Construction drawings and records are generally less than 100% accurate and one study found that typically 4 of 5 such drawings contain errors.
The best way to ensure that you have accurate data on buried utilities is to develop underground utility mapping. The three main steps to this are:
Step 1: Base Plan – A base plan is developed from existing records such as site surveys, design drawings, construction drawings, as-built records, or utility company mapping. The objective is to collect and consolidate available utility information to act as a starting point for further investigation.
Step 2: Utility Locating – Existing and abandoned utilities are located and marked using EM tracing, ground penetrating radar and safe excavation methods and their positions confirmed/updated and plotted to scale on the base drawings.
Step 3: GIS Referencing – (optional but recommended for large projects) Information on the base drawings is referenced to an established geographic information system (GIS) database.
Terra Discovery is positioned to assist property owners, surveyors and design professionals obtain accurate and up-to-date underground utility mapping for residential, commercial, industrial and institutional sites.