Four public schools on Kauai will be closed Friday, the first day of the school year due to problems with the water system in Lihue and Hanamaulu.

The affected schools are Kauai High School, Chiefess Kamakahele Middle School, King Kaumualii Elementary School and Wilcox Elementary School. The state Department of Education said the water system has been compromised during a construction project in Hanamaulu. 

A total of about 3,500 students are enrolled at the schools. 

Kauai Complex Area Superintendent Bill Arakaki said the decision to close the schools was a precautionary measure to ensure the health and safety of students, faculty and staff. 

The county Department of Water and contractors were working on waterline improvements to Hoomana Road Wednesday. “As the line was being turned back on, soil entered the line and was released into neighboring service areas,” according to the water department.

The department issued a “boil water advisory” to residents in Lihue and Hanamaulu who were advised to flush out their faucets until the water was clear. Once the water is clear, the department notified affected residents to continue to flush out their faucets for 30 minutes and to then boil the water for 1 to 3 minutes when using it for drinking and cooking.

Crew members have been flushing out affected waterlines in Lihue and Hanamaulu. The water department is expected to have test results on the water Friday.