First it was just smelly. Now it's turning ugly.

The city's continuing battle with the Environmental Protection Agency has now escalated with the EPA's tentative denial of a special waiver for the Sand Island Wastewater Treatment Plant, which dumps treated effluent into Mamala Bay about 9,000 feet from shore through a diffuser pipe.

The EPA said the facility fails to meet federal water quality standards and must be upgraded to provide secondary as well as primary treatment of sewage.

This is the second such ruling in nine months: In March, the EPA tentatively held that the city's smaller Honouliuli facility had similar problems, and would also be denied a waiver.

Understandably, the city is in a tough spot and has responded with some tough talk of its own: We can't afford the upgrades. We have more critical sewage priorities, like rotting pipes in places where people actually live. Our best experts tell us the upgrades aren't even necessary.

All these arguments, unfortunately, seem reasonable. Years of neglect coupled with age have left O'ahu's sewage system in such monumental disrepair that the city finds itself facing no-win choices: A suboptimal ocean outfall system or a crumbling sewer pipe network.

Just to pay for the latter, the average monthly sewer fee will double by 2014, to $83.20.

Mayor Mufi Hannemann warned of dire consequences ahead: "If we are forced to go to secondary treatment, we could bankrupt the city."

The EPA talks soothingly about cooperating to reach a practical solution to bring the city in compliance. "We really want to get things working, as opposed to collecting fines," is how EPA spokesman Dean Higuchi put it. But, the city, at least publicly, is having none of it, challenging the EPA's findings in both cases and threatening lawsuits to protect its waivers.

Hannemann put it bluntly: "I'm not going to yield at all."

Admittedly, taking on the EPA is a calculated risk. But it's a necessary one.

Should the city prevail, it would provide some reassurance that we can solve our longstanding sewer problems in a cost-controlled, prioritized way.

This begins with repairing and replacing the collection systems — the sewer pipes under our streets and backyards. Work on this old and decrepit system has already begun and is expected to cost upward of half a billion dollars.

It's unfortunate we can't protect all of the environment all at once. But for the moment, we're stuck with protecting what we can afford.