DuPont site tar pits to be cleaned up

DuPont has applied for permission to remediate historic lime and tar pits on marshland adjacent to Lough Foyle and the River Faughan.

Friday, 17th September 2021, 5:59 pm

The works, according to a design statement, will ‘enhance the ecological amenity value of the site while addressing the human health risks posed by the legacy contamination’.

The DuPont (UK) Limited application was published this week by Derry City & Strabane District Council.

It proposes to ‘remediate the historic lime and tar deposition area at the Du Pont Maydown Works Legacy Land and its environmental improvement to include landscaping and vegetation management, pathways, fencing, car parking and associated site, access and ancillary works’.

A design statement produced by AECOM on behalf of DuPont explains how the 9.7 hectare site on the west bank of the Faughan was formerly occupied by the British Oxygen Company (BOC).

The lime and tarry waste on the land are byproducts of processes formerly used to produce acetylene there.

“Historically the construction of a railway line along the Lough Foyle (northern boundary) and subsequently a dyke along the River Faughan (eastern boundary) isolated the subject site from the adjacent watercourses. The newly dyked area resulted in reclaimed land for industrial use and was occupied by BOC. In the 1960s and 1970s surface water levels were controlled throughout the reclaimed land while a portion of low-lying land was filled with slaked lime/calcium hydroxide waste. The slaked lime was a waste product associated with the carbide process. The former Lime Pile contains naphtha tars associated with the Wulff processes and other chemicals related to historical manufacturing processes,” the statement says.

The firm proposes stabilising the tar deposits and capping the lime pits. Then nature will be allowed to take over.

Three planted floating islands, an Irish traditional hay meadow and a hibernacula for newts are among the proposed improvements.