Consult the guidebook, produced under BRGM's supervision, to help forestall and deal with risks in situations where pollution is discovered by chance.
4 November 2021

The main recommendations in the event of an accidental discovery of pollution

The industrial revolution and former waste-management practices have left behind a large number of sites whose ground may be polluted. How to react in the event of the discovery of pollution during works?


BRGM presents A guide on how to react to an accidental discovery of pollution Whether you're a private citizen or a company, if you discover harmful contaminants in the soil or groundwater, help is available. Experts in contaminated soil and water are at your disposal to help you get the situation under control. Construction projects often require digging, moving dirt around, which is often when you can encounter contaminants. Sometimes you see it: iridescent water, traces of fuel, discolored soil, viscous liquids, household waste, cisterns, back-fill that doesn't look right. ODORS Sometimes you smell it. Other times it's invisible, you don't smell it, but you feel it. ODORLESS AND COLORLESS Contaminants can delay a project, and beyond the risks to health and ecology, they can add to a budget. Here's what you should do when you discover environmental pollution. Working together with worksite managers, you must find a way to stop all operations at the site. Access must be cut off and those present must evacuate. Contact managers and inform them of the situation. In case of contact with contaminants, call the emergency services for help. Even the most common contaminants found in soil can affect long-term health. STAY SAFE! If the contaminants you come across are dripping or emitting dust, vapors, or odors harmful to those in the vicinity, or if they pollute groundwater or harm natural surroundings, once again call firefighters and inform the city. It's best to act quickly, ideally within the hour to get the situation assessed and alert the right people. There are experts on contaminated sites and soil available when you need them. Hotlines are typically free for you to talk to an expert and get a clear idea of what's going on. Within 48 hours, companies or building contractors without contamination experts in house should call on third-party experts. They're people who may take samples and recommend steps to take and protocols to safely continue the works. No matter what, the city must be notified about any and all new environmental pollution. They'll have a form ready for you to provide relevant information. Be warned that you can be liable for failing to inform the city. City hall is the preferred point of contact for reporting these events and notifying the right people. It's important to keep a record of contamination activity and the steps taken to clean up pollution. A lot of data on ground hazards are publicly available online. This and other information can help you prepare before starting works to limit your risk of coming in contact with contaminants. PREPARING CONSTRUCTION PROJECTS Getting informed before starting works can help you to avoid or at least be prepared for discovering contaminants. Another option is seeking an assessment from a pollution expert before starting. Look to our safety guide for detailed recommendations as well as notification forms. The guide is free of charge and available now.

The industrial revolution and former waste-management practices have left behind a large number of sites whose ground may be polluted. Over recent years, French policy for spatial planning has promoted the rebuilding of cities upon cities (ALUR Act) by encouraging the reuse of industrial wasteland in order to limit urban expansion in natural or agricultural areas.

This situation often leads to new, previously forgotten or unknown polluted areas being discovered during development projects or works involving the digging and extraction of earth.

Some of the pollution that is discovered by chance during construction work can end up being poorly managed and/or ignored.

We have just put produced a guidebook to help manage and prevent risks in these situations.