Wastewater Treatment in Negril

A few months ago there was some discussion about brown water coming from the Negril River and encrouching on the beach. Well, I visited the negril treatment plant in December and can positivly say it was not coming from there. I have worked in wastewater treatment for over 20 years and have experience in what is called an "activated sludge" plant. The Negril plant is what I would call a "lagoon" or "pond" plant, howqever the workers there called them "pans". Basically, wastewater treatment works on the concept of decompostion and speeds it up much faster than nature by optimizing conditions. For instance the plant I work at takes raw wastewater and turns it into near quality drinking water in about 36 hours. We have many mechanical devices (blowers, pumps, mixers etc) to achive maximum results in a short period of time. Of course we are servicing about 2.5 million gallons per day in an area of about 4 acres. The Negril plant has no mechanical devices. Granted, there are about 14 mechanical pump stations along the cliff and beach roads that pump the raw sewage to the treatment plant which is located next to the Golf Course just outside of town on the road to Sav. But once the raw wastewater reached the plant (called the "headworks" in the business) everything flows by gravity. The way that a "pan" plant works is by exposing the raw wastewater to sunlight for extended periods of time to disenfect the water. I took ball park measurement of the pans and guestimated the flow at the headworks and came up with an estimated detention time of 29 days. That means that water that is entering the plant today will not leave the plant for nearly a month! However if the flow coming into the plant is tripled during a tropical storm, detention time drops to about 10 days, a hugh difference. Also, during storm events there is little if any sunlight, so less disenfection is taking place. The pan system works okay and is designed for places that have a lot of land and little money. The Negril plant is on a 40 to 50 acre plot. The treatment plant consits of 2 sets of 3 pans. each pan is about twice the size of an American football field. At the headworks is a manual bar screen which is cleaned off daily by the workers. This collects mostly non treatable products such as tampons and condoms. More specifically once the water leaves the headworks it flows by gravity to the first two side by side pans. About a third into the pans is a baffle that holds back any floatables and the heaviest of sludge which the workers occasionally clean out. At the far end of the pans is a weir or a gateway to allow the water to flow into the next set of pans. At the far end of the second set of pans is a gateway into the third set of pans. At the end of the third set of pans the flows combine and flow into the Negri River, I don't know, maybe a mile or two upstream. As the water travels from pan to pan it becomes noticably cleaners. The workers told me there are plenty of big fish in the final pans and indeed I did see a fish at least a foot long crest the water. That is basically how the plant works.
The Upgrades. I visited the plant about 1.5 years ago when they were in the middle of "upgrades'. Cosmetically much was done. The entire plant is now completely fenced in. There is signage around to warn people and also saftey signage for the workers. The headworks was redone and is a bit more effieient. A few other things were done that MAY inprove the water quality. There is now blacktop rather than dirt between the pans. This means that during heavy rains dirt will not be washing into the pans. Also, the system that passes water from one pan to the next has been modernized and is more efficient. However, there was talk a year and a half ago about making the pans deeper. I'm not sure that this was done, and even if it was I'm not sure it would be effective. Pans should only be about 2.5 or 3 feet deep at most to be effective. What is more effective is cleaning out the pans of any sludge that accumlulates on the bottom. I am not sure if this is done, and if it is how often. I will try to show before and after photos of the plant.
Finally, what does this all mean to the Negril River, the ocean, the reef and the swimmers? Good question. The workers at the plant had no knowledge of any effluent parameters or lab results. They said that someone came weekly from Montego Bay to collect samples. I noticed that there was no chlorine or disinfection at the point where the water enters the river. The pan system is supposed to disinfect, but I'm not sure to what extent. A fecal coliform would have to be taken to find out how well it is working. For instance, Ocean City, New Jersey has a maximum fecal coliform of 200. If a 200 count is found on any of the beaches they are sut down. At the plant I work at our maximum is also 200, however our twice a week samples average less than 5. I would have to do more research, but I don't think that the pans do much to lower phosphate (from soaps), ammonia or nitrates (from urine). In fact a byproduct of pans are the massive amounts of algae that they produce. If someone will do the research and find test results for: fecal coliform, pH, turbidity, Dissovled oxygen, Phosphates, Nitrates, Nitrites, and BOD, I will compare them to US standards to find out how well they are doing.

Regards,

Bob

I'll get right on that. :)

So I thought it was like most resort areas as the sewage treatment plants are always next to the golf course, of course to water the fairways and greens with the sewage water? Seemed like a good idea to me.lol

Wow, Thanks Bob, finally some realtime, detailed info...I appreciate it... I'm still interested in the water quality and test results, (ie the fecal coliform levels, etc) Would really like to know the quality of the water near the beaches...I've written to many agencies and still have not gotten an answer-So Yes, am interested in the levels as well....Maybe you have better chance getting a hold of this place in Mobay that supposedly runs weekly tests...I have no idea who/waht runs this...

Thanks again Bob...

wow

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First photo is the headworks before repairs. Next 3 photos of repaired headworks.
Photo 3 is looking toward the manual bar screen. Workers take a rake to pull up any no organics (condoms. tampons etc) and then dispose of them. The last photo is the bar screen from the top end and shows what they pulled up for the day. You can actually see the bars (rack) that are about 1 inch apart. You would be amazed at what stuff can collect on a bar screen.

Regards,

Bob

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These 3 photos were taken during upgrades in June of 2011. Note that the area between the pans is unfinished, it seemed to be crushed limestone or something similar. Also no fencing around the perimeter.

Regards,
Bob

Very interesting.

Thanks Bob very interesting post

I always understood that ear/ throat infections were an indication of how clean the water is.

Out of interest Bob, do you still drink tap water in Ja?

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Recent photos of the paved areas between all the pans. There were a lot of birds there and you can see a few flying in the last photo which also shows the security fence.
Regards,
Bob

I was looking forward to hearing your take on this, Rjonsun.
Rob is very well informed but with your background you have the capability of detailed observation & a description that very few can offer...thank you.

I've always heard the color of the water is caused by the color of the peat that washes down the river after a rainstorm in the hills.

I wonder what some of the more unexpected things turn up on those bar grates....

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Overview of the plant. On the first photo you can clearly see the 3 large pans on the right side of the plant. The water enters from the headworks at the foreground. Barely into the first pan you can see a type of baffle or dike that keeps any floatables or heavy sludge from passing farther into the pan. It is then cleaned out by the workers, but I don't know how often. The second shot shows all 6 pans which is in a 3 pan side by side configuration. Water enters equally into the top two pans and flow through the system.
Regards,
Bob

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The first photo shows how the water used to flow from one pan to the next, through these large tubes. They have been filled with cememt. The second photos show the new weir system with a baffle that more efficiently allows water to flow from one pan to the next. This would be similar to something in the States.
Regards,
Bob

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The first 2 photos are from 2011 and show the final pan flowing to the pipe which goes to the river a distance of about 50 feet or so.

The next photos are recent and show a now grated final pan flowing to the pipe. The effluent quality seems about the same both years.....GREEN, which is the expected algae. The last photo is in the final pan and shows how green the water actually is! Some of the previous overview photos of the plant give the indication the water was blue, but that was just the sky reflection. I'm guessing that a couple hundred feet downstream from the outfall you can not see any green in the water anylonger.
Regards,
Bob

The first photo shows how the water used to flow from one pan to the next, through these large tubes. They have been filled with cememt. The second photos show the new weir system with a baffle that more efficiently allows water to flow from one pan to the next. This would be similar to something in the States.

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Regards,
Bob

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Some of the birds which were abundant. A nice shot of some of the workers. I thinks there were 5 there that day. Two of the fellows I recognized from the previuous visit.

Yes, I do drink the tap water in Jamaica. negril tap water isn't coming from that section of the Negril River.
Some of the stuff I've found on a bar screen???? Gold fish, snakes, wood, stones, walnuts, religous medals, underware and clothing, little kids plastic toys (we actually have a little display of this...I know, you have to have a twisted mind) US paper money (and we do disinfect it and spend it but don't tell the recipient). But the wierdest thing we ever found was a glass eyeball.

Regards,
Bob

Great post Bob...thank you!

very informative. Thanks so much for posting.

Thanks for all RJ, Great info.

Very interesting! Learned something new today. :)

You speak very effluently!!!! LOL. (I studied waste water treatment in college!!!)

Wow. I now know, way more than I thought I would ever know about wastewater treatment. Live and learn!

wow you really know your ship,thanx

Thanks for the information. I do have a question that you may be able to answer. While walking the beach, there was a STRONG odor of sewer gas around Roots Bamboo & Aqua area everyday. Also similar smell near Country Country. I couldn't see any sewer pipes. Where would this be coming from? It was disturbing, as I would have been extremely disappointed to stay near those places & smell that all day long. We had 1 big rainstorm one evening, so I don't think it was "run-off".

The discussion that rjonsun referenced in his original post in this thread started with a comment that I made back when Sandy visited our shores and explains that "wonderful" aroma... It has nothing to do with the sewer pipes which explains why you didnt see them. Here was the original paragraph I posted:

"Every now and then a combination of sea conditions bring on the cleansing of our Caribbean Sea of lots seaweed. This occurred once again last month when Hurricane Sandy passed over the island. Many pics of the seaweed have been posted on various trip reports here on our Negril Message Board. And as anyone who lives by the sea knows all too well, seaweed begins to create a rather vigorous aroma as it decays."

What you were sensing was the rotting seaweed that had been buried in the sand and then uncovered by the sea waves. And when seaweed decays - you now know exactly what it smells like!

Nature at work.... (grin)

Quote:

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Originally Posted by Rob

The discussion that rjonsun referenced in his original post in this thread started with a comment that I made back when Sandy visited our shores and explains that "wonderful" aroma... It has nothing to do with the sewer pipes which explains why you didnt see them. Here was the original paragraph I posted:

"Every now and then a combination of sea conditions bring on the cleansing of our Caribbean Sea of lots seaweed. This occurred once again last month when Hurricane Sandy passed over the island. Many pics of the seaweed have been posted on various trip reports here on our Negril Message Board. And as anyone who lives by the sea knows all too well, seaweed begins to create a rather vigorous aroma as it decays."

What you were sensing was the rotting seaweed that had been buried in the sand and then uncovered by the sea waves. And when seaweed decays - you now know exactly what it smells like!

Nature at work.... (grin)

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Thanks Rob! Makes sense, as I know from past pics of the huge amounts of seaweed that were buried . The beach was clean & water clear. I said to my husband that it seemed to be coming from the sand!

The pump stations in Negril that I have seen are on the morass side of the road or on the far side of the road in the cliffs area. The pump station doors are often left open and I can always tell when I am near one from the odor. I doubt that the smell would ever make it over to the beach area. If it was near my house I would insist that either the doors be kept closed (which would help but not eliminate the smell) or better yet hang a bag of hocky puck sized chunks of pool chlorine tablets in the wet well. Next trip I'' try to get a few photos of the pump stations or transfer stations as they may be called in Jamaica. I belive ther are about 14 pump stations in and around Negril.

Regards,

Bob

awsome and informative. we too last feb and again in late march noted a few occasions where the brown river water was entering the sea and traveling up the beach all the way past Rooms, being diluted along the way but very noticeable and disconcerning. i have heard many stories of what this might be from sewage to brown dirt runoff. it would be nice if someone local could perform the tests as suggested for rjonsun to analyze AND to have someone test the sea water down the beach when the "brown tide" is noted. many thanks rj for the details and education!

rjonson....looks like we are in the same biz....although I was never interested to check out the Negril plant while visiting...and have seen my share of lift stations....can you say "Suit Up?" lol:rolleyes: