Procedures to prevent a risk to public health during industrial action by water workers have been agreed with the trade unions, officials from NI Water have said.
More than 1,000 NI Water workers began a work-to-rule on Monday in response to a dispute over pensions.
Talks held last week between unions and management from NI Water failed to reach agreement.
Members of the Unite, Nipsa and GMB unions voted for the withdrawal of on-call services and overtime with immediate effect, leading to a warning from Regional Development Minister Danny Kennedy that householders and businesses could be left in “abject misery” if supplies are disrupted in any way.
In a statement released on Tuesday, NI Water bosses said some progress had been made on the issue of water supplies.
It said: “NI Water management and trade unions have agreed procedures for addressing critical issues which present a risk to public health or vulnerable customers.
“There may, however, be an impact on customers who should contact NI Water in the normal way, for example by phoning Waterline on 08457 440088 or look out for updates on www.niwater.com.”