What’s the problem?

Dalkeith lies 7 miles north-east of Bilston within the same mining block and several collieries operating between 1854 and 1978 with interconnecting underground passages or roadways.

Junkies Adit was constructed in the 1800s to allow water extracted from the local mines to be discharged into the river South Esk which this was common practice for the era. As we have become more aware of the impact of untreated discharges, it is now recognised how damaging this can be.

In 1989, the coal production at Bilston Glen colliery ceased and as the colliery closed, the pumping system used to remove water that entered the mine workings was also stopped. This has resulted in water building up in the mine workings over time, referred to as a mine water rebound. The rebounded mine water has elevated levels of minerals and metals, and this eventually spills out from adits at surface level due to the workings being over capacity with water, known as breaking surface.

Mine water discharges from Junkies Adit, concentrated with iron and manganese

As the water has risen and progressed through the mine workings, it has accumulated minerals and traces of metals – notably iron and manganese – from interaction with the coal seams. These minerals and metals remain either suspended or dissolved in the mine water as the water progresses towards the surface. The adit is at a low point in the underground labyrinth and, as the mine water level has increased, it has become a natural escape for the mine water that flows through the interconnecting passages underground.

A clear split in colour is showcased above, showing the impact the mine water is having

Since around 2010, the mine water within the Bilston Glen shafts has broken surface and been discharging from the workings at the Old Fordell adit (or Junkies Adit) in Dalkeith. The discharge is heavily concentrated with iron, causing the flow from the adit to be a noticeable opaque, orange stream of mine water that is flowing directly into the River South Esk, causing pollution to the watercourse’s ecology.

The dissolved iron in the river water oxidises and then settles to the river bed, coating it with an orange layer which reduces the habitat for aquatic invertebrates which are part of the food chain for fish; this subsequently causes a decline in fish life. The discharge at Dalkeith has occasionally extended to impact the River South Esk as far as the Firth of Forth estuary at Musselburgh, which has now presented a “fish barrier”, stopping fish from migrating up the river.

Ochre covered river bed further downstream from Junkies Adit

Furthermore, the high iron levels and associated discolouration is impacting local beauty spots, such as Dalkeith Country Park, and public/visitors noting the colour of the river passing through and the lack of biodiversity within its waters.

Other sources of mine water

It is not uncommon in areas of high mining activity for there to be more than a single discharge of mine water

Within the Midlothian area, historical, small-scale coal mining thrived throughout the 19^th and 20^th century, and discharges from these mining operations are inevitable. These are typically small discharges with low levels of iron and have limited impact on the local ecology.

Location of Junkies Adit in Dalkeith