ST. LOUIS — Some Missouri school districts are preparing to test for lead after elevated levels were found in the drinking water of several St. Louis school buildings.

Workers began replacing 11 sinks in St. Louis Public Schools last weekend, and they plan to replace 71 more water sources where elevated levels of lead were found over the summer, The St. Louis Post-Dispatch ( ) reports.

The school district is working to determine the source of the contamination. According to Walter E. Browne professor of Environmental Engineering at Washington University, when elevated levels of lead are found, “the source will be the premise plumbing.”

Before 1986, lead supply pipes were often installed to connect plumbing in homes, schools and businesses with water supplies.

St. Louis school district staff were prompted to test 744 water sources in the district’s 72 school buildings after revelations that the water supply in Flint, Michigan, was contaminated by lead.

High levels of lead exposure can contribute to decreased IQ or development of learning disabilities, especially in young children.

An environmental firm is scheduled to test drinking water at Clayton public schools next week, starting with elementary and preschool buildings.

The Parkway School District has begun getting bids for water testing. The Normandy Schools Collaborative had water samples drawn on Thursday, and testing is underway in Ferguson-Florissant.

Other districts that plan to test drinking water include Maplewood-Richmond Heights, Rockwood, Ladue, Pattonville, Francis Howell, Jennings, Ritenour, Hazelwood and Affton.

Kurt Nelson, superintendent of Catholic Education, said some of the 73 elementary schools the St. Louis Archdiocese has in the city and St. Louis County have already been tested.

Information from: St. Louis Post-Dispatch,