So long as Councillors and the Whangarei community disagree on whether the problem with Whangarei’s sewerage system is inflows or overflows then we’re not going to agree on a solution. The Whangarei community and Council need to get to the same position so we can have a clean harbour and still swim at places like Whangarei Falls, Onerahi and Mair Park.

There can be up to 112 overflow sites in the Whangarei sewerage network in one year and simply focusing on eliminating sewage overflows at Okara ignores the bigger picture.

Even worse; it is not going to stop sewage overflows in to the harbour.
During the March storm last year there were many recorded overflow sites including Takahe St in Tikipunga, Railway Rd and Tawera Park.
Each of those overflows continued for at least seven hours and all of these overflows would have happened even if the new Okara pipeline was in place. And there were others.

I believe that the NRC and WDC need to get their heads together and come up with a resource consent for the whole system.

The NRC could force the issue by refusing consent for the WDC to discharge any more untreated water from its Kioreroa plant. That would force the WDC to look at reducing inflow to the plant which would require a citywide approach.

Therefore, I urge people to make a submission to the Northland Regional Council asking it to reject a resource consent application from the WDC to increase inflow to the waste treatment plant from 90,000 to 140,000 cubic metres. Insist instead that the WDC apply for a resource consent for the entire stormwater/sewerage network and treatment plant systems.

Most of the overflows occur in Whangarei city and suburbs where stormwater can increase sewer pipe flows tenfold - in Ruakaka, by comparison, it’s only twofold.
Despite that, much of the $11m collected annually from ratepayers in the Whangarei wastewater catchment has been, and is being, being spent in places like Ruakaka, Oakura, Whangarei Heads, Ngunguru, Hikurangi and other small centres. The need is not for more money, but for the city to get its share.

One third of my, and your, rates bill is targeted on sewerage. Back in 2006 the annual sewerage charge was just $275 - now it’s $485
That’s a 76% increase and the number of sewage overflows has been increasing as well. Reduce the volume and reduce the bill.

The main cause of the overflows is stormwater getting into the system through wrongly connected down pipes and faulty gully traps.
It’s relatively easy to identify those problems.
Stormwater infiltration through cracked pipes underground is minor in comparison so the $180m estimated to replace the whole sewer treatment system is unnecessary. 

Identifying and fixing the main stormwater inflows will fix the problem of sewerage overflows while saving a lot of money on the way.

A maintenance check last year in Riverside found a 25% failure rate with sewerage/stormwater connections and that could be expected in the other 26 catchment areas around the city. However under the current approach only one area is being examined a year even though one wrongly connected household down-pipe can put as much material into the sewerage system as 40 correctly connected households.
We need at least a three year maintenance check to find and fix those faulty connections, not the 25 years it will take under the current programme.

Instead of that however there is a move to spend ratepayer money and increase capacity to handle and treat the unnecessary stormwater inflows - that is an ambulance at the bottom of the cliff - stopping the stormwater getting in is a barrier at the top of the cliff.
Those maintenance checks have been started in the past, but with little success.

There have been serious problems with sewage overflows (during storms) at Butter Factory Lane and there were warnings a fix could cost several millions of dollars.
Monitoring however revealed the problem could simply be caused by a blockage in the pipe there and a couple of months ago some 15tonnes of silt were sucked out and disposed of. That simple maintenance check saved ratepayers a lot of money – and got rid of a serious public health risk.

That’s despite the conditions in the Whangarei District Council’s current, though 20 year old, wastewater consent which restricts wet weather inflows to just five times that of a dry weather inflow. Those wet weather inflows today can be more than ten times dry weather flows.

A consistent and genuine monitoring programme can identify problem areas and allow them to be fixed, it’s practical, and – as the Butter Factory Lane incident demonstrated – monitoring is cost effective.

Obviously taking the same approach as we did 20m years ago would not work without improved processes. The Whangarei CBD is an area known for low-lying gully traps. The Council, alongside private enterprise invented a simple non-return valve that could be installed for just a couple of hundred dollars.  This technical fix enabled us to overcome this problem and inspections went ahead.

Some infrastructure spending is necessary. Whangarei is currently spending $4m of ratepayers’ money on a new pipeline and pumps to carry occasional stormwater diluted sewage to the Kioreroa treatment station. The old pipe is past its best and can’t operate at full capacity without the risk of a major blowout.
The new pipe will run in conjunction with it and allow one or the other to be closed for maintenance.
However, it’s also planned to spend another $5 or $6m on a sand filter and other systems to treat wet weather sewage even though 90% of it is simply stormwater.
Stopping that stormwater getting in to the system will save money (less capital and operating expenses) – dealing with it once it’s in the system will cost ratepayers’ money.

The system can easily cope with the 11,000 cubic metres of sewage produced on a normal dry season day. Even if Whangarei’s population doubled the existing plant could still cope - there’s capacity there to handle 23,000 cubic metres.
The system can’t cope, and shouldn’t be expected to cope, with the 100,000 plus cubic metres produced during a storm.