Ubja oil shale quarry was opened in 2005, and is the smallest of its kind in Estonia. Oil shale is one of the components of cement plant fuel. The size of the land is 165,73 ha, including extracting permit area – 152,22 ha. About 50 ha have been extracted so far.
Quarry is located in West-Viru county, Sõmeru parish, west from Ubja village. Quarry is surrounded from the north with Ubja-Kohala road and Ubja village, from the west with railway and Ubja-Sõmeru road and from the east with Toolse river.
The commercial bed is mined below the groundwater table, thus the main problem in mining is the removal of water. Water from the open cast mine is pumped into a sedimentation pond. From the other end of the reservoir, water flows by gravity into the Toolse River.
Mining technology that is applied in the Ubja oil shale surface mine is open-cast stripping. Restoration is done together with mining. Dumps are leveled and covered with separately stored fertile humus layer, after that, the trees are planted.
Before mining, there were about 79 ha farmland and 73 ha woodland. On the northeast of the quarry there is not so valuable alder and birch forest. The farmland is still in use to arable crops, because mining activity is not that far jet. Due to growing crops, there are also bears, wild boars and migratory birds.
There are over 200 different plant species, among others also II category protected species like Sisymbrium supinum.
About 2 Mm3 of water is pumped out from Ubja mine every year, to Toolse river
Ongoing nature projects:
- Tree planting every year.
- Biota inventory