Evaluation of drinking water supply schemes in estate sector: A case study on Telbedda estate, Sri Lanka

Abstract

In the past, Tamil workers on tea plantations in Central Sri Lanka depended on the management of the estate for all their basic needs. In 1992, the plantation industry was privatized and plantation companies claim they cannot afford social welfare programmes (Van & Anita, 1998). As well, District and Provincial government programmes for housing, water supply and sanitation, health care and education in the village sector do not reach the estate communities. As a result of that Plantation workers are among the most economically deprived and therefore the most vulnerable to disease and ill-health.

The purpose of this study was to evaluate the present status of drinking water supply schemes in tea estate sector in Sri Lanka. For this purpose six (6) water supply schemes of three (3) divisions of Telbedda Estate, Badulla, Sri Lanka were evaluated in  November 2010. In all schemes water sources; Intakes; storage tanks; pipe lines; pump stations; stand posts, etc. were thoroughly studied. Catchment type and area, water flow quantity and quality (visual), water treatment methods and house hold level usage and wastewater disposal methods were also studied. Health Status with regard to water-borne dieses in the scheme collected from the Estate Medical Officer and Climatic data (2009) were also incorporated.

The results show that the coldest month is December and the hottest is April. Even though the average annual rainfall is slightly over 2000 mm, the area falls into the wet zone of Sri Lanka. February is usually the driest month of the year. May-June-July and October-November are the two seasons with heavy rain falls. Most of the water schemes are based on open water sources in which water is harvested for supply through gravity flow by weir constructed across stream.  The catchments are mostly under tea plantation or with a small scrubland. The high flows as 2 m3/min (during heavy rains) and low flows of around 0.075 m3/min in dry periods. Quality of the stream water is very low in turbidity, no colour, and no objectionable taste. The weirs are made of rubble masonry work provide sufficient clear head and small water pool to extract water from the stream. There was no intake chamber that prevents blockage of inlet due to siltation. The intake pipe, storage tanks and distribution lines are in poor condition, thus water overflows and with risk of contamination. The buried portions of the pipes only have very minimal cover. The distribution system does not include valves for control and water loss is about 10% through the leaks. Also other essential components for proper supply as washouts are not provided in the system. In fact there is no proper maintenance of the system. No treatment is provided to the raw water before distribution, boiling of consumptive water is not practiced in general. The entire population is served using stand posts. Approximately one stand post is available for 2-2.5 households.

Since the water sources are located in the tea plantations, extensive application of agrochemicals, inadequate toilet facilities for working communities, improper solid waste and waste water discharge are the identified risk factors for the water sources. Improper design of wires, storage tanks, distribution system, and water stored at households are very likely to be contaminated by human activities. Monitoring of water quality, provision of systematically designed water supply schemes with adequate healthcare and sanitary facilities are highly advisable for the estate community in order to secure their living condition.