REMEDIATION OF FORMER URANIUM IN-SITU LEACHING AREA AT STRAZ POD RALSKEM - HAMR NA JEZERE, CZECH REPUBLIC
A large-scale development in exploration and production of uranium ores in the Czech Republic was done in the 2nd half of the 20th century. Many uranium deposits were discovered in the territory of the Czech Republic. Over a period of 50 years approximately, 110 000 tons of uranium in concentrate were produced. Different mining methods were developed and used. One of the most considerable deposits in the Czech Republic is the site Hamr na Jezere – Straz pod Ralskem where both mining methods – the underground mining and the acidic in-situ leaching – were used. The extensive production of uranium led to widespread environmental impacts and contamination of groundwaters. Over the period of “chemical” leaching of uranium (ca. 32 years), a total of more than 4 million tons of sulphuric acid and other chemicals have been injected into the ground. Most of the products (approximately 99.5 %) of the acids reactions with the rocks are located in the Cenomanian aquifer. The contamination of Cenomanian aquifer covers an area larger than 27 km2. The influenced volume of groundwater is more than 380 million m3. The total amount of dissolved SO4 2- is about 3.6 million tons. Approximately 0.5 % of the contamination is located in the Turonian aquifer. After 1990, a large-scale environmental program was established and the Czech government decided to liquidate the ISL Mine and start the remediation in 1996.
Aquifers; Waters; Water; uranium; Mines; Mine; Mines; leaching; Groundwaters;