Environment and health

All drilling works and surface technologies will be located in the area of the former Jiřího z Poděbrad barracks, so public spaces will not be disturbed.

Leaving aside the purpose of the borehole, geothermal boreholes and production hydrogeological boreholes differ in their usual depth and construction. The aim of a hydrogeological borehole is to reach the aquifer, where the rock is saturated with groundwater. In the part of the borehole that extends into the aquifer, the casing (steel or plastic pipe) lining the borehole is perforated. This allows water flowing into the borehole to be pumped out. The depth of hydrogeological boreholes is usually up to 200 m, but more often it´s just tens of metres. In geothermal boreholes, on the other hand, the aim is usually to reach as deep as possible, but with due regard for the economics of the project. This is because the ambient temperature of the rock environment and the amount of thermal energy we are able to extract increases with increasing borehole depth. Geothermal boreholes for heating individual buildings are usually between 50 and 200 m deep, boreholes up to 500 m deep can be used for heating larger building complexes or residential areas, and boreholes with depths of usually 2 to 5 km are used for large geothermal sources producing large amounts of heat or even electricity. The design of geothermal boreholes can vary. For shallow geothermal boreholes using a heat pump to pump the heat, the borehole design is usually closed, with no contact between the heat transfer fluid and the rock environment. When using heat from medium and deep hydrothermal sources or hot dry rock, the borehole design is similar to an open hydrogeological borehole, but these boreholes are much deeper and use deep aquifers that are not suitable for drinking water supply.

The supply of water to the population is a basic, fundamental and priority requirement for the use of natural resources. With this in mind, geothermal boreholes are being built and constructed in such a way that both the quality and the available quantity of groundwater are not affected in any way. In the case of the RINGEN geothermal centre projects, the geothermal boreholes will be of the closed type, so that there will be no contact between the heat transfer medium and groundwater. The future deep geothermal boreholes will be open, but at a much greater depth of more than 2 km and will not come into contact with the groundwater sources of the Cretaceous basin, which are located at depths of up to 200 m. In addition, hydrogeological boreholes are planned as part of the research projects. However, these will not be for the purpose of pumping water, but rather to monitor the condition and quality of the groundwater.

Every drilling project takes into account the presence of groundwater resources and assesses the risks to these resources when preparing the documents. In addition to the technical design of the borehole, a hydrogeological assessment is an integral part of the drilling project to eliminate project risks. Geothermal boreholes are drilled in such a way as to avoid damaging the aquifers in terms of both their quality and the pressure-hydraulic relations in the aquifer. It is true that some impact on the immediate surroundings of the well under construction may occur during drilling. The temporary pressure impact on the surrounding area may occur within the first tens of metres and is temporary for the duration of the geothermal well construction. After completion, the pressure conditions in the aquifer return to their original state. Environmentally friendly reagents and biodegradable lubricants are used for drilling. The risk of contamination of water sources is therefore absolutely minimal.

The basic limits for outdoor noise other than from traffic are 50 dB for daytime (6 a.m. to 10 p.m.) and 40 dB for nighttime (10 p.m. to 6 a.m.).