The National Water Supply and Drainage Board (NWSDB) of Sri Lanka highlighted certain requirements that the new water treatment system had to fulfill. The new water treatment system that was constructed had to supply a large volume of treated water to the growing population in Greater Kandy. In addition, there had to be little maintenance work necessary upon the completion of the project through the procurement of high quality pumps. As the supply of treated water was important to future economic growth in the area, there must not be any disruption in its supply. Hitachi Plant Technologies understood the importance in the successful delivery of the project and set out to bring about solutions that would meet the pressing needs of the Sri Lankan population.
Delivery of quality pumps
Under Phase I, Stage I, an Intake structure was constructed to obtain water from the Mahaweli River. The transmission pipeline was 700mm in diameter and it was to be built across the Mahaweli River. A pump bridge was constructed at Gohagoda for the purpose of pumping water across the bridge. The water would then be purified at a treatment plant that was constructed at Katugastota and the purified water would then be distributed to service reservoirs through a 26.5 km pipeline in the greater Kandy area. Besides the need to supply large volume of water to the Greater Kandy region, the pumping station also had to be able to pump water up to elevated areas within Kandy such as Kurugoda.
To meet the sophisticated challenges of the project, Hitachi Plant Technologies chose pumps that were of the highest quality to ensure the smooth delivery of water to its required location. The distribution system of water in the project was extensive and there were several opportunities for lapses had there not been excellent quality in the pump system of Hitachi Plant Technologies. Since its inception in 2006, the water treatment system built by Hitachi is still functioning at high performance without any disruption.
Supervisory Control and Data Acquisition System (SCADA)
As the project was massive in nature with the pumping facilities and reservoirs spanning a wide area, it was important to have a central control system to monitor the status of the facilities. Hitachi constructed a SCADA system that is currently situated in NWSDB headquarters with trained operators currently monitoring it. One of the main benefits of the SCADA system is that the water losses in existing systems could be identified that would call for immediate remedies.
The SCADA system consists of several subsystems that operate together. Firstly a computer system acquires data of the process taking place in the facilities. There are remote terminal units that are attached to the sensors in the process. They are responsible for transmitting the digital data to the supervisory computer system. It also comprises of a communication network that is used for the transmission of data between the supervisory system and the remote terminal units. Finally, the process data and the analysis of the facilities are displayed on an interface in real-time. Through the interface, the trained operators gain access to critical diagnostic data so as to monitor and control the process more effectively.
Through the implementation of the SCADA system, the preservation of the limited clean water resource is enhanced. Also, maximum utility could be derived from the money spent out of foreign loans and this helps with the future expansion of the pipe borne water supply facility to the rest of the Sri Lankan population.
The mechanical and electrical engineering component of the project was very important for its success, and we have to select a competent contractor for it
Mr. M. S. Pinto
Chief Engineer, Hitachi Plant Technologies Ltd. (Sri Lanka) )
They have trained our people and even though it's outside of the contract, they were able to help us, especially in the operation of the SCADA system, which is new to our country.
~ Mr P.H. Sarath Gamini, Project Director,
National Water Supply and Drainage Board (NWSDB)
Solutions eventually delivered by Hitachi:
- Delivery of quality pumps that ensure durability in the lifetime of the water treatment system
- SCADA system that enables the monitoring of the water treatment process in multiple sites
- Training of local engineers in the operation of the water treatment plants