Site Evaluation and Design Challenges of MS4/TMDL ... · Environmental feature data • Water features, waterways, wetlands, floodplains • Existing trees and forest areas • Critical

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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


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


➢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


➢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


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


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


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


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


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



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



OBTAIN BMP OPPORTUNITY SITE LIST FROM CITYSTEP 1



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



IDENTIFY ADDITIONAL BMP OPPORTUNITY SITESSTEP 3



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)


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


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


➢Utilities

➢Environmental Features

➢Roadway Constraints

➢Site Location

➢Land Owner Approval

➢Drainage Area

➢Tier I/Tier III Opportunities

➢Existing BMP Conflicts

Site Constraints


➢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



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)



PERFORM FIELD VISITSSTEP 5



PROVIDE SITE INITIAL SELECTION RECOMMENDATIONSTEP 6



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.



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.


Challenges➢Site Constraints

➢Design Standards

➢Public Outreach

➢Stakeholders

➢Costs

➢Permitting

➢Project Schedule

Challenges for TMDL/MS4 Restoration in Urban Settings


➢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)


➢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



➢Public Outreach• Public outreach for planning level

• Public outreach at design phases

• Public outreach during construction



➢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



➢Costs

• High construction costs

• High O&M costs

• Low cost effectiveness

➢Permitting

• Permitting for boring and utility designation

• Permitting for construction


Cost

Cost

Cost


➢Project Schedule

• Initiate project in November 2016

• Complete all designs by October 2017

• Start construction in March 2018

• Finish construction in November 2018



➢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


Contact information:

John Shen, Ph.D., PE, LEED AP BD+CEmail: [email protected]

Michael Blose, PE, MBAEmail: [email protected]

Andrew Sankowski, EITEmail: [email protected]

mailto:[email protected]




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Site Evaluation and Design Challenges of MS4/TMDL ... · Environmental feature data • Water features, waterways, wetlands, floodplains • Existing trees and forest areas • Critical