows onto the screened Trash Shelf. As water flow spreads out across the shelf,
debris is removed and retained. Both the internal structural wall of the Trash
Shelf and the weir wall of the Internal Bypass Weir serve to retain the influent
debris. The water quality treatment flow volume exits the Trash Shelf and enters
the Pretreatment Chamber. Flow volume in excess of the water treatment flow
can flow over the weir wall of the Internal Bypass, configured on the edge of the
Trash Shelf, and into the underlying Outlet Chamber. Bypass flows are screened
in order to retain trash and debris.

Figure 1. AquaShieldTM Bio-FilterTM System and its five design elements
Step 2: Pretreatment
The water quality treatment flow enters the Pretreatment Chamber where coarse
sediment and oil are captured and retained by principles associated with
hydrodynamic vortex separation, such as that incorporated into the design of the
field proven Aqua-Swirl® Stormwater Treatment System. Water enters the
Pretreatment Chamber by a tangential inlet between the Trash Shelf and
Pretreatment Chamber. This inlet sets up the swirling flow motion forcing coarse
sediment to fall out of suspension and accumulate at the base of the chamber.
Any floatables and oil will be retained by the arched baffle positioned on the
outlet side of the chamber. Water exits the Pretreatment Chamber underneath
the arched baffle and through a horizontal opening that extends along the width
of the chamber wall. Water then enters the Biofiltration Chamber.
Step 3. Biofiltration
The water quality treatment flow is distributed across the entire top of the
Biofiltration Chamber via a flow distribution channel that extends entirely along
the outer edge of the chamber. The distribution channel also dissipates the water
flow’s energy to avoid disturbing the engineered soil biomedia and tree. Water
then flows downward driven by gravity flow through the biomedia and plant root
ball to remove fine sediment, heavy metals, residual oil and phosphorus. Next,
1
2
3
4
5

filtered water enters a 4-inch inner diameter perforated Schedule 40 PVC
Underdrain Pipe placed within 8 inches of gravel at the base of the chamber.
Treated water is conveyed within the pipe to the adjacent Outlet Chamber
positioned directly underneath the Trash Shelf.
Step 4. Outlet Chamber
Both the water quality treatment flow from the Biofiltration Chamber and any
associated bypass flow is routed into the Outlet Chamber prior to discharge. The
outlet pipe can be placed on either of the two sides of the chamber to facilitate
installation designs.
Step 5. Internal Bypass Weir
The standard Bio-FilterTM design includes an Internal Bypass designed not only to
accommodate high flow conditions, but also to minimize the device’s installation
footprint by eliminating the need for any external bypass structures. Internal
bypass occurs when the head level rises within the unit such that flows in excess
of the water quality treatment flow will spill across the overflow weir on the
Trash Shelf and downward into the underlying Outlet Chamber. The bypass weir
is screened to prevent escape of trash and debris during high-flow events.
Bio-FilterTM Biomedia
The natural proprietary engineered biomedia used in the Bio-FilterTM system is
capable of removing waterborne pollutants such as fine silts and clays, oil and
heavy metals bound to particulate matter (copper, lead, zinc) and phosphorus.
The media is configured within the Biofiltration Chamber from top to bottom as
follows:
 Three (3) inches of mulch,
 18 to 24 inches of a proprietary blend of natural biomedia having an
infiltration capacity between 120 and 135 inches per hour.
 8 inches of gravel containing a 4 inch inner diameter Schedule 40 PVC
underdrain pipe perforated on the underside.

Bio-Filter
T
M
Inspection & Maintenance
The long-term performance of
the stormwater treatment
structures (including
manufactured systems,
ponds, swales, etc.), and the
effective protection of
receiving waters, depends on
a consistent maintenance
plan. Inspection and
maintenance (I & M)
functions are simple and easy
for AquaShield™ Stormwater
Treatment Systems allowing
all inspections to be
performed from the surface.
It is important that a consistent and routine I & M program be established for
each unit based on (1) the volume or load of the contaminants of concern, (2)
the frequency of releases of contaminants at the facility or location, and (3) the
nature of the area being drained.
In order to ensure that our systems are being properly maintained, AquaShield™
offers a maintenance solution to all of our customers. We can arrange to have a
maintenance event performed.
Inspection and Maintenance Data Sheets are provided in the Appendix of this
Manual.
Bio-Filter
TM
Inspection
The AquaShield
TM
Bio-Filter
TM
can be inspected from the surface, eliminating the
need to enter the system to determine when cleanout should be performed.
In most cases, AquaShield™ initially recommends a frequent inspection cycle
following installation. Inspection frequency will be dependent on site loading
conditions. At a minimum following installation and/or activation, we recommend

a quarterly inspection of the system for the first year of operation to develop an
appropriate schedule of maintenance.
Based on experience of the system’s first year in operation, we further
recommend that the inspection schedule be revised to reflect the site-specific
conditions encountered.
Inspections for Bio-FilterTM components of the Inlet, Trash Shelf, Pretreatment
Chamber, Biofiltration Chamber, Outlet Chamber and the tree should be
performed generally on a quarterly basis, but at least annually. Conditions of
both metal covers, metal tree grate, and any external bypass structure(s) should
also be noted. Information gathered during the first year of service can often be
used to create a maintenance plan appropriate for the site.
Bio-FilterTM Maintenance
Inlet and Trash Shelf
Inspections of the Inlet and Trash Shelf can be viewed at the Inlet itself and
through a 15 inch diameter metal access cover located closest to the Inlet. It is
important to consistently keep both the Inlet and Trash Shelf significantly free of
accumulated materials to ensure proper operation of the Bio-FilterTM unit.
Materials can be removed by the use of a vacuum truck while performing
maintenance of the other Bio-Filter
TM components. Given the nature of typical
curb inlet designs, manual removal of debris may be necessary depending on
site-specific conditions.
Pretreatment Chamber
Access to the Pretreatment Chamber for inspections and maintenance tasks can
be accomplished at the surface through a 15 inch diameter metal access port
(located furthest from Inlet). The Pretreatment Chamber retains coarse material
and sediment and any free floating oil. Underground entry to the Pretreatment
Chamber is not needed given its accessibility through the access port.
Maintenance is triggered when no more than six (6) inches of sediment depth
(thickness) accumulates in the Pretreatment Chamber. The sediment pile
thickness is easily determined by comparing the distance to the top of the
sediment pile to the distance to the base of the chamber. The distance to the
base of the Pretreatment Chamber can be obtained (a) in the field by using a
stadia rod or other rigid measuring device or (b) reviewing a model specification
drawing.

Biofiltration Chamber
I & M events for the Biofiltration chamber are accomplished from the surface,
but it may be necessary to step into the media to accomplish media repositioning
or removal. It is first necessary to remove the metal tree grate. The conditions of
both the mulch top layer, biomedia and tree should be documented. Any filter
media replacement should include, at a minimum, the top layer of mulch. Further
inspection may indicate that the top 3 to 6 inches of the biomedia (below the
mulch layer) may also need replacement, being careful not to disturb the tree’s
trunk, rootball or its stability. The mulch and top layer of biomedia can be
vacuumed from the chamber if feasible, but manual removal and replacement
may be appropriate depending on whether unique circumstances indicate such
action. Replacement mulch and biomedia is available from AquaShieldTM.
The Underdrain Pipe is accessible through the metal access port for the Trash
Shelf. A vacuum snake line can be inserted through the Internal Bypass opening
and down to the opening of the Underdrain Pipe. Any sediment in the pipe can
be vacuumed out accordingly.
Outlet Chamber
The Outlet Chamber is designed to be free of any significant accumulated
material. Yet, if any sediment has accumulated in this chamber, it is accessible
through the Internal Bypass opening, similar to the approach to access the
Underdrain Pipe described above.
Filter Media and Removed Materials Disposal
All I & M activities can be performed from the surface without the need for an
AquaShieldTM representative to be on site. AquaShieldTM recommends that all
materials removed during the maintenance process be handled and disposed in
accordance with all applicable federal, state and local guidelines. Depending on
the influent pollutant characteristics of the facility drainage area, it may be
appropriate to perform Toxicity Characteristics Leaching Procedure (TCLP)
analyses on representative samples of the spent filter media and recovered
materials to ensure that the handling and disposition of the materials complies
with applicable environmental regulations and practices.