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Site Evaluation and Design Challenges of MS4/TMDL Restoration Projects in the Urban Environment of Baltimore City
2018 National Capital Region
Water Resources Symposium
April 6, 2018
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1. City of Baltimore (COB) Municipal Separate Storm Sewer System (MS4) and Total Maximum Daily Load (TMDL) Restoration Background Information
2. Goals of TMDL/MS4 Restoration Project
3. Stormwater Management (SWM) best management practices (BMPs)
4. Site Evaluation and Analysis Approach
5. Challenges for TMDL/MS4 Restoration in Urban Settings
6. Other factors to be considered for using MDE State Revolving Fund (SRF)
Presentation Outline
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➢National Pollutant Discharge Elimination System (NPDES) MS4 permit reissued December 27, 2013
➢5 year permit covering all stormwater discharges from the MS4 owned and operated by Baltimore City
➢Permit requires 20% restoration of the impervious surface area within Baltimore City limits
➢20% restoration = 4,291 acres
➢Watershed Implementation Plan (WIP) details strategies for meeting restoration requirements
Baltimore City MS4 Restoration Requirements
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➢Structural/Traditional BMPs• Stormwater Pond Retrofits• New Wetlands / Stormwater Ponds• Bioretention (large scale)
➢Environmental Site Designs (ESD) Practices• Micro-bioretention• Rain Gardens• Green Roofs• Enhanced Filters• Permeable Paving
➢Alternative BMPs• Stream Restoration • Impervious Area Removal• Reforestation / Afforestation• Lot Greening• Programs (Street Sweeping, Catch Basin Cleaning,
Public Education, Enforcement, Partnerships, etc.)
MS4 Restoration Project Types within the City
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Project Description
➢Straughan Environmental, Inc. (Straughan) was retained by COB Department of Public Works (DPW) in 2016
➢Engineering design for up to 52 BMPs
➢Total project area of 7,695 acres spanning 3 watersheds, 10 MS4 WIP project areas, and 30 neighborhoods
MS4/TMDL Restoration ER-4130 Project
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Project Tasks
➢ Data collection
➢ Desktop analysis
➢ Field investigation
➢ Topographic survey
➢ Utility designation
➢ Geotechnical survey
➢ 30% concept designs
➢ 60% semi-final designs
➢ 90% final designs
➢ 100% Plans
➢ Specifications and Estimate (PS&E) designs
➢ Pre-construction award services
➢ Post award services
MS4/TMDL Restoration ER-4130 Project
Additional Reports, Permits and Approvals
➢ Primary Engineering Report (PER) for Maryland Department of the Environment (MDE) State Revolving Fund (SRF)
➢ Grading permits
➢ SWM/ESC permits
➢ Roadside tree permits,
➢ Wetland/waterway permits
➢ Forest conservation permits
➢ Critical area commission (CAC) permits,
➢ Floodplains permits
➢ Baltimore City Commission for Historical and Architectural Preservation (CHAP) review and approval
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MS4/TMDL SWM Best Management Practices (BMPs)
Tier I (upland nonstructural) Tier II (upland structural) Tier III (outfall and in-stream measures)
• Rooftop and non-rooftop disconnections• Tree planting areas• Removing curb and gutter or pavement
areas• Utilizing sheetflow to conservation areas
• Infiltration berms/trenches• Bioretention• Bioswales• Rain gardens• Stormwater retrofit
• Outfall rehabilitation• End of pipe retrofit• Offline pond retrofit or new ponds• Energy dissipaters• Bank and in-stream stabilization
measures
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Project Goals
➢ Identify and prioritize cost-effective (capital and maintenance cost) BMPs to treat urban runoff and meet MS4/TMDL requirements
➢Meet or exceed the treatment goal with least, most cost-effective BMPs
➢Provide public education and participation
➢ Improve public safety
MS4/TMDL Restoration ER-4130 Project
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Site Evaluation Approach
PROVIDE FINAL SITE SELECTION RECOMMENDATION
INCORPORATE STAKEHOLDER FEEDBACK
PROVIDE SITE INITIAL SELECTION RECOMMENDATION
PERFORM FIELD VISITS
PERFORM DESKTOP ANALYSIS
IDENTIFY ADDITIONAL BMP OPPORTUNITY SITES
GATHER & REVIEW BACKGROUND INFORMATION
OBTAIN BMP OPPORTUNITY SITE LIST FROM CITYSTEP 1
STEP 2
STEP 3
STEP 4
STEP 5
STEP 6
STEP 7
STEP 8
REFINE DESKTOP ANALYSIS RESULTS WITH FIELD DATA
UPDATED SITE SELECTION GIVEN FEEDBACK
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Site Evaluation Approach
OBTAIN BMP OPPORTUNITY SITE LIST FROM CITYSTEP 1
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Site Evaluation Approach
GATHER & REVIEW BACKGROUND INFORMATIONSTEP 2
➢ Geographic data• Topography• Neighborhood boundaries• Land use• Historical areas• Parcels, ROW• Buildings• Streets, alleys, bike paths, trails, etc.
➢ Utility data• Water lines, sewer lines, storm drains• Gas lines• Power transmission lines, street light
cables• Telephone lines, cable lines, fiber optic
lines
• As-builts
➢ Environmental feature data• Water features, waterways, wetlands,
floodplains• Existing trees and forest areas• Critical areas, etc.
➢ Design criteria• State of Maryland• City of Baltimore• Stakeholders• Urban ESD design guidance from other
jurisdictions for reference➢ Studies
• Watershed Implementation Plan• Direct Harbor Water Characterization
Report• Small Watershed Action Plans• Neighborhood Master Plans
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Site Evaluation Approach
IDENTIFY ADDITIONAL BMP OPPORTUNITY SITESSTEP 3
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Site Evaluation Approach
PERFORM DESKTOP ANALYSISSTEP 4
➢Evaluate opportunity sites for BMP feasibility (BMP prioritization process)
➢Generate proposed BMP footprint and estimate provided Equivalent Impervious Area Restored (EIAR)
➢Develop planning level life cycle cost (LCC) estimates
➢Perform two-step site ranking analysis of alternatives, first prioritizing sites by feasibility and then prioritizing the most feasible sites based on cost-effectiveness (LCC/EIAR)
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BMP Prioritization Process
1
10
NO DIRECT IMPACT ON BMP FEASABILITY
IRRECONCILABLE BMP FEASABILITY CONFLICT
CONSTRAINT WEIGHTING SCALE
234
56789
MODERATE IMPACT ON BMP FEASABILITY
5
1
NO SITE CONSTRAINT ISSUE
MAJOR SITE CONSTRAINT ISSUE
SITE SCORING SCALE
4
3
2
MODERATE SITE CONSTRAINT ISSUE
➢ BMP feasibility prioritized using weighted site scoring matrix
➢ Constraints assigned weight based on importance
➢ Sites assigned constraint scores through desktop evaluation
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BMP Prioritization Process
WEIGHTED SITE SCORE
0
5
REJECTED: SCORE OF “1” FOR “10” WEIGHTED CONSTRAINT
MOST FEASIBLE BMP SITE
2
3
4
1HOLD: MISSING DATA OR STAKEHOLDER FEEDBACK
𝑊𝐸𝐼𝐺𝐻𝑇𝐸𝐷 𝑆𝐼𝑇𝐸 𝑆𝐶𝑂𝑅𝐸 =𝑆𝑈𝑀𝐴𝐿𝐿 [ 𝐶𝑂𝑁𝑆𝑇𝑅𝐴𝐼𝑁𝑇 𝑊𝐸𝐼𝐺𝐻𝑇 𝑥 𝐶𝑂𝑁𝑆𝑇𝑅𝐴𝐼𝑁𝑇 𝑆𝐶𝑂𝑅𝐸 ]
𝑆𝑈𝑀𝐴𝐿𝐿 [𝐶𝑂𝑁𝑆𝑇𝑅𝐴𝐼𝑁𝑇 𝑊𝐸𝐼𝐺𝐻𝑇]
LESS FEASIBLE BMP SITE
➢ Weighted site constraint score calculated to quantify BMP feasibilityand prioritize site selection
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➢Utilities
➢Environmental Features
➢Roadway Constraints
➢Site Location
➢Land Owner Approval
➢Drainage Area
➢Tier I/Tier III Opportunities
➢Existing BMP Conflicts
Site Constraints
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➢Most ESD BMP types not feasible in urban environment when restricted to publicly owned land /right-of-way➢ Green roof
➢ Permeable pavement
➢ Rooftop/non-rooftop disconnection
➢ Rainwater harvesting
➢ Submerged gravel wetland
➢ Landscape infiltration
➢ Dry wells
➢Feasible ESD opportunities typically located within right-of-way➢ Impervious removal (City owned vacant land)
➢ Tree planting (City owned open space)
➢ Micro-bioretention
➢ Bioswales
ESD Constraints
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Site Evaluation Approach
PERFORM DESKTOP ANALYSISSTEP 4
➢Evaluate opportunity sites for BMP feasibility (BMP prioritization process)
➢Generate proposed BMP footprint and estimate provided Equivalent Impervious Area Restored (EIAR)
➢Develop planning level life cycle cost (LCC) estimates
➢Perform two-step site ranking analysis of alternatives, first prioritizing sites by feasibility and then prioritizing the most feasible sites based on cost-effectiveness (LCC/EIAR)
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Site Evaluation Approach
PERFORM FIELD VISITSSTEP 5
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Site Evaluation Approach
PROVIDE SITE INITIAL SELECTION RECOMMENDATIONSTEP 6
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Site Evaluation Approach
INCORPORATE STAKEHOLDER FEEDBACKSTEP 7
Jurisdiction Agency*Selected Approved Not Approved Pending
Tier 1 Tier 2 Tier 1 Tier 2 Tier 1 Tier 2 Tier 1 Tier 2
DOT 5 23 0 21 0 0 5 2
BCRP 3 9 0 0 3 9 0 0
DHCD 0 0 0 0 0 0 0 0
PABC 0 4 0 4 0 0 0 0
HABC 7 0 0 0 0 0 7 0
Total** 15 35 0 25 3 9 12 2
Total** 50 25 12 14
*Jurisdiction agency identified by SEI during desktop analysis.
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Site Evaluation Approach
PROVIDE FINAL SITE SELECTION RECOMMENDATIONSTEP 8
Jurisdiction Agency*Selected Approved Not Approved Pending
Tier 1 Tier 2 Tier 1 Tier 2 Tier 1 Tier 2 Tier 1 Tier 2
DOT 4 31 4 31 0 0 0 0
BCRP 0 2 0 2 0 0 0 0
DHCD 8 0 8 0 0 0 0 0
PABC 0 4 0 4 0 0 0 0
HABC 3 0 3 0 0 0 0 0
Total** 15 37 15 37 0 0 0 0
Total** 52 52 0 0
*Jurisdiction agency identified by SEI during desktop analysis.
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Challenges➢Site Constraints
➢Design Standards
➢Public Outreach
➢Stakeholders
➢Costs
➢Permitting
➢Project Schedule
Challenges for TMDL/MS4 Restoration in Urban Settings
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➢Site Constraints• Utility conflicts
• Sensitive environmental features
• Narrow streets
• Steep slopes
• Lack of available space
• Lack of supporting stormwater infrastructure
• Conflicts with building frontages
• Conflicts with parking spaces
• Conflicts with bus stops
• Illicit dumping locations
• Property ownership
• Excessive drainage areas
Challenges for TMDL/MS4 Restoration in Urban Settings(Con’t)
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➢Design Standards
• Design standard details
• Design plan templates for MS4/TMDL restoration projects
• Design specification templates for MS4/TMDL restoration projects
• MDE State Revolving Fund (SRF) requirements• First large scale urban ESD project in MD to use SRF
• MDE NOI application
Challenges for TMDL/MS4 Restoration in Urban Settings(Con’t)
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➢Public Outreach• Public outreach for planning level
• Public outreach at design phases
• Public outreach during construction
Challenges for TMDL/MS4 Restoration in Urban Settings(Con’t)
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➢Stakeholders• Department of Public Works (DPW)
• Department of Transportation (DOT)
• Department of Recreation & Parks (BCRP)
• Department of Planning (BCDP)
• Parking Authority (PABC)
• Department of Housing and Community Development (DHCD)
• Housing Authority of Baltimore (HABC)
• Contract Administration (CA)
• DPW’s Office of Compliance and Laboratories (OCAL)
• Community Organizations
• Maryland Department of the Environment (MDE)
• Utility Companies, BGE, Verizon, Comcast, Veolia
Challenges for TMDL/MS4 Restoration in Urban Settings(Con’t)
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➢Costs
• High construction costs
• High O&M costs
• Low cost effectiveness
➢Permitting
• Permitting for boring and utility designation
• Permitting for construction
Challenges for TMDL/MS4 Restoration in Urban Settings(Con’t)
Cost
Cost
Cost
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➢Project Schedule
• Initiate project in November 2016
• Complete all designs by October 2017
• Start construction in March 2018
• Finish construction in November 2018
Challenges for TMDL/MS4 Restoration in Urban Settings(Con’t)
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➢Preliminary Engineering Report Challenges• First urban ESD restoration project in MD to require PER for SRF
• Alternative Analysis for over 200 sites
• Selection of an Alternative based on
▪ Life Cycle Cost Analysis
▪ Non- Monetary Factors
MDE State Revolving Fund (SRF) Requirements
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Contact information:
John Shen, Ph.D., PE, LEED AP BD+CEmail: [email protected]
Michael Blose, PE, MBAEmail: [email protected]
Andrew Sankowski, EITEmail: [email protected]
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Questions?