Third-generation Melbourne market gardener David Wallace is one of dozens of landholders who have been told to stop using water from the Maribyrnong River after toxic chemicals from firefighting foam were detected in runoff from Melbourne Airport.
Now he has been told to stop, after an EPA alert was issued on September 20, following tests for per- and poly-fluoroalkyl chemicals – known as PFAS – at Melbourne Airport and in nearby waterways.
The Department of Health maintains there is no consistent evidence the toxins cause “important” health effects, in contrast to the US EPA, which has concluded they are a human health hazard that – at high-enough levels – can cause immune dysfunction, hormonal interference and certain types of cancer.
Thirty-nine landholders with Melbourne Water diversion licences have been advised to stop using water from the Maribyrnong River as a precautionary measure until further testing could be done.
Testing on water, soil, plants and aquatic life by government authorities will assess any risk to the public posed by chemicals in the waterways.
Mr Wallace has reduced the amout of Maribyrnong water he used in recent years and was reluctant to grow anything in soil outside his greenhouses.
Diversion customers were notified on September 7 that PFAS had been found in soil and water at the airport, a spokesman said, and then again on September 17, after receiving further information from the airport and preliminary advice from the EPA.
Melbourne Airport said it was "really pleased" that the EPA and Melbourne Water were investigating the presence of PFAS in nearby waterways.
Last year the airport tested surface water and groundwater, as well as more than 800 soil samples, for PFAS, a spokesman said.
"These investigations found that PFAS contamination is concentrated in a few locations associated with the historical use of PFAS-containing fire-fighting foams.

Bottled water will be handed out to some residents in West Drayton after a water main burst has left hundreds of home without water.
There have also reported sewage pouring from their taps, following the burst main in Falling Lane and Camomile Way, West Drayton, late on Sunday night (September 16).
An Affinity Water spokesman told getwestlondon this morning: “We are sorry for any inconvenience caused by a burst at Falling Lane in West Drayton last night.
“This caused flooding to a number properties in the area and we are providing support to those whose homes have been flooded.
“We would like to thank our customers for their patience during this time.” As well as a lack of water, some residents reported sewage pouring from their taps.
A photograph shared with getwestlondon by Jake Webb, shows sewage water in his bath tub.
Both Metropolitan Police and the London Fire Brigade were at the scene of the flooding overnight, and firefighters even used a lifeboat to rescue a newborn child as well as others.
The Affinity Water spokesman said engineers are currently working to fix the burst main, and that repair work would be completed later today.
If you have any updates or pictures of the flooding, please contact our reporter Vicky Munro at vicky.munro@trinitymirror.com.
Follow our live blog for continuing updates on the situation here .

ASIAN flour millers are expected to seek rare wheat shipments from Argentina in coming months as a second year of drought in traditional supplier Australia curbs supplies.
But Russia and Ukraine are expected to run out of surplus supplies by the end of the year due to an autumn in output and strong demand for exports, forcing buyers are seek shipments from alternative origins, traders and analysts said.
“From December onwards and in the first quarter of 2019, we expect some of Argentina’s surplus wheat to come to Asia,” said one Singapore-based trader at an international trading company.
“We have lower wheat production in many exporting countries but Argentina is looking at a bigger crop.” Asia is the world’s biggest consumer of wheat.
Demand is expected to top 304 million tonnes during the 2018-19 crop year, a record 41.1 per cent share of global consumption, according to US Department of Agriculture forecasts.
However, several key wheat exporting countries have faced droughts in recent months, and traditional sources of supply may struggle to fulfil all of Asia’s needs.
Production in Russia, the world’s biggest wheat supplier, is expected to drop to 71 million tonnes in the year to June 2019 from an all-time high crop of 84.99 million tonnes a year ago, according to USDA data.
Australia lowered its wheat forecast by nearly 13 per cent to 19.1 million tonnes on Tuesday as a crippling drought across the country’s east coast has cut output from the world’s fourth-largest exporter to a 10-year low.
But wheat output in Argentina is expected to climb to 19.5 million tonnes from last year’s 18 million tonnes, well above the 11.3 million tonnes produced in 2015-16, the USDA data shows.
“There were some concerns over dryness earlier but recent rains have been very good in Argentina,” said one India-based agricultural commodities analyst at an international bank.

Falling water levels at hydroelectric dams and coal-fired power stations are ringing alarm bells as the NSW drought raises the risk of blackouts in the south-east this summer.
While plant owners say the situation is far from the crisis of last decade, the energy market operator highlighted the threat in its latest electricity outlook on Friday, noting the situation for water availability for hydro and thermal power generation would be "closely monitored" and reported on later this year.
Water levels at 14pc Water levels at Snowy Hydro’s plants are "on the low side" at about 14 per cent, compared with a mid-20s per cent level a year ago, said Snowy chief executive Paul Broad.
"Our real worry is that the forecast for the rest of the winter is really dry, and so making sure what’s up there runs into the dams," Mr Broad said, noting that in 2007 water levels fell as low as 3 per cent while the snowpack was very shallow as well.
AGL Energy, owner of the large Bayswater coal power station in the Hunter Valley, which had to curtail generation in 2008 due to water shortages, said prolonged drought over many years "is a challenge for managing reliable electricity production".
AGL Macquarie draws cooling water for Bayswater from the Hunter River under licenses negotiated with the state government.
Origin Energy also said the drought wasn’t affecting water availability at its Eraring coal generator in NSW, the country’s biggest, which uses water from Lake Macquarie, nor at its Shoalhaven hydropower plant.
"Customers can be assured that even through the drought and hot summer months Origin power stations can continue to play a critical role powering NSW, with secure water supply for both Shoalhaven pumped hydro scheme and Eraring, which accounts for around a quarter of the state’s power needs," said head of energy supply Greg Jarvis.
Weekend outages The concerns on summer power supplies come after outages during the weekend in two interstate power cables, causing mass blackouts in NSW and elsewhere as Queensland and South Australia were "islanded" from the rest of the grid.
Still, Mr Broad described Mr Taylor as having "enormous knowledge" about Snowy Hydro’s operations and noted he is the grandson of William Hudson, the engineer who headed up construction of the Snowy hydroelectric scheme.

Standing in front of the microphone in the searing bare heat outside the Tully family’s house paddock, the Prime Minister holds up a message of hope.
The questions soon round on that of climate change.
He also points the family’s own records which he believes show this drought is not unusual.
"We’ve got 100 years of (rainfall) records," Mr Tully says.
The Prime Minister echoed that position.
"If people want to have a debate about that, fine.
"Now the challenge is: do you keep them in boarding school, or are they not educated?"
"But you’re still going to educate those kids.
In the town of Quilpie there is a noticeable decrease in the sound of children laughing and playing.
"We’ve had families move away because they can’t afford boarding school," Mrs Hall said.

Parsa, Chhattisgarh: Banmati, a middle-aged woman from Parsa village in Udaipur block, Chhattisgarh, looks distraught.
Situated close to the Parsa East & Kenta Basen (PEKB) block, the village of Parsa is facing the environmental consequences of coal mining.
In 2013, the Adani Group’s subsidiary, Adani Mining, started extracting coal from PEKB.
However, the Supreme Court ordered suspension of the mining operations for the PEKB block (Civil Appeal No.
The people of Parsa are completely dependent on the company for their daily drinking water needs.
The villagers claimed that when someone from one part of the village submits a complaint, the water supply from another part of the village is diverted temporarily.
The panchayat leadership, once persuaded by the rhetoric of mining-led development, has now reached a breaking point since they receive constant calls from company officials asking them to ‘take over’ the provision of water supply.
We will not take responsibility for the water unless they build a water tank for this village like they initially promised.” The denial of constant supply of drinking water only brought to the surface the latent discontent and anger of the villagers.
Geeta Bai, who had to part with her land, found herself tasked with cleaning toilets at the company.
For the moment, what they say they want urgently is clean water from Adani Mining.

Himachal Residents getting rationed supply after four-five days Kuldeep Chauhan Shimla, May 25 Residents in the city are reeling under acute water shortage for the last few days.
While the residents are buying bottled water for drinking and cooking, hoteliers are solely depending on tankers in the tourist season.
The Shimla Municipal Corporation (SMC) is struggling to ration 21 MLD of water that was pumped from its major sources these days.
The water availability per resident was just 5 litre as on Friday.
The city needs 45 MLD water daily, but the water availability has come down from 29 MLD last week to 21 MLD on Friday.
Guma, which has 20 MLD capacity, and Giri, which has 20 MLD capacity, could supply just 4 MLD and 14 MLD, respectively, revealed MC supply chart.
“The BJP-led MC has failed to provide water to its residents and hence its Mayor should resign,” said former Mayor Sanjay Chauhan.
“To meet the water needs in the coming weeks, the MC is floating tenders to press in service private tankers to lift water from Chaba,” he added.
Crisis at peak The city needs 45 MLD water daily, but the water availability has come down from 29 MLD last week to 21 MLD on Friday.
Guma, which has 20 MLD capacity, and Giri, which has 20 MLD capacity, could supply just 4 MLD and 14 MLD, respectively.

Unseasonably warm spring temperatures has Siloam Mission calling for donations of bottled water months earlier than they’ve had to in past years.
(CBC) The unseasonably hot and humid temperatures seen in Winnipeg this spring have left Siloam Mission scrambling to provide water for the city’s homeless population.
"We’re getting down to low levels of bottled water so we are putting out the call for donations — it’s a genuine and immediate need here at Siloam."
While it’s not the first time the homeless shelter has had to make a plea for bottled water as temperatures soar in the city — they made a similar call to the community last July — Bell says it’s rare they’ve needed to do it so early in the season.
But with temperatures hovering around the 30 C mark during midday this week, he says the risk of dehydration is already very real for the city’s homeless population.
And there’s not much relief in sight, according to CBC meteorologist John Sauder.
‘One of those staples of life’ The heat has been driving those living outdoors in Winnipeg to Siloam Mission for relief, says Bell.
"I can also tell you, that for the people we serve, that bottle of water is always, always met with a thank-you.
"We believe that when we put a call like this out our communities will respond and that’s why we say thank you in advance because it’s just so much appreciated."
Donations of bottled water can be dropped off at Siloam Mission at 309 Logan Avenue.

"This basic scientific research has the potential to be able to improve farming productivity not just in Australia, but potentially in other countries that suffer from drought stress," Dr Pogson said.
"If we can even alleviate drought stress a little it would have a significant impact on our farmers and the economy."
Dr Pogson said the research found chloroplasts in cells surrounding the pores on leaves, called stomata, can sense drought stress and thereby activate a chemical signal that closes stomata to conserve water.
"This finding was completely unexpected and opens new avenues of inquiry into how chloroplasts can contribute to plant responses to the environment," Dr Pogson said.
"Boosting the levels of this chloroplast signal also restores tolerance in drought-sensitive plants and extended their drought survival by about 50 per cent," Dr Chan said.
"Dr Pornsiriwong, who has started her own research lab in Thailand, is currently investigating breeding strategies that naturally enhance levels of this drought tolerance-promoting chloroplast signal in rice," Dr Chan said.
The research was funded by the Australian Research Council Centre of Excellence in Plant Energy Biology and was a collaboration between ANU, the University of Adelaide, University of Western Sydney, CSIRO, Kasertsart University (Thailand) and the University of California San Diego (United States).
The research has been published in eLIFE.
More information: Wannarat Pornsiriwong et al. A chloroplast retrograde signal, 3′-phosphoadenosine 5′-phosphate, acts as a secondary messenger in abscisic acid signaling in stomatal closure and germination, eLife (2017).
DOI: 10.7554/eLife.23361

Nanobionic spinach plants can detect explosives.
Spinach is no longer just a superfood: By embedding leaves with carbon nanotubes, MIT engineers have transformed spinach plants into sensors that can detect explosives and wirelessly relay that information to a handheld device similar to a smartphone.
When one of these chemicals is present in the groundwater sampled naturally by the plant, carbon nanotubes embedded in the plant leaves emit a fluorescent signal that can be read with an infrared camera.
The paper’s lead author is Min Hao Wong, an MIT graduate student who has started a company called Plantea to further develop this technology.
Environmental monitoring Two years ago, in the first demonstration of plant nanobionics, Strano and former MIT postdoc Juan Pablo Giraldo used nanoparticles to enhance plants’ photosynthesis ability and to turn them into sensors for nitric oxide, a pollutant produced by combustion.
In the new study, the researchers embedded sensors for nitroaromatic compounds into the leaves of spinach plants.
The signal could also be detected with a smartphone by removing the infrared filter that most camera phones have, the researchers say.
"These sensors give real-time information from the plant.
Nitroaromatic detection and infrared communication from wild-type plants using plant nanobionics.
ScienceDaily, 1 November 2016.