five questions about CVM contaminating certain French pipes

They decided to take legal action “forcing the country to react”. Two associations filed an appeal with the Nantes administrative court, Monday 27 October, for the sake of“ordering the state” to better detect water contamination with vinyl chloride monomer (VCM). This carcinogenic gas is present in certain PVC drinking water pipes installed in the 1960s and 1970s. However, water quality analysis shows concentrations of these pollutants are higher than European standards. What concerns residents in the area concerned.

1 What is CVM?

Vinyl chloride monomer (VCM) is a gas that comes from some PVC (polyvinyl chloride) pipes installed before the 1980s. These chemicals can pollute the water that passes through these pipes and accumulate in groundwater. The risk of contamination increases depending on the residual VCM content in the PVC, the water temperature and the residence time of the water in the pipe.

2 What are the health risks?

Vinyl chloride monomer has been classified since 1987 as a definite human carcinogen, according to the International Agency for Research on Cancer (IARC). It particularly causes liver cancer, explains the Ministry of Health, which reminds that this classification is based on studies carried out in professional settings, with inhalation exposure to high doses of CVM. However, according to the ANSES report (PDF)Vinyl chloride monomer may also be carcinogenic “through consumption” for humans, and therefore drinking contaminated water.

The quality limit set by the authorities is 0.5 micrograms MVC per liter of water (µg/L). If this limit is exceeded, a second check must be carried out within four weeks. If it is exceeded again, the water is considered ineligible and may be subject to consumption restrictions.

3 Where is CVM found in tap water in France?

Vinyl chloride monomer has been sought after in water health control since 2007, according to the Ministry of Health. However, public data on this is still very fragmentary. In fact, only a quarter of non-compliance cases identified by Regional Health Agencies (ARS) are made public, according to data from the NGO Générations future. In addition, the results of drinking water analysis, which you can consult in our search engine, are published for each distribution unit, while water contamination by CVM is a very localized phenomenon and only affects a few pipes in the network.

The Ministry of Health estimates that between 50,000 and 340,000 km of pipes in France could potentially be affected. For researcher Gaspard Lemaire, a specialist in this field, CVM is present in 15% to 30% of the French network, or about 275,000 km of pipes at risk of contamination. This situation is mainly found in residential areas spread across the rural network.

4 How do I know if my water is contaminated?

You can view the latest water analysis results at your address in our search engine as well as reports from previous years on the Générations futures website. These bulletins are also available from city hall or from your city’s water distribution manager. Finally, a summary note prepared by ARS regarding water quality is attached to your invoice once a year.

If your drinking water distribution network is affected by exceeding the threshold, the NGO Générations futures recommends contacting your city hall to find out whether your home is actually served by the problematic pipe.

5 What to do if pollution occurs in CVM?

If drinking water regulatory limits are exceeded, those responsible for production and distribution must notify the public and take corrective action. Purification can thus be carried out to reduce the pollutant content in the water, however “only associated pipework can guarantee long-term compliance with CVM”explained the Ministry of Health. Replacing one kilometer of pipe costs between 50,000 and 200,000 euros, depending on the site configuration, and is the responsibility of the community that owns the network.

While waiting for the implementation of these measures, residents in the relevant areas are asked to consume bottled water for drinking and preparing food. If the MVC concentration does not exceed 1 µg/L, storage for 8 hours at room temperature in a clean jug allows the MVC concentration to be halved, the Ministry of Health also explained. Filter cartridges are not recommended.