Members of Cwmbran Angling Club are worried that the pollution incident on the Afon Lwyd that saw the river turn orange may have killed or damaged fish stocks.

Natural Resources Wales and The Coal Authority say it was caused by mine water pollution from the Cwmsychan Brook Culvert, a former iron works site near Abersychan. The colour has cleared but orange sediment remains on riverbed.

Cwmbran Life spoke to Stewart Matthews, club chairman of Cwmbran Angling Club. He said: “The river is primarily a trout and salmon river. We’re not sure of the impact on fish stock yet. We are worried about any fish loss, and habitat loss to wildlife, that’s food and anything on the bottom and sides of the river.

“The orange sediment is on the rocks and bed of the river. You can now see orange on the roots of the exposed trees, like a sludge.”

He said it’s the time of year when fish eggs hatch on the river.

“I always want to say around December and January, you end up having fish lay their eggs and fry hatching out of those eggs. Have all those been destroyed, which means a whole year of stock? And of course, snails and other things that the fish eat. That’s our major worry.”

Mr Matthews lives near the river and spotted a large number of dog walkers standing and staring at the orange water on Saturday morning. He said he hasn’t seen the river run orange since the 1970s following a pollution incident.

“When I walked there, I saw ducks, dipper and other birds. They were sitting on the rocks, out of the water looking down at the orange river. What concerns us is, are there any lasting effects and are the fish dying? Did any fish die? What about the ecology? Will there be any compensation?”

He said that following the incident in the 1970s the river was restocked with fish as compensation.

NRW are testing water samples and Mr Matthews said he would be sent a copy of their report.