Stormwater Regulation

801 South Caroline Street | Baltimore, MD 21231
443.224.1824 | ader@wrallp.com
Presentation for Lorman Educational Services
in Annapolis, MD
June 12, 2012

STORMWATER
EFFECTS ON WATER
QUALITY AND THE
ENVIRONMENT

Four Categories of Effects
• Hydrology
• Geomorphology
• Habitat
• Water Quality

Hydrology
• Increase in flow and
velocities
• Increase in flooding
• Increase in frequency
• Increase in bankfull flows

Geomorphology
• Stream Widening
• Channel Instability
• Erosion

Habitat
• Fish Barriers
• Loss of Substrate
• Loss of Riparian Zone
• Loss of
Micro-topography

Water Quality
• Sediments
Channel erosion can be the
primary sediment source!
• Nutrients
Maintained vegetated areas
• Temperature
Warm pavements and
pond pools
• Other
Oils, Greases, heavy metals,
toxics

Regulations and
Permitting Overview

What is a Stream?
• Waters of the U. S.
• Definition includes tidal navigable water, nontidal
navigable water and adjacent headwaters and
wetlands adjacent to such waters – but how far
up does it go?
• Determines extent of Sec 401 (Water Quality
Certification), 402 (NPDES) and 404 (Dredge
and Fill) components of the Clean Water Act.

What is an impact?
• Impacts are discharges or grading
• Discharges can be out of a pipe or placement
of material (CWA Sec 402 & 404)
• Discharges can be permitted
• Individual Permits or General Permits

Types of Stormwater Permitting
• NPDES Phase I and II – U. S. EPA delegated to States by GP – regulates
new construction AND existing older stormwater sources – passes
through localities – only permit means to retrofit
• New DoD and federal facility SWM mandates
• State/local Stormwater Management Regulations – new construction
• State/local Erosion and Sediment Control Regulations – new construction
• Other (Wetlands, Flood Plain, etc.)
• Both Individual & General NPDES permitting - Most new construction
under GP

NPDES Phase I &II Permitting
• 1972 amendments to the Federal Water Pollution
Control Act (Clean Water Act) prohibit the discharge
of any pollutant to waters of the United States from a
point source unless the discharge is authorized by a
National Pollutant Discharge Elimination System
(NPDES) permit.
• Past efforts to address stormwater discharges under
the NPDES program have generally been limited to
certain industrial categories

Background
• Stormwater out of a pipe was not necessarily a
point source discharge
• National Urban Runoff Program (NURP) – first
meaningful stormwater study showed stormwater
impacts
• In response to water quality concerns, in 1987,
the EPA was required to issue regulations
addressing stormwater discharges under the
NPDES program

Phase I
• NPDES established first regulations in 1990 permit
requirements for:
1) existing “medium” and “large” municipal separate storm
sewer systems (MS4) – individual permits by State to locality
with conditions
2) new construction activity disturbing 5 acres of land or greater
– general permits
3) certain industrial activities
• Many continue to operate under Phase I

MDE Phase I Permit
Conditions
• ID legal authority and data sources
• Assess existing programs
• Watershed Management and
Restoration (often needs its own
construction controls and 404 and
state wetland permit!)
• Utilize current collected best
management practice (BMP) data
to modify and improve programs
• Fiscal Analysis

Phase II
• In 1999, new rule automatically covers on a nationwide
basis all existing small MS4s located in urbanized areas
and new construction activities of 1 acre or more
• Most localities already complying
• Can authorize industries or facilities
• Have more flexible permitting options
GP including the NOI process
Utilizing existing programs in place
Combine with other Phase II
Combine with a Phase I

Six Requirements of
Phase II
• Personnel education/outreach
• Public involvement/participation
• Illicit discharge detection elimination
• Construction site stormwater runoff control
(E/S)
• Post construction stormwater management
• Pollution prevention/good housekeeping

Phase II Can be Subjective
• Monitoring, public outreach and BMPs can be flexible as long as:
– Reduces pollutants to the maximum extent practical
– Protects water quality
– Satisfies CWA
– Many existing SWM programs are satisfactory
– Montgomery County & Washington DC will be templates

How Does NPDES Affect
Construction Activities?
• Compliance with NPDES Stormwater permits is
primarily through BMP implementation
• E/S and SWM plans are not the same as NPDES
compliance – but can usually serve as compliance
with NPDES requirements
• However, a good E/S and SWM plan alone does not
necessarily assure compliance with all NPDES criteria

To comply with NPDES Maryland General Permit (GP) requirements,
Submit Notice of Intent to MDE if 1 acre or more of disturbance
New GP criteria
• Permittees no longer can start work at moment of
NOI submission
• MDE needs notice that SWM and E/S plan approved
• New submission forms

New GP criteria - continued
• Individual discharge permits for construction disturbing 150 acres or more – GP lost
• Individual permits required for construction disturbing between 30 and 150 acres that
discharge to waters impaired by pollutants if MDE receives a timely objection to NOI
that credibly supports technical standards included under the GP are not sufficient to
ensure the protection of water quality standards
• Identify whether the receiving waters are listed on the 303(d) list as impaired for
sediment
• MDE posts project for 45-day public notice for sites 3 acres or more disturbed area or a
30-day period for sites with 1 to less than 3 acres disturbed area

• MDE will not approve coverage under GP until PN ends and applicant notifies
that E/S plan approved – work can’t begin until SWM plan approved
• PN process may result in IP
• Include written explanation how ESD and sensitive construction techniques used
for waters with an established Total Maximum Daily Load (TMDL)
• If significant sediment discharge occurs, required to inspect, evaluate and repair
or install all site controls - if second event occurs, required to have engineer
evaluate if E/S plan needs additional on-site practices or modifications

• Permittee must select, install, implement and maintain control measures at site
that minimize pollutants in the discharge as necessary to meet applicable water
quality standard
• If MDE determines discharges may cause “an excursion” above any applicable
water quality standard, required to modify controls to indicate receiving water is
attaining water quality standards
• Conduct weekly inspections and the next day (changed from next business day
last year) after a rainfall event resulting in runoff
• Must implement measures to ensure discharges from the site meets
requirements of TMDL
• Potential for flocculent or turbidity controls?

• 1 to 3 acres of disturbance = submit for coverage with minimum 30-day public
comment and local E/S coordination
• 3 to 5 acres of disturbance = submit for coverage with minimum 45-day public
comment and local E/S coordination
• 5 to 10 acres of disturbance = as above but potential requirement for passive
chemical treatment
• 10 to 20 acres of disturbance = as above but potential for active chemical
treatment
• 20 to 150 acres of disturbance = was to comply with 280 NTU turbidity
• Over 150 acres of disturbance = does not qualify for NPDES GP and individual
permit is required (similar to industrial discharge permit in terms of processing)

• Compliance is reflected in a Stormwater Pollution Prevention
Plan (SWPPP) – what is it and when is one required?
- Includes E/S and SWM plans (structural) but also
includes ESD and nonstructural: other pollutant
management considerations (spillage, storage, litter),
monitoring records
- In MD, not typically required under general permit
• Potential vs. Actual Discharges – treated the same?!

State & Local SWM
Concurrently along with new NPDES compliance, need to comply with
following regulations
• State Erosion and Sediment Control Law
• State Stormwater Management Law
Incorporates SWM Manual by reference - Revised by 2007
Maryland Stormwater Management Act – Effective May 2009
Formalizes “LID-like” or Environmental Site Design to “Maximum
Extent Practicable” - MEP is met if channel stability and
predevelopment groundwater recharge rates are maintained and
nonpoint source pollution is minimized…. structural stormwater
practices may be used only if determined to be absolutely
necessary

State & Local SWM
State Stormwater Management Law - continued
• Applies via approved local ordinance to all new and
redevelopment projects that have not received final
approval for erosion and sediment control and
stormwater management plans by May 4, 2010
• Primary MEP standard is to use ESD to reduce post
development runoff to levels found in natural,
forested conditions – need to treat 1 to 2.6 in rainfall
depending on site and design conditions
> 5,000 s.f. disturbance

Waters Disturbance Triggers - Indirect
• Both MDE permit processes incorporate CWA Section 401 Water
Quality Certification Requirements required when 404 Corps permit
required
Numeric and Narrative Water Quality Standards are basis for
sensitive waters requirements
• Numeric - DO, Temp, pH, Turbidity, fecal coliform, toxics
• Narrative – basis of more stringent controls
Protection of aquatic life...fishable…swimmable…includes EPA
Anti-degradation policy:
“…To accomplish the objective of maintaining existing
water quality…Nonpoint sources shall achieve all cost
effective and reasonable best management practices for
nonpoint source control…”

Waters Disturbance Triggers –
less common
• CWA Section 404 dredge and fill permit
- U. S. Army Corps of Engineers – Waters of the U. S.
including wetlands (MDE joint process if < 1 acre) up to
ephemeral
• Nontidal Wetland and Waterways Permit
- MDE – State waters up to intermittent including
wetlands and 100-year flood plain
- Has special NTW E/S BMP Conditions
• Tidal Wetlands License/Permit
- MDE – State waters including wetlands

Other Criteria
• Coastal Zone Management Act
• Chesapeake Bay Critical Area Law
Administered through local zoning and subdivision
ordinances for overlay 1,000 feet from shoreline
100-foot Buffer is the most restricted
10% SWM rule in Intensely Developed Areas
• State Forest Conservation Law
Delegated to localities
Requires NRI or FSD which could be first SWM concept
under new regulations
Silt fences frequently double as tree save fence

Even More Water Quality
Initiatives in Progress!
• Chesapeake Bay
TMDL for N & P
• Largest most
complex TMDL in the
country, covering the
64,000 s. m.
watershed in six
states & DC =
Watershed
Implementation Plans
(WIP) in progress
now

Issues under Deliberation
• What should be most
sound priorities of
focus? From CBF,
percent nutrient
contribution – some
variations in data but
current is:
• ESD (and LID) versus
Smart Growth versus
impervious surface
criteria?
• TMDL models
challenged by PA
Farming & NAHB

Construction Compliance
• Usually oriented to E/S compliance
• Locality inspects for E/S, FC and Critical Area
• MDE (and occasionally EPA) inspect for NPDES, E/S
and Wetland and Waterways Permit (and mining
compliance)
• Corps inspects for Wetland and Waterways Permit

Newer Compliance
Requirements
• Usually oriented to post-construction assessment
• Third party quality control construction monitoring
• Specific SWM device maintenance conditions
• Post-construction BMP performance can be required

• Used also for MS4
Compliance
• Can be MDE requirement
• Preconstruction,
construction and post-
construction
• Macroinvertebrate Studies
(from WWTP & mining)
• Chemistry
• Geomorphology
• Groundwater
Post-Construction BMP and Water
Quality Monitoring

For Construction Activities -
Remember!
• Have most current approved plans on site during construction
• Diligence over perfection – develop a good relationship with regulatory
agencies
• Any E/S modifications made after permitting may potentially have other
regulated impacts.
• Any temporary material storage, staging or heavy equipment in or near
flood plain, streams, wetlands, buffers, forest, specimen tree may
potentially be a regulated impact
• Document all E/S plan changes, rectification measures and spill control
measures in log book

Types of Designs for
Storm Water Control

What is a Best Management
Practice (BMP)?
Best Management Practices (BMPs) are policies, practices, procedures, or
structures implemented to mitigate the adverse environmental effects on
surface water quality resulting from development. BMPs are categorized
as structural or non-structural.
• Early Planning
• Low Impact Development
– “LID-like” or Better Site Design or Environmental Site Design
• Local stream buffers and setbacks
• Minimize or disconnect impervious surfaces sheet flow, open section
pavement
• Devices
Most significant factor affecting performance is construction
and maintenance

Erosion and Sediment Control
vs. Stormwater Management
E/S
• Construction Phase
• Sediments are primary criteria
• Can be temporary or “permanent”
SWM
• Post-construction
• Manages various pollutants
• Permanent

Common E/S Practices
• Silt Fence
• Vegetative Stabilization
• Stone lined conveyance
• Temporary Sediment Basin/Trap
• Temporary Use of Permanent Pond or other facility

Common Compliance Issues
Similar for E/S & SWM
Construction
Maintenance

Common SWM Practices
• Better/Environmental Site Design
• Sheet flow management – prior to and after
conveyance
• Open section surfaces
• Engineered practices

Common ESD Practices per
Regulations
• Preserving and protecting natural
resources
• Conserving natural drainage
patterns
• Minimizing impervious area
• Reducing runoff volume
• Using ESD practices to maintain
100 percent of the
• Annual predevelopment
groundwater recharge volume
• Using green roofs, permeable
pavement, reinforced turf,
• And other alternative surfaces
• Limiting soil disturbance, mass
grading, and compaction
• Clustering development
• Any practices approved by the
Administration.

ESD Planning Techniques and
Practices
• Disconnection of rooftop runoff
• Disconnection of non-rooftop runoff
• Sheetflow to conservation areas
• Rainwater harvesting
• Submerged gravel wetlands
• Landscape infiltration
• Infiltration berms
• Dry wells
• Micro-bioretention
• Rain gardens
• Swales
• Enhanced filters

The Best BMP - Work with Forest
and Wetland Conservation

Work with Site Character Before
Devices

When Using Engineered Practices
Smaller Volumes
Most compatible with ESD
goals of 2007 SWM Act –
At Source & Pretreatment
Quality Control Only
• Infiltration
– trench/basin
• Filtering
– sand filter/bioretention
• Hydrodynamic Devices
• “New” Technology
– pervious surfaces/green roofs
Larger Volumes
When preferred is
Insufficient
Central Locations
For Quantity and Quality
Control
• Stormwater Ponds
– wet pond
– wet ED pond
– dry ED pond (for cold water w/
pre-treatment)
– multiple pond system
• Stormwater Wetlands
– shallow marsh
– ED shallow wetland
– pond/wetland systems

Landscaped Bioretention Facility

SWM & Amenity Not Incompatible

Enhance & Plant Dry Ponds Also

Stream Stabilization as a BMP
• Can be effective watershed sediment control practice
• Can be local approval requirement
• Can be a traded credit
• Can be out-of-kind wetland mitigation

Resources
• For:
• NPDES MS4 and Notice of Intent (NOI) Compliance
• Stormwater Management Act & Regulations
• Maryland Stormwater Design Manual
• Erosion and Sediment Control Regulations
• Waterways and Wetlands
• Go to MDE: www.mde.state.md.us/Programs/WaterPrograms/SedimentandStormwater/index.asp
• For US EPA related information:
• Regulations http://cfpub.epa.gov/npdes/npdesreg.cfm?program_id=45
• National Menu of Stormwater Best Management Practices
http://cfpub.epa.gov/npdes/stormwater/menuofbmps
• Urban BMP Performance Tool Urban BMP Performance Tool
http://cfpub.epa.gov/npdes/stormwater/urbanbmp/bmpeffectiveness.cfm
• Stormwater Discharges From Construction Activities http://cfpub.epa.gov/npdes/stormwater/const.cfm
• Or, “Google it” – web pages changing rapidly
• Or Contact me : Andrew T. Der 443 224 1824
ader@wrallp.com

Stormwater Regulation

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