After reports of high nitrate levels in Grand Forks’ water wells several years ago, water quality in the area has been monitored to ensure residents’ health.
The BC Ministry of Environment in Victoria and the Ministry of Forests, Lands and Natural Resource Operations has been monitoring the water wells in the Grand Forks area since the 1990s.
Sasha Bird, city manager of technical services and utilities, noted that a full report is currently underway. The recent Kettle River Watershed report has also listed nitrate levels in Grand Forks as a part of its study of the watershed.
“While we have not reviewed the water quality data for the City of Grand Forks’ wells in detail, there are locations in the Grand Forks area that show nitrate levels are declining,” explained Bird. “Our consultant’s current assignment will be to look specifically at nitrate levels in both the city wells and from the larger network of wells to identify if levels are rising and if they are an issue.”
Nitrate-nitrogen is a groundwater contaminant of greatest concern, with the highest levels generally found in the shallowest wells. The concentration decreases with well depth.
The Kettle River Watershed study also found that though there is relatively little information on groundwater quality in public domain, Grand Forks does have some statistics.
Hugh Hamilton, the project manager for the study from Summit Environmental, stated, “Nitrate has been the contaminant of greatest interest. Concentrations of nitrate-N have exceeded the 10 mg/L drinking water guideline, especially in the southeast part of the aquifer (in the Kettle watershed).”
Bird added that several things could cause contamination from nitrates, including fertilizers, septic systems and sites with concentrated livestock wastes.
“The most likely sources in the Grand Forks area are thought to be fertilizer application and residential sewage disposal (septic) fields,” Bird said. “There isn’t much that can be done about sewage disposal fields, except limit the residential development density in areas that are not serviced by the community sewer.”
Nitrate found in drinking water due to fertilizer use could be caused from water runoff from fields.
In regards to fertilizer use, Bird explained that Lorraine Thompson – who used to be a representative of Agriculture Canada in Grand Forks 10 years ago – worked with the local agricultural community and the previously informal Grand Forks Aquifer Protection Committee.
“Thompson used to promote more conservative fertilizer application methods,” said Bird.
The Kettle River Watershed study pointed out that nitrate-nitrogen groundwater levels range from <0.01 mg/L to >30 mg/L, with a median of 3.4 mg/L. The Canadian Drinking Water Guideline is 10 mg/L nitrate-nitrogen level.
“I would like to think that this has contributed to some of the declining levels we are seeing,” concluded Bird. “Having said this, more public awareness and further reduction in fertilizer use will go a long way to managing nitrate levels in the Grand Forks Aquifer.”
The final evaluation report for the Grand Forks area nitrate levels is due Sunday, Sept. 30.