No soil testing for flooded fields, says province
As planting season begins, government says visual inspections are enough to assess possible contamination
Soil on farmland flooded this spring along the St. John River is not being tested for potential contamination, leaving farmers to trust what the government finds during visual inspections and consumers to trust that any produce will be safe.
But farmers and consumers shouldn't be uneasy about what comes out of the ground this year, the province says.
'It's not a real common practice to test the soil following flooding," said Kevin McCully, the provincial agriculture director.
Eleanor Thomas, who owns True's Plant Nursery in Maugerville, plants vegetables in the field behind her greenhouses to sell at the Boyce Farmers Market in Fredericton.
3 small oil spills
During the record flood in late April and early May, oil spilled from three drums on Thomas's property near her greenhouses. Inspectors from the Department of Environment told her the soil will have to be dug up.
Her field was also flooded, but after an inspector walked through the back field about two weeks ago, she told Thomas and her husband the floodwater had moved too fast to contaminate the soil.
"She said there's not one bit of contaminated soil out there," Thomas said.
McCully said consumers should not be concerned about eating vegetables from areas that were flooded.
"We certainly felt the time between planting and time between harvest was long enough, that with sunlight and air and soil tillage that the risk for soil contamination will be minimal," he said.
Department employees have contacted all known farms that produce food for human consumption and were affected by the flood to assess individual sites and provide guidance.
The province hasn't tested soil for contamination because there are no standards for interpreting the results, McCully said.
Instead, inspectors are using visual observation to determine the risk of contamination.
"We're not convinced you'd gain a lot of knowledge by the testing," McCully said.
He said natural contamination in soil from birds and animals makes it hard to interpret results.
But environmental scientists in Dalhousie University's faculty of agriculture say soil testing for contamination, while complicated, can still be done, and there are standards and guidelines.
"You're always better to measure than to just go based on visual," said David Burton, a professor in the department of plant, food and environmental sciences, who has experience in petroleum contamination remediation.
"It's very difficult to make a statement without actually having done a measurement."
Burton said the Canadian Council for the Ministers of Environment has soil quality guidelines for petroleum. Contamination-level guidelines are specific to land use, including agricultural, industrial and residential soil use.
The council and other resources have guidelines for various types of contamination, from petroleum to sewage pathogens.
Different factors in assessment
Assessing the risk of contamination can be tricky, since so much depends on the specific situations around the potential exposure to contaminants.
During a flood such as the one southern New Brunswick suffered, where the toxins go will depend on whether the floodwater evaporates on a site, leaving toxins behind, or recedes and takes the toxins with it.
It's hard to explain what we lost until you've seen everything that we had to start with.- Eleanor Thomas
Other factors include the original source of the contamination, the distance from the site in question, the volume of the contaminate and the volume of the water it was dispersed in.
Burton said soil does have the ability to degrade toxic compounds found in petroleum, depending on the size of the spill.
"In fact, one of the ways we try to encourage the degradation of petroleum compounds spread on soil is to plant a crop, and to get the biological activity going in that soil," he said.
"And those microbes, as they're growing on the root, will also degrade some of those petroleum compounds to carbon dioxide."
McCully said if any plants did manage to grow in soil contaminated by petroleum they would appear obviously unhealthy and would not be harvested.
Thomas lost one greenhouse, three-quarters of her nursery stock, peat moss, pots, six furnaces and one oil tank, as well as all of her household appliances and most of her furniture to the flood.
The oil spill left a dead patch of grass on her property.
Thomas was told two companies that handle that kind of cleanup have been contacted and will be out to do an assessment, then return to the Department of Environment with quotes. Once the department picks a contractor Thomas will get her spill cleaned up.
She doesn't know how long that will take.
Risk assessment and soil testing
Another complexity of soil testing is that the composition of soil can vary, even in a small area.
Gordon Price, also a professor in the faculty of agriculture at Dalhousie, said that for accurate results with testing, you need to either test lots of samples or collect a large representative sample, mix it together and then test.
Price said the first step in determining the risk of contamination is to look at the nature of the exposure in each specific circumstance.
For agricultural soil, that includes the type of crop and how it is grown.
"If it's a food crop like a potato, even a modest-to-low concentration might be a big concern, and growers and processors might want to have much more active testing to make sure that it isn't a concern."
McCully said farmers are adjusting their management practices to reduce risk and protect customers. The adjustments include delaying planting, he said.
Thomas hasn't planted her back field yet, but she's not behind schedule. She said she normally waits until the greenhouse business has subsided and usually plants the first week in July.
"We got really good ground here," she said.
"It's nothing big but it's enough to keep me going, get my hands dirty, but I love my farming."
Thomas said that during inspection, a water test was done at her greenhouses and came back fine.
Her house still doesn't have water or electricity again, and she and her husband have been living at a friend's house down the road for five weeks.
\While her vegetable garden isn't behind schedule, normally all four greenhouses would have been filled by early June, she said.
Now two of them are half-filled with plants.
"It's hard to explain what we lost until you've seen everything that we had to start with."