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Examples of current and recent solutions CDG has been able to provide to its partnering agencies and community.  


Light Rail - Goodwin Run Stream Bank Repair N/E, Timonium

(Baltimore County, MD - MTA)


This project Maryland Transit Administration (MTA) project provided both emergency and permanent stabilization to a section of the Goodwin Run affected by rapidly eroding streambanks. The erosion was in danger of encroaching on the adjacent MTA light rail tracks and BGE pole, having already exposed a sewer line. This is a Class II Stream with  adjacent non-tidal wetlands. 


Constellation provided the following design support for both the immediate emergency stabilization and the permanent bank and stream restoration:

  • Hydrology/Hydraulics Analysis including GIS Hydro/TR-20 and Hec RAS

  • Preparation of maintenance of stream flow plans

  • Erosion/sediment control plans

  • Preparation of Specifications/Quantities/Cost Estimates

  • MDE review and permits

I-695 Outer Loop Widening (SWOL2) MDOT SHA, Baltimore County, MD 
(Baltimore County, MD - SHA)


This MDOT SHA project is located on I-695 Southwest Outer Loop in Catonsville, Maryland in Baltimore County. The project limits span approximately 1.5 miles of the beltway outer loop between the US 40 interchange and the MD 144 (Frederick Road) interchange. The purpose of the project was to increase traffic volume by widening the outer loop approximately 36 feet in order to incorporate one additional travel lane and shoulder. In addition to lane widening, the project required bridge replacement, noise walls, retaining walls, and median barrier.


Constellation Design Group provided civil engineering services as follows:

Provided staged Sediment and Erosion control plans coordinated   with maintenance of traffic scheme.

  • Storm drain design within the project limits, including systems   paralleling the concrete median barrier and outside shoulder

  • Design of stormwater management facilities, including: one   extended detention wet pond within the I-695/Edmondson Ave   outer loop interchange and three micro-bioretention ESD facilities   within the I-695/Edmondson Ave inner loop interchange

  • Performed dam break analysis for the SWM pond. Obtained   required approvals from the Maryland Dept of the Environment

  • Preparation of construction cost estimates and special provisions.   Prepared SWM reports, complete with hydrologic analysis and ESD   computations. Obtained required SHA PRD SWM/ESC approvals

Replacement of Canton Viaduct
I-895 over I-95 Ramps, Railroads & City Streets
(Baltimore City, MD - MdTA)

A Maryland Transportation Authority (MDTA) project for the design of extensive bridge replacement and roadway improvements located at the I-895 north entrance/exit portals to the Harbor Tunnel in Baltimore City. Removal and replacement of approximately 3,400 linear feet of bridge section (north and southbound lanes) between the FMT Toll Collection facility and Interstate Avenue. The new bridge will be approximately four to six feet wider than the existing one.

Constellation Design Group provided civil engineering services as follows:

  • Roadway design (both horizontal and vertical alignments), geometrics and lane configurations, roadway profiles, details and typical sections for I-895 as well as several streets below the bridge. Additionally, CDG prepared reports, specifications, construction documents.

  • Storm drain improvement design, including bridge scupper spacing, approach roadway drainage, storm drain relocation and upgrades to roads and areas below the bridge.

  • Four Environmental Site Design (ESD) practices and one structural BMP have been employed to the MEP to address both water quantity and water quality liability issues for the project. Retrofit of two existing SWM ponds were retrofitted to serve the proposed reconstruction of the existing northern stormwater management pond, which serviced the FMT maintenance building complex and adjacent areas.

  • Staged E&S designed to coordinate with the bridge construction sequence and complex traffic control design.

  • SWM/ESC approvals from MDE

Back River WWTP Headworks Project
(Baltimore County, MD - City of Baltimore DWP)

The project, located in the eastern portion of Baltimore County, Maryland on the campus of the existing Back River Wastewater Treatment Plant, is owned and operated by the City of Baltimore, MD.  The plant campus consists of 400+ acres adjacent to Back River. The purpose of the project is to provide a facility that will mediate the influx of sewage volume during storm events with the addition of Equalization (EQ) Pump Station, multiple EQ Tanks, an Influent Pump Station, Mechanical Screen Building and a Grit Facility. Extensive site work and improvements accompany these additions.


Constellation Design Group provided the following design services for this Baltimore City owned project:

  • Provided ESC for temporary quarantine earth loading.

  • Design of Permanent site drainage.

  • Design of fifteen (15) Environmental Site Design (ESD) practices

  • Design of one Chapter 3 BMP extended detention wet pond

  • Management of impervious within the wastewater treatment process was used to   address both water quantity and water quality liability

  • Met Baltimore County requirements for Qp management for new development   projects

  • Multiphase ESC design for both the excavation and stockpile phase of the project   as well as the facility construction phase.

  • Site grading, roadway and parking paving, associated equipment installation and   enclosure.

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