Investigating flooding sources in Fife, UK
Over several years, a small residential development in Cardenden, Fife, has been repeatedly flooded and contaminated by red-orange ochreous deposits. Ochre is a natural clay earth pigment consisting of a mixture of ferric oxide and varying amounts of clay and sand. The ochreous deposits were affecting drainage ditches, ponds and gardens that flooded. Consequently, residents organised themselves and voiced their concerns about the potential health effects of this material on themselves and their pets, and about potential damage to building foundations because of the repeated inundation. Parabis Scotland commissioned RSK to undertake a site inspection to determine the source of the flooding and to identify the responsible agency for implementing the control measures necessary to prevent or manage future flooding.
Our programme of work included desk and field studies to collate geology, hydrogeology, hydrology, historical land use, flooding patterns and land ownership data. Our specialists visited the site, identified the key sources of water in the area close to the properties and collected samples for laboratory analysis of the water facies, pH, electrical conductivity and mineral content. A hydrogeological assessment of the system was conducted. Once we had collected all the data, we wrote an in-depth final report.
From the site visit, RSK identified the water contributing to the flooding as a combination of surface run-off and a series of springs. The source of contamination was identified from the water chemistry, which strongly indicated that the interaction of the spring water with former coal mine workings or spoil deposits was causing the ochreous deposits.
RSK created a conceptual model of the flow pathways showing the likely surface and groundwater flow paths that were giving rise to the springs and seepages and the likely source of the contamination. Our experienced team also provided recommendations for water management strategies to Parabis Scotland so that it could formulate plans to satisfy residents and mitigate the adverse effects of the ochreous deposits.