A mine waste water treatment scheme in north-east England is removing over 98% of the metals from drainage from old ironstone mines which feed into Saltburn Gill.
In 1999 a large mine water outbreak occurred which flowed into the gill quickly turning the stream a bright orange colour. This severely impacted the fish and river insects and smothered the stream bed in the gill and Skelton Beck. It also affected the bathing water quality on the beach.
Following initial work, the Coal Authority was asked, in 2013, to develop and build a mine water treatment scheme because of our expertise in treating water at historical mining sites. The treatment scheme works by using four lagoons, with cascades and a drying bed, to remove the iron from the raw mine water. The mine water is pumped to the top of aeration cascades and over a period of two days it flows down through each settlement lagoon where the majority of the iron settles. The sludge is then transferred through underground pipes from the bottom of the lagoons through into the drying bed where it is collected and removed. The treated water then passes through a polishing reed bed that acts as a further filter.