A three-day test burn at the St. Marys Cement plant here was scheduled to begin yesterday following equipment testing and calibration that started on Tuesday.

The test, which was approved a year ago by the Ministry of Environment (MOE), involves the use of shredded plastic film as a substitute for about 30% (in thermal terms) of the normal fuel used in the kiln.

Martin Vroegh, corporate environmental manager for the company, said the test burn should be imperceptible to town residents.

Vroegh said that although 30% fuel substitution is the goal, realistically it will be no more than 20-24% so the change in material in the kiln will be less than 2%.