The reopening of Boracay to tourists will depend on the coliform level in the water of the island-resort – from a most probable number (MPN) reaching millions to only 400 per 100 millimeters. Environment Secretary Roy Cimatu said the coliform level should be brought down to a standard of 400 MPN within the next five months before the island could be reopened. Cimatu said the coliform level in some areas of Boracay registered between 10,000 to 72,000 MPN per 100 ml. Others are in millions.

Talavera, C., Villanueva, R., Simeon, L. M., & Rendon, J. (2018, May 23). DENR: Boracay reopening depends on water quality. The Philippine Star, p. 14.