Workers at the wastewater treatment plant in Negril are the people that informed me that Montego Bay employees sample the plant weekly.
Also, consider this story. The wastewater treatment plant I work at is about a mile from the source of the stream we discharge into. We actually double the flow of the stream where we discharge. During high flows when our plant actually overflows we take fecal coliform readings above and below our outfall. Normally we are not allowed to put any chlorine into the stream, but during high flow events we are allowed and chlorinate the daylights out of our overflow. Fecal samples taken upstream of our plant often range in the 5000 to 8000 count. Mind you, this is only run off from roads and yards with in a mile of the plant. Because we chlorinate so heavily during these times, our downstream fecal counts are always lower than upstream. So runoff anywhere in the world will cause high fecal counts. That is why the Jersey shore will occasionally close beaches, not from the wastewater treatment plants but from run off from the streets.
When I checked the outfall of the Negril plant, my estimate would be that it was less than 1\20 of the river flow.
Regards,
Bob