NOLDOR S.R.L. offers assessment, developments and studies related with hydrology and environment. In these fields its main tools are radiotracers and isotopic indicators included the environmental ones. A complement for these techniques is the application of mathematical models to simulate the behaviour of water bodies and to evaluate extreme situations.
In this framework NOLDOR has capabilities to envisage studies on surface water and groundwater pollution, determination of leakage in lakes and reservoirs, hydrological studies, analysis of natural or human induced extreme events and assessment in all of these fields.
For the sake of sustainability of hydrological resources is necessary and convenient to have suitable techniques and methods for the control and surveillance of the biosphere pollution. The environmental impact of each hydroelectric complex, industry, village or navigable water body cannot be considered as an isolate or located fact. They should be taken into account as a result of concatenated effects generated not only in the own basin but also in the neighbour ones.
In such a context, NOLDOR offers heavy metal determinations, radioactive material measurements, toxic products analyses and evaluation of any factors that contribute to degrade the environment. This proposition is addressed to national agencies and private companies related with the treatment of industrial, mineral or urban wastes.
All the dynamic tracers and indicators as well as the methods and techniques suggested here have very high sensitivity, specify and reliability. They are suitable for detection, measurement and control of inadequate practises for waste management in the basin under study.
At present, there are more than
5,000 known atoms (isotopes) being radioactive around of 95% of them.
Radioactivity is present in almost every material or biological organism
in concentrations that depends on the physical, chemical or biological
characteristics of the considered material.
The contribution of fossil fuels (coal, oil, gas) to increase the
environmental radioactivity level is very well known. The generation of one electric
gigawatt from coal releases to the environment between
109 y 1011 Bq of radon (220Rn and
222Rn) in a year as well as lead-210 (210Pb), radium- 226
(226Ra), radium-228 ( 228Ra) and polonium-210 (210Po)
among other radioisotopes in a range from 108 to 1010
Bq in a year. These effluents are mainly discharged to the
atmosphere and the hydrosphere and their release rates are comparable to
those generated by nuclear power plants operating in standard conditions.
NOLDOR offers the following techniques to measure or to evaluate the contamination level in surface water, groundwater and sediments: alpha, beta and gamma spectrometry, mass spectrometry, X-ray diffraction, atomic absorption, nuclear activation analysis chromatography and "in situ" determinations.
Leakage from lakes and reservoirs
Leakage in water storage and conveyance systems may influence the economic value of a project and create serious problems related to the stability of the hydraulic works. Therefore, to find the rate of leakage and its preferential paths it is important to identify as precisely as possible the regions where the leakage occurs. Various isotope techniques can be applied with that purpose.
Tracer application is one of the better methods to investigate leakages in huge reservoirs. The information got in preliminary studies allow to elaborate hypothesis about the location of the areas where infiltrations are likely. Artificial tracers can be applied to test the validity of such hypothesis, being iodine-131(131I) the most commonly radioisotope used to accomplish this task.
Preliminary studies should include the collection of as
much information as possible in terms of the available time and resources
to solve the problem. The most important data to collect should include:
geological information, inventory of the outflows possibly connected with
the reservoir, modifications in the outflows, precipitation regime,
changes in the reservoir level, vertical thermal profiles in the lake,
water geochemistry and borehole information. The behaviour of many of
these variables should be followed along a complete hydrological cycle.
Whenever any kind of facilities have to be sited in a river bank or in the proximities of a water body the knowledge of the hydrological behaviour of a basin is a previous condition
A hydrological study gives invaluable information not only with regard to the past or present but also is useful to predict the trends of the variables involved in the project.
The collection of historical data, its analysis and interpretation are the basic tools for any hydrological study. This data is used later to feed mathematical models which will produce reliable results and valuable forecasts.
The climatic, hydrological and geological aspects are analysed through the information obtained regarding temperatures, pressures, precipitations, flow rates, soil composition, aquifer interconnections and recharge sources.
The knowledge of meteorological variables (winds, pressures, temperatures, rains) and hydrological variables (flow rates, water levels) related with their daily changes as well as with their historical evolution along months and years is on the basis of the understanding of the behaviour of any water body.
This information makes it possible not only the evaluation of standard situations but also the foresight of extreme floods and water shortages with the help of mathematical models.
In this framework, the human induced events have also
to be considered, such as construction of new hydroelectric works, dams
and canals as well as different kind of accidents that could generate
extreme hydrological events.