The Manx Utilities Authority spent nearly £12,000 to clean up water pollution from Douglas supplies in December.

The authority expects to fully recover its costs from the Steam Packet Company, which has accepted responsibility for accidentally pumping seawater back into the fresh water supply during the washing down of the Ben-my-Chree.

The chairman of the MUA, Dr Alex Allinson MHK, said: ’The board and I take the matter of contamination of our water supply extremely seriously and as such, we have not yet ruled out utilising our enforcement powers under the Water Byelaws, as outlined in the 1991 Water Act.

’The quality and safety of our water supply has to be one of our first priorities in terms of protecting public health.’

It was established that the pollution was caused by sea water being pumped back into the fresh water supply, while the Ben-my-Chree was being washed down in the harbour on December 7.

In a joint statement, the Steam Packet and the MUA confirmed that the accidental intake of sea water during the routine procedure to wash down the vessels had never occurred before.

A non-return valve was fitted to prevent further contamination at the time, however this will act as a safety precaution until a full resolution is agreed.

The MUA spent a total of £4,000 on providing bottled water to residents and businesses within the contaminated area, which stretched from the east side of the North Quay to the Villa Marina.

It took three days to ensure that tap water was once again drinkable, which affected a number of cafes and restaurants.

Little Fish Cafe director Nigel Taylor said: ’We had to close business on the Friday because by the end of the Thursday service we were piled with plates and needed to be ready to hit the ground running the next morning.’

An investigation to find out what trace elements were in the contaminated water, which had smelled of fuel, is still ongoing.