The team from the Clean Environment Management Centre (CLEMANCE) at the University of Teesside, U.K., says that it is close to finding a solution after identifying a way of pumping and treating the minewater to tackle the pollution seeping from old ironstone mine workings at Saltburn Gill. CLEMANCE'S team believes an existing shaft or a new borehole could drain away the polluted water, instead of letting it coming to the surface in the Saltburn Gill Nature Reserve, which is a Site of Special Scientific Interest because of its ancient woodland.
The pollution began in May 1999, when a new discharge from abandoned ironstone
mine workings turned the beck a rust color, raising concerns for the health of
the Saltburn Gill Beck, which runs into Skelton Beck through Valley Gardens
Park and on to the beach.
The water is not toxic, but contains
high levels of dissolved iron. Nearly half a tonne of iron ochre is deposited
on the stream bed every day, smothering it to such an extent that wildlife
struggles to survive. The discharge means that more than 100 tonnes of the iron
flow into the North Sea every year via the beck.
The ongoing investigation into the problem has been carried out by
organizations including CLEMANCE and the Environment Agency, working with
Saltburn, Marske and New Marske Parish Council, Tees Valley Wildlife Trust and
the Saltburn Gill Action Group (SGAG), which was set up on 2005 to work towards
The Environment Agency has secured funding to follow up recommendations from
the feasibility study this year, which could lead to a long-term solution. The
Coal Authority is supporting the work, using expertise gained from treating
coal mine water problems.
Drilling a borehole to pump and treat is seen as the best option by CLEMANCE
after the idea of creating reed beds to filter the water at the discharge point
in the steeply wooded valley of Saltburn Gill proved impractical because they
would have to be huge to do the job properly.
Dr Richard Lord, CLEMANCE's Reader in Environmental Geochemistry &
Sustainability, says: “We were excited when we found an old mine shaft, which
had not been closed off, and we wondered if we could be somewhere to pump the
water underground from, rather than letting it come to the surface naturally in
”Through the use of CCTV cameras, we have been able to check the shaft's
condition. It was disappointing when we discovered that the shaft was blocked
off further down, but the survey gave us critical information about the
minewater levels, and it did get us thinking about pumping as a way of
controlling the pollution.
”Drilling a borehole nearby to pump the water
from the underground workings will allow it to be treated and discharged back
into the Beck. That way, we could make sure that it does not leak out untreated
close to the Saltburn Gill nature reserve. We are hopeful that we are nearing a
solution to this difficult problem at last.”
Dr Lord explains that the work is important because the European Union's Water
Framework Directive calls for all catchments to be of good status by 2015.
However, some former metal mining areas still experience serious problems from
He notes, “The work at Saltburn Gill is very exciting. There are plenty of becks
and streams across the country with similar problems from old metal mines, and
if the solution works at Saltburn Gill, it could be used elsewhere. At the
moment, many of them simply are not up to the standard that will be required.”
Pumping and Treating Polluted Mine Water
April 28, 2009