After seeing Houston’s tap water get more and more discoloured, a local paediatrician has asked Northern Health to investigate.
Dr. Clare Moisey, who has worked in Houston for 20 years, sent a letter to the health authority last week to report a significiant amount of new discolouration in the water over the last six to eight months.
“At times, the water in the toilet will look as though someone with hematuria [bloody urine] had used the toilet and not flushed,” he wrote.
“During the day, this will settle out and the water will become a reasonable colouration.”
High manganese has long been a problem in Houston’s water supply. Residents voted last April to reject a $4.5-million water treatment system that would remove manganese from the water.
Doug Quibell, northwest manager of public health protection, was part of the consulting team that helped the District of Houston decide on that proposal.
When it comes to a health risk, Quibell said Houston water is well protected.
Four wells pump water into Houston’s system, he said, and samples taken at each well consistently pass tests for bacteria and chemicals that pose a risk to human health.
Only one element, manganese, regularly exceeds Canada’s guidelines on drinking water, Quibell said, adding the guideline in question is only meant to control taste and visual quality.
“But it never gets within 40 per cent of the health-based guideline,” he said.
That guideline is 0.5 mg per litre of manganese stretched over an average human lifetime.
At the levels Houston has, Quibell said the main concerns are stains on laundry and plumbing fixtures as well as an unpleasant taste. Consumer-grade water filters such as Britta pitchers are enough to remove most manganese, he added.
Manganese is a very common element, Quibell said, and in trace amounts it is considered part of a healthy diet.
A Health Canada fact sheet notes that manganese is among the least toxic of the elements, and even in places with high manganese in the water, Canadians ingest more of it in their food than they drink.
But a 2010 study funded by the Canadian Institutes for Health Research suggested that the manganese levels found in towns supplied by groundwater may cause intellectual impairment in children.
After tracking manganese levels in the food and water of 362 Quebec schoolchildren, researchers found lower IQ scores among those living in towns supplied by groundwater.
Quibell said the study suggests there are potential long-term health effects at a manganese level lower than the Canadian health guidelines.
“But that was only one study,” he said, adding that more research is now underway at Environment Canada.
“This is new and it could be legitimate, but it needs to be followed up,” he said.
“What they recommended at the end is that other scientists look into this.”