For all their differences, one strong theme binds former mayors Frank Fasi and Jeremy Harris and current mayor Mufi Hannemann:

They are in vigorous agreement that the federal Environmental Protection Agency is all wet in its efforts to get Honolulu to substantially upgrade its sewage treatment plants at Sand Island and Honouliuli on O'ahu's Leeward Coast.

This is far more than another home-rule argument for the mayors past and present. It is a multi-million dollar fight that will severely impact sewer fees paid by Honolulu property owners and will dictate the course of action for years as the City struggles to bring its overall sewage treatment system up to par.

After years of waivers and back-and-forth between the city and federal regulators, the EPA is now moving toward a demand that the city upgrade its treatment to "secondary" standards. Today, sewage handled at those plants receives primary treatment (with work under way for a more "advanced" form of primary treatment). Without getting technical here, the difference is in the quality of water discharged after treatment.

Fasi fought the EPA (and environmentalists) for years on this and finally won a waiver. Harris, no mean environmentalist himself, also came around to the idea that there was no pressing need for secondary treatment. Hannemann is on board and has made his point in full-page newspaper ads and at a hearing the other night in Kapolei, where he encouraged hundreds of people to show up and tell the EPA, in effect, "get off our backs."

No decision was reached at the hearing and none will be for some time as the EPA continues to invite commentary and criticism from local folks about the plan.

It's important to remember that the argument here isn't whether secondary treatment would be a "nice" thing to do, money and time permitting. All three mayors have argued that our current system is adequate because the processed sewage is dropped off in the deep ocean.

And Harris made the additional point that if quality of the ocean environment is what really matters, the money would be far better spent on upgrading our land-locked sewer pipes and cracking down on pollution from runoff and the like.

In matters such as this, pure science is not the final word.

The scientists at EPA are likely to come back with a decision that an upgrade is required. Then politics will take over. And when you have the mayor, council members and even U.S. Sens. Daniel K. Inouye and Dan Akaka and U.S. Rep. Neil Abercrombie supporting a waiver, it's a decent bet that is precisely what will happen.

Reach Jerry Burris at jburris@honoluluadvertiser.com.