This is not the news that Honolulu wanted to hear — not ever, and certainly not now. The Environmental Protection Agency has tentatively decided not to renew the waiver enabling the Honouliuli Wastewater Treatment Plant to continue providing, as it has for decades, less-thorough treatment than the feds usually require.

The decision is tentative because there will be a public hearing (see box) and time for written reaction to pour in before the final verdict is inked. If the initial conclusion is upheld, the city will be faced with an enormous expense, particularly because the EPA is also reviewing a similar variance for the Sand Island plant. Upgrading both plants to perform secondary treatment of sewage before discharge into the ocean is expected to cost $1.2 billion.

This mammoth bill, of course, is added to the already mountainous cost of improvements to O'ahu's deteriorating sewage collection system. Years of deferred maintenance to that system led to last year's calamitous failure and the dumping of untreated sewage in the Ala Wai Canal.

Even the EPA will have to admit that replacing the aging sewer pipes needs the most immediate attention.

But with plans in place for population growth in 'Ewa, city leaders have been taking a long-range view of public utility needs. Applying that lens to the wastewater treatment challenge surely would suggest that Honolulu can't get by forever with less than secondary treatment at its major sewage outfalls. In addition, secondary treatment can produce water suitable for reuse in irrigation and other needs, and relieving the burden on our groundwater supply is also a valuable dividend.

It would be wise for the city to begin charting the course toward compliance with federal water-quality standards. Paying for it is a painful prospect, but there may be options for the city and Hawai'i's congressional delegation to explore.

For example, the city already is tapping the EPA-backed Water Pollution Control Revolving Fund for some of its collection-system upgrades and may be able to secure more financing there. To a limited extent, outright grants also may be available through the Federal Water Pollution Control Act.

EPA officials have acknowledged that demanding immediate compliance would be unrealistic in the extreme. And Honolulu is certainly not alone in embarking on a long trek toward improving the treatment of municipal wastes that are discharged offshore.

For example, in California, the Orange County wastewater authority has struck an agreement with the EPA to have its own coastal facility ramp up to secondary treatment over the course of a decade.

That's the sort of accord Honolulu needs to reach with the federal government.

Granted, enforcing uniform water quality standards on a national basis is problematic and even unjustified. The city has persuaded federal courts in the past that Hawai'i's coastal environment is distinct, its currents able to disperse and its marine life able to absorb a great deal of the residue from primary treated sewage. Scientific studies have supported this argument, which is one reason Honolulu was able to win approval of the current waivers.

However, those variances were granted in the late 1980s following an amendment to the federal Clean Water Act, and the intervening decades have brought further refinements to the law. John Kemmerer, regional associate director for the agency's water division, said one of the criteria that doomed Honolulu's renewal application is relatively new: a measure of pathogens that indicates whether water has become unsafe for recreational use. The Honouliuli outfall is more than a mile offshore, but fishing and boating in the area would thus be deemed risky.

The renewal application has been in the EPA's hands since 1995. The review process was extended because of various operational changes at the treatment plant, requiring additional data. However, Kemmerer acknowledges that after 12 years of delay, during which the waiver was extended, environmental groups were pressing for resolution and pointing out their legal recourse through the courts.

But he said the decision was driven by science, not legal pressure. He added that there's ample evidence that Honolulu needs ultimately to bring all its sewage treatment up to standard, and he's right.

Our Island population is growing at a rapid pace, as is the strain on our resources. Our ocean environment is simply too precious to our economy and way of life to be approached with anything less than the most careful stewardship.