Site-Specific Ecological Risk Assessment - Dealing with Contaminated Sites: From Theory Towards Practical Application - page 716

15.7 Outlook
In the Dutch Soil Protection Act the ecosystem is relevant for any kind of land
use, although the ecological protection level varies (e.g. nature is considered more
sensitive than industrial land use; Rutgers et al. ( 2008b ); Swartjes ( 1999 )). This has
triggered attention to ERA, principally at all contaminated sites, also outside nature
areas. Public support of this policy is limited, especially in cases where there is no
visible damage to the terrestrial ecosystem. This has to do with lack of knowledge
and, hence, appreciation for the tasks and significance of the soil ecosystem, among
the general public (see Chapter 13 by Swartjes et al., this topic). Results from a Triad
approach-based assessment will support the acceptation of remediation measures
by the general public in these cases. Acceptation is expected to improve further
from increased environmental awareness due to climate change and rephrasing soil
functions into the goods and services of the soil system (Rutgers et al. 2009 ).
A compelling recommendation to use the Triad approach in the higher tiers
of ERA will result in increased attention on ecological issues and habitat pro-
tection. This was observed in the Netherlands (SKB 2009 ). In the lower tiers of
ERA (tier one and two in the remediation criterion; Rutgers et al. ( 2008b )), the
surface area exceeding a threshold for Toxic Pressure of the mixture of contami-
nants has to be remediated. In many cases in the Netherlands, the goal of a Triad
approach-based ERA in tier three and subsequent tiers is then to reduce the surface
area to be remediated and hence to reduce costs. Step by step, the Dutch regu-
lators have become less hesitant with respect to interpreting Triad approach-based
results. This was concluded from an inventory from 42 Triad approach-based assess-
ments with an evaluation of the interpretation and integration of the results, and the
decision-making process (SKB 2009 ). In 63% of the cases (total 45: the unknowns
were omitted from the analysis), the management and remediation decisions were
adjusted in reaction to the results from the Triad-based assessments. Since local
administrations (e.g. provinces) and the national government have ratified an agree-
ment on speeding up the soil remediation (Covenant 2009 ), and the procedural
standard for a guidance on incorporation of a Triad in ERA will be soon available
(NEN 2010 ), it is expected that the number of Triad-based Risk Assessments will
further increase.
Although many tools for a Triad approach in ERA are available, there is still
a strong demand for improved and robust methods in many cases. Also, many
methods are considered not cost-effective or too laborious for smaller cases.
Consequently, increasing the number of Triad-based Risk Assessments will demand
for improved, new, standardized, robust and cost-effective tools.
Although ecological surveys in principle are the most site-specific part of an
ERA, it is often hampered by a weak relation between contamination levels in
soil and ecological observations and, hence, may lack plausibility. Ecosystems,
communities and populations of organisms are shaped by a comprehensive set
of environmental factors, where soil contamination is only one of those factors.
Furthermore, ecological field observations occasionally need highly-trained experts
and a relatively large effort.