Agriculture Reference
In-Depth Information
important to have control of: (1) the pollution source, (2) the behaviour of pollutants in soils
as influenced by spatial variability of the subsurface, (3) their removal rates (adsorption,
degradation, precipitation) and how these can be optimised, and (4) long term effects on the
soil system. In the above sections some of these aspects related to contaminants from winter
maintenance in cold climate have been discussed, as well as different methods for
subsurface characterisation and contaminant transport monitoring. The importance of
dealing with heterogeneities in modelling strategy has also been dealt with.
6.1 Legal and political incentives
How contaminants are dealt with at contaminated sites in general, is not only determined by
whether the scientific community can overcome present challenges as those discussed in the
previous sections, but also within which political and legal framework contaminated site
managers work under. Whether the optimal strategies for monitoring and cleanup are
chosen depends on the following:
A correct conceptual understanding of the processes which determine flow and
transport of the contaminants, which is the prerequisite for correct choice of modelling
tool to assist management at the site.
The scientific knowledge, do we have the right methods and understanding of the
processes to be able to deal with the contamination in a good way? which implies
Good methods exists for mapping and monitoring surface and subsurface
heterogeneities, at present a combination of destructive and non-invasive
techniques are recommended in combination with transport modelling.
Robust relationships exist between geophysical properties and hydrogeological
properties and sufficient resolution of survey at the site.
Robust relationships exist between geophysical properties and contaminant
situation in the soil, and sufficient resolution.
A sound method for coupling of different methods destructive and non-invasive
methods, for quantitative description of contamination levels and remediation
efficiency.
Appropriate remediation techniques for heterogeneous systems exist.
Managers' knowledge about the system they are in charge of, the quality depends on:
Size of company, in view of available resources made available for such purposes.
Type of contaminant - available information about reactive properties
Company regulations and policies
The authorities knowledge about contaminants, survey possibilities, modelling and risk
factors, as well as their capacity to follow up contaminated sites and validate that
accepted procedures are being followed.
Legal international and national framework regulating expectations to contaminated
sites.
6.2 Cold climate implications
Scientifically many processes are still not well described for low and freezing temperatures,
such as physical conditions in freezing soil and how to model these, especially the
combination of de-icing chemicals which lower the freezing point in a soil system near 0ºC
is complicated. Degradation and biological dynamics as a function of low temperature is
generally not well described. Instrumentation may work poorly under frozen conditions,
