Archive for the ‘Water’ Category

New detection system revolutionises water quality tests

Students on an Environmental Health Monitoring course at Massey University in Wellington are the first in the country to use a new rapid automated microbiology detection system to monitor water quality.

The students used the TECTA B16 system to detect Total coliforms and E.coli in drinking water and river water samples from a range of sites in the Wellington region.

Stan Abbott, course supervisor and leader of Massey’s Roof Water Harvesting Centre, said the students quickly familiarised themselves with the sophisticated workings of the TECTA B16 machine.

“In this digital age our students are all so tech savvy, they understood how to operate the machine with a minimum of fuss, much like them using a new computer or smartphone for the first time,” he says.

Havelock North waterborne disease outbreak last year, when more than 5,000 people contracted Campylobacter, highlighted the need for fast and accurate water quality monitoring tests.

“This new monitoring system is relevant also to the E.coli threshold level, which has been hotly debated around the Government’s recent launch of its new Clean Water policy,” Mr Abbott says.

“There has been an endless tide of opinions about the risks that will confront the public when they swim in many of New Zealand’s rivers and lakes, proving that water quality safety for both drinking and swimming in is paramount.”

Mr Abbott said the major advantages of the TECTA B16 automated detection system include:

• A complete, self-contained desktop, touch screen control automated microbiology testing system that is simple to operate and does not require specially qualified personnel.

• Minimal handling of samples and no sample preparation is required. A test can be initiated anytime, while all samples do not have to be loaded into the machine at the same time.

• Full automation of the test analysis and interpretation processes eliminates the need for subjective, visual interpretation of results. An objective, written test report is produced automatically for each sample tested.

Another big advantage is that the machine automatically transmits the data through a network connection to allow immediate notification on electronic devices, such as cell phones or laptops, as soon as a contaminated water sample is detected.

Total coliform and E.coli results are available in two to 18 hours, depending on the level of contamination in the water sample. This immediate notification and early warning of positive sample results as soon as they occur should revolutionise water testing,” he says.

The TECTA B16 system received United States Environmental Protection Agency approval in 2014 and the New Zealand Ministry of Health approved the system for testing drinking water samples for compliance in August 2016.

Three water-testing agencies in New Zealand so far have bought the system.

Govt sets freshwater target: 90% of rivers and lakes to be swimmable by 2040

The Government has announced a target of 90 per cent of New Zealand’s lakes and rivers meeting swimmable water quality standards by 2040.

Environment Minister Dr Nick Smith said the plan is backed by national regulations requiring stock to be fenced out of waterways, new national policy requirements on regional councils to strengthen their plan rules on issues such as sewage discharges and planting riparian margins, a new Freshwater Improvement Fund and new maps that clearly identify where improvements are needed.

Meeting the goal is estimated to cost the Government, farmers and councils $2 billion over the next 23 years.

Primary Industries Minister Nathan Guy (HERE) said the Ministry for Primary Industries continues to work with the primary sectors to invest in good ideas which promote environmental best practice. One example is the Farm Systems Change program, which identifies high preforming farms and uses farmers’ networks to spread their knowledge.

Another is a major programme under the Primary Growth Partnership, called Transforming the Dairy Value Chain. Under this programme effluent management systems have been improved, and every region now has a riparian planting guideline developed in conjunction with regional councils, Guy said.

“We also know that science will play a major role in improving our freshwater. The ‘Our Land and Water’ National Science Challenge is investing $96.9 million over 10 years into this, hosted by AgResearch and involving six other Crown research institutes.

In his announcement (HERE) Dr Smith said the target recognised that our frequent major rainfalls mean a 100 per cent standard is not realistic.

The target covers the length of rivers over 0.4m deep and the perimeters of lakes greater than 1.5km, which total 54,000km.

The plan is about improving the frequency that we can swim in our lakes and rivers, noting that even our cleanest rivers breach swimming water quality standards during storms.

The swimmable target is based on meeting the water quality standard at least 80 per cent of the time, in line with European and US definitions. Currently 72 per cent by length meet this definition, and the target is to increase that to 90 per cent by 2040. This means an additional 10,000km of swimmable rivers and lakes by 2040, or 400km per year.

The maps provide comprehensive and consistent information on water quality for swimming of New Zealand’s rivers and lakes. They are intended to help focus councils and communities on improving their local water quality, as well as helping people make decisions about where they can safely swim.

The maps are connected to the Land, Air, Water Aotearoa website that provides real-time information on water quality, which is particularly relevant for the fair and intermittent categories.

The target not only requires an improvement in areas that are swimmable, ie into the fair category, but also rivers and lakes being moved from fair to good, and good to excellent. Regional targets to achieve the national goals are to be worked through with regional councils by March 2018.

Some regional targets will need to be greater than the 90 per cent and others, where it is more difficult to achieve, will be less, Smith said.  .

The National Policy Statement (NPS) for Freshwater Management is being strengthened to support the new 90 per cent by 2040 swimmability target, as well as changes to address the issues of ecological health and nutrients.

New regulations on excluding stock from waterways are an important part of this plan to improve water quality. The rules progressively apply to dairy, pig, dairy support, beef and deer farms from this year to 2030 relative to the steepness of the country, at an expected cost of $367 million.

Bids have been opened for the new $100m Freshwater Improvement Fund and announcing the eligibility and assessment criteria, which closes on 13 April. This comes on top of the $350m already committed by the government, of which more than $140m has been spent on specific river and lake clean-ups.

The detail of the NPS and Stock Exclusion Regulations are open for consultation until 28 April 2017.

The press statement was accompanied by a Q& A paper and a paper titled Clean Water. 

To read the proposals, and find out how to have your say, visit

Simultaneous water and nitrogen use can enhance sustainability

Water management is the biggest influence .on problems caused by the overuse of nitrogen, such as nitrate contamination of natural water reservoirs and increase of greenhouse gases in the atmosphere.

That’s a key observation in a study of diverse techniques to enhance the water- and nitrogen-use efficiency in cropping systems, according toa Universidad Politécnica de Madrid news release (here).

The results of the study carried out by two researchers from the university’s Research Group on Agricultural Systems show management practices oriented towards reducing nitrogen losses and maintaining farm productivity should rely on optimising nitrogen and water inputs at the same time.

The coordinated improvement of both elements on agriculture has more productive and environmental advantages than separately.

Water and nitrogen availability are, globally, the most limiting crop growth factors. These two elements have a fundamental effect on food sovereignty of many regions and on the reduction of the gap between the potential food and the actual food produced in the world. Thus, problems caused by the overuse of nitrogen, such as nitrate contamination of natural water reservoirs and increase of greenhouse gases in the atmosphere, are mostly influenced by water management.

In addition, it has been proven strong interactions between water- and nitrogen-use efficiency in most cropping systems. Thus, the practices that seek to improve both efficiencies simultaneously are more successful than those that aim to optimize each element separately.

This study was carried, who  out by Miguel Quemada and José Luis Gabriel, who assessed seven practices to improve both elements at the same time in cropping systems.

  • First, when there is crop water deficit the use of nitrogen has to be adjusted to the actual demand of the stressed crop since the plant will grow only as far as the most limiting factor allows it (water in this case), thus the rest of nitrogen remains on the soil ready to disappear from the system.
  • Second, another good practice is to improve water management in irrigated crops since excessive water use favours its loss and the dissolved nitrogen in it outside the range of the roots.
  • Third, researchers suggest the use of fertigation that consists in the application of dissolved nutrients into irrigation water, this technique has a great potential to adapt the punctual demand of water and nitrogen per plant.
  • Fifth, the study suggests soil mulching . When this technique is properly applied using remains of previous crops or synthetic materials, large loss of water caused by direct evaporation of the soil is prevented. Besides, soil mulching can favour the conditions to achieve a higher mineralisation of soil nitrogen and can increase water infiltration reducing the loss of both water and nitrogen caused by soil erosion.
  • The fifth technique suggests the amendment of nitrogen dose taking into account the doses given by mineralisation from soils and organics, thus the synthetic fertiliser can be totally replaced in some cases for instance when soil has appropriate humidity conditions.
  • Another technique is based on the use of species and crops that can better adapt to the cycles of climate and soil, searching for species more adapted to the water available in each region, combining species with depths of roots capable of taking water and nitrogen from where the other could not, including cover crops that can prevent the loss of nutrient and can be used as soil mulching and green manure in the future.
  • Finally, the seventh practice studied is the monitoring of water and nitrogen availability by using remote and proximity sensors. There exists an increasing number of affordable sensors that allow us to measure the physiological state of the plant and the availability of soil water, thus the fertilization and irrigation forecasts can be adjusted according to the deficiencies observed.

In short, the researchers of the study say, “the crop techniques addressed to reduce the loss of nitrogen, identifying the most effective practices in every case, will contribute the improvement of environment worldwide.”

Hydrology professor to deliver Darcy lecture

Plant and Food Research will host Dr Ty Ferré, a professor of hydrology and water resources at the University of Arizona, as the 2016 Darcy Lecturer. His talk is entitled ‘Seeing Things Differently: Rethinking the Relationship between Data, Models and Decision Making’.

Dr Ferré will build from the basic concepts of decision science to present concepts and recent developments in optimal design of hydrogeologic monitoring networks. He will also discuss how hydrogeologic models can be used for decision support under uncertainty. Finally, he will show that focusing hydrologic analysis on the specific, practical problems of interest can guide optimal measurement selection, advance hydrologic science, and improve the integration of science into economic and policy decisions.

The Darcy Lecture Series is sponsored by the US’s National Groundwater Association and honours Henry Darcy of France for his 1856 investigations which established the physical basis of groundwater geohydrology.

View Ty’s Darcy odyssey:

Details: 1– 3pm Friday 5 August, Lecture Room C2, Lincoln University

Contact: Brent Clothier –

Organiser: Plant and Food Research

Lecturer will talk on whether Canterbury’s problem waterways can be rehabilitated

A free public lecture at Canterbury University at 7pm next Wednesday will focus on the problems facing Canterbury’s fresh waterways.

The address will be delivered by Professor Angus McIntosh, one of the leaders of the team of freshwater ecologists involved in the Canterbury Waterway Rehabilitation Experiment (CAREX). The team has been working to test solutions for important in-stream problems in lowland Canterbury waterways associated with intensive agriculture.

The group has worked closely with farmers and other stakeholders to trial solutions in nine kilometres of waterways.

Professor McIntosh will outline CAREX findings so far. These highlight the need for channels to be protected from their source (“start at the top”) and for measures to prevent contaminants bypassing the protection system (or “prevent leaky plumbing”).

Work tackling three important stressors, fine sediment deposition, excessive weed growth and high nutrients, is now focusing on promising solutions including bank re-shaping, sediment traps, targeted shading and bioreactors for nutrient removal.

Professor McIntosh is the Mackenzie Foundation Chair of Freshwater Ecology in the School of Biological Sciences at the University of Canterbury. He is also a Principal Investigator in the Centre for Integrative Ecology at UC and a member of the Waterways Centre for Freshwater Management and he is involved in the Biological Heritage National Science Challenge.

Register to attend at:

Careful management reduces nutrient losses from winter-grazed crops

Recent results from Ag Research trials in South Otago, undertaken as part of the Pastoral 21 project, have shown that grazed winter forage crops contribute significantly to the risk of nutrient losses to water but that with careful management, sediment and phosphorus losses can be reduced during grazing.

DairyNZ developer Maitland Manning says strategic grazing and careful management of wet areas such as gullies and swales in winter forage crops can reduce losses of sediment and phosphorus (P) to surface runoff by 80-90 percent.

Manning says:

“Gullies and swales are where overland flow and seepage converge to form small channels of running water, which may then flow to streams and rivers. By minimising stock movements and soil treading damage in these areas, any rainfall and runoff that occurs is more likely to infiltrate the soil, reducing the amount of runoff and loss of sediment and P.

“Simple changes in grazing management of winter crops can result in huge benefits for farmers as well as the environment.”

Strategic grazing means letting cows graze the drier parts of the paddock first and the wetter parts last. This usually means that the cows start at the top of the catchment and graze their way downhill towards the gully or swale. The uneaten crop acts as a buffer to minimise the runoff risk.

Manning says:

“If it needs to be grazed at all, the break nearest the gully or swale should be grazed at a time when the soil moisture content is not too high.

“Back fencing as much as possible will minimise soil pugging and compaction damage, and will also help to reduce volumes of surface runoff,” says Maitland.

Southland farmer Geoff Baldwin says he has noticed an improvement in sediment runoff since he has made changes to the way he winters his stock on swedes and kale at his Riverton property.

“Wintering can be a mission here with wet soil, so anything we can do to mitigate sediment losses is beneficial,” says Baldwin.

“We have identified and fenced off swales and we leave a three to four metre boundary along the fence line which is kept in grass and not ploughed. Sediment is washed into the swales and settles in the grass, so sediment from the crop is reduced. We always graze the crop in front of the cows so the swale is the last place the cows get to.”

More information can be found at

Pastoral 21 Next Generation Dairy Systems is a five year farm programme that aims to provide proven, profitable, simple adoption-ready systems that lift production and reduce nutrient loss. It is a collaborative venture among DairyNZ, Fonterra, Dairy Companies Association of New Zealand, Beef + Lamb New Zealand and the Ministry of Business, Innovation and Employment, and managed by AgResearch. The Pastoral 21 programme has been set up in four regions to address issues relevant to each area.

Water quality up for discussion at Winter Lecture Series

Questions about water and its quality will be explored on August 12 at “Do We Need To Worry About Our Water?” a panel discussion to be conducted as part of the University of Waikato Winter Lecture Series at Hamilton City Council’s Civic Reception Lounge, 6-7pm.

Iain White, professor of environmental planning, will host the panel.

Green Party water spokesperson Catherine Delahunty, who will join the discussion, says New Zealanders are right to be concerned about the quality of their water.

“There are figures that show more than 60% of our monitored rivers aren’t clean enough to swim in,” she says, “and a big part of that problem is down to large-scale dairy farming,” she says..

“A recent OECD report highlighted New Zealand’s poor freshwater quality – and this is the country with the clean, green brand.”

Ms Delahunty believes dairy growth is costing the environment more than ever before, citing a report from the Parliamentary Commissioner for the Environment that shows dairy intensification is causing more pollution to our waterways, and the water quality of many waterways is continuing to decline.

Professor Jacqueline Rowarth, another of the panellists, says we need to be mindful of context.

“We tend to focus on reports of change rather than absolutes when it comes to our water quality,” she says.

“The Waikato River, which runs through heartland dairy country in New Zealand has one of the lowest nitrate concentrations, 0.44mg of nitrate per litre of water, reported by the OECD for 2011. In comparison, London’s Thames river, which is reported as healthy, is consistently higher at 6mg of nitrate per litre, and is home to 120 species of fish. These fish have returned to a river that was, due to sewerage discharge, considered to be biologically dead at Tower Bridge in 1985.”

She also says our rivers are much cleaner than they were 50 years ago.

“We routinely monitor E.coli (bacteria) levels, which indicate whether the water quality is suitable for swimming and other contact recreation. We know that much of the Waikato River is safe to swim in – but other factors such as the current and submerged hazards are also a factor in determining the safety for swimming.

“Although more than 60% of monitored sites were declared a problem in 2013, they were being monitored because of high human and animal concentrations – which are found in cities and towns, for instance.”

Maori and indigenous legal issues expert Associate Professor Linda Te Aho, economist Dr Dan Marsh and Waikato Federated Farmers president Chris Lewis will join the discussion too.