Since phreatic (water-table) aquifers on contaminated sites are often the principal transfer pathway
for pollutants, the setting up of a groundwater quality monitoring network around a site liable to
cause pollution is of primary importance for rapid detection and warning.
Experience feedback acquired in groundwater monitoring generally shows that once the primary
source of pollution is treated or has dried up, the contaminant plume, after an initial period of spreading,
stabilizes and is, in some cases, slowly diminished by natural attenuation.
Experience feedback also shows that some substances can be degraded into other substances with
a different physical nature or into more toxic decomposition products.
Therefore, when environmental monitoring is implemented, it is recommended that the resulting
data be periodically assessed – every four years, for example. These assessments aim to correctly
determine the evolution of any contamination over time and to modify, if needed, the monitoring or
Periodic analysis and assessment do not, however, exempt the owner/operator from taking necessary
and suitable measures to deal with any anomalies revealed during a monitoring campaign.
In practice, the situations that might be encountered are highly varied and it is very important
that a hydrogeological study be carried out to determine:
•the type of monitoring system to set up (number and location of boreholes, equipment, etc.)
•what pollutants should be monitored
The quality of the monitoring system and the data collected is the site owner's responsibility.
It is, therefore, highly recommended that work be subcontracted to an expert.
Before the work begins, any boring must be declared (DRIRE). Once the monitoring system has been
installed, the results of analyses should be sent to the Inspectorate of Classified Installations.
The Ministry of Ecology and Sustainable Development has prepared specific guidelines for stakeholders
and, in particular, for the Inspectorate of Classified Installations. These Guidelines are called
'Guide méthodologique pour la mise en place et l'utilisation d'un réseau de forages permettant d'évaluer
la qualité de l'eau souterraine au droit ou à proximité d'un site (potentiellement) pollué'.
The French Bureau of Standards, AFNOR, has published recommendations for borehole siting. These
guidelines must be adhered to in all situations (AFNOR FD-X 31-614 October 1999).
Article 65 of the Ministerial Order of February 2, 1998 (modified by the Ministerial Order of August
3, 2001) determines how a groundwater monitoring system should be implemented (number of boreholes,
Regulations stipulate obligations concerning the implementation and supervision of monitoring
networks. In the event of non-compliance with regulations or faulty monitoring, the site owner can
be ordered to rapidly comply.
New regulations went into effect on February 8, 2007:
•Note of the Ministry of Ecology of February 8, 2007 concerning Contaminated sites and soils - Contaminated
site management and remediation procedures
•Circular of the Ministry of Ecology of February 8, 2007 concerning Classified Installations
- Prevention of soil contamination - Contaminated site management
•Circular BPSPR/2005-371/LO of the Ministry of Ecology of February 8, 2007 concerning the Closure
of Classified Installations - Chain of liability - Defaulting of responsible parties
•Circular BPSPR/2006-77/LO of the Ministry of Ecology of February 8, 2007 concerning Classified
Installations - Application procedure for the detention of funds as mentioned in Environmental
Code no. 514-1
They are based mainly on the Decree of September 21, 1977 concerning the Application of the Law of
July 19, 1976 concerning Classified Installations.
Site Project Funding
No further funding information available on the EUGRIS system
The cost of groundwater monitoring depends on the characteristics of the network (borehole depth,
number of boreholes, geology, etc.). The average cost range is:
•10 to 20 K€ for installation
•1 to 3 K€ for annual follow-up
The owner is responsible for these costs. Some financial aid can be obtained from the Water Authorities.
To reduce costs, industrialists in a given region or in the same activity sector have grouped together
and successfully undertaken joint monitoring actions. In any event, monitoring is less expensive