Trinidad and Tobago


10.5N 61.5W

Information supplied by

Vidjaya L. Ramkhalawan

1235 Military Trail J-4-H, Scarborough Ontario M1C 1A3 Canada



Dated Sun Nov 28 08:45:23 1999

Information Topics:

City Description:

Trinidad is the southern most Caribbean island, located off the north east coast of Venezuela. Trinidad has a total area of 4828 (1864 sq.miles). The island is surrounded by the Atlantic Ocean in the north, the Pacific Ocean to the east, the Columbus Channel in the south and the Gulf of Paria in the west. There are three major mountain chains in Trinidad: the Nothern Range, which extends from the north western most end of the island to the northeasten end, the Central Range and the Southern Range, located at the southeastern end of the island. Trinidad and Tobago is located south of the hurricane belt. During the hurricane season, the Nothern Range acts as a protective barrier, minimizing any hurricane effects on the island. Trinidad and Tobago has an estimated population of 1,300,00. The official language is English. The capital city of Trinidad is Port-of-Spain. In the 1970's the largest contributor to the economy in Trinidad and Tobago was the oil and petroleum industry. However, since then Trinidad and Tobago's economy has diversified and become more industrialized with the establishment of industries such as gas, iron and steel, methanol and tourism (

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Trinidad and Tobago both have tropical climates. the maximum temperature in trinidad is 32 C (89 F), however, due to the northeast trade winds Tobago's temperature is a bit lower. Both islands experience a dry season during the months of January to May and a wet season during the months of June to December. The annual rainfall in Trinidad is approximately 200 cm (40 inches) (

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Basic Hydrogeology:

Trinidad lies on the plate boundary between South American and Caribbean plates,hence, Trinidad is in an earthquake zone ( Thus, Trinidad's geology comprises of folde and faulted sediments and low-grade metamorphic focks. Fissured limestone in the northwestern area of the Nothern Range allows the development of small springs. Alluvial fill deposits in the metamorphic rock of these valleys forms coastal aquifers. As alluvial fans at the mouths of the valleys coalesce, a series of aquifers known as the Nothern Gravels are formed (Home, October 5th-11th, 1980). Located to the east of the Nothern Gravels are the Port-of-Spain Gravels. The aquifers consists of gravel fan, limestone beds and alluvial deposits consisting of interbedded sand and gravel with boulders and clay The Port-of-Spain aquifer is a coastal aquifer, which is open ended to and is in direct with the Gulf-of-Paria. This aquifer consists of gravel beds, which are over 91.4 m (300 feet)deep in the low-lying are of Port-of-Spain. "The gravel beds of the Port-of-Spain aquifer are extremely porous and act as a storage for the wells sunk into it" (Water And Sewage Authority, 1998). Discharge takes place primarily along the coastline (B.Beckles, personal interview). Recharge occurs via direct infiltration from the surface during the wet season and from lateral flow via the river valleys crossing the aquifers (Water And Sewage Authority, 1998).

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Water Use:

Port-of-Spain currently receives approximately 19 million gallons of groundwater per day. The primary source (approximately 10.2 million gallons of groundwater per day) is from the Caroni Arena surface water treatment plant located to the south of Port-of-Spain (B. Beckles, personal interview).

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Groundwater Issues:

Groundwater is affected by contamination, urban and industrial wastes and other anthropogenic wastes. Reduction and shortage of groundwater supply is due to the demands of a developing town and its surrounding area.

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Groundwater Problems:

Pollution of the groundwater by illegal dumping of sewage and industrial waste increases the hardness and ion concentration in the water. As the shallow alluvial fill and fan aquifers are overpumped, the seawater moves inland, i.e. salt-water intrusion occurs (United Nations, 1980). This intrusion is responsible for the increase in the ionic concentrations in the well water (Home, October 5th-11th, 1980).

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In Trinidad and Tobago there are twelve public wastewater treatment plants, operated by the Water And Sewage Authority of Trinidad and Tobago, and 150 private plants.The total treatment capacity of the public plants is 89,466 m3/day. The public plant in Port-of-Spain treats the largest volume (66,673 m3/day)of wastewater (Water And Sewage Autority,1998). The salt-water intrusion has been recorded and is at present being monitored (B. Beckles, personal interview).

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References and Other Author(s):

Milne-Home, William A, "Geological Aspects of the Management of Water Quality in
some Coastal Aquifers of Trinidad", Regional Seminar on Water Resources Assessment,
Development and Management in Small Oceanic Islands of the Caribbean and West Atlantic,
Bridgetown, Barbados, October 5th-11th, 1980

United Nations Commonwealth Science Council, "Caribbean Small Islands Water Resources
Assessment Development Management", Seminar on Small Island Water Problems, Bridgetown,
Barbodos, October 6th-11th, 1980

Water And Sewage Authority of Trinidad and Tobago; Water Resources Agency, "Assessment
of Potential From the Queen's Park Savannah Aquifer", Techical Report, December 1998.

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Island Connoisseur: (, 1999

Tourism and Industrial Development Company of Trinidad and Tobago, Limited (, 1999

Water And Sewage Authority of Trinidad and Tobago
Water Resources Authority Valsyn
St.Joseph Trinidad, West Indies
Telephone: (868) 662-2302
Fax: (868) 663-9117
U. Maharaj, Manager
Brian Beckles, Geologist

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