Hydro Tasmania has advised the Environment Protection Authority of a spill of diesel fuel at Meadowbank Power Station.

The spill of approximately 500 litres of fuel occurred while on-site storage tanks were being filled yesterday afternoon. Hydro Tasmania advised the EPA last night.

"The spill was onto a five metre square area of crushed rock. It did not enter, and was not near, Lake Meadowbank," said Manager Major Works, Andrew Hickman.

"Hydro Tasmania’s spill response was deployed effectively, the spill was contained and the contaminated material will be disposed of in accordance with EPA regulations."

The spill was the result of human error.

Hydro Tasmania is working with contractors to improve processes around fuel refilling.