Eight Years Experience with an ECHOTec. On-Shore Watermaker

When I purchased land and run-down buildings on Gasparee Island, Trinidad & Tobago, I realised immediately that I would need a regular supply of inexpensive clean water. Of a number of options considered, I chose an ECHO Tec. 900-BHL-2 Reverse Osmosis Desalination, which I later upgraded to the model 1800-BHL-4. The engineering standards impressed me, as I am a qualified chartered engineer. I was specifically looking for a reliable operating unit that would optimise the life cycle, or lifetime costs.

I calculated the cost of water from all other available sources neglecting the chance of collecting rainwater, which is quite small on the island, particularly in the dry season. I amortised the capital cost over a period of 10 years, taking into account daily running costs and preventive and corrective maintenance costs. The resulting calculations indicated that the system would meet my requirement to provide precious water for human consumption, household and building needs.

The installation needed a strong sea-water feed pump in order to overcome the 40 feet height from the sea and restrictions of the sand and cartridge pre-filter. The rocky coast made it impossible to locate the entire plant close to the sea level. A small pump house was built as near to the sea as practicable. The seawater is supplied via a sand filter to the standard factory fabricated desalination plant, which includes the pre filters, the high-pressure pump, the RO membranes and the control unit.

I have used the system for more than eight years for between 10 and 24 hrs per day to supply water for normal household and building needs and finally a 15,000 sq.ft. garden maintenance with lawns, fruit trees and vegetable garden. My average fresh water production is 700 gallons per day, for a total of over 2 million gallons to date.

The system has been very reliable. Careful attention to the regular oil change for the high pressure pump and normal consumable replacement at intervals is all that is required to maintain a high quality of product water.

The capital cost of my desalination plant was completely 'paid for' by the non-purchase of shipped water in the first 9 month period only. There are now many others on the Island whom have taken my initiative. Access to seawater is essential of course and only owing land too far from the sea has prevented some homeowners from taking advantage of this exciting and economical supply of clean water on command. 

Colin Schofield     
Gasparee Island, Trinidad