The objective of a hydrogeological study is the identification of potential water sources – surface water or groundwater – and the setting of water catchment conditions in order to ensure the necessary water flow and to avoid any negative impact upon the groundwater and the environment. Also, a hydrogeological study determines the characteristics of the water sources in order to efficiently exploit them in favourable conditions.
The level of detail required in the hydrogeological study is normally expected to be commensurate with the level of risk posed by the water abstraction and the level of uncertainty of the available information.
Conditions and Parameters for a Hydrological Study
A Hydrogeological Study is developed in order to assess conditions and parameters such as:
- groundwater infiltration and recharge, groundwater discharge and groundwater flow rate;
- groundwater elevations and flow pathways, water quality and temperature;
- cumulative watershed impact;
- discharge and impacts on public drinking water sources.
Types of Hydrological Studies
These studies can be of several types:
- A preliminary Hydrogeological Study for ensuring the water supply from a groundwater source; the study consists of: general considerations, thematic considerations, site considerations, previous works, geomorphological data, geological data, the hydrogeology of the area: the shallow, average and deep aquifer, conclusions and work proposals, as well as graphic appendices. According to the legislation in force, a Hydrogeological Study should be prepared for any type of activity, before performing a well (or a group of wells - catchment front);
- Hydrogeological studies for delimiting the sanitary protection areas of the water catchment from groundwater sources; the study contents will include: introduction, geomorphological, geological and hydrogeological considerations, data about the existing water supply system, technical characteristics of the catchment equipment, legal requirements about the organization of sanitary protection areas, delimitation of the sanitary protection area, determination of the sanitary protection perimeter, conclusions and graphic appendices. There are several types of sanitary protection areas, with different protection levels from contamination sources: the severe sanitary protection area, the restricted sanitary protection area and the hydrogeological sanitary protection perimeter.
Main Stages of a Hydrological Study
A Hydrogeological Study includes the following main stages:
- drilling water wells through shallow, average and deep drilling, on a case by case basis;
- research made through wells and pumping;
- development of an inventory of the groundwater sources and their hydrological characteristics;
- evaluation of the status of aquifer layers;
- determination of the hydrostatic level;
- determination hydrodynamic level;
- determination of the oscillation of water level;
- evaluation of the influence radius of the water wells;
- determination of the optimal exploitation flows;
- identification of the physical status of the existing wells;
- chemical and bacteriological analyses.
The National Institute of Hydrology and Water Management is the only national institute specialized in the field of hydrology, hydrogeology and water management. As such, the institute assesses and approves all Hydrogeological Studies developed in Romania.
The legal framework is represented by the following regulating acts:
- Ministry Order no. 1278/2011 approving the Instructions concerning the delimitation of areas of sanitary protection and the perimeters of hydrogeological protection;
- Government Decision no. 930/2005 approving the Special Norms concerning the type and size of the sanitary and hydrogeological protection areas and perimeters.
AUDITECO GES holds Certificate no. 168 valid until 16.10.2021, issued by the Ministry of Environment, Waters and Forests, being certified to develop Hydrogeological Studies.