| Raw water fed to the treatment plant is extracted from an irrigation reservoir. |
The project, built between 1999-2007 in the Ampara district, 350km from the capital Colombo, is comfortably coping with harsh local conditions, including unreliable power supply, limited maintenance, large seasonal raw water quality variations and fluctuations in demand.
"After more than two years from Phase II commissioning, the treatment plant is continuing to provide good quality water to consumers, within design targets, 24/7," said Outotec Project Director Steve Giffin, based in Sri Lanka.
The project – which NWS&DB plans to follow with another covering a further 350,000 people – is a source of satisfaction to Outotec, which undertakes turnkey projects throughout Asia and Australasia.
The Ampara district on the east coast of Sri Lanka is one of the least developed areas in the country, being semi-rural, affected by civil war and disturbance, with the completion of large-scale projects presenting a significant challenge.
In 1997, Sri Lanka's National Water Supply and Drainage Board launched a program to provide a large population of previously unserved communities with quality piped drinking water under the ECTAD (Eastern Coastal Towns of Ampara District) project.
Outotec was awarded the initial and subsequent phase of this project, carried out from 1999 to 2007. As the complete turnkey supplier, Outotec was tasked with the design, construction and commissioning of a water supply scheme, which was to provide piped water to 300,000 people in the Ampara District for the first time.
The NWS&DB is the principal government authority for the nation of Sri Lanka responsible for providing safe drinking water and sanitation for the population. A workforce of about 8,000 is employed nationwide.
Ampara District
The Ampara district is on the east coast of Sri Lanka, population circa 611,000, with a tropical climate and a long dry season. The district is rural and primarily agricultural, relying on a large irrigation network of reservoirs and canals for rice paddy farming.
However, there are water quality and scarcity issues with the traditional water sources due to intensive farming and resultant fertilizer, soil and chemical run-off. In the densely populated coastal towns, limited land availability has resulted in some septic sanitation systems being installed very close to drinking water wells, with contamination common.
With a growing population, the need for pipe borne safe water has never been greater in Ampara.
Project Scope
Working closely with NWS&DB, Outotec's resulting solution was challenging but achievable.
The project structure was turnkey "catchment to consumer", meaning that all design, construction and commissioning from the raw water reservoir all the way to the distribution networks at town street level, was under the direct responsibility of Outotec. Outotec was the head contractor, working closely with process designers and equipment suppliers, and hand-in-hand with local Sri Lankan partners.
The combined Phase I and II project scope included raw water intake structure, a 15.86 mgd (72 ML/day) DAF filtration treatment plant including all chemical dosing and residuals handling, clearwater storage, transmission mains, five booster pump stations each with 1600 m3 capacity, nine elevated storage towers of 1125 m3 or 1600 m3 capacity, and nine distribution networks, covering a total project area of approximately 500 km2.
Remote Location
The Ampara District location, 350 km from the capital Colombo, created difficulties. An undeveloped region, poor in infrastructure, with limited available technology and little local skilled/semi-skilled labor, the region's recent history of civil unrest and difficulty in attracting outside contractors had its own unique set of challenges, requiring patience, flexibility and strong management.
Coordination
Project management was an extremely complex task due to the magnitude of the project, interaction between the various cultures on the job, language barriers and geographic distance between involved parties. Mechanical and process design was carried out in Australia, civil and electrical design and detailing in Sri Lanka, with significant participation from NSW&DB. An office of expat and local personnel was established in Sri Lanka to manage the various project phases, providing project management, drafting and engineering personnel. Equipment was sourced from vendors in Asia, Europe, USA and Australia.
