1. Balancing Wetland and StreamBalancing Wetland and Stream
Preservation with StormwaterPreservation with Stormwater
Management:A Case StudyManagement:A Case Study
Presentation for
National Association of Environmental Professionals
39th
Annual Conference
St. Petersburg, Florida
April 8, 2014
Andrew T. Der & Associates, LLC
Environmental Consulting
1000 Fell Street | Baltimore, MD 21231
1.410.491.2808 | AndrewTDer@comcast.net

2. Habitat Avoidance – can be -Habitat Avoidance – can be -
InsufficientInsufficient

3. What HappensWhat Happens

4. Secondary Impacts = NewSecondary Impacts = New
Construction SWMcriteriaConstruction SWMcriteria
Disturbance to Surface water resources
• State nontidal waters and wetlands including 100 year floodplain and water
quality criteria
• State tidal waters and wetlands
• Federally regulated waters of the United States
Disturbance to Land (nonpoint source pollution)
• State stormwater management regulations – includes delegated point and
nonpoint source federal criteria
• State and local erosion and sediment control criteria
• Special state tidal water criteria

5. Classification of State Waters inClassification of State Waters in
MarylandMaryland
• Use I & I-P:Water Contact Recreation and Protection of
Aquatic Life
• Use II: Shellfish Harvesting Waters
• Use III & III-P: Natural Trout Waters
• Use IV & IV-P: Recreational Trout Waters

6. State WaterQuality StandardsState WaterQuality Standards
Numerical
• Dissolved Oxygen,Temperature, pH,Turbidity, Fecal Coliform,Toxics
Narrative include CWA
•...Protection of Aquatic Life ...Fishable ...Swimmable...Includes EPA Anti-
Degradation Policy (ADP):
“...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...”

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

8. Hierarchy of Engineered PracticesHierarchy of Engineered Practices
Smaller Volumes
“First Flush”
Preferred and most compatible
with ESD at-source and/or
pretreatment quality control
• Infiltration
– trench/basin
• Filtering
– sand filter/bioretention
• Hydrodynamic Devices above
or underground
– Curb & gutter
vortex/filter basin
• “Newer”Technology
– pervious surfaces/green
roofs
Larger Volumes
When preferred is Insufficient
for quantity and quality
• Stormwater Ponds
– wet pond
– wet ED pond
– dry ED pond (for cold
water w/
pre-treatment)
– multiple pond system
• StormwaterWetlands
– shallow marsh
– ED shallow wetland
– pond/wetland systems

9. Location of Example Project AreaLocation of Example Project Area

10. Location of Project AreaLocation of Project Area

11. Watershed and InitialWatershed and Initial
Development at Low PointDevelopment at Low Point

12. Initial Permit Review StepsInitial Permit Review Steps
• Higher Quality Use I-PWater
• Purpose and Need
• Avoidance and Minimization of Waters of the U. S. from Roads,
Utilities, and Other Disturbances
• Nonpoint Source Pollution Management: Quality
• Stormwater Management (SWM): Quantity
• Coordination with Local Authorities, NGOs, and Stakeholders
• How to Address ADP and SWM

13. Apply Hierarchy of SWMApply Hierarchy of SWM
Preferences to Site CharacterPreferences to Site Character
• Vegetative buffers, disconnects, open
section pavement
• Infiltration Practices if Soils Allow
• Bioretention, Swales,Wetland Filtering
• Retention or Extended Detention Pond with
Wetlands (to include quantity management)

14. ProposedProposed Site-specificSite-specific MitigationMitigation
and BMP’sand BMP’s
• Stream/wetland impacts limited to necessary roads/utilities
• In-stream SWM in marginal/poor areas only
• Minimum stream buffer of 100‘ (30.5 meters)
• Wetland mitigation and replanting in cropped riparian buffer areas
• “First flush” stormwater quality management in uplands
• Infiltration/filtration where feasible (permeable soils and depth)
• Primary quantity stormwater management in “horseshoe” pond
• Water pooling areas planted with wetland vegetation

15. BMPs and Mitigation – Forest andBMPs and Mitigation – Forest and
Wetlands – Workwith SiteWetlands – Workwith Site

16. BMPs and Mitigation - MaximizeBMPs and Mitigation - Maximize
Site CharacterSite Character

17. BMPs and Mitigation - Pond andBMPs and Mitigation - Pond and
Wetlands ManagementWetlands Management

18. BMPs and Mitigation – ImpactBMPs and Mitigation – Impact
Avoidance and Wetland FiltrationAvoidance and Wetland Filtration

19. BMPs and Mitigation - SensitiveBMPs and Mitigation - Sensitive
ResourcesResources

20. BMPs and Mitigation - TransitionBMPs and Mitigation - Transition
HabitatHabitat

21. BMPs and Mitigation - SWM&BMPs and Mitigation - SWM&
LandscapingLandscaping

22. BMPs and Mitigation – SWMandBMPs and Mitigation – SWMand
LandscapingLandscaping

23. BMPs and Mitigation – UrbanBMPs and Mitigation – Urban
AreasAreas

24. BMPs and Mitigation – UrbanBMPs and Mitigation – Urban
AreasAreas

25. BMPs and Mitigation – UrbanBMPs and Mitigation – Urban
AreasAreas

26. BMPs and Mitigation - StreamBMPs and Mitigation - Stream
Stabilization and RestorationStabilization and Restoration
• Can be effective
watershed sediment
control practice
• Can be local approval
requirement
• Can be a traded credit
• Can be out-of-kind
wetland mitigation

27. Public & NGO InvolvementPublic & NGO Involvement
• Public Notice
• Waters may have Use III or IV (higher quality trout
water) potential
• Temperature and ponds potential concern
• EPA Antidegradation Policy may apply
• Implemented stream Rapid Bioassessment
• Findings - no Use III or IV standards but higher
quality Use I

28. Additional Mitigation and WaterAdditional Mitigation and Water
Quality Management PracticesQuality Management Practices
• Water Quality Monitoring Plan
• Stream Reach Temperature Model and Percent
Contribution of “QED” 2, 10 year event to Stream Flow
• Maximum 20% Diversion Base Flow
• Shade Planting of SW Conveyance and Management
Areas
•Toe Drain Pipes Under Embankment Fill

29. Streamand WaterQualityStreamand WaterQuality
MonitoringMonitoring
Can be used for state Watershed
Compliance
Can be used for state natural resource
studies
Preconstruction, construction and post-
construction
Macroinvertebrate studies
(more common examples are WWTP &
mining requirements)
Chemistry
Geomorphology
Groundwater

30. Primary Monitoring ComponentPrimary Monitoring Component

31. Historic Bioassessment DataHistoric Bioassessment Data
Rapid Bioassessment Metric Comparisons to Pre-Construction Scores
Year ST2 ST6 ST10
1993 Non Impaired ** Non Impaired **
1994 Non to Mod. Impaired Non Impaired Non Impaired **
1995 Non to Mod. Impaired Non to Mod. Impaired Non Impaired
1996 Non to Mod. Impaired Moderately Impaired Non to Mod. Impaired
1997 Non to Mod. Impaired Non to Mod. Impaired Moderately Impaired
1998 Moderately Impaired Non to Mod. Impaired
1999 Moderately Impaired Moderately Impaired Moderately Impaired
2000 Moderately Impaired Non to Mod. Impaired
2001 Non to Severely Impaired Moderately Impaired Non Impaired
2002 Non to Mod. Impaired Mod. to Severely Impaired
** Non Impaired value is given to the first (reference) date for comparison purposes;
the streams on those dates are not necessarily truly non-impaired.

32. Historic Dissolved Oxygen DataHistoric Dissolved Oxygen Data
Piney Branch Mean Dissolved Oxygen Levels for Stations 2, 6 and 10
0
2
4
6
8
10
12
14
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
Year
mg/l
ST. 2 Mean D.O. ST. 6 Mean D.O. ST. 10 Mean D.O. Use I Min. D.O.

33. Historic Temperature DataHistoric Temperature Data
Piney Branch Instream Peak Temperatures
Stations 2, 6 and 10
0
5
10
15
20
25
30
35
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
Year
Temperature(oC)
ST. 2 ST. 6 ST. 10

34. Lessons LearnedLessons Learned
• Basis for “how we do it now”
• Basis for groundbreaking county Special Protection
Area legislation
• Basis for local, state, federal coordinating committees
and public processes
• Basis for initial findings for CWA Section 402 Phase I MS4
NPDES Municipal Permit Compliance