Transcript Stormwater Outlets - Stockton University

Stormwater Outlets
Effectiveness of the Options
Stormwater Outlets
• Several options are available, such as the
infiltration basins under the parking lots on
campus.
• Pollutants must be considered when dealing
with stormwater. The guidelines call for New
Jersey call for suspended solids to be reduced
by at least 80%, and for nutrient content to be
reduced by the maximum feasible amount.
• Rooftop runoff is considered “clean,” and can
therefore be dealt with through different
strategies that don’t remove pollutants.
Bioretention Cells
• Use native plants and organic
layers to filter stormwater as it
infiltrates into the ground.
• Native plants have the added
benefit of requiring less
maintenance and watering.
• A list of native plants can be
found at
http://www.georgian.edu/pineb
arrens/
• Can be easily added to
existing buildings.
• Cost efficient.
Total
Phosphorous
Removal Rate
(%)
Total Nitrogen
Removal Rate
(%)
Total Suspended
Solids Removal
Rate (%)
60
30
90
http://www.epa.gov/owow/nps/bioretention.pdf
Rain Gardens and Stockton
• Stockton is an ideal
environment to become a
leader in bioretention
research.
• The sandy soils in the
Pinelands facilitate quick
drainage.
• Relatively uniform
topography would help
keep construction costs
down, as well as provide
numerous areas to
perform research.
Raingarden in the Pinelands
http://www.icdc.com/~larsende/land.htm
Vegetative Filters
• Areas of vegetation
designed to remove
pollutants from runoff.
• Stormwater must enter
and flow through filter as
sheet flow for effective
removal capabilities.
• Design must incorporate
an evenly graded slope,
determined by both the
vegetation and soil type.
• Indigenous plants are
most effective.
Total
Phosphorous
Removal Rate
(%)
Total Nitrogen
Removal Rate
(%)
Total Suspended
Solids Removal
Rate (%)
30
30
60-80
Vegetative Cover
Adopted TSS Removal
Rate
Turf Grass
60
Native Grasses,
Meadow, And plated
Woods
70
Indigenous Woods
80
Constructed Stormwater Wetlands
Total
Phosphorous
Removal Rate
(%)
Total Nitrogen
Removal Rate
(%)
Total Suspended
Solids Removal
Rate (%)
50
30
90
http://www.thcahill.com/wetlands.html
• Designed to handle
runoff from areas
from 10 to 25 acres.
• Remove high
percentages of
pollutants.
• Provides new habitat
for wildlife.
• Not suitable in areas
of existing wetlands.
Infiltration Structures
Total
Phosphorous
Removal Rate
(%)
Total Nitrogen
Removal Rate
(%)
Total Suspended
Solids Removal
Rate (%)
60
50
80
http://clean-water.uwex.edu/plan/drbasins.htm
• Designed to allow stormwater to recharge groundwater
while removing pollutants.
• Must be designed to drain within 72 hours to prevent
water quality and mosquito problems.
• Should not be used in areas with high levels of
pollutants, to prevent contamination of groundwater.
Pervious Paving
• Used to decrease
runoff from paved
areas.
• Suitable for light duty
applications, such as
parking lots and
sidewalks.
• Can be used to
decrease demand on
other structural
systems.
http://www.psat.wa.gov/Publications/LID_studies/permeable_pavement.htm
Dry Wells
• Dry wells are
specialized infiltration
structures designed to
recharge groundwater
with clean roof runoff.
• They do not remove
pollutants, so they
cannot be used to
handle other
stormwater.
http://www.njstormwater.org/tier_A/pdf/NJ_SWBMP_9.3%20print.pdf
Green Roofs
• Vegetative cover on
roofs of buildings.
• Can reduce runoff by
up to 75%.
• Have the added
benefit of adding to
the heating and
cooling efficiency of
the building.
http://www.hrt.msu.edu/greenroof/WebSite%20Images/19%20%20ChicagoCityHallAerial%2062703.jpg