Oil contamination investigation in Karosta, Liepāja

Name: VentEko JSC
Address: Rīgas iela 22, Piņķi, LV-2107, LV
Telephone: +371 26 559 949

Pre-remediation (detailed) investigation of oil product contamination in soil and groundwater in the Karosta district of Liepāja

Year: 2020
Scope: 14+ ha

Project structure

Challenge

More than a century of operations involving oil products at the site has caused complex contamination, the extent and distribution of which needed to be clarified. Data from previous investigations had to be compiled and a detailed investigation carried out to obtain an up-to-date assessment of the contamination and prepare well-founded remediation recommendations for further work.
Solution

A comprehensive investigation was carried out: site inspection, LIF probing at 102 points, drilling of 22 boreholes, soil and groundwater sampling, PID and BTEX measurements, LNAPL thickness measurement and data analysis. The results were compiled in maps, cross-sections and a 3D model, and a SWOT analysis and remediation recommendations for further action were prepared.
Result

An area of more than 14 ha was investigated, the distribution of contamination was precisely determined and a detailed 3D map was produced. Contamination volumes were calculated in m³, separately for LNAPL, contamination dissolved in groundwater and contamination absorbed in the soil mass. An analysis of three remediation alternatives was prepared for further action.

Project facts

Client: Confidential
Industry: Municipalities & Government Agencies
Services used: High Resolution Site Characterization (HRSC)

Detailed Contamination Investigation

Remediation strategy development

The project involved a detailed contamination investigation at a site in the Karosta district of Liepāja, on the bank of the canal, where more than 100 years of operations involving oil products have caused “historical” soil and groundwater contamination. The aim of the work was to determine the extent, distribution and migration directions of the contamination and its potential threat to the environment and human health, and to lay the groundwork for planning remediation measures. The investigation included a site inspection and LIF probing at 90 points and at a further 12 points to refine the extent of the contaminated area. 22 investigation boreholes were drilled, soil, groundwater and oil product samples were taken, and PID measurements, BTEX analyses and LNAPL thickness measurements in monitoring wells were carried out. The results were processed into cross-sections, maps, plans and a detailed 3D conceptual model showing the spatial distribution of the contamination.