Local Government Magazine
3 Waters

New testing regime for on-site wastewater units

Homeowners in many parts of the country have been wasting tens of thousands of dollars installing failing wastewater units while some regional and district councils have turned a blind eye, says Noel Roberts. He reports on steps to address the problem.

Ray Hedgland is the manager of the On-site Effluent Treatment National Testing Programme (OSET-NTP). He says there are dozens of untested wastewater units on the market and many are simply not fit for purpose.

He knows of at least one plant that badly failed the OSET test but has been selling for around $20,000 to unwitting homeowners.

“In that case, the unit performs no better than a normal old-fashioned septic tank.”

These underperforming units are being installed, not just in larger rural properties or even city fringe lifestyle blocks, but also in many new subdivisions.

“In these cases it is obvious they can become a significant public health hazard.”

Ray has been managing the OSET programme, based in Rotorua, for the past five years. The programme provides councils, manufacturers, designers and homeowners with the only independent assessment of the performance of onsite wastewater units in this country.

Recently OSET underwent a major upgrade which means that it will be putting wastewater treatment systems through a far more rigorous and accurate examination.

The new testing regime meets the recently-revised Australian Standard 1546.3:2017 which is a big improvement on the previous AS/NZS1546.3:2008 standard and goes even further than the previous OSET-NTP testing standards.

“It now means we’re testing plants at their nominated capacity rather than just 1000L/d and testing includes real-world conditions such as laundry day stress levels, power cuts, chemical stress and surge flows.”

The OSET-NTP programme puts domestic and small commercial units through their paces and can now test up to a 5000 litre per day capacity as well as reviewing installation, management and operation manuals, and other quality control measures such as noise level.

Under the current system, manufacturers voluntarily submit their units for testing. However, Ray believes that OSET-NTP testing ought to be mandatory and regional councils should insist on such testing before allowing units to be installed in their area.

If a unit passes the OSET-NTP test, it will be issued with a Performance Certificate. These are valid for five years although they can be extended to eight if there is no change in the specifications.

In the 10 years since the Rotorua plant has been in operation, around 50 units have been tested.

But Ray points out many of those now have either expired certificates or were tested under the former standards.

There are currently around 48 manufacturers of domestic and small commercial wastewater units in this country, and some produce multiple plants. Nineteen companies have not had their units tested at all. Even for manufacturers that do test their products, many don’t submit their entire range for scrutiny.

“Some manufacturers will only test one plant and then market their entire product range on the back of that success,” he says.

With little regulatory clout, manufacturers lack real incentives to put their products to the test.

For homeowners, it’s definitely a case of buyer beware. An expensive investment can leave a purchaser with an even more costly mess to clean up. Or even worse, leave the mess to spill into the environment with all the potential public health consequences.

Where do buyers turn in such an information void?

Bay of Plenty Regional Council senior regulatory project officer Terry Long says he often fields calls from people in other parts of the country seeking advice because their own council simply doesn’t have the information.

In some cases, the councils have even advised residents in their area to contact BoP Regional Council for more information.

Terry cites at least one regional council that has literally no rules for OSET and agrees that too many regional councils have simply been snoozing over this issue.

“I guess it’s not a sexy, flavour-of-the-month topic when councils are busy dealing with things like farm dairy effluent which is in the political spotlight.

But he says this is something that strikes at public health as well as the environment.

“In my view, this is more important than farm effluent.”

Both he and Ray agree that more regional councils need to lift their game – for the sake of their ratepayers and their environment.

OSET-NTP is a self-funding operation run by Water New Zealand, Rotorua Lakes Council and the Bay of Plenty Regional Council. It’s been operating for the past 10 years and relies on funding from both manufacturers and funding partners, such as regional and district councils.

Putting up the money

Funding partners for a 2017-18 On-site Effluent Treatment National Testing Programme (OSET-NTP) trial were: Ashburton District Council, Auckland Council, Bay of Plenty Regional Council, Christchurch City Council, Environment Canterbury, Gisborne District Council, Hawke’s Bay Regional Council Horizons Regional Council, Horowhenua District Council, Hutt City Council, New Plymouth District Council, Northland Regional Council, South Wairarapa District Council, Tasman District Council, Taupo District Council, Tauranga City Council, Waikato District Council, Waikato Regional Council, Western Bay of Plenty District Council and Whangarei District Council.

Only councils supporting the OSET-NTP as funding partners have exclusive access to detailed individual reports and reporting on the comparative test results for each trial.

Onsite wastewater management is a Planned Permitted Activity in the regional rules under the auspices of the regional councils.

This means regional councils could ensure that their Permitted Activity rules include mandatory testing by OSET or similar. As well, they could require that the entire onsite treatment system investigation, design, construction, installation, operation, management and monitoring is in accordance with AS/NZS 1547:2012.

Also in the picture are the district and unitary councils. In the wake of poor, or in some cases, no regulations, district and unitary councils use the building consent process to oversee the installation of new units. The responsibility for ensuring ongoing maintenance of wastewater units then becomes the job of the district and unitary councils.

Yet, it’s sobering to note that monitoring of maintenance is carried out in just three places in the country – Northland, and in pockets of Auckland and Rotorua.

Terry says some councils are starting to introduce stronger rules around wastewater unit performance, but not enough.

In the meantime, OSET-NTP needs to continue to fund its assessment programme and is seeking more funding partners to ensure the operation’s ongoing viability.

Manufacturers currently pay the bulk of the cost of testing and running the unit while funding partners contribute just under 25 percent.

While rates are open to negotiation, standard charges for funding partners are only $5000 a year for regional councils, $3000 a year for unitary councils and $1500 a year for district councils.

For that, funding partners get access to full test results and, importantly, information about why units have failed. Understandably, manufacturers will share test success stories but not failures.

This means many councils and homeowners are missing vital information that could save plenty of strife further down
the track.

It’s in the interests of not just homeowners but also councils faced with the downstream costs of polluted waterways and environmental contamination, to ensure that all wastewater treatment units on the market are up to standard.

And before this is seen as a fringe topic, it should be noted that more than 607,000 New Zealanders live with non-reticulated wastewater. Contaminated land and bacteria in the ground is not a great legacy for regional authorities. In the end, this comes down to a matter of public health.

“Our objective is to ensure that our children and grandkids can play outside in these areas and other rural areas and be safe,” says Ray. 

• Noel Roberts is technical manager at Water New Zealand. noel.roberts@waternz.org.nz

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