FORMCELL® Living Filter®, Wastewater Infiltration Units
INSTALLATION MANUAL (Connecticut)
Application of use
The Living Filter product can be used to replace conventional infiltration
devices such as, galleries, stone trenches, wrapped pipe, plastic chambers,
pipe and stone trenches etc. and can also be used in recirculating sand filters,
sand mounds and special construction and FORM CELL BIOREN Systems etc.
The Living Filters when used for simple infiltration into soils, comprises
aggregate (inert or synthetic) filled expandable cellular arrays, fully enclosed
by a membrane, surrounded by select sand/aggregate and covered by insulation
where specified, all meeting the manufacturers specifications.
Licensing and Certification
The Living Filter products (in Connecticut) are installed by persons and/or
companies licensed and certified by FORM CELL Research, Inc.(FCR)
to perform the installations to FCR specifications (or under the supervision
of a FORMCELL representative) in addition to compliance with local, state
and applicable regulatory standards as they may pertain.
All installers must be properly licensed by the State of Connecticut,
Department of Public Health. In some jurisdictions, homeowner
permits may invalidate the requirement for state licensing, but would
require FCR certification for a one time installation for their residence
provided the company is assured their training is adequate to perform the
installation.
A register of certified installers is maintained by FCR, Inc., to be shared
with the State of Connecticut Department of Public Health, the Department
of Environmental Protection and all Connecticut Health Agencies.
Living Filter Storage and Handling
The Standard Living Filter is manufactured using biodegradable materials
for some components and require dry storage and transport. The Filters
must be kept in a dry location until use. The installation is preferably
done on days without precipitation but can be installed during rainy conditions
using some precautions. If rain develops prior to complete backfilling,
it is recommended that the filters be covered by tarps to reduce soaking
of the biodegradable forms.
If forms are saturated, not walking on the filters is important or to otherwise
disturb the aggregate inside the forms until the exterior is backfilled
with sand/aggregate to within a couple of inches of the top.
Design Considerations
It is imperative that the site is thoroughly investigated before proceeding
to the design phase. There should be at least two deep test holes in
the area of the proposed filter location. If ledge (rock) is present
on the site be sure to confirm adequate separation between ledge and the
bottom of filters at time of installation. The system must be
installed the specified distance above seasonal high groundwater or at least
18 inches above a modified/lowered watertable. Divert rainwater from
filter system location. If rainwater must traverse the system, the grade
should slope at least 5% with no depressions to cause water to enter the
system. Normal installation in soils with a percolation rate faster
than 20 minutes per inch requires a minimum of 3 inches of medium/fine sand
or aggregate under the filter bottom (*min k=24 ft/day, 100% passing a 1 inch
sieve and max 5% passing #200 sieve and/or per manufacturers specifications).
In applications where the percolation rate of underlying soils is slower
than 20 minutes per inch a minimum of 6 inches of *sand under the filters
is required and if the percolation rate is slower than 30 min/inch a minimum
of 12 inches of *sand will be required if the filter effective leaching area
per lf exceeds 7.5 sf/lf. The sand/aggregate` would not be required
if naturally occurring materials meet specifications.
INSTALLATION
Preparation of Site
Remove all trees at and in the immediate vicinity of the installation.
Tree to system separation should be maintained by cutting trees where the
crown of the tree encroach on the installed system unless special barrier
materials are placed between the root system of the trees and the filters.
Strip and store all topsoil for reuse.
Remove all roots, stumps and other deleterious materials and remove all
organic material under the filters to at least 8 inches outside the footprint
of the filters.
Erosion Control
Install erosion control where required by local and State Regulations.
Attempt to preserve naturally occurring vegetative filters (low growth, brush
and other vegetation). Install silt fence and/or hay bales. Grade
the area to reduce accumulation and concentrated run off.
Excavation for Living Filters
Excavate to desired depth and width as shown on the cross-section part
of the installation drawings.
Be sure not to excavate deeper or wider than shown in the drawings.
If the bottom of the trench, in parts, appear to have soils of lesser
permeability than design basis, undercut and fill, mechanically compact with
select sand/aggregate to a satisfactory density. If the depths of low
permeability soils exceed 12 inches, contact system designer for guidance.
Be sure to place excavated materials, at least, a minimum of 4 feet from
the edge of the trench to prevent overloading of soils and thus reducing
the likelihood of cave-ins.
The machine operator while excavating the trench should take special care
to remove any projecting large rocks or boulders that could fall and cause
injury and damage.
Select Sand Placement
Place specified sand/aggregate at bottom of trench up to bottom of filter
elevation. If less than 6 inches hand compact or use mechanical means
to achieve a uniform density. Grade the sand to within .02' +/-.
Working the sand with grading tools will usually achieve adequate compaction.
If sand depths exceed 6 inches use a mechanical vibratory compactor or the
equivalent. Compact in lifts not to exceed 6 inches. Cover all
areas at least twice. Use your good judgement to assess compaction.
If in doubt, lightly sprinkle with water, run a third pass with the compactor.
The grade of the sand bottom for all filters must be level in all directions.
Select sand/aggregate must meet manufacturers' specifications.
Install Filters
1.
Start filter installation by placing the bottom membrane, which will be
approximately six inches wider than the filters being placed. Place
roll at one end and unroll for total length. Leave sufficient membrane
at ends of filter row.
2.
Properly align and proceed to install filters. (If a regeneration
pipe [optional] is called for, install according to instructions before the
placement of filters).
Expand filters from collapsed storage condition. Place centered on
bottom membrane at 6 inches on center for models LF1210 through LF3610.
Place centered on bottom membrane at 8 inches on center for models LF1226
through LF 3626.
All membrane materials, covering all sides of the Living Filters must meet
manufacturer's specifications.
3.
Insert special 4 inch perforated corrugated pipe into keyhole slots in
the divider walls between cells at spacing specified making sure that the
pipe is pressed and seated firmly in the keyhole. After pipe is in
place, align filters to desired position and as shown on the plans.
The pipe, an integral part of the Living Filter, placed inside the units,
must meet manufacturer's specifications.
4.
Place aggregate chute (approximately 30" wide by 96" +long and at least
the width of the bucket) on the filters and proceed to fill with specified
aggregate. Fill to a point where aggregate mounds up about four inches
above the top of the Living Filter form. Move the chute and proceed
with the aggregate filling until row is complete. The aggregate must
be clean and free of deleterious materials and meet manufacturer's specifications.
5.
Remove chute and cover stone with membrane, proceed to fill with specified
sand/aggregate on the exterior of the filters. Use a tamping tool to
compact sand between cells. Once up to grade, move membrane to one
side, level stone to top of LF form and cover top of filters with
membrane overlapping at least 3 inches on both sides of filters. Make
sure that sand/aggregate is adequately compacted between filter cells.
Water may be used to settle the sand further and enhance compaction.
Ensure that there are no sharp protrusions on the compaction tool that could
damage the membrane.
6.
Record vertical and horizontal location of all major components of the
system before backfilling as follows; all Living Filter inlet and
outlet ends, Distribution Boxes, Septic Tanks, Pump Chambers and all installed
pipe including elevation and location at foundation. If regeneration
pipes and monitoring tubes are installed, these should be noted on the record
drawings.
Call for inspections by the Health Agency as required, and Engineer if
specified.
7.
Where called for, on the plans, cover filters with insulation according
to manufacturer's specifications. Backfill with suitable materials (no
stones larger than 2 inches for longest dimension) in non-traffic areas to
achieve at least 8 inches of cover over the top of pipe (or as specified on
the drawings and per manufacturers specifications). In traffic areas
the minimum cover must be 16 inches of evenly graded structural sand/gravel
with appropriate road surfacing for intended loading or as specified by the
manufacturer. If installed under roads and parking in heavily traveled
commercial areas, the cross-section must also include one layer of reinforcing
fabric placed 8 inches above the top of pipe to at least 36 inches beyond
the extremities of the filters or as specified by the manufacturer.
All backfill materials shall contain no stones or particles larger than
2 inches for longest dimension.
It is imperative that no heavy equipment or vehicles are driven over the
filter areas in non-traffic areas and that no loading occurs for traffic
areas until the full depth of cover (with reinforcing fabric) is installed
and the backfill material compacted and stabilized.
Grade so that surface water does not collect over or near the installed
system, check to make sure Distribution Boxes are tightly covered to prevent
surface water from damaging the system. Seed and mulch for erosion
control.
8.
All filters are set level and are interconnected at the ends by pipe and
fittings as specified on the drawings. Connect the Living Filters
to septic tank or other chamber using pipe compliant with State and Local
Regulations. Ensure that slope of pipe entering the first filter has
a slope of at least 3/8 inch/lf within four feet of inlet. If inlet
pipe is laid at shallow depth (<12") insulate with at least 2' wide foam
insulation (minimum R-5) centered over the pipe. Although not required
by code, it is recommended that insulation be placed over all Pipe, Septic
Tanks and Pump Chambers to conserve heat that will aid in the treatment
of the effluent.
NOTE:
If the filters are installed under paved or otherwise impervious areas
a NITRAP™ filter vent pipe, placed alongside the bottom of the filter, will
be required along the portion of Living Filter covered by impervious surfacing.
The filter vent is brought to the surface using Sch.40 PVC of appropriate
diameter with a 180 elbow at top sufficiently placed above the ground surface
and max. snow height. The NITRAP filter vent pipe comprise a perforated
pipe covered by proprietary fibers. The effluent delivery conduit
present inside the Living Filters is vented through the Septic Tank and
Roof Vent as per code, only.
Manufacturers specifications are subject to change without
notice, to reflect changes in design, materials and other improvements
made to increase the performance of our products.
***
NOTE to Engineers, Designers and Installers: If Living Filter
products rated at over 10.2 sf/lf (effective leaching area) are to be used
to meet reserve area requirements, the plans, specifications and site must
be reviewed and approved by FORM CELL Research, Inc.
Effective leaching area ratings for all devices approved in Connecticut
© Copyright, All Rights Reserved, No Duplication,
Dissemination or distribution without permission, FORMCELL Research, Inc.,
Kjell E Berg, 1989-2005. All FORM CELL products
are proprietary, patented or patents pending, incorporate trade secrets, trade
marks and copyrights. FCR,LF installation manual, 1999-LF1210-LF3626, WP.CTmanual
FORM CELL and LIVING FILTER are
registered Trademarks in USA and Sweden. Copyright 1989-2006, All Rights Reserved,
FORM CELL Research, Inc., Kjell E. Berg. Patents
in the US and the European Union. Pat. Pend. in key countries.Licensing available.
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