Making things worse, laboratory tests conducted from September to October also showed that portions of the beaches extending from Bolinao to Bauang and San Fernando City in La Union were also found to be positive for coliform.
Eduardo Janairo, Region 1 (Ilocos) director of the Department of Health, attributed the coliform presence to the resorts and other establishments that have sprouted on the beaches of Bolinao.
Aggravating the problem, he said, is the habit of fishpen workers to defecate in the waters for lack of toilets.
Janairo said the mayors of Bolinao and San Fernando City have acted on their findings, the former putting up a toilet near the shore.
At the moment, Janairo said they are not discouraging swimming, "but in due time we will, especially if we see that the coliform (is still there)."
Janairo said coliform occurs intermittently, thus the need to place colored "floater marks" to indicate which places swimming is allowed (blue) and where beachgoers face the risk of skin diseases or diarrhea (white).