Irish Water had to spend €160,000 on providing water in Achill Island after aluminium levels skyrocketed to five times recommended levels.
Records released by the water utility reveal how at one stage aluminium levels in the water rose above 1,000 micrograms per litre, when the recommended maximum safe amount in drinking water is 200 micrograms.
Irish Water said it had contracted a third-party supplier to provide tankered water on the Co Mayo island during the peak tourist season. The total cost of this over the 28-day period of the water warning came to €160,000, or the equivalent of more than €5,700 daily.
Internal records reveal that pressure on water supply in the area was such that pumping water into tankers for Achill threatened to cause shortages in the Westport and Castlebar area.
The problems were being compounded by frequent bursts on the mains water pipe on Achill whenever the raw water supply was switched off.
As a result, Irish Water laid a new pipe on the island to help deliver a continuous supply of water to the Achill water treatment plant.
The internal records – which were released following a request under Access to Information on the Environment Regulations – show how the plant reached capacity with rising water temperatures on August 7th.
An email said: “The plant cannot cope with demand and there’s a serious problem with water quality.”
Another message confirmed an immediate “do not consume” notice was being put in place. According to census figures, there were 2,373 on the water scheme but it was believed up to 7,000 people may actually be served by it. The “do not consume notice” ended on September 4th.
Copies of minutes from an incident management meeting explained how levels of aluminium of above 800 micrograms per litre were a matter for deep concern.
“Any levels between 200 and 800 sporadically are concerning and warrant action,” said the notes.
The records also said there had been a 20 per cent increase in demand from previous years due to an increase in tourism because of “staycations”.
Questions were also raised about whether it would be possible to upgrade the plant to avoid a repeat next year.
“As a result of the Do Not Consume Notice,” the minutes said, “the Achill water treatment plant will be prioritised and will become an emerging need for Irish Water to consider.”
Aluminium sulphate is used to remove impurities by combining them into larger particles which can be extracted more easily. The Achill works had switched from manual to automated application of the coagulant before the increased demand. The compound is relatively non-toxic in healthy individuals but there is evidence high levels may cause adverse effects on the nervous system. Those with underlying conditions and the very young may also be vulnerable to its effects.
A statement from Irish Water said: “[The final bill] included the provision of a number of tankers so customers could access an alternative water supply; mobile tankers which were used to augment supply in a number of reservoirs and the supply of and delivery to the island of over 20,000 bottles of water for distribution to vulnerable customers.
“The audit of the plant carried out by the EPA found that Irish Water and Mayo County Council ‘acted decisively’ after the incident began and that both organisations ‘worked tirelessly’ throughout the incident to ensure water was available for sanitation, while vulnerable customers received deliveries of bottled water and finding a solution was prioritised.”