The horrible stench that has driven teachers and students from The Lester Vaughan School -- prompting its week-long closure on Monday -- is coming from a seriously defective sewage system, according to two weekend environmental tests, Barbados TODAY has learned.The problems were so severe that the plumbing contractor conducting the tests declared the campus “unhealthy” and in a “scary” state.A smoke test -- a sewer inspection method -- was conducted twice on Saturday and Saturday by the plumbers, a report of which was obtained by Barbados TODAY. Both tests were conducted from 10 a.m. to 3 p.m. in the presence of the principal, a representative of the school’s board of management, a teacher and a teachers union’s shop steward.Nontoxic smoke is pumped into the lines to identify pipe leaks, uncapped lines and other defects.Many breaches and defects were identified on both days at various locations across the school, the report said.