Current Issues in Stormwater
Management
Stormwater Management and Water
Resources
Presentation for Lorman Educational Serv...
STORMWATER EFFECTS ON
WATER QUALITY AND THE
ENVIRONMENT
Why Are We Here?
What Happens
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
& ag
...
Water Quality
Instability
Instability
Regulations and
Permitting Overview
What is a Stream?
• Waters of the U. S.
• Definition includes tidal navigable water, nontidal
navigable water and adjacent...
What is an impact?
• Impacts are discharges or grading
• Discharges can be out of a pipe or placement
of material (CWA Sec...
Types of Stormwater Permitting
• NPDES Phase I and II – U. S. EPA delegated to States by GP – regulates
new construction A...
NPDES Phase I &II Permitting
• 1972 amendments to the Federal Water Pollution
Control Act (Clean Water Act) prohibit the d...
Background
• Stormwater out of a pipe was not necessarily a
point source discharge
• National Urban Runoff Program (NURP) ...
Phase I
• NPDES established first regulations in 1990 permit
requirements for existing stormwater:
1) existing “medium” an...
MDE Phase I Permit
Conditions
• Effectively prohibit pollutants in stormwater discharges
as necessary to comply with water...
Phase II
• In 1999, new rule automatically covers on a nationwide
basis all existing small MS4s located in urbanized areas...
Six Requirements of
Phase II
• Personnel education/outreach
• Public involvement/participation
• Illicit discharge detecti...
Phase II Can be Subjective
• Monitoring, public outreach and BMPs can be flexible as long as:
– Reduces pollutants to the ...
How Does NPDES Affect New
Construction?
• Compliance with NPDES Stormwater permits is
primarily through BMP implementation...
How Does NPDES Affect
New Construction?
To comply with NPDES General Permit (GP) requirements, submit Notice of
Intent NOI...
How Does NPDES Affect
New Construction?
• NPDES Compliance is by NOI and a Stormwater Pollution
Prevention Plan (SWPPP) – ...
State & Local SWM
Concurrently along with new NPDES compliance, need to comply with
following regulations
• State Erosion ...
State & Local SWM
Applies via approved local ordinance
• In MD, primary MEP standard is to use ESD to reduce
post developm...
Other Permitting Criteria
• CWA Section 404 dredge and fill permit
U. S. Army Corps of Engineers Waters of the U. S. inclu...
Water Quality Standards for
Permitting Criteria
• Wetland permitting processes can incorporate CWA Section 401 Water
Quali...
Even More Water Quality
Initiatives in Progress!
• Chesapeake Bay
TMDL for N & P –
what does this mean
for SWM?
• Largest ...
Issues under Deliberation Now
• What should be most sound
priorities of focus? Sediments,
P, O, Flow?
• ESD (and LID) vers...
Construction Compliance
• Usually oriented to E/S compliance
• Locality primary inspector
• State (and occasionally EPA) i...
Newer Compliance
Requirements
• Usually oriented to post-construction assessment
• Third party quality control constructio...
• Used also for MS4
Compliance
• Can be state requirement
• Preconstruction,
construction and post-
construction
• Macroin...
For Construction Activities -
Remember!
• Have most current approved plans on site during construction
• Diligence over pe...
Types of Designs for
Storm Water Control
What is a Best Management
Practice (BMP)?
Best Management Practices (BMPs) are policies, practices, procedures, or
structu...
Erosion and Sediment Control
vs. Stormwater Management
E/S
• Construction Phase
• Sediments are primary criteria
• Can be ...
Common E/S Practices
• Silt Fence
• Vegetative Stabilization
• Stone lined conveyance
• Temporary Sediment Basin/Trap
• Te...
Common E/S Practices
Common E/S Practices
Surface Stabilization
Sensitive Resources
Newer Technologies
Common Compliance Issues
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 sec...
Common “ESD” Practices
• Preserving and protecting natural
resources
• Conserving natural drainage
patterns
• Minimizing i...
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 and BSD
At Source & Pretreatment
Quality Control ...
Bioretention & Infiltration
Bioretention & Infiltration
Landscaped Bioretention Facility
Hydrodynamic Devices
Get Creative
Pond and Wetlands
Pond and Wetlands
Transition Habitat
Transition Habitat
SWM & Amenity Not Incompatible
Detention or Dry Pond
Enhance & Plant Dry Ponds Also
Stream Stabilization as a BMP
• Can be effective
watershed
sediment control
practice
• Can be local
approval
requirement
•...
“Newer” Technologies
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Current Issues in Stormwater Management

  1. 1. Current Issues in Stormwater Management Stormwater Management and Water Resources Presentation for Lorman Educational Services Washington, DC March 20, 2014 Andrew T. Der & Associates, LLC Environmental Consulting 1000 Fell Street | Baltimore, MD 21231 1.410.491.2808 | AndrewTDer@comcast.net
  2. 2. STORMWATER EFFECTS ON WATER QUALITY AND THE ENVIRONMENT
  3. 3. Why Are We Here?
  4. 4. What Happens
  5. 5. Four Categories of Effects • Hydrology • Geomorphology • Habitat • Water Quality
  6. 6. Hydrology • Increase in flow and velocities • Increase in flooding • Increase in frequency • Increase in bankfull flows
  7. 7. Geomorphology • Stream Widening • Channel Instability • Erosion
  8. 8. Habitat • Fish Barriers • Loss of Substrate • Loss of Riparian Zone • Loss of Micro-topography
  9. 9. Water Quality • Sediments Channel erosion can be the primary sediment source! • Nutrients Maintained vegetated areas & ag • Temperature Warm pavements and pond pools • Other Oils, Greases, heavy metals, toxics
  10. 10. Water Quality
  11. 11. Instability
  12. 12. Instability
  13. 13. Regulations and Permitting Overview
  14. 14. 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.
  15. 15. 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
  16. 16. 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 • 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
  17. 17. 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
  18. 18. 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
  19. 19. Phase I • NPDES established first regulations in 1990 permit requirements for existing stormwater: 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 (changed to 1) acres of land or greater – general permits 3) certain industrial activities • Many continue to operate under Phase I
  20. 20. MDE Phase I Permit Conditions • Effectively prohibit pollutants in stormwater discharges as necessary to comply with water quality standards • Attain wasteload allocations (WLAs) for approved TMDL • Assess existing programs and ID licit and illicit Sources • Implement SWM and E/S • Hot spots • Trash and litter • Watershed Management and Restoration (often needs its own water and state wetland permit!) • Utilize current collected best management practice (BMP) data to modify and improve programs • Monitoring and mapping • Reduction in impervious surfaces • Fiscal Analysis and Annual Reports
  21. 21. 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
  22. 22. 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
  23. 23. 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 – Newer MS4 permits will be templates
  24. 24. How Does NPDES Affect New Construction? • 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
  25. 25. How Does NPDES Affect New Construction? To comply with NPDES General Permit (GP) requirements, submit Notice of Intent NOI if 1 acre or more of disturbance. In addition to customary (“sediment- centric”) E/S plans, compliance can include: • Water quality and sensitive construction techniques for waters with an established Total Maximum Daily Load (TMDL) • If significant sediment discharge, then additional inspection, evaluation and installation of site controls • Control measures that minimize pollutants as necessary to meet applicable water quality standard • Conduct weekly inspections and the next day (changed from next business day) after a rainfall event resulting in runoff • If there is “an excursion” above any applicable water quality standard, modify controls to indicate receiving water is attaining water quality standards • Hot topic - Potential for flocculent or turbidity controls?
  26. 26. How Does NPDES Affect New Construction? • NPDES Compliance is by NOI and 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?!
  27. 27. 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
  28. 28. State & Local SWM Applies via approved local ordinance • In MD, 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 • In Virginia starting July 2014 will require TP oriented management of 1 inch runoff of entire site utilizing their Srormwater BMP Clearinghouse also emphasizing nonstructural disconnections
  29. 29. Other Permitting Criteria • CWA Section 404 dredge and fill permit U. S. Army Corps of Engineers Waters of the U. S. including wetlands • State Wetland and Waterway Permit Can have special NTW E/S BMP Conditions • State Tidal Wetlands and Waters permits • Coastal Zone Management Act • MD Tier II Waters Criteria • MD Chesapeake Bay Critical Area Law Administered through local zoning and subdivision ordinances for overlay 1,000 feet from shoreline - 10% SWM rule in Intensely Developed Areas • MD 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 • VA Chesapeake Bay Preservation Act Through localities Resource protection Areas, Better Site Design
  30. 30. Water Quality Standards for Permitting Criteria • Wetland permitting processes can 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…”
  31. 31. Even More Water Quality Initiatives in Progress! • Chesapeake Bay TMDL for N & P – what does this mean for SWM? • 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
  32. 32. Issues under Deliberation Now • What should be most sound priorities of focus? Sediments, P, O, Flow? • ESD (and LID) versus Smart Growth versus impervious surface criteria? • TMDL model assumptions challenged • Financing TMDL WIPs (rain tax) • TMDL AFG Offset credits vs. existing SWM criteria • Nutrient trading
  33. 33. Construction Compliance • Usually oriented to E/S compliance • Locality primary inspector • State (and occasionally EPA) inspect also for NPDES, E/S and Wetland and Waterways Permit • Corps inspects for Wetland and Waterways Permit
  34. 34. 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
  35. 35. • Used also for MS4 Compliance • Can be state requirement • Preconstruction, construction and post- construction • Macroinvertebrate Studies (from WWTP & mining) • Chemistry • Geomorphology • Groundwater Post-Construction BMP and Water Quality Monitoring
  36. 36. 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
  37. 37. Types of Designs for Storm Water Control
  38. 38. 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
  39. 39. 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
  40. 40. Common E/S Practices • Silt Fence • Vegetative Stabilization • Stone lined conveyance • Temporary Sediment Basin/Trap • Temporary Use of Permanent Pond or other facility
  41. 41. Common E/S Practices
  42. 42. Common E/S Practices
  43. 43. Surface Stabilization
  44. 44. Sensitive Resources
  45. 45. Newer Technologies
  46. 46. Common Compliance Issues
  47. 47. Common Compliance Issues Similar for E/S & SWM Construction Maintenance
  48. 48. Common SWM Practices • Better/Environmental Site Design • Sheet flow management – prior to and after conveyance • Open section surfaces • Engineered practices
  49. 49. Common “ESD” Practices • 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.
  50. 50. The Best BMP - Work with Forest and Wetland Conservation
  51. 51. Work with Site Character Before Devices
  52. 52. When Using Engineered Practices Smaller Volumes Most compatible with ESD and BSD 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
  53. 53. Bioretention & Infiltration
  54. 54. Bioretention & Infiltration
  55. 55. Landscaped Bioretention Facility
  56. 56. Hydrodynamic Devices
  57. 57. Get Creative
  58. 58. Pond and Wetlands
  59. 59. Pond and Wetlands
  60. 60. Transition Habitat
  61. 61. Transition Habitat
  62. 62. SWM & Amenity Not Incompatible
  63. 63. Detention or Dry Pond
  64. 64. Enhance & Plant Dry Ponds Also
  65. 65. 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
  66. 66. “Newer” Technologies

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