Cutting out contamination in Kingston Harbour
Peter Espeut, Contributor
JAMAICA IS rightly proud of Kingston Harbour, the seventh-largest natural harbour in the world, roughly 10 miles long and two miles wide (eight sq miles).
For over a millennium, its clear aquamarine waters provided fish for the Tainos, a port for the Spanish, and a base for British pirates and naval forces from which they attacked the Spanish Main. Kingston Harbour made Kingston the commercial capital of Jamaica for over 300 years, even when Spanish Town was the political and administrative capital.
At Independence, and for centuries before, Kingston Harbour was an important locus of recreation for the many who lived on its rim, as well as for the thousands who would commute from far and wide. The harbour sported important bathing beaches - Sirgany, Gunboat Beach, Port Henderson, Hunt's Bay, Jung San - and dozens of places where amateur anglers cast their lines and tried their luck. Pleasure boating and sailing were launched from two marinas: Morgan's Harbour and the Royal Jamaica Yatch Club. My family regularly took part in the 'Cross the Harbour (swimming) Race' from Bournemouth Bath to Gunboat Beach escorted by a flotilla of small craft in case of distress.
Swimming in Kingston Harbour is no longer recommended as its water has become seriously polluted. As a result, it has been devalued as a national resource, and Jamaica is the poorer for it.
There are four principal sources of the contamination: (1) untreated or improperly treated sewage; (2) industrial discharges draining directly into the harbour or into waterways draining into the harbour, as well as leaching and run-off from solid-waste landfills receiving industrial waste; (3) the dumping of untreated ship wastes, and (4) agricultural run-off.
Once Port Royal was destroyed by the 1692 earthquake, many of its merchants chose to relocate to the other side of the harbour and a city called Kingston was laid out on Col. Samuel Barry's hog crawle. The human waste from its thousands of human residents was deposited in soakaway pits which were very efficient: all the sewage soaked away underground into the aquifers from which Kingston's wells also extracted drinking water.
There are two main problems with human waste: it usually contains harmful bacteria, which can cause gastro-enteric problems like 'running belly' and vomiting; and it contains nitrogen as urea, a fertiliser which causes the plants (algae) in the sea to grow and smother everything, including coral reefs. This is called "eutrophication" and increases the quantity of organic material in the waters of the harbour.
As Kingston's population grew to tens of thousands and hundreds of thousands, all living in houses with efficient soakaway pits, Kingston's wells had to be closed; but the polluted aquifers continued to discharge polluted water downstream into Kingston Harbour, which had become a giant cesspool. In the early 20th century, two primary sewage treatment plants were built - Western and Greenwich - which offered only the bare minimum treatment to the raw sewage. The effluent was not a threat to public health - the bacteria were killed - but the nitrogen was still present and deadly to coral reefs and the marine environment.
convenient for discharge
In the 1950s, Jamaica industrialised and factory space on the harbour was prized since inputs could be landed by ships right at the plant and the product similarly easily loaded aboard ships for export. The downside was that the harbour was right there for industries to conveniently discharge their effluent, some of it quite toxic, with little or no treatment.
Over 2,500 ships pass through Kingston Harbour annually, and each needs to discharge its sewage. Jamaica has no infrastructure to receive it, and there is evidence that the sewage is discharged into the harbour.
There are two rivers which flow into Kingston Harbour - Rio Cobre, Duhaney River - and two springs, Naggo Head Spring and Rock Spring. The Rio Cobre is Jamaica's third-longest river (50.8 km). Its tributaries drain a wide area including Lluidas Vale, Glengoffe, Riversdale, Croft's Hill, and the whole Linstead Basin, all of which are major agricultural regions. The fertilisers used there - intended to assist with the growth of economic crops - contain nitrogen, phosphorus, and potassium (NPK) in various proportions. NPK not absorbed by the crops is washed by rain into the aquifer sand into the rivers, and ultimately, into Kingston Harbour, where they contribute to eutrophication. Pesticides are also washed down, adding toxic chemicals to the harbour soup.
Approximately 20 gullies also empty into Kingston Harbour, depositing the chemicals and organic material and garbage dumped into them. Micro-organisms in the harbour use some of the organic material as food, combining it with oxygen dissolved in the sea water to produce energy for growth and reproduction. This is called "biological oxygen demand", or BOD. When eutrophication is high, the BOD increases, and the microbes consume dissolved oxygen faster than atmospheric oxygen can dissolve into the water. Fish and aquatic insects will die at high levels of BOD.
Assessments of pollution in Kingston Harbour were done in the 1970s, '80s, and '90s, each more serious than the last. Below is a quote - interspersed with my comments - from the 1992 study:
"The results of the 1992 assessment of environmental conditions in Kingston Harbour conducted by the UWI has shown that pollution has worsened since the last definitive environmental monitoring work was done in the mid-seventies. Specifically:
Bacterial contamination was found to be severe at all sites tested."
[These are the bacteria which cause gastro-enteritis.]
"Dissolved oxygen concentrations at depth have been further reduced."
[Less oxygen at depth means less life on the bottom.]
" Species diversity and numbers of benthic organisms have declined, with abiotic or nearly abiotic conditions extending over greater portions of the harbour."
[Abiotic means no animal or plant life at all exists there.]
" There are very high concentrations of nitrate in the harbour water … "
[From sewage and fertiliser.]
" Algae proliferate in the nutrient-rich harbour waters, further depleting oxygen."
" Fewer varieties and reduced numbers of fish are evident compared to 1982 data."
" There has been a sharp decrease in shrimp populations since 1985, although the number of shrimp species has not declined."
" Some metals were found to be at somewhat elevated levels in fish, suggesting the possibility of concern over similar concentrations of other more toxic elements such as mercury (not tested for in the 1992 programme) in fish and shellfish."
[These are highly toxic heavy metals like cadmium, lead, and arsenic.]
" Pesticides were found to be present at concerning levels in fish, water, and sediment, posing potential health hazards for bird and human populations that consume the fish. Five of the seven pesticides identified have been banned in Jamaica for many years."
[Fish concentrate pesticides in their tissues. These deadly chemicals can stick around in the environment for decades.]
It is not only the water column in the harbour that is polluted; deadly pesticides and heavy metals accumulate in the sediments at the bottom of the harbour. Anything which disturbs the seafloor will cause the sediments to rise and be carried along, where they may come into contact with humans - with deadly effect.
Once in a while, well-intentioned, but misguided people, suggest that the way to clean the harbour is to punch a hole in the Palisadoes near Harbour Head and pump the polluted harbour water into the open sea. This would contaminate the seawater, kill the coral reefs by Lime Cay and Maiden Cay, make the sea fish poisonous to eat, and pass on the toxic sediments to Hellshire Beach with the east-west current. Terrible idea!
Many scientists date the serious deterioration of Kingston Harbour from the period of Jamaica's industrialisation, around the time of Independence. Despite repeated warnings from UWI scientists such as Professor Ivan Goodbody and Dr Jeremy Woodley, governments since Independence have failed to clean up Kingston Harbour, have failed to prevent the private sector from using Kingston Harbour as a wastewater pond, and have failed to require that sewage technology remove the nutrients from its effluent.
A step in the right direction is the closing down of the non-functioning and outdated sewage treatment plants at Western and Greenwich and the commissioning of the new ponds at Soapberry. Soapberry, however, still discharges nutrient-rich effluent into Kingston Harbour, contributing to the nutrient loading. In all of Jamaica, only the Greater Portmore sewage-treatment plant discharges nutrient-free water. North America and Western Europe, from where we import our sewage-treatment technology, have no coral reefs, and so maybe the Soapberry-type technology may be adequate for them; but it is not appropriate for us.
The Government will have to do much better than this over the next 50 years. We need to adopt technology, which will restore to the Jamaican people the full value of Kingston Harbour.
Kingston Harbour can be cleaned up if the pollution dumped into it can be substantially reduced. It will be necessary to ban soak-away pits by sewering all of Kingston and removing the nitrates and phosphates before discharging the effluent into the harbour. All Jamaica will benefit from a pesticide-reduction programme. Nowadays, this does not imply a decline in productivity. And private industry must be urged to comply with international best practices for treating their discharges.
Peter Espeut is a sociologist and Roman Catholic deacon. Email feedback to firstname.lastname@example.org.