AQUATERRA STORY LINE
As one piece of work to set the work of AquaTerra into a wider context of research and application, the rationale behind
AquaTerra was summarised in a brief statement known as the AquaTerra storyline. The purpose of this text was to place the
work of AquaTerra into a continuum of both human activities on the planet and research activities into river basin management.
A development of the storyline (originally produced by Peter Grathwohl, project manager of AquaTerra) is presented below.
With the onset of mining, man started to distribute elements on the earth's surface, which until then had been to a large
extent hidden in the earth's crust. During many centuries of mining operations river sediments, and consequently floodplain
soils became enriched with heavy metals. In addition, as the world's population began to increase markedly following the
agricultural revolution, the, burning of biomass and coal caused the deposition of soot, chars and associated organic compounds
such as carcinogenic polycyclic aromatic hydrocarbons (PAHs) in the environment. Sites with coal-based industries
(such as ore smelters, glass production, charcoal piles) produced severe local and diffuse pollution. As the industrial
revolution took hold in the nineteenth century, emissions of pyrogenic compounds increased by a factor of ~100, mostly as a
result of increased energy demand, which was satisfied by the use of fossil fuel (coal and later oil). With the technological
advance of the early industrial revolution, further developments in technology and design produced further, different forms of
contamination. From the early 20th century manufactured chemicals for various purposes were released into the environment.
The most prominent group are chlorinated compounds used as pesticides (DDT, lindane, PCP), flame retardants (PCBs later PBDE),
solvents (TCE, PCE, etc.). These anthropogenic compounds are often stable and often occur now at a global scale and throughout
the food chain. Despite environmental regulations such as the Stockholm Convention on persistent organic pollutants (regulating
the so-called "dirty dozen"), new compounds are continuously designed and produced and will enter various environmental compartments
(such as water, soil and sediment) over time as they are used.
Without doubt, these manmade compounds have produced a chemical footprint on the entire planet, which is an often overseen yet
important aspect of global change. Apart from hotspots, concentrations are low and often occur at trace levels. Thus it remains
debatable whether toxicological effects on man or biota have to be expected. Do low concentrations of xenobiotic compounds matter
at all and are compounds, especially organic compounds, not quickly degraded or diluted in the environment? How much can the system
take before a "real" damage occurs and is such damage permanent or reversible? These are some of the questions that AquaTerra has
tried to answer.
The scientific work in AquaTerra follows the pathway of the pollutants in the environment from their input into soils (through
atmospheric deposition, land use or contaminated sites, for example), leaching from soils, transport to and in groundwater to
surface water, transport with sediments to the floodplain soils and finally into the atmosphere again (the "chemocycle" of pollution).
The aim is to assess the biological, chemical and physical processes involved in the movement and amendment of contamination in order
to predict the long-term fate and impact of man-made pollutants in the environment. Such a prediction requires data collection from
the field and the laboratory, and the development of numerical models, which couple relevant processes and simulate pollutant
distribution and turnover rates over periods of time raging from decades and centuries through to millennia. In addition the social
and economic impacts of human activity need to be considered in terms of the impact they may have on both contamination and pollutant
transport both now and in the future. Climate change is another global consideration that needs to be considered when assessing the
fate of contaminants in the environment.
Major achievements and impact of AquaTerra include findings such as:
- The most effective degradation of contaminants occurs at the groundwater surface interface
- Resilience works, but for many compounds the time scale is 1000 years or longer
- Natural Attenuation works only sometimes and often only partially in the field
- Many compounds are still accumulating in environmental compartments, while new compounds are still being released -
their concentration in soils will increase continuously
This leads to key questions such as:
- Are future generations at risk?
- How do we adapt river basin management plans?
- How can we mitigate and improve the situation?
AquaTerra does not provide definitive answers to these questions, nor was it intended to do so. It does, however, provide
information that can be used to answer, or help to answer, these questions. It has also provided an abundance of information
that is of interest to a wide range of stakeholders, who may care to use the information generated in a variety of ways.
Consequently, AquaTerra has made a conscious effert to make its work as accessible as possible to as wide an audience as possible,
through stakeholder workshops, press releases, audio visual material, news reports, technical summaries, factsheets and peer-reviewed
literature, as well as project deliverables.
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