The Erra River bed and banks, will be cleaned from residual waste, to the extent of 1.5 kilometres in the Uhaka Karst area. The pitch deposited on the bottom, is in places up to half a metre thick. The cleaned sites will afterwards be levelled and the river like habitats restored. The territory of the former Kohtla-Nõmme tyre plant will see the removal of 1 200 tons of waste mixed with oil, which will stop the continued spread of pollution. A cleaning technology will be developed and tested on the Pahnimäe residual waste site.
The bed and banks of the Erra River, will be cleaned from residual pollution, in the course of the project, to the extent of 1.5 km, within the Uhaka Karst Area.
The thickness of the pitch spots in the Erra River are mainly between 0.1 and 0.3 metres, in some places up to 0.5 metres. The estimated volume of pitch spots is 14 700 cubic metres. The so-called pitch is present on the banks of the Erra River, both as a pure layer and mixed with the soil. The pitch spots and the surface mixed with pitch, will be removed by peeling with an excavator and transported to the handling site. Maintenance works will be performed, after the removal of the contaminated mud, soil and pitch spots. The cleaned sites will be levelled and the river habitats restored. The activity supports three bodies of surface water that are in poor condition.
The Erra River is a 21 km long tributary of the Purtse River. The water catchment area of the Erra River is 97.4 square kilometres and the water body type is a heavily changed water body. The Erra River is in public use. The Uhaka Karst Area and its sources are at the mouth of the river. There is above ground drainage in the downstream karst area, only during periods of high water. The river is water poor, in periods of low water, also above the karst area.
The larger scale pollution of the Erra River started from the time when the mining and processing of oil shale was started. It continued throughout the entire period of the existence of the Soviet Union. The untreated effluents of mines and the chemical industry, were directed into rivers, together with closed drainage from mines, which resulted in the deposition of bitumen like substances, on the bottom of the river. This is why the bottom sediments of the Erra river are contaminated with hydrocarbons (petroleum products and PAH) and the banks have large fields of solidified bituminous residues (so-called ‘pitch fields’). The section chosen for the project has the most intensive pollution and is additionally also located within a Natura 2000 site.
The former Kohtla-Nõmme tyre plant residual pollution site will be made safe, during the duration of the project.
About 1 200 tons of waste mixed with oil and contaminated surfaces, in the framework of the CleanEST project, will be removed from the territory of the former Kohtla-Nõmme tyre repair plant and replaced with clean soil. The removal of the residual pollution site of the tyre plant, will in the future ensure the improvement of the condition of the groundwater.
The territory of the former Kohtla-Järve tyre plant, currently belongs to the AS Viru Keemia Grupp (VKG). The VKG acquired the territory after 2010. Pollution caused prior to 1993 is considered to be residual pollution, wherefore it is possible to provide state aid for its liquidation.
A study in 2013 clarified that the pollution source within the site, is located in the area of the boiler house and above ground fuel containers. There is a thick, partially solidified layer of petroleum products on the surface of a 2 000 square metre area, near the containers. The quantity of petroleum products, including shale oil, is estimated to be 500-1 200 tons. The polluted layer, reaches a depth of 0 to 1.9 metres from the surface. The groundwater is heavily polluted by petroleum products and phenols. The contents of petroleum products, exceed up to a thousandfold the limits for groundwater. The compounds are toxic and carcinogenic. The pollution source may also be affected by the semi-coke mounds, of the old oil plant to the south of it.
The use of groundwater layers close to the surface has been abandoned, due to the general contamination of the area. This means that there are no drinking water wells in the area of the pollution source and there is today, no direct threat to drinking water through pollution. The pollution source on the Kohtla-Nõmme site needs to be liquidated, to improve the condition of groundwater and prevent the contamination of water bodies, (the Kohtla River, which is being cleaned today) through the carriage (for example by rainwater and drainage) of residual pollution. The contaminated soil is stored in accordance with the rules of handling hazardous waste and soil samples taken from the site by an interval of 10x10 are analysed for evaluating the resultfulness of the works.
Pahnimäe residual pollution site
A feasibility test will be performed at the Pahnimäe residual pollution site, for restoring the contaminated soil in situ. An area of 340 cubic metres will be cleaned within the surface, without digging up the soil. The suitable technology, timing and cost of cleaning the entire site will be determined, during the course of activities. The pollution source at the Pahnimäe residual pollution site has been removed, but the soil is at the moment still extensively polluted. The territory is in use, so it is not possible to remove the soil. The use of in situ technology has been successful in Estonia, but unfortunately there have been projects where the results of using the method have not met expectations. It is therefore reasonable to start with a smaller volume of practical preliminary work, based on which it is possible to decide and plan the volume of the final investment.
Research measures will be applied during the project, for repairing the Soolika Creek. A study will determine the pollution load and pressure factors, on the Soolika Creek and measures will be developed to reduce pollution. The Soolika Creek is a significantly changed body of water, in a poor ecological condition, to the extent of 7.5 kilometres. Its catchment area is 122.1 square kilometres.
Studies of residual pollution sites
Five studies of residual pollution sites will be conducted during the project, to establish the exact impact of residual pollution on surface and groundwater bodies.
The aim of the activity is to obtain a systematic overview of the efficiency of the removal of residual pollution, performed to date, as well as to evaluate the improvement of the aquatic environment and ecosystems dependent on water. The overview will be used for planning the operationally required pollution transformation works, during the LIFE IP project and the water management plan for following periods, as well as the activities of the nature protection action plan.
The sites of investigation are:
- Ahtme mnt 88 ABT
- Kiviõli Industrial Park (chemical industry)
- Rakvere helipad
- Tamsalu railroad tie impregnation plant, groundwater pollution
- OÜ Rakvere vehicle depot filling station
Tööde kavaDone Planned
|Studies of the Soolika Creek||2019||2020|
|Transformation of the Kohtla-Nõmme residual pollution site||2020||2021|
|Pahnimäe residual pollution site||2020||2021|
|Cleaning of the Erra River||2020||2021||2022||2023|
|Repairing of the Soolika Creek||2021||2022||2023|
|Studies of residual pollution sites||2021|
|Residual pollution removal, project in preparation||2022|