A deep dive into Sumas Prairie’s soil

Before Sumas Prairie farmers till their fields they may still not know what, exactly, is in the soil.

Crews have worked to remove debris from roadways, streams, and public spaces. But researchers are still trying to determine where November’s floodwaters deposited invisible contaminants.

In December, the province completed preliminary sampling of surface water at six Sumas Prairie locations.

Results from five of the six testing locations revealed poor water quality. The samples exceeded the limits of the Canadian drinking water quality guidelines for E coli, fecal coliform bacteria, metals, and turbidity (the last of which measures the clarity of a fluid). Results for the sixth testing location, at the Sumas border, were not available in the online database.

During and immediately after November’s floods testing revealed water quality was “poor and unsuitable for drinking water,” the province said. (Water quality can commonly decline after flooding). The City of Abbotsford had implemented boil advisories following the flood; they were lifted on Dec. 20 and there are currently no water advisories in effect.

The province still plans to sample several sites on the Fraser River downstream of the Sumas and Vedder Rivers. Those samples will be tested for nutrients, fecal coliform bacteria, metals, pesticides, and hydrocarbons.

Although the published data indicates the samples tested exceed limits, the ministry has said they are still interpreting the data.

“Tests from the Fraser Valley are still being analyzed and compared to water quality guidelines. Once completed, the analysis will be posted.”

It’s important to note those samples are only a snapshot in time.

The province began collecting water samples from the area in December. On Feb. 7, BC Agriculture Minister Lana Popham said there are “some instances of contamination.” A $228 million recovery package to help farmers affected by the floods will include assistance to remediate soil, Popham added. But contamination issues are not believed to be widespread, the Ministry of Environment said in a statement on Feb. 10.

It may require several rounds of testing to determine what areas, if any, will need to be remediated, UFV agriculture professor Dieter Geesing said. The testing process can be a challenge if you don’t exactly know what you’re looking for.

“There’s so many organic and inorganic components in this world that it is almost impossible to analyze for everything if you don’t know what’s inside,” Geesing said.

But there are often clues in the results that can suggest the presence or absence of related compounds. Even when test results indicate some elevation of certain matter in the soil, it isn’t always bad news.

“So let’s say you find a component that is a little bit elevated; we don’t actually know whether that has been naturally elevated in that area to begin with,” Geesing said.

To determine if any elevated test results are concerning, scientists will be looking at something called threshold values.

The agencies responsible for analyzing test results in BC will compare that data with historical measures to determine what levels are safe.

Those results will also provide information to help suggest plant quality, but Geesing noted the plants are very selective about what they absorb. But if there is reason to believe any contaminants were absorbed by the plants, then those plant tissues would likely also be sampled too.

The process is an issue of public trust, Geesing said, pointing to Canada’s high food safety standards. And the stakes are high for the farmers too. They aren’t interested in investing time and money into farming the land before learning whether the product from the soil is safe to sell.

Whatever the testing process might reveal, Geesing said the province has every reason to get it right.

“I think that everybody involved has some flesh in the game, right? And we are all consumers.”