CLEANING SEWAGE POLLUTION IN NEGRIL
May 7, 2024
Thomas J. F. Goreau
President, Global Coral Reef Alliance, former Science Advisor, Negril Coral Reef Preservation Society & Negril Environmental Protection Trust
Negril: not enough clean water and too much dirty water
Negril, one of Jamaica’s major tourism areas, faces a double water problem, not enough clean water, and too much polluted water, badly damaging the health of people and the environmental resources on which tourism is based.
Negril water supply problem
Jamaica has plenty of water, but the Negril Watershed is the driest in Jamaica, and suffered from shortage of fresh water during the long dry season long well before tourism began. The largest spring, at Logwood, is essentially fully utilized by the National Water Commission (NWC) to supply treated water to westernmost Jamaica. The spring is recharged by rainfall on the Fish River Hills, which is simply not sufficient to serve Negril’s year-round water needs.
This fundamental limitation was recognized in the original Negril development plans, drawn up by Town Planner Bill Hodges in the 1950s. The intention at the start was to add a pipeline to springs fed by wetter and higher areas in Westmoreland and Hanover. Unfortunately, after the road and bridge were built in 1959 to allow development of the beach, the essential water infrastructure was completely neglected by all subsequent governments, inevitably causing water shortages in a rapidly growing tourist region. These problems were made worse because excessively deep canals were dug to flush fresh water out to sea, instead causing sea water intrusion into the Negril Morass, now exacerbated by sea level rise.
The Negril clean water supply problem can be resolved by pipelines to the Cabaritta and Roaring Rivers once NWC is funded to do so, a political funding issue beyond the scope of this discussion. Here we discuss only how to clean up the serious water quality problem in Negril resulting from poor sewage management, as presented 30 years ago in the First Negril Water Quality Workshop organized by the Negril Coral Reef Preservation Society (NCRPS).
Negril Water Quality Problem
Because long term water supply and waste infrastructures were ignored in Negril, water supply was provided by tapping the Logwood Spring. This had previously been the major source of freshwater to the Negril Morass, flowing out through the Middle River (which has now disappeared), whose mouth was protected by Sandy Cay, an offshore island (now so washed away so long ago by hurricanes that very few now remember it, the Negril community used to camp out on the island for fish fries and bammy).
To make up for loss of fresh water in the Morass caused by the NWC water treatment plant at Logwood, the Orange River was diverted from Orange Bay into a long, deep canal, the new North River, and the South Negril River was dredged deep as well. The canals were dug too deep in order to maximize dredge fill for raising the road along the beach, which allowed sea water to penetrate up the entire length of the new canals in the dry season, causing mangroves to spread across the Morass, making the “river” water too salty to drink.
All the sewage from hotels and residents was disposed of into groundwater or rivers by “soak away” toilets, contaminating ground water. The beach septic pits were submerged in the rainy season, making them ineffective, causing complaints of bad smell on the beach. Disposal sites soon took the foul smell of rotting eggs, caused by seawater sulfate and sewage bacteria. At the same time local divers noticed that algae were spreading over the reef and smothering corals. NCRPS was founded by Katy Thacker and local divers to try to reverse the damage caused by sewage effluents that over-fertilized sea weeds and killed the reef.
The first environmental study of Negril was made in the 1950s before any development had taken place, when the beach was reachable only by boat or a long slog through swamp and bush. The Negril Marine Protected Area Management Plan, prepared in 1959 for the Jamaican Government by Dr. Thomas F. Goreau, founder of the Marine Science Program at the University of the West Indies, noted that the area was ecologically fragile, and could easily be irreversibly damaged by unwise tourism projects. The Negril Environmental Management Plan recommendations were ignored until the spread of algae, fueled by sewage, along with the smell, became too strong to ignore:
https://jamaica-gleaner.com/article/lead-stories/20231210/multibillion-dollar-negril-river-pollution
In 1991 NCRPS asked Goreau’s son, Dr. Thomas J. F. Goreau of the Discovery Bay Marine Lab, to study the algae and corals on Negril reefs. He found clear sewage problems in rivers, coastal waters, and coral reefs. NCRPS led the public call for improved sewage treatment in order to save Negril’s coral reefs and organized The Negril Water Quality Workshop (1994), where the ecological problems, environmental measurements, and solutions were discussed in detail.
Negril Sewage Treatment
Based on public calls for proper sewage treatment in Negril, the European Union (EU) awarded funds to NWC to build a sewage plant for Negril. The resulting sewage plant, intended to help improve Jamaica’s tourism earnings, had several serious flaws. First, the sewage collection system only extended along the Negril beach road the length of Long Bay Beach to Bloody Bay, and along the West End Road to Negril Lighthouse. The sewage collected was pumped to new sewage treatment ponds in the Negril Morass near Sheffield.
Although Sheffield is one of the largest towns in the Negril Watershed, it was not provided with sewage collection, so its wastes continue to pollute the South Negril River upstream of the sewage plant, which has now become the largest source of nutrients in the watershed, focusing all the sewage from the tourism areas of the Beach and West End into a single point in the river, instead of trickling into the sea all along the entire length of the beach, as before. Since the vast majority of the population living in the Negril Watershed are not connected to the sewage system, and this population may have doubled in the last 30 years, there has been only a minor effect on pollution of the entire watershed and coastal area. The sewage plant protects tourists from swimming in their own excrement, but not that of most of the local population!
An insufficient collection system was not the only fatal flaw in the sewage plant design, implementation, and environmental impacts, there were many more, in particular failure of the sewage plant to remove nutrients causing the environmental degradation from inadequate sewage treatment, and failure to take local water quality conditions into account. For these reasons, 30 years ago NCRPS described the Negril Sewage Plant as a “cosmetic” sewage treatment plant, one that gives the impression of real treatment, but acts to conceal the sewage problem rather than solving it.
Negril sewage mistreatment
NCRPS holds that the purpose of the Negril sewage system is to restore safe health for the people and ecosystems of Negril. Since the major environmental problem is excessive sewage-derived nutrients in the water, causing harmful algae blooms that injure people, coral reefs, and sea grasses, the goal of sewage treatment should be to remove all sewage nutrients that flow into the sea, as was clearly outlined in the Negril Watershed Environmental Management Plan developed by NCRPS and the Negril Environmental Protection Trust (NEPT) for the National Environmental Planning Agency (NEPA). Conventional sewage treatment, as practiced at NWC’s Sheffield Plant, has the first two stages of sewage treatment, but not the most crucial third stage!
Sewage is first treated by settlement and filtration. This allows sludge to be collected for land disposal, however the nutrients remain almost entirely in the water. The filtered liquid effluent of primary settlement and secondary filtration is to remove obvious solid material, but bacteria and dissolve pollutants remain in the liquid effluent. This is typically chlorinated in order to kill bacteria, and such treated water is regarded as “safe” to dispose of because it doesn’t obviously smell or taste (except of chlorine) or contain measurable concentration of E. coli bacteria, a sewage indicator that can cause sickness.
These effluents are NOT “safe” for marine ecosystems, the level of nitrogen and phosphorus in secondarily treated sewage effluents are hundreds to thousands of times higher than the levels that make coral reefs and seagrasses sick and die. To protect Jamaica’s coral reefs NCRPS proposed using coral-reef specific water quality standards, not irrelevant water quality standards based on human health, which are thousands of times too high to protect coral reef ecosystems from being smothered by sea weeds, and that the missing tertiary stage of sewage treatment, which removes the nutrients, be added to the existing plant. NCRPS recommends people vote only for politicians who promise to treat their sewage properly!
Because the Negril Sewage Plant does not have tertiary sewage treatment to remove most nutrients, it concentrates all Negril tourism area sewage nutrients into the South Negril River at a single point, where they flush downstream into Long Bay, causing a vile stink all the way downriver to the beach, making the river and downtown Negril unbearable, and giving the area’s tourism a bad international reputation. Sewage nutrients fuel blooms of stinking slimy cyanobacterial mats that float downstream, where they are widely thought to be raw excrement (which indeed flows down the river from upstream where there is no sewage collection for local communities). When these stinking mats decompose, the nutrients they release cause harmful algae blooms in Long Bay that may sicken people, cause ear, nose, throat, and skin infections, and over-fertilize sea weeds, which smother and kill coral reefs and sea grass beds. They may also cause bacterial toxins that kill fish and shellfish, or those who eat them. NCRPS proposed Tertiary sewage treatment was needed at the NWC plant, but no funding had been allocated for it, and it was ignored, with the precise environmental consequences predicted (Goreau & Thacker, 1994; Goreau et al. 1996).
The bad smell of sewage is made much worse by sea water penetration up the canal to the sewage ponds. When oxygen is removed from the sewage ponds by bacteria decomposing organic matter in sewage, stinking hydrogen sulphide gas quickly forms if there is any trace of seawater, giving the vile odour of rotten eggs that stinks all the way downriver from the sewage plant to the beach. High levels of this gas can cause unconsciousness and death. Nutrients must be removed and oxygen restored to the water to restore Negril’s environmental health.
The NCRPS/NEPT Negril Watershed Water Quality Study
Because data on Negril Area water quality was so scarce and unreliable, in 1996 NCRPS and NEPT set up a local water quality laboratory to measure water quality to develop a data base needed for sound environmental management of the Negril Watershed. Water quality measurements were made, including nutrients, at a hundred locations all across the Negril Watershed, including along the entire length of all rivers, all along the coastal waters, and all major springs and water sources (Goreau & Goreau, 1996). The results of this study found nutrients were excessive by coral reef water quality standards in all samples except for a remote “control” site far away from land.
The study, done before the Negril sewage plant began to operate, found that all major water sources were contaminated with high nutrients at their sources. In rural areas people commonly dump their trash and sewage into sinkholes in the limestone rock, from which they flow by underground rivers directly into the springs used as drinking water sources. The nutrient levels in river water continue to rise downstream wherever the river flows past agricultural areas or populated areas. The sugar cane and ganja fields may receive large amounts of fertilizers and pesticides, and are ploughed right to the river banks, without the vegetated buffer zone to prevent erosion required by Jamaican environmental laws. In poor rural areas people must use the river for drinking water in the dry season, causing internal sickness and external skin infections, especially for children. Where people are too poor to have toilets in their homes, they must defecate into the river, or into a plastic bag that can be tossed into the river. The bushes along the river are also used as toilets by people who come to Negril from other parts of Jamaica to sell goods on the street.
However, wherever, and only where, the river flows through intact Morass wetlands, nutrients are removed from the water by the natural vegetation. This does not happen along river banks where the morass has been filled up with dredged-dump material or where the morass has been drained by canals to make land available for agriculture. In all drained and elevated land, the nutrients build up in the rivers due to decomposition of organic matter. The drained areas of the morass are oxidizing, turning underground peat into atmospheric carbon dioxide, causing more global warming, while nutrients from decomposed organic matter accumulate in the rivers. Meanwhile, the land surface of the Morass itself is sinking wherever it is drained, making it more vulnerable to global sea level rise and sea water infiltration, made worse by drainage canals and loss of fresh water supply from Logwood Spring.
The results of the NCRPS/NEPT water quality study were analyzed with a state-of-the-art Geographic Information System (GIS) model at Trinity College, Dublin, along with a detailed elevation model of the entire watershed topography, and maps of land use, hydrology, population density, slope, geology, soil type, vegetation, etc. This allowed the different sources and sinks of nutrients to be quantified, providing information needed for sound whole-watershed environmental management of the rivers, the Negril Morass, and coastal waters. A follow-through study by Dr. Brian Lapointe at many fewer sites done after the Negril Sewage Plant was set up, found nutrients had greatly increased downstream of the sewage plant. The fundamental patterns shown nearly 30 years ago have not changed in character, but they have become more intense as population has increased, further stressing fresh water resources while causing more sewage pollution.
Cleaning Negril sewage and natural waters
An ecologically sound tertiary sewage strategy was proposed in 1994 by NCRPS to remove nutrients from sewage effluent and re-oxygenate fouled waters at low cost, but was never implemented. Now that strategy needs to funded and implemented by NWC more urgently than ever.
The first stage is to increase the collection system to capture all major sewage sources in the Negril Watershed, such as Sheffield, while building a third sewage pond for biological tertiary sewage treatment of effluents that removes nutrients from the treated water and efficiently recycles them while oxygenating the water, removing the hydrogen sulphide rotten egg stink.
The key to efficient biological treatment of waste water is to grow plants that rapidly take up nutrients while releasing oxygen to the water. One local plant that does so most efficiently is the giant reed, Arundo donax, one of the fastest growing plants in the world, which grows in the Negril Morass to exceptional size, up to 30 feet or 10 m tall (Devi Prasad, 1994). It tolerates mildly salty conditions, and its roots are most efficient at pumping oxygen down into the soil. However, it is best used in constructed wetlands. In these an impervious concrete layer is overlain by coarse gravel layer through which sewage flows underneath an upper layer of soil in which reeds and other aquatic plants are grown. These are efficient at nutrient removal if they are regularly cropped to keep plants taking up nutrients at maximum rates, but are expensive to build and maintain. If left untended the plants become saturated and can’t take up any more nutrients. Water hyacinth, Water lettuce, and other floating plants rot before they dry, and produce only a small amount of energy by very inefficient methane fermentation. Here I propose a more efficient and lower cost alternative to these plants.
Vetiver zizanoides (Khus Khus) to Negril’s rescue
Vetiver zizanoides, a bunching grass from southern India, known in Jamaica by the Indian name Khus Khus, is the world’s best erosion control plant, and has many other benefits. Vetiver’s many extraordinary advantages are outlined in around half a dozen chapters by Vetiver experts in my book, Geotherapy: Innovative Methods of Soil Fertility Restoration, Carbon Sequestration, and Reversing CO2 Increase: http://www.crcpress.com/product/isbn/9781466595392
Vetiver is extremely fast growing, but unlike giant reeds, a weed that can quickly spread out of control, Vetiver is exceptional, it grows only where it is planted and never becomes a weed! It forms large clumps of plants that can only be propagated by splitting, subdividing, trimming, and replanting root clumps. The roots grow vertically straight down, up to 5 meters, and it has no horizontal spreading roots or runners to produce new plants at a distance like the worst invasive plants. Furthermore, although it flowers and produces prolific seeds, these are sterile and do not grow if planted. Vetiver was introduced to Jamaica by the British Imperial Agricultural Service researchers to Boodles, in Clarendon, where it was used in the late 1940s to make “bench terraces” on sloping hillsides for yam cultivation, with vetiver roots stopping soil erosion. The experimental terraces were abandoned after Independence, and completely overgrown by secondary forest, what we call “ruinate” land in Jamaica. Many decades later these forests were cleared for agriculture, and the dormant vetiver grass sprang right back 50 years later!
Vetiver is exceptionally tolerant of drought, flooding, and salt, every stress except for freezing weather! It is typically planted in rows along hillside contours, where the long vertical roots trap soil and water, stopping soil erosion and creating soil terraces that are used for very productive agriculture on otherwise barren hill slopes. It is salt tolerant, I have grown Vetiver right down to the high tide mark on Bali island beaches.
The key features of Khus Khus relevant to Negril water quality are that the extremely dense roots intensively remove nutrients and pump oxygen into the water, and can remove nutrients and add oxygen all along canal banks as well as from floating rafts in waste treatment ponds. Sewage treatment applications have been developed in Australia by Dr. Paul Truong, based on work done in Viet Nam, China, and India, where vetiver is used on a large scale to stabilize river banks and prevent soil erosion. Vetiver can be planted all along the canal banks to clean up the water and the roots can grow from floating rafts on top of the proposed tertiary treatment pond, to remove nutrients and oxygenate effluents before release into the river.
Vetiver builds up large amounts of biomass that is easily converted by pyrolysis (burning without oxygen) into biochar, a nutrient-rich, long-lasting form of carbon that enriches soils in carbon and retains nutrients and water as a nutritiously balanced fertilizer for much more productive agriculture (there are another half dozen chapters on biochar in my book). It also produces excellent forage for cattle and goats, a thatch for roofs that lasts longer than any other because natural chemicals repel insect infestation, and a valuable oil used in expensive perfumes.
Negril Sewage Cleanup Action Strategy
NCRPS, NEPT, and GCRA propose to 1) work with NWC to build floating Vetiver rafts for the third biological tertiary sewage treatment pond, and document their production of biomass, nutrient removal, oxygen production, and other water quality parameters, 2) establish a NEPT community-managed Vetiver nursery in Sheffield to propagate Vetiver plants for planting along river and canal banks, 3) set up a pyrolysis plant in Sheffield to make Biochar from harvested Vetiver for local production of fruits, vegetables, and native ornamental plants, and 4) re-establish the NCRPS/NEPT Community Water Quality Laboratory for independent measurements of the actual environmental performance of these measures on water quality and environmental health.
References
T. F. Goreau, 1960, Report on a biological survey of the offshore regions bordering upon the Negril-Green Island area, Negril-Green Island Area Authority, Negril
M. Hendry, 1982, The structure, evolution, and sedimentology of the reef, beach, and Morass complex at Negril, Petroleum Corporation of Jamaica, Kingston
T. J. F. Goreau, 1992, Coral reef health in the Negril Area, p. 32-66 In D. V. Quirolo and K. Thacker (Eds.), Protecting Jamaica’s Reefs: Final Report of the Negril Mooring Buoy Workshop and Installation Project, Reef Relief, Negril
T. J. F. Goreau, 1994, Negril environmental threats and recommended actions, p.9-37 in K. Thacker (Ed.), Protecting Jamaica’s Coral Reef Ecosystems, Phase II: Water Quality Issues, Final Report, Negril
T. J. F. Goreau, 1994, Coral reef protection in Western Jamaica, p. 39-82 in K. Thacker (Ed.), Protecting Jamaica’s Coral Reef Ecosystems, Phase II: Water Quality Issues, Final Report, Negril
P. V. Devi Prasad, 1994, Aquatic plants and waste water treatment, p. 163-170, in K. Thacker (Ed.), Protecting Jamaica’s Coral Reef Ecosystems, Phase II: Water Quality Issues, Final Report, Negril
T. J. F. Goreau & K. Thacker, 1994, Coral Reefs, sewage, and water quality standards, Proc. 3D. Caribbean Water and Wastewater Association Conference, Water and Wastewater Needs For The Caribbean: 21ST Century, Kingston, Jamaica, 3:98-116
M. I. S. Goreau & T. J. F. Goreau, 1996, Water Quality in the Negril Area Watershed, Jamaica: Environmental Management Implications. Global Coral Reef Alliance study for the Negril Coral Reef Preservation Society and the Negril Environmental Protection Trust
T. J. F. Goreau, L. Daley, S. Ciappara, J. Brown, S. Bourke, & K. Thacker, 1997, Community-based whole-watershed and coastal zone management in Jamaica, Proc. 8th International Coral Reef Symposium, Panama 2:2093-2096
A.T. Eirum, 1998, Applicability of GIS as a water quality management tool in the Negril and Green Island Watersheds, Jamaica, 149 p, MSc thesis in Environmental Sciences, Trinity College, Dublin, Ireland
B. E. Lapointe & K, Thacker, 2002, Community-based water quality and coral reef monitoring in the Negril Marine Park, Jamaica: Land-based nutrient inputs and their ecological consequences, p. 939-963 in J. W. Porter and K. Porter (Eds.), The Everglades, Florida Bay, and Coral Reefs of the Florida Keys, CRC Press, Boca Raton, FL
T. J. F. Goreau, 2003, Waste Nutrients: Impacts on coastal coral reefs and fisheries, and abatement via land recycling, 28p., United Nations Expert Meeting On Waste Management In Small Island Developing States, Havana, Cuba
A. DeGeorges, B. Reilly, & T. J. F. Goreau, 2010, Land-sourced pollution with an emphasis on domestic sewage: Lessons from the Caribbean and implications for coastal development on Indian Ocean and Pacific coral reefs, Sustainability, 2: 2919-2949
B. E. Lapointe, K. Thacker C. Hanson L. Getten, 2011, Sewage pollution in Negril, Jamaica: Effects on nutrition and ecology of coral reef macroalgae, Chinese Journal of Oceanology and Limnology, 29:775-789
P. Truong, & L. T. Danh, 2015. The vetiver system for improving water quality. The Vetiver Network International, San Antonio, TX.