Using surveillance cameras, police identified 40 different dumping sites throughout the city being used to illegally dispose of garbage.
In a press conference Tuesday, RNC officers said a Canada Post employee caught dumping advertising mail is among those charged since October.
The male employee, 37, used a Canada Post truck while disposing mail in the woods.
St. John's Mayor Dennis O'Keefe said it doesn't make sense for residents to go through the effort to dump trash illegally instead of legally.
"If you're going to put it in your truck, why not drive out to Robin Hood Bay?" said O'Keefe.
Robin Hood Bay — the regional waste management facility in St. John's — offers residential drop-off services five days a week.
Mayor O'Keefe said the city will continue to pursue and prosecute people illegally dumping in the city.
The maximum fine for illegally dumping is $10,000.
City employees have been monitoring up to 60,000 surveillance photos of illegal dumping each month.