Both electronic and radio detection methods (above) and Ground Pentrating Radar (below) can be used to gather Level B utility data.

Level D
A basic level of information, Level D data is gathered by reviewing existing records obtained from utility providers and/or plans of the project site. Giving a general overview, Level D offers data for planning purposes but is not verified in the field, so it is limited in its accuracy. 

Level C
Level C uses surface indicators such as valves, cable markers, manholes or other visible evidence of underground utilities to verify existing utility information correlated with existing records. This provides a more accurate depiction of the underground utilities. However, no verification of the utilities underground is made.  

Level B
Known as “designating,” Level B employs surface geophysical techniques, including electronic and radio detection methods as well as Ground Penetrating Radar, to designate underground utilities and the two-dimensional horizontal positioning of those utilities. Suitable to meet preliminary engineering goals, Level B data allows confident decisions to be made on the placement of design features in order to avoid utility conflicts. However, at Level B no vertical measurements are made, so depths below grade are not known. 

Level A
Known as “locating,” Level A involves nondestructive vacuum excavation to map both the horizontal and the vertical positions of underground utilities, as well as determine the size, material and condition of each utility. The highest level of quality available, Level A data comes mapped in three dimensions allowing for planning around the utility in place. All verified utility positions are accurately surveyed and tied both horizontally and vertically to the project control. Surface markers are set for future recovery and historic preservation of these verified points. The comprehensive data of Level A can be easily transferred into a CADD system and/or onto project plans.

Two-In-One
At Lochrane, we combine Subsurface Utility Exploration with a topographic survey, using one crew to work on both in order to bring you comprehensive, accurate information in the most cost-effective amount of time.

The most comprehensive way to collect data, Level A involves vacuum excavation.

Availability of Information
Information gathered on any level is available one day after field work is completed and digital data is available within a few days upon final field work completion.

Formats
Information can be provided in a variety of drawing formats to meet your needs including Micro-Station and AutoCAD in either 2-dimensions or 3-dimensions depending on the level of service chosen. These can be transferred to your computer-aided design and drafting (CADD) system or onto your project plans via CD ROM, diskette or the Internet. Hardcopies, plotted to any scale, can also be provided.