Transcript Why are we here today? - University of South Carolina

Why are we here today?
• To discuss the challenges we face in meeting
NPDES Phase II minimum requirements for
stormwater control.
• The NPDES program requires permits for the
discharge of "pollutants'' from any "point source''
into "waters of the United States.''
• Point sources include stormwater.
• Permitted discharge includes management and
regulatory programs, appropriate “treatment”
methods, planning, financing, long term
maintenance, life cycle analysis, minimizing offsite (downstream) impacts, etc.
Post-construction stormwater
management
(i) You must develop, implement, and enforce a program to address
stormwater runoff from new development and redevelopment projects
that disturb greater than or equal to one acre, including projects less
than one acre that are part of a larger common plan of development or
sale, that discharge into your small MS4. Your program must ensure that
controls are in place that would prevent or minimize water quality
impacts.
(ii) You must:
• (A) Develop and implement strategies which include a combination of
structural and/or non-structural best management practices (BMPs)
appropriate for your community;
• (B) Use an ordinance or other regulatory mechanism to address postconstruction runoff from new development and redevelopment projects
to the extent allowable under State, Tribal, or local law; and
• (C) Ensure adequate long-term operation and maintenance of BMPs.
EPA Model Ordinance Language
• The purpose of this ordinance is to establish minimum stormwater
management requirements and controls to protect and safeguard…
through the following objectives:
– minimize increases in stormwater runoff from any development in
order to reduce flooding, siltation, increases in stream temperature,
and streambank erosion and maintain the integrity of stream
channels;
– minimize increases in nonpoint source pollution caused by
stormwater runoff from development which would otherwise degrade
local water quality
– minimize the total annual volume of surface water runoff which flows
from any specific site during and following development to not exceed
the pre-development hydrologic regime to the maximum extent
practicable.
– reduce stormwater runoff rates and volumes, soil erosion and
nonpoint source pollution, wherever possible, through stormwater
management controls and ensure these management controls are
properly maintained and pose no threat to public safety.
• Innovative BMPs for Site Plans
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Alternatived Pavers and Turnarounds
Conservation Easements
Development Districts
Eliminating Curbs and Gutters
Green Parking
Green Roofs
Intrastructure Planning
Low Impact Development (LID)
Narrower Residential Streets
Open Space Design
Protection of Natural Features
Redevelopment
Riparian/Forested Buffers
Street Design and Patterns
Urban Forest
• Infiltration
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Grassed Swales
Infiltration Basin
Infiltration Trench
Porous Pavement
• Filtration
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Bioretention and Rain Gardens
Catch Basin Inserts
Sand and Organic Filters
Vegetated Filter Strip
• Retention/Detention
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Dry Detention Ponds
In-line Storage
On-lot Treatment
Stormwater Wetland
Wet Ponds
• Other
– Alum Injection
– Manufactured Products for Stormwater Inlets