Iron and Manganese Testing undertaken Instead of Remediation
An effervescent (oily) and rusty sheen was noted on water within initial foundation excavations and concern was raised about possible contamination from a nearby former railway siding.
A walkover survey and geological knowledge identified the effervescent and rusty sheen as being of natural origin. Some bacteria (leptothrix discophora) that live in waterlogged places get their energy from iron and manganese, and, as these harmless bacteria grow and decompose, the iron may appear oily or form red or orange films, fluffs and coatings. It was also noted that a mining report stated that mines in the area were mainly mined for manganese, i.e. the underlying geology is rich in manganese. Therefore, no remedial measures were required.
This was confirmed by UKAS accredited contamination laboratory testing.