A. Morton Thomas & Associates, Inc.: Services: Subsurface Utilities: MWAA Subsurface Utility Designating, Locating and Plotting

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MWAA Subsurface Utility Designating, Locating and Plotting

A. Morton Thomas and Associates, Inc. provided utility locating, designating and plotting services at Reagan National and Dulles International Airports on an as-needed basis. Services included determining the location of all existing underground and above ground utilities within the limits of MWAA construction projects; and providing services to determine how these existing utilities were impacted by proposed projects including all necessary test holes, research, field investigations, plotting, design analysis, and recommendations relative to impacts on existing or proposed utility systems.

Specific services have included:

Accurately and comprehensively identifying, characterizing, and mapping underground utility features
Designating utilities including indicating the presence of the horizontal location of underground utilities using geophysical prospecting techniques, including electromagnetic, magnetic, sonic or other energy fields
Locating utilities including obtaining precise horizontal and vertical position of the utility feature by excavating a test hole
Data management including the development and delivery of CADD or GIS data specifically including digitizing, attributing, and repositioning
Networking including establishing a topologically correct depiction of the utilities network indicating all point of connectivity, direction of flow, sources and sinks and impedances to flow
Management of task orders and deliverables including contract oversight and coordination

All projects services were performed in accordance with the Standards Guideline for the Collection and Depiction of Existing Subsurface Utility Data, American Society of Civil Engineers, 2003 (CI/ASCE 38-02).

Task assignments have included:

Washington Dulles International Airport Existing Conditions Survey - International Arrivals Building: AMT performed a topographic survey of project limits including 0.2 ft contours, surface features, paint striping, FF elevations, and underground utilities based on visible above ground features, available records, and utility designating. Inverts of storm drains and sewers were obtained, where readily accessible and shown on the drawing. Utility Designating (Quality Level B) services were provided including marking and identifying underground utilities described within the limits of the topographic survey. Conductive utilities were marked utilizing Geophysical prospecting techniques in conjunction with radio, audio and electromagnetic equipment. A utility sweep was performed to identify any unknown conductive utilities. Non conductive utilities were marked utilizing above ground features, utility plats and/or as built and recollections. Sewer and storm drain information was collected utilizing inverts. Utilities were marked utilizing standard marking paint and/or flags in accordance with APWA standard code to ensure accuracy in the collection of the information. Survey collected data in the field and include designated information within the topographic survey drawing. Non conductive utilities were designated on the CAD file as DATR (Data According To Records). Basic Maintenance of Traffic (MOT) was provided including cones and signs as needed. Additionally, AMT performed 8 utility test holes as directed by client in locations where precise utility depths may be required. These test holes locations were determined by the future A/E during the design phase of the project.

DCA In-Line Baggage Facility: AMT provided utility designating (Quality Level B) services for (20) proposed geotechnical borings involving the construction of a new baggage sorting facility underneath the upper ramp deck and above the commercial lanes between terminal curbside and the outer curbside areas to be completed at Reagan International Airport Terminals B and C between two pedestrian bridges connecting the terminals to the Metro station. AMT marked and identified known underground utilities in a 20 foot radius around each individual bore hole location. Conductive utilities were marked utilizing geophysical prospecting techniques in conjunction with radio, audio and electromagnetic equipment. Multiple utility sweeps were performed to identify any unknown conductive utilities. Non conductive utilities were marked utilizing above ground features, utility plats and/or as built and visual inspections. Utilities were marked utilizing standard marking paint and/or flags in accordance with APWA standard code to ensure accuracy in the collection of the information.

All task assignments were completed on time and within budget.

Other Subsurface Utilities Projects