The Purple Line

Purple Line Transit Project, Montgomery and Prince Georges Counties, Maryland

The planned Purple Line Transit Project (PLTP) is a 16.2-mile, 21-station, east-west, light rail transitway that will extend from its western terminus at the Bethesda Metro Station in Montgomery County to its eastern terminus at the New Carrollton Metro Station in Prince George’s County. Located just inside the Washington, DC Capital Beltway, PLTP will serve five major activity centers just north of Washington, DC: Bethesda, Silver Spring, Takoma-Langley Park, College Park / University of Maryland, and New Carrollton.

As a subcontractor to Atkins North America (Atkins), ESD Associates (ESDA) played a significant role during PLTP design-build environmental permitting activities. PLTP is divided into eight (8) design segments. ESDA coordinated with Atkins and other subcontractors to complete SWM design for segments 1 through 4 and supported those designing segments 5 through 8, for consistency in approach, comment assessment and response, scheduling and development of priorities. 

ESDA joined the Purple Line Transit Constructors (PLTC) team as a relatively young company in 2017. By the conclusion of our involvement in the project we had grown to 7 employees and had an office in South Baltimore. ESDA, as a subcontractor to Atkins, remained on the project after PLTC left the project in the fall of 2020. All of our staff contributed to the project from Admin to technical to management.

  • Project Leadership, 
  • Project Task Management
  • Environmental / Water Resources Design including 
    • Design/Peer Review and Quality Control, 
    • Design and Analysis of SWM / BMPs, 
    • Erosion and Sediment Control Plan Development
    • Hydrologic and Hydraulic Modeling,
    • Dam Breach Modeling and Analysis,
    • Dam Safety Compliance, 
    • Dam Operation and Maintenance Protocol Development, 
    • and regulatory coordination.

Project Leadership

ESDA’s Daniel O’Leary, P.E. was initially hired by PLTC in 2017 to assist PLTC’s design team struggling to obtain SWM Concept approvals from MDE. Already a year into the project with several submittals made, numerous comments received, and no SWM Concept approvals granted, Atkins leadership requested ESDA’s help to review MDE Delegated Authority (DA) comments, determine when to push back and when to comply, and better understand the regulatory process in Maryland. ESDA representatives joined PLTC in high level meetings to strategize critical path decisions to move the project forward. PLTC’s efforts, even with ESDA’s assistance, had marginal success because of the deal MTA had struck with MDE, new MDE dam safety requirements that interrupted the work flow, a lack of project advocates at MTA and MTA’s Project Management Consultants (PMC), and no incentive for the DA or it’s subcontractor reviewers to move the project forward. Although significant gains had been made, PLTC left the project in the fall of 2020 citing environmental permit and right-of-way delays and monetary losses, eventually settling with MTA.

Following the departure of PLTC, MTA contracted with Atkins directly to complete procurement of environmental permits and design of the overall project, and support MTA’s search for a replacement prime contractor. At this stage MTA and PMC shifted to advocate for the project and provide direct support for design and permitting efforts. ESDA continued to work under Atkins providing leadership and insight into MDE permitting and requirements and meeting regularly with the project team to help push the project to the finish line.

Following the departure of PLTC, MTA contracted with Atkins directly to complete procurement of environmental permits and design of the overall project, and support MTA’s search for a replacement prime contractor. At this stage MTA and PMC shifted to advocate for the project and provide direct support for design and permitting efforts. ESDA continued to work under Atkins providing leadership and insight into MDE permitting and requirements and meeting regularly with the project team to help push the project to the finish line.

(Photos below: October 2018 ESDA attended a field meeting representing PLTC with then Secretary Pete Rahn of MDOT and Secretary Benjamin Grumbles of MDE. The meeting was about implementing new dam safety requirements and discussing the effects on project schedule and cost.)
(Photos below: October 2018 ESDA attended a field meeting representing PLTC with then Secretary Pete Rahn of MDOT and Secretary Benjamin Grumbles of MDE. The meeting was about implementing new dam safety requirements and discussing the effects on project schedule and cost.)
(Photos below: October 2018 ESDA attended a field meeting representing PLTC with then Secretary Pete Rahn of MDOT and Secretary Benjamin Grumbles of MDE. The meeting was about implementing new dam safety requirements and discussing the effects on project schedule and cost.)
(Photos below: October 2018 ESDA attended a field meeting representing PLTC with then Secretary Pete Rahn of MDOT and Secretary Benjamin Grumbles of MDE. The meeting was about implementing new dam safety requirements and discussing the effects on project schedule and cost.)

Project Task Management

ESDA’s role on the project grew from just Project Leadership to project task management when ESDA hired Bruce Harrington, P.E. and Mahendra Bastakoti, P.E. in early 2018. Bruce, having recently retired from MDE Dam Safety Division after 35 years, was brought on to assist with the new Dam Safety requirements. Mahendra joined to support the SWM Design and Permitting with his vast experience as a design team leader working for a design-builder on Segment C of the ICC project. In the late summer of 2018 Solomon Adamu joined ESDA. Solomon had spent 8 years prior working for MDE’s Plan Review Division performing technical reviews of projects like PLTP sent in for MDE SWM and ESC approval. Each of these strategic hires was for the purpose of bringing the design team task leadership and direction from professionals with proven experience in their fields.

ESDA supported PLTC’s pursuit of claims on the project by tracking regulatory comments, assessing validity of comments, participating in comment resolution meetings, and ensuring follow through on commitments. Eartha Ballard, who has an MS in Environmental Engineering and joined ESDA in the fall of 2016, and Saliha Kahn,  a recent graduate also with an MS in Environmental Engineering who joined ESDA in 2019, helped develop spreadsheet based comments/responses, requirements and commitments trackers and performed data QC. ESDA developed a customized downstream property owner concurrence dataset that tracked over 150 PLTP outfalls, corresponding pre- and post- 1, 10 and 100-year discharges from thousands of pages of SWM reports, whether a waiver or variance was required and being requested to fulfill SWM waiver requirements, and, if so, the names and addresses of downstream property owners that would need to provide concurrence.

ESDA can provide leadership for your project too. As a MDOT Minority Business Enterprise (MBE # 16-355) with deep design and design-build experience, ESDA is well positioned to provide high level expertise in project design and project management, brings extensive Maryland environmental permitting experience, understands the intensity of deadlines and critical activities, and is ready to jump in.

Design/Peer Review and Quality Control: 

ESDA performed formal and informal SWM and ESC plan quality control reviews on behalf of the PLTC team. Informal “over-the-shoulder” reviews were often requested to garner ESDA’s expertise on a specific design situation. Formal, structured QC was performed using Bluebeam software. Atkins trained and involved ESDA staff in their internal 5-step, Bluebeam software-based QC process, a process that has since been adopted by ESDA, to ensure that all project submittals receive proper internal peer review before formal submittals are made. Bluebeam enables creation of “sessions” that engage invited discipline peer reviewers to coordinate, comment, and mark-up plan submittals, and tracks comments and how they were resolved prior to submittal. ESDA staff filled different roles in the QC process including designer, reviewer, and approver for submittals.

purple-line-map-4

Dam Safety Compliance

ESDA lead the PLTP project team efforts to comply with MDE Dam Safety Division requirements for hydraulic crossings (culverts) beneath the railroad alignment. Culverts were analyzed to determine headwater and tailwater elevations for various storms and results were compared with Dam Safety criteria to determine if existing or proposed crossings acted as dams. Culvert analyses included development of hydrology models and performing hydraulic analyses to best represent pre- and post-development headwater and tailwater conditions at culverts. The results are (1) compared to criteria established by Maryland Department of the Environment (MDE) Dam Safety Division (DSD) Policy Memorandum #2 (Policy Memo #2) dated June 11, 2019, revised October 9, 2019; (2) ensured fulfilment of information requested by MDE; and (3) used to demonstrate compliance with Joint Permit Authorization No. 201661278/16-NT-0297 regarding hydraulic trespass, aquatic passage, and stable conveyance.

The Culvert Screening Analyses at Culvert 1-2 demonstrated that the proposed hydraulic crossing, including 54” Auxiliary pipe, met the requirements for “culvert” found in MDE DSD Policy Memo #2 and complies with MDE NTWWD permit conditions regarding hydraulic trespass (Q100 water surface extending beyond right of way) and outfall stability.
The Culvert Screening Analyses at Culvert 1-2 demonstrated that the proposed hydraulic crossing, including 54” Auxiliary pipe, met the requirements for “culvert” found in MDE DSD Policy Memo #2 and complies with MDE NTWWD permit conditions regarding hydraulic trespass (Q100 water surface extending beyond right of way) and outfall stability.
ESDA completed Culvert 1-2 analyses, design, agency coordination and detailed Screening Analysis Report as well as assisted the PLTC team with railroad culvert screenings in several other PLTP locations to obtain MDE concurrence.
ESDA completed Culvert 1-2 analyses, design, agency coordination and detailed Screening Analysis Report as well as assisted the PLTC team with railroad culvert screenings in several other PLTP locations to obtain MDE concurrence.

Dam Operation, Inspection, and Maintenance Protocol Development:

ESD Associates prepared a dam operation, inspection, and maintenance protocol and assessment report for Veterans Pond dam located on the PLTP as required by MDE Dam Safety Division (DSD). DSD has determined that Veterans Pond dam, although impounded volume of water is relatively small, is considered a significant hazard because the PLTP and Veterans Parkway traverse the pond dam embankment. The report includes a photographic log of existing Veterans Pond, proposed Veterans Pond design plans, inspection requirements, maintenance schedule, and a completed pond inspection checklist from MDE Dam Safety Manual (1996) and USDA-NRCS Conservation Practice Standard for Ponds MD-378 APPENDIX A (NRCS, January 2000). Further, the report addresses removal of woody vegetation from the dam embankment, preventing erosion or gullying of embankment surfaces, clearing of toe drains, removing accumulated trash and debris, and protecting structural components against rust and spalling. The purpose of the report is to establish a benchmark of dam conditions that can be revisited and updated annually, similar to what MDE DSD requires on large dams within the state.

ESDA can prepare a dam operation and maintenance plan for your pond or lake, regardless of size. ESDA will research available records, assess analytical needs, perform dam inspections, prepare hazard classification determinations and danger reach studies, file necessary paperwork with the appropriate approval authority and coordinate permitting on your behalf.
ESDA can prepare a dam operation and maintenance plan for your pond or lake, regardless of size. ESDA will research available records, assess analytical needs, perform dam inspections, prepare hazard classification determinations and danger reach studies, file necessary paperwork with the appropriate approval authority and coordinate permitting on your behalf.

Floodplain Analyses and Permitting:

Coquelin Run is a stream with headwaters in Chevy Chase, MD, draining east under Connecticut Avenue (MD185) and ending at a confluence with Rock Creek. The PLTP alignment, along Georgetown Branch Trail, is north of and parallel to Coqueline Run with several tributary pipe crossings to accommodate drainage from north to south. During culvert analyses and MDE Dam Safety coordination, it was determined that Culvert 1-2, a major crossing with over 20 feet of fill on the Columbia Country Club property, is considered a dam in existing conditions. To avoid ownership of a high hazard dam, PLTC and Atkins tasked  ESDA with performing hydrologic and hydraulic studies to determine hydraulic crossing alternatives that would negate classifying the crossing as a dam and associated liabilities as well as coordinating with MDE DSD on the matter.

ESDA prepared alternative analyses that lead to selection of adding hydraulic capacity to the crossing in the form of an additional 54” concrete pipe parallel to the 54” pipe crossing required to meet the project drainage criteria. However, with additional hydraulic capacity comes downstream floodplain impacts. As a follow-up task, ESDA prepared a floodplain study to assess the impacts of the additionally hydraulic capacity at Culvert 1-2 on the Coquelin Run mainstem and downstream properties, documented the findings in technical reports and, after regulatory reviews, obtained approval for the floodplain study that created benchmark floodplain water surface elevations on Coquelin Run upstream and downstream from Connecticut Avenue.

Technical analyses performed by ESDA included development of HydroCAD hydrology models and output as input to HEC-RAS 2D model simulations for 2-year, 10-year and 100-year return period storms. Analyses were performed for existing and proposed conditions along Coquelin Run to analyze the impact of the project on the downstream flow conditions, i.e. tractive force and water surface elevation. ESDA was assisted in these efforts by Atkins’ Global Design Center located in India, to provide peer review, technical model development and troubleshooting. The complex model included 2-year and 10-year shear stress comparisons, 100-year maximum water levels and flow comparison, 100-year flood extent comparison with convergence analysis for MDE and Montgomery County permit compliance. ESDA coordinated directly with Maryland State Highway Administration (regarding Connecticut Avenue), Montgomery County Department of Permitting Services for floodplain permitting, and MDE Waterway Construction, Nontidal Wetlands and Dam Safety Divisions regarding the PLTP’s joint permit authorization conditions.
Technical analyses performed by ESDA included development of HydroCAD hydrology models and output as input to HEC-RAS 2D model simulations for 2-year, 10-year and 100-year return period storms. Analyses were performed for existing and proposed conditions along Coquelin Run to analyze the impact of the project on the downstream flow conditions, i.e. tractive force and water surface elevation. ESDA was assisted in these efforts by Atkins’ Global Design Center located in India, to provide peer review, technical model development and troubleshooting. The complex model included 2-year and 10-year shear stress comparisons, 100-year maximum water levels and flow comparison, 100-year flood extent comparison with convergence analysis for MDE and Montgomery County permit compliance. ESDA coordinated directly with Maryland State Highway Administration (regarding Connecticut Avenue), Montgomery County Department of Permitting Services for floodplain permitting, and MDE Waterway Construction, Nontidal Wetlands and Dam Safety Divisions regarding the PLTP’s joint permit authorization conditions.
Photos: Coquelin Run Floodplain upstream and downstream of PLTP Culvert 1-2.
Photo: Coquelin Run Floodplain and In-line Columbia Country Club Pond
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