Assessment of soil and groundwater contamination at a former Soviet Military Base. Valmieras Iela Armoured Vehicle Workshop, Riga, Latvia APPENDICES
Frie emneord: Olje " " : Tungmetaller A former Soviet military armoured vehicle workshop has been subject to site investigation to examine soil and groundwater contamination. Site investiga- tions have indicated that groundwater is contaminated by hydrocarbons, free phase LNAPL oil being found in one of the boreholes (borehole 3 beneath the scrapyard). Soils at the site are contamonated by oil and the heavy metals, Pb, Cu, Zn and Cd. Risk assessment techniques have been applied to make a so-called "Tier2" assessment of risk to human health and risk to water resources. The asessment has concluded that contamination from the site will not reach the River Daugava within 39 years, even without taking into account sorption and biodegradation. The risk assessment concludes that the site can remain in its current usage or be redeveloped for commercial purposes without any risk to human health. The assessment predicts no unacceptable risk to off-site groundwater resour- ces (well in Quaternary aquifer at 200 m distance or bore in Devonian at 500 m distance) or to the River Daugava from the site. If the site id redeveloped for residential use or for open public access (parkland), an unacceptable human health risk may be present. If suck redevel- opment is proposed, either (a) a "Tier 3" risk assessment should be carried out to make a more refined, less conservative assessment of risk or (b) cleanup of selected areas shoould be carried out to cited risk-based clean-up levels.