Remediation of the area contaminated by the wood impregnation plant in Srní

Remediation of the water intake area of the water source Česká Lípa - south

MEGA, in cooperation with DEKONTA, carried out an extensive project to remediate an old environmental burden in the water source catchment area of Česká Lípa – South. The area was contaminated by the historical wood impregnation operation, posing a significant risk to a regionally important groundwater source.

Project objective

The main goal was to reduce the potential risk of contamination of the groundwater source by polycyclic aromatic hydrocarbons (PAHs) and petroleum substances. The project focused on removing the source of contamination, the extremely polluted rock environment, in the contamination centre and the drip areas.
Implementation Period
The project took place from September 24, 2019, to August 31, 2023.
Funding
The project was co-financed by European Union funds through the Operational Programme Environment and additionally supported financially by the Liberec Region and the municipality of Provodín.

Remediation technologies applied

The following remediation technologies were used to achieve the project goals:

1. Excavation of intensely contaminated sandstone eluvium and its treatment through on-site bioaugmentation.
2. Treatment of contaminated sandstone bedrock using the in-situ chemical oxidation (ISCO) method with Fenton's reagent.
3. Protective pumping followed by groundwater purification using the photooxidation method.

Achieved results

• Total remediated area: 8,617 m².
• Treatment of 12.943.80 m³ of contaminated soil through bioaugmentation.
• Treatment of 13.729 m³ of groundwater at the remediation station.
• Removal of 27.87 tons of PAHs and 13.3 tons of C₁₀-C₄₀ petroleum substances.
• Removal of 812.33 tons of hazardous waste.
• Application of 302 tons of Fenton's reagent into the bedrock.

After completing the remediation work, we reached the specified remediation limits with a safe margin. The potential risks from residual contamination are now at an acceptable level.

Environmental benefit

The project significantly contributed to the protection of an important groundwater source in the region. By removing the main contamination hotspots, further increases in contaminant levels in groundwater were prevented, thus eliminating the threat to the catchment area and domestic wells in the village of Srní near Česká Lípa and other locations in the potential direction of groundwater flow.

Follow-up measures

After the remediation, a two-year post-remediation monitoring plan was proposed, with semi-annual PAH analysis in groundwater from selected boreholes. This monitoring aims to evaluate the long-term effectiveness of the remediation measures.