Fish discovered at sewage works

It is thought the fish are feeding on algae in the sewage tank

Eighteen fish have been discovered living in a tank at a sewage works in West Yorkshire.

The fish were found last week during a routine inspection of a sewage settlement tank in South Elmsall.

Lurking just below the surface were chub, bream, trout and roach - all of which appeared to be in good health.

Site operator Jeff Eades said: "I thought I'd seen pretty much everything until I discovered the mini-aquarium we have here."

It is not known for certain how the fish got in, although staff at Yorkshire Water think they may have been washed in back in 2007 when a nearby beck burst its banks, engulfing part of the adjacent works which includes the final settlement tank.

Abundant algae

The tank is used in the final stages of the sewage treatment processes to remove any remaining particles from the water before it is discharged back into the local river.

As the water subsided, it is thought the fish remained in the tank, feeding on the abundant algae deposits.

Mr Eades said: "For some time now I've had my suspicions that there was something in the tank but every time I or anybody else approached the side of the tank, the fish must have heard us coming and dived to the bottom.

"However, over time, they appear to have got used to the sound of us nearby and they're now quite happy swimming near the surface."

A fish expert was called in to the site and he verified that the fish appeared to be in good health and happy living in the tank, taking advantage of its plentiful food supplies.

Mr Eades said: "If the fish really wanted to escape back into their beck they could simply swim over the small weir, but they seem to have chosen to remain here which obviously bears testament to the quality of the final product leaving the works."