New technology will reveal all on water quality

Riverwatch launched a PledgeMe campaign on August 9 to raise funds to get the award-winning water quality tester to the next stage of development. That the $50,000 target was met inside five weeks probably says quite a bit about its potential.

The solar-powered, Wi-Fi enabled floating sensor unit can house up to seven interchangeable probes to measure water quality over a sustained period.

The founders of Water Action Initiative (WAI) NZ, Wairarapa farmer Grant Muir and his biologist son James, developed the device in conjunction with Victoria University and believe it can be released on the market for $2500.

That's just 10-20 per cent of the cost of current single test methods.

With Callaghan Innovation recently coming on board to help fine-tune design of the units, including a new sturdy aluminium casing, and with interest from corporates and iwi entities percolating nicely, Mr Muir hopes roll-out of production and sales could happen as early as March next year.

Currently the RiverWatch unit can house sensors to measure water turbidity (murkiness), temperature, dissolved oxygen levels, pH and conductivity. Mr Muir said his team is collaborating with ESR to develop an E.coli probe and is doing more research into nitrate and phosphate testing.

Current quality nitrate probes from Germany rely on optic sensors and cost $15,000. Mr Muir said they don't work well here because our rivers have 10 times the sedimentation of the global average. The WAI NZ team is confident more cost-effective sensors will emerge in the next 12-18 months from China, which also has problems with nitrates and phosphates in waterways.

Testing inadequate

Grant Muir is scathing of current testing here. Of the 450,000 kilometres of rivers and streams in New Zealand, there is water quality data for only 8 per cent. "A lot of that is only flow rates or temperature.

"I used to think it was our farmers but it's not. Some of the worst pollution is happening right under our nose [in our cities]."

For probably only 1 per cent would we have anything like the full array of measures, like dissolved oxygen and so on.

"If the country as a whole wants to get on top of the water management crisis, we need to start measuring and accumulating that data."

Mr Muir said the current practice of regional councils sending out a staff member with a wand and meter to do a test is not only expensive - a cost ultimately borne by farmers and other property owners - it's also not "robust" scientifically because it will only give a measure at a given point in time.

The floating RiverWatch takes measurements every five or 10 minutes, 24/7. The data is downloaded to a memory chip in the device, and it can also be connected by Wi-Fi to a phone or iPad.

"We have a phone app that has been developed in Android, but not yet licensed, and will also be developed for IOS and Windows phones. It will interpret the data for you; instead of a line of figures it will show it to you in graphic format so you can see exactly what is happening in the water."

Data can be downloaded to WAI NZ's website, with GPS tagging so the location is clear to everyone. The intention is that the data be open source, but Mr Muir said if farmers buy the unit themselves, it's their proprietary data to share or not. They might rent units from the regional council, and share it with them as part of compliance regimes.

Major benefit

A major benefit is that RiverWatch can be deployed in isolated areas with no cellphone coverage and left to do its job for weeks. With low wave radio technology, which relies on line of sight, the data can be bounced from one ridge to another until it reaches a station with internet or cellular coverage.

WAI NZ and Grant and James Muir were behind the RiverDogs documentary film on water pollution in the Wairarapa that ruffled some feathers among farmers. But at the PledgeMe launch Grant Muir said that while there were certainly plenty of farmers who needed to lift their environmental game, "you know where it's worst?

In our cities. There are major problems in Manukau Harbour, with heavy metals, E.coli and sewage. Porirua Harbour is a cesspool, an absolute cesspool."

The only reason he could think of why government isn't currently funding development of RiverWatch is that they're ashamed of the data that would be gathered.

Mr Muir said there are plenty of farmers who would welcome a low-cost, easy to use and scientifically robust device they could use to prove or improve the sustainability work they already do.

"There's a lot of discussion about this in the farming community and what really gets the goat of a lot of guys is that they spend $50,000 fencing and riparian planting but the guy upstream doesn't spend a cent."

Deploying a RiverWatch sensor on the upstream boundary, and downstream, will provide evidence of the effectiveness of environmental actions for Farm Management Plans, etc.
"It's testing water but it also leads into other monitors that will be going into farms in the next 10 years.

Expect a dramatic shift towards technology - collecting data on soil temperature, soil moisture, fertiliser application, dry matter in grass ..."

Add in real-time water testing data and the farmer has a full picture of inputs and outputs.

"Those data sets will enable farmers to build a great model, reduce input costs and improve margins."