Centertown School will be closed Tuesday as a precautionary measure after school officials noticed a grainy substance in the water on Monday.Warren County Utility District has been on the scene and has already conducted a preliminary test. Utility district general manager Mike Green said Monday afternoon several additional tests will be done to ensure the water is safe.“There may be something loose in a line or something like that because we haven’t done any work in that area in awhile,” said Green, who stressed safety is always a top concern. “We’re going to do everything we can to make sure students are safe.”Incoming Director of Schools Bobby Cox said with the results of the tests not available for 24 hours, the decision to close school at Centertown was made.“It’s more precautionary than anything else,” said Cox.