N.J. Macpherson School has high levels of lead in its water, the N.W.T. government said Saturday.

It's the third Yellowknife school where testing has found lead levels above Health Canada recommendations.

In a news release, the government wrote that the chief public health officer issued a health order requiring the school to flush its whole system daily and provide a separate source of drinking water until the government can address the issue.

The territory tested 22 sinks and fountains at the school that were used for drinking or food preparation. All the high results came from sinks.

Drinking fountains will remain available for use.

In May, parents and staff at two other Yellowknife schools were notified that drinking water contained high levels of lead. The lengthy delay in publicly reporting triggered an independent investigation. Earlier this month, the territory announced a suite of measures to address the issue before school starts.

The territory said all N.W.T. schools will be tested as soon as possible, and it prioritized N.J. Macpherson because of the school's age, the age of its students and the fact that earlier results showed elevated lead.

In a statement Saturday, Yellowknife Education District No. 1 assistant superintendent Graham Arts said the territory's Department of Education co-ordinated water testing at the school.

The school district is taking "immediate steps" to provide drinking water in the school, said Arts.

What the testing showed

The territory did the same two types of testing it performed at the other two schools.

The first involved letting water sit for eight hours to see whether lead leached in from the plumbing.

That testing showed high levels of lead at 13 of the 22 locations -- all classroom sinks.

The highest levels reached up to 29.2 micrograms per litre. Health Canada's standard is five micrograms per litre.

The second kind of testing involved letting taps run for five minutes, and then letting water sit for half an hour, to more accurately reflect how water would be used during the day.

Children with lead in their blood do not show symptoms right away. However, even low levels of lead can affect a child's development, the government release states.

The Northwest Territories Health and Social Services Authority is taking appointment requests for bloodwork through its callback request form. To schedule an appointment, select YK Primary Care Regarding Public Health Order to book an appointment and bloodwork in one visit.

The government says its regular testing confirms there are "no concerns" about lead in municipal drinking water or in other N.W.T. communities.