The excavation limits of a new water main are marked on the street. Consistent with state regulation, the excavator calls in the excavation limits to the One-Call System. Soon the street is marked with utility locations. Surprisingly, the excavator receives a fax describing that the excavation site as occurring in a zone of environmental contamination. The responsible party who faxed the notice of contamination is pleased to have averted a hazardous substance release and to have protected the excavators and the public from harm. The excavator, however, is not pleased; their fixed bid did not anticipate the cost of handling contamination and work delays.
Excavations are a common event around contaminated sites as each flash of light signifies. This map shows flashes for each excavations around contaminated sites in New Castle County, Delaware. Try adjusting the map, the date may be adjusted on the slider, and the coverage area adjusted by the zoom control.
You are watching about 3,500 excavation clearances resulting in over 1,000 advisories automatically sent to excavators by Terradex’s DigClean service. Terradex’s client since 2012 is Delaware Department of Natural Resources and Environmental Protection (DNREC). A one minute video overviews how the excavation clearance system can not only protect buried pipelines, but also convey health and safety information to workers about to dig.
Construction excavations threaten remedies, breach institutional controls, create circumstances where contaminated soils are mismanaged, and introduce health hazards to construction workers. The value of DigClean is to bring tangible information to excavators so that they can make timely, smart decisions to control these threats. Avoiding chemical contamination in the field is manageable once DigClean transmits an advisory.
The advisory provides links to general soil management plans, but can also provide a link to a site-specific soil management plan. There are also links to NIOSH Pocket Guide and Agency for Toxic Substances and Disease Registry (ATSDR) Toxic Substances Portal for chemical specific hazard information. The NIOSH Pocket Guide to Chemical Hazards is intended as a source of general industrial hygiene information for workers, employers, and occupational health professionals, while ATSDR provide guidance to non-work related public exposure scenarios. For a spill containing benzene, the respective chemical links in the advisory would include:a NIOSH benzene link and a ATSDR benzene link.