Sustainability of the Natural Attenuation of Aromatics (BTEX)- NICOLE project
Country: Netherlands
Start Date:   1/8/2004         Duration: 24 months         Project Type: RTD
Contract Number: 
Organisation Type:  Consultancy, contractor or other service provider
Topics: 
Contaminated land-->Remediation options-->MNA
Contaminated land-->Wider impacts / sustainability-->Environmental
Project objectives: 
Besides chlorinated solvents, the aromatic hydrocarbons (BTEX) form an important group of contaminants in industry that are frequently detected in groundwater 
plume areas for which natural attenuation is considered. Also for BTEX contaminations the sustainability of NA processes is important. However, only parts 
of the existing S-NA protocol for chlorinated ethenes can be used to predict the sustainability of NA processes for BTEX contaminations. This is caused by the 
fact that the biological degradation processes for aromatics require different circumstances than the biological degradation processes for chlorinated 
solvents. In order to meet the requirements for BTEX degradation, the existing S-NA protocol has to be adapted. The objective of this NICOLE project is to develop 
a protocol to determine the sustainability of NA of BTEX, which can be used as a management tool to make decisions concerning NA processes and to optimise monitoring 
activities.
Project Summary: 
Monitored Natural Attenuation (MNA) is increasingly recognised as an interesting process that can result in loss of contamination – especially in plume areas 
of contaminated sites. Due to naturally occurring processes, active remediation efforts can be reduced and risks for receptors (in the source-path-receptor) 
are much lower than expected. Most protocols that are available to determine the occurrence of NA are mainly focussed on monitoring processes that indicate 
whether degradation has occurred in the past. In most cases this information is extrapolated to predict plume development in the future, for instance using 
modelling.         
         
However, when predicting plume behaviour in the future over longer periods of time, the sustainability of NA processes is important. None of the existing 
protocols considers this element. Will the processes that are needed to counterbalance migration of the contamination also occur in the future? Are estimations 
used in modelling still valid in, for instance, 5 years from now? Based on monitoring of Bioclear at more than 100 sites in The Netherlands and abroad, it was concluded 
that the occurrence of NA may be overestimated. This is mainly caused by a lack of understanding and detailed information about the underlying mechanisms of 
these processes. This information is essential to give a reliable extrapolation of plume behaviour in the future.         
         
Together with governmental and industrial parties a new systematic protocol for determining the sustainability of NA processes was developed in 2002. 
This protocol (S-NA) focussed on contaminations with chlorinated ethenes. The developed protocol helps industry, governments and consultants to get a reliable 
picture of the NA processes and – more important – the sustainability of the process in the future. The developed S-NA methodology has proven to be a useful management 
tool in order to make decisions in the case of NA processes for chlorinated ethenes.
Achieved Objectives: 
A report to NICOLE is in preparation, a summary of which will be posted on http://www.nicole.org
Product Descriptions:
Additional Information:
Project Resources:
Weblink:
http://www.nicole.org/projects/DisplayProject.asp?Project=24
Funding Programme(s): 
NICOLE Funding Scheme
Link to Organisations:

Network for Industrially Contaminated Land in Europe
Submitted by: EUGRIS Team Professor Paul Bardos  Who does what?  10/10/2006 09:59:00
Updated by: EUGRIS Team Professor Paul Bardos  Who does what?  13/10/2006 10:10:00