Groundwater environmental forensic investigation combining multivariate statistical techniques and screening analyses

• Heavy metal contamination was identified in groundwater monitoring wells surrounding a waste deposit facility at the Rönnskär Cu–Pb–Zn smelter in Skellefteå, northern Sweden. The main objective of this study is to identify the sources of contamination, utilizing element screening analyses and multivariate statistical techniques. A second objective is to determine the usefulness of these techniques in Environmental Forensics investigations of contaminated groundwater at a complex industrial site. Water samples were collected from four groundwater monitoring wells and six waste deposit cells surrounding the contaminated area. Seventy-two elements are statistically examined and the dataset is reduced to the variables representative of the contaminated source material from the smelting process. A three-component model is identified and explains 88% of the total variation in the dataset. Component 1 includes concentrations of Cd, Co, Ni, Rb, Re, and Zn. This component displays a high correlation with two of the deposit cells and their associated groundwater monitoring wells. Component 2 is comprised of Sb, Cu, and Mo. This component displays a correlation between all monitoring wells and deposits likely due to the high mobility of these elements as oxyanions. Component 3 is dominated by As and displays high correlation to three older deposit cells representing a completely different source than for Components 1 and 2. The application of screening analyses and multivariate statistics in this study has achieved a meaningful identification of sources of contamination in the investigated area. It was also shown to be useful as an initial survey aiming to optimize a full-scale monitoring program at the site.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Geokemi (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geochemistry (hsv//eng)

Keyword

Rönnskär

multivariate statistical techniques

principle component analysis

multi-elemental screening

groundwater contamination

heavy metals

Tillämpad geokemi

Applied Geochemistry

Publication and Content Type

ref (subject category)

art (subject category)