Galway's public water crisis may run well into the summer, due to technical difficulties in drawing water from an alternative supply.
City council officials have admitted there has been a "slide" in meeting a deadline of June 15th for closing the old Terryland waterworks, where the cryptosporidium parasite was detected three months ago.
This means that boil water measures are likely to extend into July, the busiest month in Galway's tourism calendar.
The number of laboratory confirmed cases of the gastrointestinal illness caused by the parasite has reached 236 since the start of the year, according to the Health Service Executive (HSE) West, although the total figure could be greater, experts believe.
The council said tests on the water supply are showing "negligible" levels of the parasite, and it has been working to draw in an alternative supply from the Luimnagh-Tuam system, allowing it to close Terryland.
However, a June 15th target of 17,000 cubic metres from Luimnagh may not now be met, and the HSE West will still need to test over two cycles of the parasite - four weeks in total - before it can lift its boil water order.