What's more, this choice was made despite the Hawke's Bay Regional Council having already approved a well-tested alternative - discharge to forested land - and even provided the land for it.
So one could be forgiven for thinking CHBDC chose a different method simply to thumb its nose at HBRC - which, doubtful of the outcome, was very reluctant to accept that decision.
Originally, there was no time pressure. At least a decade earlier, CHBDC knew its existing systems were overloaded and would fail to meet new discharge standards. And it had been told quite clearly by the regional council it needed to act well before its consent expired.
Instead, CHBDC ignored its sewage problems, even arguing there was no problem and the Tukituki River was just fine, thanks.
So that decade ticked by. And, left to its own devices, the council may well have stayed constipated; it took proactive intervention by the regional council to finally get the district into motion.
However, by hastily plumping for their own "cheaper" option, councillors may now repent at leisure as the cost of implementing an acceptable sewage treatment system for the CHB townships soars.
Yet as late as October, CHBDC Mayor Peter Butler was staunchly insisting the new system was compliant and testing would prove it. Evidentially, not.
It's this attitude of denial and the "we know best" stance that frustrates environmentalists and the more senior governmental bureaucracy. Which only fuels calls for amalgamation by illustrating the sort of mess a staunchly-parochial council can create.
And parochialism is what Mayor Butler and his team have become renowned for.
They've no doubts about backing the Ruataniwha water storage scheme simply because it's their own land that will supposedly benefit.
With an eye on climate change, the Wairoa and Hastings districts are doubtless chaffing at missing out and wondering gloomily whether they'll ever see such a scheme of their own.
Growers on the Heretaunga Plains must be particularly worried that HBRC has itself ineptly decided on expansion. Yet HDC has remained on the sidelines, when it should be pushing hard for its regional counterpart to revise its priorities and protect existing investment.
Perhaps that's happening behind the scenes. But instead of respectfully co-operating and using the strengths of a multi-tier system, councils continue blindly following their own agendas.
However, rather than that supporting amalgamation, if you put all those councils together and have a unitary authority, with no debate and no one to counter them, there's even more chance wrong decisions will be the norm.
Bruce Bisset is a freelance writer and poet.