Water at Mount Si High School’s new modular classrooms has too much lead, a test found.

Late last week, the Snoqualmie Valley School district received word that water from one of the fixtures at the modular building tested at a higher level of lead than federal guidelines recommended.

Classrooms at the portable buildings, built last fall on the site of the school’s old tennis courts, don’t have drinking fountains. But some rooms have sinks, such as science classes. Other classrooms have faucets where students wash their hands.

Still unknown is whether the contamination is at an isolated sink or building-wide.

“In some classes, we’ve ensured that teachers don’t let students drink out of the faucets until we learn more,” said Carolyn Malcolm, Snoqualmie Valley School District spokeswoman.

Malcolm said school staff are taking steps to identify the source and scope of the problem. The school district hired PBS Environmental to test all the plumbing fixtures in the building, and expects to find the source of contamination this week.

Snoqualmie Valley schools and portables were tested in 2004 and no health concerns were found. If contamination is linked to new parts at the new portables this summer, the district will work with manufacturers to ensure appropriate repairs. The lead issue may still be covered under warranty.