Wastewater plants located in Honolulu, Haiwaii, have to be updated, according to the city council.
Two plants, located in Sand Island and Honouliuli, will not be granted licenses to continue their operations without first carrying out upgrading requirements, stated the US Environmental Protection Agency (EPA).
This news comes after city officials highlighted that the cost of this could total around $1.2 billion (£787 million).
Mufi Hannemann, mayor of Honolulu, said: "We had hoped that the EPA would reconsider its tentative decision, in light of the overwhelming evidence presented by our local scientists and engineers that secondary treatment at these plants is not necessary or beneficial."
He said that the next step would be for the council to seek a review of the decision.
In related developments, Northern Ireland Water announced last month that it is to invest £22 million into improving
wastewater facilities in the Ballymoney region, reported the Ballymoney Times.
