The waste water treatment is a separate issue from storm run-off water. But many people confuse the two as was asked here earlier. I wanted to clarify the point that waste water is and has been treated at the current treatment plant since 1998.
The storm run-off waters are the same as with many US cities and coastal cities world-wide. This rain water run-off has nothing to do with the water treatment plant waters as RockRobster pointed out and is a typical situation.
But while the brown water in the sea can be caused by storm run-off water, that is not always the case. At times of high seas and high tides, when the tide goes back out, the same thing can happen to the sea. The Negril River water has always had a dark brown tint to it. This is one of the possible reasons why Negril was named Negril by the Spanish. There are three possible reasons.
One theory has to do with the black eels that were found in the Negril River hundreds of years ago that was mentioned in a thread here not long ago. The second theory has to do with the dark cliff face of the West End which is visible from the sea. The third theory has to do with the dark brown color of the Negril River. The Spanish documented this hundreds of years ago as well. The tree leaves and other vegetation lining the river turns the sun warmed shallow river water brown, just as tea leaves do in a cup of warm water.
The tea colored water of Negril River is the ultimate cause of the brown water in the sea issue.
