U.S. patent application number 13/962995 was filed with the patent office on 2015-02-12 for underground bioretention systems.
The applicant listed for this patent is Zacharia Kent. Invention is credited to Zacharia Kent.
Application Number | 20150041379 13/962995 |
Document ID | / |
Family ID | 52447702 |
Filed Date | 2015-02-12 |
United States Patent
Application |
20150041379 |
Kind Code |
A1 |
Kent; Zacharia |
February 12, 2015 |
UNDERGROUND BIORETENTION SYSTEMS
Abstract
Embodiments of the present invention provide underground
bioretention systems that capture and treat surface water runoff.
Such underground bioretention systems have a chamber formed by a
chamber floor, a chamber ceiling, and at least one chamber wall; an
access opening in the chamber ceiling fitted with an access opening
cover; an influent opening in the chamber ceiling or the at least
one chamber wall; an effluent opening positioned in the chamber
floor or the at least one chamber wall beneath the influent
opening; a filtration media positioned in the chamber beneath the
influent opening; and an underdrain system positioned in proximity
with the chamber floor. Also in such bioretention systems, the
chamber floor, the chamber ceiling, and the at least one chamber
wall are comprised of a material and a design adapted to form the
chamber in a manner that withstands pressure applied thereon by
subterranean and ground surface materials.
Inventors: |
Kent; Zacharia; (Oceanside,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kent; Zacharia |
Oceanside |
CA |
US |
|
|
Family ID: |
52447702 |
Appl. No.: |
13/962995 |
Filed: |
August 9, 2013 |
Current U.S.
Class: |
210/170.03 |
Current CPC
Class: |
C02F 1/001 20130101;
Y02A 10/30 20180101; E03F 1/002 20130101; Y02W 10/15 20150501; C02F
2101/32 20130101; Y02W 10/10 20150501; E03F 5/16 20130101; Y02A
10/36 20180101; Y02W 10/18 20150501; Y02W 10/37 20150501; E03F
5/101 20130101; C02F 2103/001 20130101; C02F 3/04 20130101; C02F
3/327 20130101; E03F 5/0404 20130101 |
Class at
Publication: |
210/170.03 |
International
Class: |
E03F 1/00 20060101
E03F001/00 |
Claims
1. An underground bioretention system, to capture and treat
contaminated surface water runoff, comprising: a chamber formed by
a chamber floor, a chamber ceiling, and at least one chamber wall;
an access opening in the chamber ceiling fitted with an access
opening cover; an influent opening in the chamber ceiling or the at
least one chamber wall; an effluent opening positioned in the
chamber floor or the at least one chamber wall beneath the influent
opening; a filtration media positioned in the chamber beneath the
influent opening; and an underdrain system positioned in in
proximity with the chamber floor, and wherein the chamber floor,
the chamber ceiling, and the at least one chamber wall are
comprised of a material and a design adapted to form the chamber in
a manner that withstands pressure applied thereon by subterranean
and ground surface materials that surround the underground
bioretention system.
2. The underground bioretention system of claim 1, further
comprising live vegetation in the filtration media.
3. The underground bioretention system of claim 1, further
comprising a mulch above the filtration media.
4. The underground bioretention system of claim 1, further
comprising a rock backfill in proximity with the underdrain
system.
5. The underground bioretention system of claim 1, wherein the
filtration media is placed over a layer of matrix underdrain
structure.
6. The underground bioretention system of claim 1, further
comprising a plant establishment media in proximity with a surface
of the filtration media and live vegetation in the plant
establishment media.
7. The underground bioretention system of claim 1, further
comprising a splash guard positioned under the influent
opening.
8. The underground bioretention system of claim 1, further
comprising an inlet flow distributor and sedimentation chamber
positioned under the influent opening.
9. The underground bioretention system of claim 1, further
comprising a flow restrictor, and wherein the flow restrictor is
positioned in the underdrain system and operative to restrict a
flow of water passing through the bioretention system.
10. The underground bioretention system of claim 1, further
comprising weep holes in the chamber floor.
11. The underground bioretention system of claim 1, further
comprising a bypass riser.
12. The underground bioretention system of claim 1, wherein the
filtration media is at least one member selected from the group
consisting of an inert material and a cation exchange material.
13. The underground bioretention system of claim 2, further
comprising an irrigation system.
14. The underground bioretention system of claim 2, further
comprising an access riser and a reflective material mounted on an
inner surface of at least one of a wall of the access riser and the
at least one chamber wall, wherein the access opening cover is
adapted to allow natural light to enter the chamber.
15. The underground bioretention system of claim 2, further
comprising an artificial light operative to emit an amount of light
energy that promotes a growth of the live vegetation.
16. The underground bioretention system of claim 15, further
comprising at least one of a battery and a solar panel operative to
supply electrical power to the artificial light.
17. An underground bioretention system, to capture and treat
contaminated surface water runoff, comprising: a first chamber
formed by a first chamber floor, a first chamber ceiling, and at
least one first chamber wall; a second chamber formed by a second
chamber floor, a second chamber ceiling, and at least one second
chamber wall, wherein: at least one of the first chamber ceiling
and the second chamber ceiling further comprises an access opening
fitted with an access opening cover, at least one of the first
chamber ceiling or the at least one first chamber wall and the
second chamber ceiling or the second chamber wall further comprises
an influent opening, at least one of the first chamber floor or the
at least one first chamber wall and the second chamber floor or the
second chamber wall further comprises an effluent opening, the
second chamber comprises a filtration media in proximity with the
second chamber floor and an underdrain system in proximity with the
second chamber floor, the at least one first chamber wall further
comprises a first coupling opening and the at least one second
chamber wall further comprises a second coupling opening, the first
coupling opening and the second coupling opening are fitted
together in a manner that places the first chamber and the second
chamber in substantially leak-free fluid communication, the
influent opening and the effluent opening are not both positioned
in the first chamber or the second chamber, the first chamber
floor, the first chamber ceiling, and the at least one first
chamber wall are comprised of a material and a design adapted to
form the first chamber in a manner that withstands pressure applied
thereon by subterranean and ground surface materials that surround
the underground bioretention system, and the second chamber floor,
the second chamber ceiling, and the at least one second chamber
wall are comprised of a material and a design adapted to form of
the chamber in a manner that withstands pressure applied thereon by
subterranean and ground surface materials that surround the
underground bioretention system.
18. The underground bioretention system of claim 17, further
comprising live vegetation in the filtration media.
19. The underground bioretention system of claim 18, further
comprising an access riser and a reflective material mounted on an
inner surface of at least one of a wall of the access riser, the at
least one first chamber wall, and the at least one second chamber
wall, and wherein the access opening cover is adapted to allow
natural light to enter the chamber.
20. The underground bioretention system of claim 18, further
comprising an artificial light operative to emit an amount of light
energy that promotes a growth of the live vegetation.
21. The underground bioretention system of claim 18, further
comprising at least one of a battery and a solar panel operative to
supply electrical power to the artificial light.
Description
FIELD OF THE INVENTIONS
[0001] The present invention relates, in general, to water capture
and treatment systems and methods of using the same. More
particularly, the present invention relates to modular, underground
biofiltration systems for developments where a sub-optimal or
inadequate amount of surface area is available for biological
treatment of stormwater prior to discharge from the property.
BACKGROUND OF THE INVENTIONS
[0002] Water treatment systems have been in existence for many
years. These systems treat stormwater surface runoff or other
polluted water. Stormwater runoff is of concern for two main
reasons: i. volume and flow rate, and ii. pollution and
contamination. The volume and flow rate of stormwater runoff is a
concern because large volumes and high flow rates can cause erosion
and flooding. Pollution and contamination of stormwater runoff is a
concern because stormwater runoff flows into our rivers, streams,
lakes, wetlands, and/or oceans. Pollution and contamination carried
by stormwater runoff into such bodies of water can have significant
adverse effects on the health of ecosystems.
[0003] The Clean Water Act of 1972 enacted laws to improve water
infrastructure and quality. Sources of water pollution have been
divided into two categories: point source and non-point source.
Point sources include wastewater and industrial waste. Point
sources are readily identifiable, and direct measures can be taken
to mitigate them. Non-point sources are more difficult to identify.
Stormwater runoff is the major contributor to non-point source
pollution. Studies have revealed that contaminated stormwater
runoff is the leading cause of pollution to our waterways. As we
build houses, buildings, parking lots, roads, and other impervious
areas, we increase the amount of water that runs into our
stormwater drainage systems and eventually flows into rivers,
lakes, streams, wetlands, and/or oceans. As more land becomes
impervious, less rain seeps into the ground, resulting in less
groundwater recharge and higher velocity flows, which cause erosion
and increased pollution levels of watery environments.
[0004] Numerous sources introduce pollutants into stormwater
runoff. Sediments from hillsides and other natural areas exposed
during construction and other human activities are one source of
such pollutants. When land is stripped of vegetation, stormwater
runoff erodes the exposed land and carries it into storm drains.
Trash and other debris dropped on the ground are also carried into
storm drains by stormwater runoff. Another source of pollutants are
leaves and grass clippings from landscaping activities that
accumulate on hardscape areas and do not decompose back into the
ground, but flow into storm drains and collect in huge amounts in
lakes and streams. These organic substances leach out large amounts
of nutrients as they decompose and cause large algae blooms, which
deplete dissolved oxygen levels in marine environments and result
in expansive marine dead zones. Unnatural stormwater polluting
nutrients include nitrogen, phosphorus, and ammonia that come from
residential and agricultural fertilizers.
[0005] Another major concern are heavy metals, which come from
numerous sources and are harmful to fish, wildlife, and humans.
Many of our waterways are no longer safe for swimming or fishing
due to heavy metals introduced by stormwater runoff. Heavy metals
include zinc, copper, lead, mercury, cadmium and selenium. These
metals come from vehicle tires and brake pads, paints, galvanized
roofs and fences, industrial activities, mining, recycling centers,
etc. Hydrocarbons are also of concern and include include oils and
grease. These pollutants come from leaky vehicles and other heavy
equipment that use hydraulic fluid, brake fluid, diesel, gasoline,
motor oil, and other hydrocarbon based fluids. Bacteria and
pesticides are additional harmful pollutants carried into waterways
by stormwater runoff.
[0006] Over the last 20 years, the Environmental Protection Agency
(EPA) has been monitoring the pollutant concentrations in most
streams, rivers, and lakes in the United States. Over 50% of
waterways in the United States are impaired by one of more of the
above-mentioned pollutants. As part of the EPA Phase 1 and Phase 2
National Pollutant Discharge Elimination Systems, permitting
requirements intended to control industrial and non-industrial
development activities have been implemented. Phase 1 was initiated
in 1997 and Phase 2 was initiated in 2003. While there are many
requirements for these permits, the main requirements focus on
pollution source control, pollution control during construction,
and post construction pollution control. Post construction control
mandates that any new land development or redevelopment activities
incorporate methods and solutions that both control increased flows
of rain water off the site and decrease (filter out) the
concentration of pollutants off the site. These requirements are
commonly known as quantity and quality control. Another part of
these requirements is for existing publicly owned developed areas
to retrofit the existing drainage infrastructure with quality and
quantity control methods and technologies that decrease the amount
of rain water runoff and pollutant concentrations therein.
[0007] A major category of technologies used to meet these
requirements are referred to as structural best management
practices (BMPs). Structural BMPs include proprietary and
non-proprietary technologies designed to store and/or remove
pollutants from stormwater. Technologies such as detention ponds
and regional wetlands are used to control the volume of runoff
while providing some pollutant reduction capabilities. Over the
past 10 years, numerous technologies have been invented to
effectively store water underground, which frees up buildable land.
Various rain water runoff treatment technologies such as catch
basin filters, hydrodynamic separators, media filters are used to
remove pollutants. These technologies commonly work by using the
following processes: screening, separation, physical filtration,
and chemical filtration.
SUMMARY OF THE INVENTIONS
[0008] Bio-swales, infiltration trenches, and bioretention areas,
commonly known as low impact development (LID) have been
implemented to both control flow volumes and remove pollutants on a
micro level. LID technologies have also proven successful at
removing difficult pollutants such as bacteria, dissolved
nutrients, and metals because they provide not only physical and
chemical, but also biological filtration processes. They do so by
incorporating a living vegetation element that supports a microbial
community which assists in pollutant removal. Biological filtration
processes have proven excellent at removing many of the pollutants
that physical and chemical filtration systems alone cannot.
[0009] Conventional LID technologies, however, require substantial
amounts of space. For instance, a typical bioretention design takes
up approximately 4% of the buildable area of any construction
project. This space requirement translates into significant
reductions in the amounts of parking spaces, and therefore building
sizes that can be incorporated into construction projects. The
significant amounts of space taken up by conventional stormwater
biofiltration systems make it more expensive, and therefore less
feasible, to develop property.
[0010] Embodiments of the present invention provide underground
bioretention systems that capture and treat contaminated surface
water runoff. Such underground bioretention systems have a chamber
formed by a chamber floor, a chamber ceiling, and at least one
chamber wall; an access opening in the chamber ceiling fitted with
an access opening cover; an influent opening in the chamber ceiling
or the at least one chamber wall; an effluent opening positioned in
the chamber floor or the at least one chamber wall beneath the
influent opening; a filtration media positioned in the chamber
beneath the influent opening; and an underdrain system positioned
in proximity with the chamber floor. Also in such bioretention
systems, the chamber floor, the chamber ceiling, and the at least
one chamber wall are comprised of a material and a design adapted
to form the chamber in a manner that withstands pressure applied
thereon by subterranean and ground surface materials that surround
the underground bioretention system and that are at least one
material selected from the group consisting of a subterranean soil,
a subterranean rock, a ground surface pervious material, and a
ground surface impervious material.
[0011] In some embodiments, the underground bioretention system
further comprises live vegetation in the filtration media. In some
embodiments, the underground bioretention system further comprises
mulch above the filtration media. In some embodiments, the
underground bioretention system further comprises a rock backfill
in proximity with the underdrain system. In some embodiments, the
underground bioretention system further comprises a plant
establishment media in proximity with a surface of the filtration
media and live vegetation in the plant establishment media. In some
embodiments, the underground bioretention system further comprises
a splash guard positioned under the influent opening. In some
embodiments, the underground bioretention system further comprises
an inlet flow distributor and sedimentation chamber positioned
under the influent opening. In some embodiments, the underground
bioretention system further comprises a flow restrictor positioned
in the underdrain system contains and operative to restrict a flow
of water passing through the bioretention system. In some
embodiments, the underground bioretention further comprises weep
holes in the chamber floor. In some embodiments, the underground
bioretention further comprises a bypass riser. In some embodiments,
the underground bioretention system further comprises an irrigation
system. In some embodiments, the underground bioretention system
further comprises an access riser and a reflective material mounted
on an inner surface of at least one of a wall of the access riser
and the at least one chamber wall, wherein the access opening cover
is adapted to allow natural light to enter the chamber. In some
embodiments, the underground bioretention system further comprises
an artificial light operative to emit an amount of light energy
that promotes a growth of the live vegetation. In some embodiments,
the underground bioretention system further comprises at least one
of a battery and a solar panel operative to supply electrical power
to the artificial light.
[0012] In some embodiments, the underground bioretention filtration
media is placed over a layer of matrix underdrain structure. In
some embodiments, the filtration media is at least one member
selected from the group consisting of an inert material and a
cation exchange material. Some embodiments of the present invention
provide underground bioretention systems that capture and treat
contaminated surface water runoff. Such underground bioretention
systems have a first chamber formed by a first chamber floor, a
first chamber ceiling, and at least one first chamber wall and a
second chamber formed by a second chamber floor, a second chamber
ceiling, and at least one second chamber wall. In such bioretention
systems, at least one of the first chamber ceiling and the second
chamber ceiling further comprises an access opening fitted with an
access opening cover; at least one of the first chamber ceiling or
the at least one first chamber wall and the second chamber ceiling
or the second chamber wall further comprises an influent opening;
at least one of the first chamber floor or the at least one first
chamber wall and the second chamber floor or the second chamber
wall further comprises an effluent opening, the second chamber
comprises a filtration media in proximity with the second chamber
floor and an underdrain system in proximity with the second chamber
floor; and the at least one first chamber wall further comprises a
first coupling opening and the at least one second chamber wall
further comprises a second coupling opening, the first coupling
opening and the second coupling opening are fitted together in a
manner that places the first chamber and the second chamber in
substantially leak-free fluid communication, the influent opening
and the effluent opening are not both positioned in the first
chamber or the second chamber, the first chamber floor, the first
chamber ceiling, and the at least one first chamber wall are
comprised of a material and a design adapted to form the first
chamber in a manner that withstands pressure applied thereon by
subterranean and ground surface materials that surround the
underground bioretention system and that are at least one material
selected from the group consisting of a subterranean soil, a
subterranean rock, a ground surface pervious material, and a ground
surface impervious material, and the second chamber floor, the
second chamber ceiling, and the at least one second chamber wall
are comprised of a material and a design adapted to form of the
chamber in a manner that withstands pressure applied thereon by
subterranean and ground surface materials that surround the
underground bioretention system and that are at least one material
selected from the group consisting of a subterranean soil, a
subterranean rock, a ground surface pervious material, and a ground
surface impervious material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a side view of an underground bioretention system
according to the present invention equipped with a perforated pipe
underdrain system.
[0014] FIG. 2 is a side view of an underground bioretention system
according to the present invention equipped with a matrix
underdrain structure.
[0015] FIG. 3 is a side view of an underground bioretention system
according to the present invention equipped with a perforated pipe
underdrain system and weep holes.
[0016] FIG. 4 is side view of an underground bioretention system
according to the present invention equipped with a perforated pipe
underdrain system, a splash guard, and a vertical riser.
[0017] FIG. 5 is a side view of an underground bioretention system
according to the present invention equipped with a mulch layer, a
perforated pipe underdrain system, and rock backfill.
[0018] FIG. 6 is a side view of an underground bioretention system
according to the present invention equipped with a perforated pipe
underdrain system, a vertical riser, living vegetation, artificial
lights, and an irrigation system.
[0019] FIG. 7 is a side view of an underground bioretention system
according to the present invention equipped with a matrix
underdrain system, living vegetation planted in plant establishment
media, and natural light sources.
[0020] FIG. 8 is a side view of an underground bioretention system
according to the present invention equipped with a perforated pipe
underdrain system and a pre-treatment and even distribution
channel.
[0021] FIG. 9 is a side view of a multi-chamber underground
bioretention system according to the present invention equipped
with a perforated pipe underdrain system.
[0022] FIG. 10 is a side view of an underground bioretention system
according to the present invention equipped with a pre-treatment
chamber and a treatment chamber equipped with a perforated pipe
underdrain system, living vegetation, artificial lights, and a
solar panel that supplies electricity to the artificial lights.
DETAILED DESCRIPTION OF THE INVENTIONS
[0023] Referring to FIG. 1, an underground bioretention system 10
to capture and treat stormwater and contaminated runoff water is
shown. The system is designed to be utilized in urbanized or other
developed areas where the majority of land is impervious. The
system may be placed adjacent to any impervious area which
generates rain water runoff or runoff of other contaminated waters
from its surface. The system may also connect directly with
specific point sources of contaminated waters. With limited surface
area in most urban areas for biological filtration systems, the
system itself is placed underground. The underground placement of
bioretention system 10 provides surface area space that may be used
for new construction and/or expansion of buildings, parking lots,
roadways, etc. in urban areas.
[0024] At the center of the underground bioretention system 10 is
chamber 100. The chamber 100 has a floor 130, ceiling 110, and
walls 120. The modular design of bioretention systems according to
the present invention allows the system to scale to various sizes
and shapes. The chambers of bioretention systems according to the
present invention are generally square or rectangular in shape, but
they may be circular or triangular in shape as needed for
particular installation sites. Referring again to FIG. 1, the
chamber walls 120, floor 130, and ceiling 110 are made of material
that is impermeable to water; and their material and design must
withstand inside pressure from water running through and
accumulating in the chamber 100. Underground bioretention system 10
is structurally sound to withstand outside pressure from soil 230
on the sides and top, as well as paved surfaces 200. There is also
the additional pressure on top of underground bioretention system
10 from the weight of vehicular traffic 50. In some embodiments of
bioretention systems according to the present invention, the
chamber walls 120, floor 130, and ceiling 110 are made of strong,
durable, and water impermeable material including, but not limited
to, concrete, metal, plastic, and fiberglass. In some embodiments,
a ground surface above an installed underground bioretention system
comprises a water pervious material that is one or more of porous
asphalt, porous concrete, porous brick, porous tile, gravel, and
soil. In some embodiments, a ground surface above an installed an
underground bioretention system comprises a water impervious
material that is one or more of asphalt, concrete, brick, flagstone
and tile.
[0025] Referring again to FIG. 1, stormwater or other surface water
runoff enters the chamber 100 from the inflow pipe 300 and an
influent opening in chamber wall 120 receives inflow pipe 300. In
some embodiments, the walls and/or ceilings of a bioretention
system chamber have multiple influent openings. In some
embodiments, the ceiling of a bioretention system chambers has at
least one grated influent opening that allows water to flow into
the chamber but prevents people, vehicles, etc. from falling into
the chamber. In some embodiments, at least one influent opening in
a wall of an underground bioretention system chamber is covered by
a screening, grating, or netting that allows water and fine
sediments to flow into the chamber and impedes larger rocks and
other debris from entering the chamber.
[0026] Referring again to FIG. 1, water flows from the inflow pipe
300 down into the filtration media 600. The filtration media 600 is
the treatment mechanism of the underground bioretention system, and
provides the primary treatment of passing water. In some
embodiments, the filtration media comprises at least one inert
material such as sand and gravel and at least one cation exchange
material such as organic matter that includes, but is not limited
to, wood chips, compost, and peat moss. Such organic matter removes
dissolved metals and other pollutants by supporting chemical
reactions. Other particulate pollutants and hydrocarbons are
physically trapped between the inert and cation exchange material
within the filtration media 600. In some embodiments, the
filtration media comprises inorganic cation exchange media such as
zeolite, expanded aggregates, lava rock, oxide-coated inert
material, alumina, pumice, and other similar oxides. In some
embodiments, inorganic cation exchange materials may be preferred
over organics because they are less likely to leach nutrients such
as dissolved phosphorous or nitrogen, which have a negative effect
on the performance of the system. In some embodiments, the
filtration media may comprise 100% cation exchange media.
Filtration media layers in bioretention systems of the present
invention can be from a few inches to several feet thick.
[0027] Referring again to FIG. 1, after passing water is treated
through the filtration media 600, it enters the underdrain system
340. The underdrain system 340 is a perforated pipe laid
horizontally underneath the filtration media 600 and above the
chamber floor 130. The perforated pipe extends the length of the
chamber floor 130. Water that enters the underdrain system 340
exits out of the bioretention system 10. In some embodiments,
underdrain systems are formed from veins of large granular material
installed in the filtration media, from a panel separated from the
filtration media by netting, or a combination thereof. In some
embodiments, water that enters the underdrain system exits the
bioretention system through an effluent opening in a chamber wall
or floor.
[0028] Referring again to FIG. 1, there is an access opening cover
500 located in the ceiling 110 of underground bioretention system
10. The access opening cover 500 is designed to allow personnel to
enter the chamber 100 and perform any necessary maintenance or
monitoring. Access opening cover 500 is designed to prevent people,
animals, cars, and other large objects from falling into the
chamber 100 and is structurally strong enough to support the weight
of vehicular traffic. Access opening cover 500 is substantially
smooth and flush with the pervious surface 200 so that it does not
damage vehicular traffic 50. When placed underground, the
bioretention system 10 may be covered with soil 230 and a pervious
surface 200. Since there is a layer of soil 230 between the chamber
ceiling 110 and pervious surface 200, the underground bioretention
system 10 comprises access riser 530 between the chamber 100 and
the access opening cover 500.
[0029] In some embodiments, access opening covers comprise a solid
hatch that prevents water from entering into the chamber. In some
embodiments, access opening covers comprise a grate that prevents
pedestrians and vehicles from entering the chamber, but allows
stormwater or other surface water runoff to enter the chamber.
[0030] FIG. 2 illustrates an underground bioretention system 10
that differs from the bioretention system illustrated in FIG. 1 by
comprising an underdrain system 380 that is formed from a vein of
pervious matrix material in the filtration media 600. In the
bioretention system 10 illustrated in FIG. 2, the pervious matrix
material in the underdrain system 380 supports the weight of the
filtration media 600. In some embodiments, matrix underdrain
systems comprise a matrix material having at least 50% void space
to allow passing water that enters it to exit the underground
bioretention system 10.
[0031] FIG. 3 illustrates an underground bioretention system 10
that differs from the bioretention system illustrated in FIG. 1 by
further comprising weep holes 160 located in chamber floor 130 that
allow water to exit through the bottom of the underground
bioretention system 10 and infiltrate into the native soil below.
After treatment by the filtration media 600, passing water may
either enter into the underdrain system 340 and then exit
underground bioretention system 10 or enter into weep holes 160 and
then exit underground bioretention system 10.
[0032] FIG. 4 illustrates an underground bioretention system 10
that differs from the bioretention system illustrated in FIG. 1 by
further comprising a splash guard 640 and bypass riser 370. In the
underground bioretention system 10 illustrated in FIG. 4,
stormwater or other surface water runoff enters chamber 100 through
inflow pipe 300. Splash guard 640 is installed below inflow pipe
300 and on top of filtration media 600 such that it slows down high
velocity water entering the chamber 100 and thereby inhibits water
entering chamber 100 from removing or displacing filtration media
600. In some embodiments, splash guards are comprised of scour pads
and/or riprap. In some embodiments, a splash guard is placed below
an access opening that allows water to enter into the chamber.
[0033] Referring again to FIG. 4, the perforated pipe underdrain
system 340 contains, inside the perforated pipe, a flow restrictor
plate which has a smaller diameter than the perforated pipe and is
sized to control the flow of water out of the underdrain such that
passing water flows through the filtration media 600 at a slower
rate that remains substantially the same, even when the filtration
media 600 begins to clog with sediments and/or hydrocarbons. By
extending the amount of time passing water spends in filtration
media 600, the flow restricted perforated pipe underdrain system
340 enhances the contaminated water treatment performance of the
underground bioretention system 10.
[0034] Referring again to FIG. 4, the bypass riser 370 also
controls water levels in and flow through the chamber 100. The
bypass riser 370 connects to the perforated pipe of the underdrain
system 340, extends vertically above the filtration media 600, and
has an open top. Although the bypass riser 370 connects with the
restricted flow perforated pipe of the underdrain system 340,
bypass riser 370 is not flow restricted, but rather provides for
high water flow rates. Accordingly, during times that water flows
into the chamber 100 at rates that do not exceed the maximum water
flow rate through filtration media 600, passing water flows through
filtration media 600 and exits the biofiltration system 10 through
the perforated pipe underdrain system 340. During times that water
flows into the chamber 100 at rates that exceed the maximum water
flow rate through filtration media 600, water levels rise in
chamber 100. When water levels in chamber 100 rise above the level
of the open top of bypass riser 370 some passing water flows
through bypass riser 370 and out of the bioretention system 10,
thereby bypassing filtration media 600.
[0035] FIG. 5 illustrates an underground bioretention system 10
that differs from the bioretention system illustrated in FIG. 1 by
further comprising a layer of mulch 620 and rock backfill 610. In
the bioretention system 10 illustrated in FIG. 5, mulch 620
pre-treats water entering the chamber 100 prior to entering
filtration media 600. The mulch 620 in the bioretention system 10
is illustrated in FIG. 5 is laid on top of filtration media 600.
Mulch 620 captures and retains pollutants, while at the same time
preventing the pollutants from coming into contact with filtration
media 600, thereby reducing the rate at which pollutants clog
filtration media 600 and extending the time that can pass between
servicing underground bioretention filtration system 10.
[0036] The rock backfill 610 is placed directly under filtration
media 600 and placed evenly around the perforated pipe of the
underdrain system 340. So placed, rock backfill 610 enhances the
transfer of passing water from the filtration media 600 to the
perforated pipe of the underdrain system 340.
[0037] FIG. 6 illustrates an underground bioretention system 10
that differs from the bioretention system illustrated in FIG. 1 by
further comprising living vegetation 700, artificial lights 800,
and an irrigation system 720. Living vegetation 700 is planted and
grown in the filtration media 600. The roots of living vegetation
700 transfer oxygen into filtration media 600, promoting the
establishment of beneficial microorganism colonies that actively
aid in the break down of nutrients, hydrocarbons, and other harmful
pollutants in passing water. The roots of living vegetation 700
themselves can uptake some of the pollutants through the process of
bioaccumulation. The roots of living vegetation 700 can also
utilize nutrients for growth, thus reducing polluting nutrient
levels in passing water. Artificial lights 800 are installed in
chamber ceiling 130 to ensure living vegetation 700 survive,
sustain, and thrive. Artificial lights 800 provide necessary energy
to for living vegetation to perform photosynthesis in a
subterranean environment.
[0038] In some embodiments, living vegetation in underground
bioretention systems according to the invention are one or more of
plants, bacteria, and fungi. In some embodiments, artificial lights
are installed into chamber walls of bioretention systems according
to the present invention. In some embodiments, artificial lights
used in bioretention systems according to the present invention are
one or more of a florescent light, a high pressure sodium light, a
metal halide light, and a light emitting diode. Florescent lights
provide moderate amounts of light spectrum range and output to
support plant growth. High pressure sodium and metal halide provide
high amounts of light spectrum range and output appropriate for
plant growth. In recent years, an array of blue and red light
emitting diodes have been used to provide the same benefits of high
pressure sodium and metal halide lights; but with less power usage,
making them an environmentally and financially sound option. In
some embodiments, lights are available with ballasts that allow for
air venting with fans to remove excessive heat. In some
embodiments, such artificial light ballasts are waterproof to
provide an additional level of safety. Artificial lights used in
some embodiments of the present invention are powered by
electricity supplied by one or more of the grid, solar panels, or
batteries.
[0039] Referring again to FIG. 6, irrigation system 720 provides
water to living vegetation 700 at times when surface water runoff
is insufficient to support living vegetation 700. Irrigation system
720 is a drip system that is routed from outside underground
bioretention system 10 to the inside through side wall 120.
Irrigation system 720 has drip tubing that provides water to living
vegetation at a rate that is beneficial to living vegetation 700.
In some embodiments of underground bioretention systems of the
present invention, an underground cistern is located nearby that
holds water treated by the underground bioretention system and
stores it for irrigation. In some embodiments, irrigation systems
installed into bioretention systems are powered with electricity
supplied by one or more of the grid, solar panels, and
batteries.
[0040] FIG. 7 illustrates an underground bioretention system 10
that differs from the bioretention system illustrated in FIG. 2 by
further comprising plant propagation media 740, live vegetation
700, and riser 530 lined with reflective material 820. In the
bioretention system illustrated in FIG. 7, natural light 850 enters
the chamber 100 through grated access opening cover 500 and access
riser 530, which is lined with reflective material 820 to increase
the amount of natural light 850 that reaches living vegetation 700.
In some embodiments of bioretention systems of the invention that
use natural light to assist plant growth, one or more reflective
material(s) line one or more of the access riser walls and the
chamber walls. Examples of reflective materials include, but are
not limited to, glass, light colored paint, tin foil,
biaxially-oriented polyethylene terephthalate, plastic, or polished
materials.
[0041] FIG. 8 illustrates an underground bioretention system 10
differs from the bioretention system illustrated in FIG. 1 by
further comprising an inlet flow distributor and sedimentation
chamber 310. The inlet flow distributor and sedimentation chamber
310 is placed so that the top portion is just below the inflow pipe
300 and access opening cover 500. The inlet flow distributor and
sedimentation chamber 310 captures stormwater and other surface
water runoff that flows into the chamber 100, allowing sediments to
fall out as well as allowing water to distribute evenly into
filtration media 600. The inlet flow distributor and sedimentation
chamber 310 contains a vertical drain down riser 330 connected to
drain down line 320. The drain down line 320 extends into
filtration media 600 allowing water to enter the inlet flow
distributor and sedimentation chamber 310 to drain during periods
in which no water is entering the chamber 100. Water exits out of
the chamber 100 through the underdrain system 340. In some
embodiments of bioretention filtration systems of the present
invention, vertical drain down risers are wrapped in a filter
netting or fabric.
[0042] FIG. 9 illustrates an underground bioretention system 10
comprising two chambers 100 interconnected. Interconnected chambers
100 are joined by one or more holes or windows in side wall 120
where the chambers 100 meet.
[0043] FIG. 10, illustrates an underground bioretention system 10
comprising chamber 100 and pre-treatment chamber 180. Stormwater or
other surface runoff water enters into pre-storage chamber 180 from
inflow pipe 300. The pre-storage chamber 180 contains no filtration
media or living vegetation, but rather allows sediment to settle
out of passing water before it enters chamber 100. Passing water
transfers to chamber 100 with filtration media 600 and living
vegetation 700 when water levels in pre-treatment chamber 180 rise
above the height of bottom of the connecting hole or window in side
walls 120. Passing water that enters chamber 100 is treated by
living vegetation 700 and filtration media 600. From there, passing
water percolates into the perforated pipe of underdrain system 340
and exits the bioretention system 100. Artificial lights 800
powered by electricity supplied by an external solar panel system
900 provide light energy for living vegetation 700.
[0044] In some embodiments, underground bioretention structures are
built to handle site specific loading conditions. Surface loads
applied to underground bioretention systems vary based upon
pedestrian and vehicular traffic, and can be broken down into the
following categories. Parkway loading includes sidewalks and
similar areas that are adjacent to streets and other areas with
vehicular traffic. Indirect traffic loading includes areas that
encounter daily low speed traffic from vehicles ranging from small
cars up to semi-trucks. Direct traffic loading includes areas, such
as streets and other parkways, that encounter a high volume of high
speed traffic from vehicles ranging from small cars to large
semi-trucks. There is also heavy duty equipment loading that
includes traffic from, e.g., airplanes and heavy port equipment.
Accordingly, underground bioretention systems of the present
invention may be constructed having walls, floors, and/or ceilings
of various thicknesses and strengths (e.g., differing thicknesses
of concrete or steel or differing amounts of rebar) such that they
achieve a parkway load rating (e.g., a H5 load rating), an indirect
traffic load rating (e.g., a H20 load rating), a direct traffic
load rating (e.g., a H20 load rating), or a heavy duty equipment
load rating (e.g., a H25 load rating), as required for a given
installation site.
[0045] Although the disclosure has been provided in the context of
certain embodiments and examples, it will be understood by those
skilled in the art that the disclosure extends beyond the
specifically described embodiments to other alternative embodiments
and/or uses and obvious modifications and equivalents thereof.
Accordingly, the disclosure is not intended to be limited by the
specific disclosures of embodiments herein.
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