2. CHAPTER 26 CFR - WATER POLLUTION
PREVENTION AND CONTROL
SUBCHAPTER I - RESEARCH AND RELATED
PROGRAMS
•§ 1251. Congressional declaration of goals and policy.
(a) Restoration and maintenance of chemical, physical and
biological integrity of Nation's waters; national goals for
achievement of objective.
• Ecosystems Based
• Technology-forcing
• Comprehensive Research
• Total Maximum Daily Load
Low Impact Development Center 2007
5. Environmental Environmental
Interests Interests
$
$
Development Development
Interests Interests
$
New Rules!
Low Impact Development Center 2007
6. Low Impact Development
Major Components
1. Conservation (Watershed and Site Level )
2. Minimization (Site Level)
3. Strategic Timing (Watershed and Site Level)
4. Integrated Management Practices (Site Level)
Retain / Detain / Filter / Recharge / Use
5. Pollution Prevention
Traditional Approaches
Low Impact Development Center 2007
7. Key LID Principles “Volume”
and Water Balance
to Achieve Objectives
Unique Watershed Design
Match Initial Abstraction Volume
Mimic Water Balance
Uniform Distribution of Small-scale Controls
Cumulative Impacts of Multiple Systems
filter / detain / retain / use / recharge / evaporate
Decentralized / Disconnection
Multifunctional Multipurpose Landscape & Architecture
Pollution Prevention
Low Impact Development Center 2007
8. 1. Conservation Plans / Regulations
Local Watershed and Conservation Plans
Forest (Contiguous and Interior Habitat)
Large and Small Scale
Streams (Corridors)
Wetlands
Habitats
Step Slopes
Buffers
Critical Areas
Parks
Scenic Areas
Trails
Shorelines
Difficult Soils
Ag Lands
Minerals
Low Impact Development Center 2007
9. 2. Minimize Impacts
Low Im pact Design
Multifunctional Use
of Landscape and
Infrastructure
Minimize clearing
Minimize grading
Save A and B soils
Limit lot disturbance Decentralized
Controls
* Soil Amendments
Roofs
Parking Lots
Alternative Surfaces
Open Drainage
Rain Barrels
Open Space
Reforestation
Turf
Educational
Disconnect
components
Reduce pipes, curb and gutters
Reduce impervious surfaces
Low Impact Development Center 2007
10. 3. Maintain Time of Concentration
and Watershed Patterns
Open Drainage
Use green space
Flatten slopes
Disperse drainage
Lengthen flow paths
Save headwater areas
Vegetative swales
Maintain natural flow paths
Increase distance from streams
Maximize sheet flow
Low Impact Development Center 2007
11. 4. Storage, Detention & Filtration
“LID IMP’s”
Uniform Distribution at the Source
Open drainage swales
Rain Gardens / Bioretention
Smaller pipes and culverts
Small inlets
Depression storage
Infiltration
Rooftop storage
Pipe storage
Street storage
Rain Water Use
Soil Management**
Low Impact Development Center 2007
Emeryville and UCD
13. 5. Pollution Prevention
30 - 40% Reduction in N&P
Kettering Demonstration Project
Maintenance
Proper use, handling and disposal
Individuals
Lawn / car / hazardous wastes / reporting / recycling
Industry
Good house keeping / proper disposal / reuse / spills
Business
Alternative products / Product liability
Low Impact Development Center 2007
14. LID is Not
A land use or zoning control
An either this or that approach
Independent of watershed planning
“The” Answer
LID is
A Water Balance Approach to Hydrology
A science and unit process based approach
Decentralized and Integrated
Technology Driven
“The” Answer
Low Impact Development Center 2007
15. Stormwater
Drinking Water
LID is a Holistic
Integrated
Approach
Wastewater
Low Impact Development Center 2007
16. N2 AIR NH3
Where did it all start?
DENITRIFICATION
RAINFALL EVAPOTRANSPIRATION
ADSORPTION
PARTICULATES
LID
BIOLOGICAL FIXATION
PLANT MATERIALS
RUNOFF RUNOFF
Manual
VOLITILIZATION METALS,
NUTRIENTS
MULCH
SANDY SOIL MEDIUM AMMONIFICATION
Stormwater
NO3 NITROGEN FIXATION
Hydrology
NH4
Standards
DENITRIFICATION NO2
Manual
Manual
DRAIN
INFILTRATION RECHAR
GE
Landscaping Water
DPW Land
NITROGEN CYCLE FOR BIORETENTION
Conservation
Development
Manual
Manual
San Diego LID Manual
Village Homes
Low Impact Development Center 2007
23. Traditional Urban Sustainable Urban
Drainage Drainage
Water
Quality
Capacity
Capacity
Amenity
The Good Old Days!
Low Impact Development Center 2007
Stahre, 2006
24. Conventional - 70’s
70’s Flood Control
Approach Single Event
Risk based storms (2-
year, 10-year, 100-year)
Site Design and
Watershed use same
approach (HEC,
NRCS) for Common
Platform
Low Impact Development Center 2007
26. 80’s/90’s
70’s Flood Control Approach
Single event
Risk based storms (2-year,
10-year, 100-year)
Site Design and Watershed
use same approach (HEC,
NRCS) for Common
Platform
Bring in Efficiency and
P × Pj × × Rv
Loadings with %.
L= × C × A × 2.72
12
L = Load, P=Precipitation
Low Impact Development Center 2007
27. Today
Moving towards Tributary
Strategies
Loadings and Limits (303d)
Site Design Models don’t link
to Watershed Models
Rapid Assessments that may
have significant data or
science gaps
Costs and Predictability
unknown
Low Impact Development Center 2007
28. THE Difference
Q = CIA
∫ C (t )Q(t )dt
C=
∫ Q(t )dt
Is this state-of-the-art?
Low Impact Development Center 2007
31. Effective Work Index (W)
Range of
Geomorphically
Significant flows
Stream Flow
τc τbi
Characteristics of
Bed and Bank
Materials
τc 1.5
n
∑ (τ − τ c) ⋅ ∆ t
W= bi
Normal Dry
i= 1
Weather Flow
Level
Low Impact Development Center 2007
Geosyntec
32. Smart Growth/LID Hydrology
Are the Metrics and Protocols Right?
Control Runoff at Microwatershed Level
Consider Hydrologic Process in Microwatershed
Layout
Maintain First Order Receiving Streams
Maintain Vegetated Buffer Zones
Control Spatial Pattern of Hydrologic Storage
Control Upland Flow Velocities
Control Temporal Characteristics of Runoff
McQuen, 2004 Low Impact Development Center 2007
36. Land Use Change is a
better indicator!
Low Impact Development Center 2007
37. Issues
Where is a watershed with less than 10%
imperviousness?
Methods
Scale and location in watershed (avoid
headwaters)
Cumulative effects
Moglen, 2007
Low Impact Development Center 2007
49. B-IBI w/BMPs B-IBI w/o BMPs
45
40
35
30
B-IBI Score
25
20
15
10
5
0
0 10 20 30 40 50 60 70
Watershed Urbanization (%TIA)
Figure 2: Showing the lack of mitigating influence of structural
BMPs on biologic conditions in Puget Sound lowland streams
(Horner and May, 2000). Note, “w/BMPs” refers to structural
facilities only. [Honer / May 2001]
Low Impact Development Center 2007
50. Figure 1. Comparison of Habitat Condition and
Montgomery County,
Biological Condition for Sites With and Without SWM
MD
Habitat Condition vs Biological Condition
Both of the datasets
Test Sites (With Stormwater Controls)
y=20.896*exp( 0.011*x)+eps
100
plot mainly below the
90
T08
line (Figure 1). Almost
80
(As % of Best Possible Score)
T01
Biological Condition
70
T06
RE2
all test sites do, and
60
DS3
T05 T07
DS2 T12DS1 RE4
T02
RE1
T04
T15
50
T10
while 6-7 of the
T14 T18
T03 T13
40
T16 T17 T09
T19 T11 T20
30
control sites plot
20
0 10 20 30 40 50 60 70 80 90 100
Habitat Condition (as per cent of Best Possible Score)
along the line, the
remainder plot below
Habitat Condition vs Biological Condition
Control Sites (Without Stormwater Controls)
y=17.126*exp( 0.016*x)+eps
the line.
100
90
Stream embedding
C04
C01
80
(As % of Best Possible Score)
C02
70
Biological Condition
Riffle areas
C05 C03
C07
60
C13
C06 C09
Flow regime
50
C18
C15
C14 C11
C12 C16 C20 C08
C17
40
C19
30
20
WMI
0 10 20 30 40 50 60 70 80 90 100
Low Impact Development Center 2007
Habitat Condition(as per cent of Best Possible Score)
59. Cost/Effectiveness
A bioretention pond costs
$2,000 to construct for a ½ site.
So it costs $4,000 per acre.
MC = c IJ + mIJ Q
* RJ
2
Low Impact Development Center 2007
62. Ecological Integrity
New Objectives
Protection
Species – Fauna / Flora
Structure – Spatial / Temp / Distribution
Processes – Cycling (Energy / Materials /
Nutrients)
Ecological Factors
• Hydrology / Hydraulics
• Habitat Structure
• Water Quality
• Energy Sources
Small Stream and Living
• Biotic Interactions
Resource Protection Impact Development Center 2007
Low
63. General Assumptions!
For the foreseeable future, urbanization will continue
mostly in the same patterns as today.
We don’t know exactly how much stress aquatic
ecosystems can sustain before they crash.
Where aquatic ecosystems are stressed terrestrial
ecosystems are dysfunctional.
Impact reduction strategies will most likely ensure
ongoing degradation of the ecological health due to
cumulative impacts.
There are no thresholds for acceptable levels of
stressors. Impacts to the ecological integrity occur
whenever ecological functions are altered or stressors
are added. Low Impact Development Center 2007
64. General Assumptions!
Our environmental technological challenge is
to integrate development into the ecosystem
as best we can in a manner that developed
areas remain a vital part of the ecosystem
instead of apart from it.
If growth and development continue
unabated, at best, technology can only delay
the onset of negative consequences.
Low Impact Development Center 2007
65. Paradigm Shifts
Watersheds to Ecosystems
Flow Centric to Volume Centric
Centralized Control to Decentralized Control
Uni-functional to Multifunctional
Impact Reduction to Functional Restoration
Good Drainage to Functional Drainage
One Size Fits All to Unique Design
Unsustainable to Sustainable
Low Impact Development Center 2007
66. Important Concepts
Terrestrial / aquatic ecosystem linkages
Ecosystem functions
Using nature to mitigate its own forces
Mimic the water balance
Hydrology as an organizing principle
Multiple systems
Volume / Frequency / Timing
Ecological functions of the built environment
Low Impact Development Center 2007
67. Conventional
Development
Centralized
Pipe and Pond
Control
Low Impact Development Center 2007
68. Multiple Systems
LID Development
Conservation
Minimization
Soil Amendments
Open Drainage
Rain Gardens
Rain Barrels
Pollution Prevention
Disconnected
Decentralized
Distributed
Multi-functional
Water Use
Low Impact Development Center 2007
72. Quantifiable Costs and Benefits
$4
1.5
$2
1.5 1.5
$0 -0.1 -0.2
-0.4
(in $ millions)
Project Cost
-$2
-4.6 O&M
Savings from Loan
-$4
Increase Home Value
-8.9
-$6
-$8
-$10
Do Nothing Option 2 & 3 Traditional
Low Impact Development Center 2007
73. Green Highways
Watershed Driven Stormwater
Recyclables and Reuse
Ecosystems and Conservation
Low Impact Development Center 2007
76. EMS/Performance Based Approach
Protect Environmental Legacy
Save Costs/Reduce Consumption
Ease Regulatory Burden
Improve Review Cycles
Low Impact Development Center 2007
77. GHP/Stormwater EMS Roadmap
1. Identify environmental
issue(s) and/or
opportunity(ies) to be 11. Managers/senior
management. Review
addressed by EMS.
progress, identify
adjustments, and confirm
2. Identify desired commitments.
environmental and
business results and
APPROVAL – benefits. 10B. PERIODIC 10A. PROJECT
Management
REVIEW REVIEW
provides
Brief management on Assess EMS
feedback to 3. Establish objectives, status in meeting project
finalize issues, quantifiable measures and objectives and targets. performance.
opportunities, targets, and associated
and expected milestones.
results. 9. Identify EMS-related
training needs,
responsibilities and
4. Obtain management
schedule. Conduct the
commitment to EMS,
training.
characterize EMS resource
needs, and identify EMS
leaders.
8. Identify personnel (by
title) affected by EMS,
define responsibilities, and
5. Identify existing
communicate
initiatives, programs,
responsibilities.
procedures, processes,
and tools relevant to the
EMS.
7. Assign responsibility for
developing enhanced or
6. Identify improvements to new procedures,
achieve EMS objectives processes, and tools.
PLAN DO CHECK ACT
LEGEND:
Low Impact Development Center 2007
78. Green Infrastructure
rs
opportunitiesive
are
R
everywhere
to s
p
to
f
o
LID tools facilitate the development of
o
green infrastructure
R
Transportation corridors provide linking
elements in a green infrastructure network
Low Impact Development Center 2007
79. It is a system of hubs and links
that provides measurable
benefits
..The term green infrastructure
emphasizes interconnected systems of
natural areas and other open spaces that
are protected and managed for the
ecological benefits that they provide to the
people and the environment.”
Low Impact Development Center 2007
80. Links and Hubs
An organizing form idea for planning green
infrastructure
Creates an interdependent network of
green
Fits a watershed model of planning
Can be implemented and maintained in
sections
Is an opportunity for public-private
partnerships
Low Impact Development Center 2007
82. Historic Construct of
Stormwater Regulations
The majority regulate the peak flow rate of stormwater
discharges.
Do not sufficiently address hydrologic modifications
and the impacts on receiving water quality – do not
address increased volume of stormwater generated by
development.
Perpetuate the use of conventional end-of-pipe BMPs –
the use of which have not demonstrated significant
water quality improvements.
Fail to consider watershed criteria.
Low Impact Development Center 2007
83. Examples of robust LID Programs
Portland, Oregon
Photos courtesy of the Portland Bureau of Environmental Services.
Low Impact Development Center 2007
84. Portland, Oregon (cont.)
Photos courtesy of the Portland Bureau of Environmental Services.
Low Impact Development Center 2007
86. Vancouver, British Columbia
Photos courtesy of City of Vancouver Greenways Program.
Low Impact Development Center 2007
87. Vancouver, British Columbia (cont.)
Photos courtesy of City of Vancouver Greenways Program.
Low Impact Development Center 2007
88. What Motivated the Use of
New Approaches?
Portland’s innovative approaches to stormwater
management are necessitated by the need to satisfy a
CSO consent decree, SDWA requirements, impending
TMDL limitations, and Superfund cleanup measures.
Stormwater runoff from Seattle and Vancouver
discharges to receiving waters with salmon populations.
Low Impact Development Center 2007
89. Conclusions
Regulatory and environmental drivers create an
incentive for using new stormwater management
approaches.
When faced with certain and defined performance
criteria, source control and biological treatment of
stormwater emerges as a preferred treatment option.
How are jurisdictions developing regulations that spur
more wide-spread use of innovative stormwater
management?
Low Impact Development Center 2007
90. How are jurisdictions
developing regulations that
spur more wide-spread use
of innovative stormwater
management?
Low Impact Development Center 2007
91. Anne Arundel County, MD
Counties are permitted to establish more stringent
requirements than those required by the Maryland
Stormwater Manual.
AA County stipulates “The use of nonstructural
stormwater management practices shall be implemented
to the maximum extent practicable for satisfying the
recharge volume requirement prior to the use of
structural stormwater management practices to more
closely mimic the predevelopment hydrology and to
discourage the reliance on structural BMPs.”
Low Impact Development Center 2007
92. Effects of AA County Standard
Low Impact Development Center 2007
93. Maryland Stormwater Management
Act of 2007
Passed by the General Assembly in April and
signed into law by the Governor.
Requires the implementation of environmental
site design to the maximum extent practicable
and review and modification of ordinances to
remove impediments to ESD.
Developers must demonstrate that ESD has
been optimized on new development sites
before using conventional BMPs.
Low Impact Development Center 2007
94. New Jersey Stormwater Regulations
Groundwater recharge requirement:
Require that 100% of pre-development average annual
groundwater recharge volume for the site is maintained post-
development, OR
That the post-development increase in stormwater runoff for
the 2-year storm is infiltrated.
Water quality requirement:
80% removal of TSS and reduction of nutrients to the
maximum extent feasible, with an emphasis on non-structural
practices.
Low Impact Development Center 2007
95. New Jersey Stormwater
Regulations (cont.)
Runoff quantity requirement:
Require that post-development runoff hydrographs for
the 2, 10, and 100-year storm do not exceed, at any point
in time, the predevelopment hydrographs, OR
Demonstrate that there is no increase in peak runoff
rates for the 2, 10, and 100-year storm events and that
the increased volume and change of timing does not
have downstream impacts, OR
Demonstrate that post-development peak runoff rates
for the 2, 10, and 100-year storm events are 50, 75, and
80%, respectively, of pre-development runoff rates.
Low Impact Development Center 2007
96. Portland Stormwater Regulations
City code requires on-site stormwater management for
new development and redevelopment (i.e., retention
and infiltration).
For other properties, stormwater must be retained or
infiltrated to the maximum extent practicable before
off-site discharge is allowed.
Required 70% removal of TSS and treatment for
pollutants with TMDL limitations in receiving stream.
Low Impact Development Center 2007
97. Washington, DC
Anacostia River Redevelopment
The AWC is responsible for
revitalization of lands along
the river and coordinating
environmental and
programming initiatives that
promote river clean up.
One-inch, on-site retention
standard and water quality
treatment for up to the 2-year
storm for new development
and re-development.
Stated preference for
vegetated controls.
Adopted by AWC board June
1st.
Low Impact Development Center 2007
98. Seattle Green Factor
Requires 30% of a parcel in the Neighborhood Commercial
Zone to be vegetated or the functional equivalent as
determined by the Green Factor.
For example, the Green Factor for green roofs is 0.7,
permeable paving is 0.6, and lawn is 0.2. Bonuses provided
for rainwater harvesting or planting low water-use
vegetation.
Encourages the planting of layers of vegetation on the
property and in public right-of-ways adjacent to the
property.
In effect as of January 2007.
Low Impact Development Center 2007
99. Recommendations for Regulations
Incorporate volume and hydrologic performance
requirements into regulations.
Create regulatory certainty.
Provide incentives for developers that use LID (e.g.,
streamline review process or move stormwater plans to
the top of the stack).
Maryland offers six different stormwater credits for
green practices.
Low Impact Development Center 2007
100. Incentives for LID Outside of
Regulatory Structure
Chicago and Portland offer density and building square
footage bonuses, respectively, for buildings with green
roofs.
Offer discounts for stormwater or other utility fees for
on-site or LID management practices – full-cost pricing
is critical.
Subsidized downspout disconnection programs.
In January 2006, Chicago provided 20 $5,000 grants for
residential and small-scale commercial green roofs and
received 123 applications.
Low Impact Development Center 2007
102. Coyote Creek Green
Infrastructure Principles
Start upstream
Connect the Dots
Use Nature as a Guide
All Fronts/No backs
Manage for the Long Term
Multiple Objectives
Low Impact Development Center 2007