After processing seawater into potable water, it is stored in 8 storage tanks on the WEB premises. This is about 98.400 m3. The water is pumped from the tanks through a UV-treatment for disinfection to a common header. Through 4 main distribution lines the water is distributed to 7 tanks around the island. The total water storage volume for these 7 tanks is about 73.900 m3. The total storage capacity of the WEB premises plus the storage around the island, sets the WEB’s storage volume at about 172.300 m3. This represents roughly 5 days of water usage including the demand of the refinery. On average Aruba uses 34.600 m3. of water per day including the refinery.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

One main line does not pass through the header: “the industrial line” to the refinery. The main transport lines diameter varies from 8” to 12”. Along each main line a pump station is located to boost the water to a tank on a elevated area. The highest tank in the system is the Urataca tank with an overflow elevation of approximately 116 meters. The lowest is the Harbor tank (C-239) with an overflow elevation of approximately 17 meters. As C-239 (leased from the refinery) is located below the desired pressure gradient, it cannot provide adequate pressure to feed the service area. Instead, this tank provides buffering volume for the “Harbor Pumping Station” feeding the harbor and the low rise hotels area.
By using the hydrostatic-pressure of the other 6 tanks, the water is distributed to the public through a distribution mains. From the several distribution lines the water branches out to secondary and finally to the service lines. The distribution lines differ from 16” to 8”, the secondary lines from 6” to 2” and the service line is usually a 1” copper alloy pipe. For temporary connections, WEB uses galvanized pipes. Only the 1”and 2” pipes are copper or galvanized, all other sizes are ductile cast iron with cement lined insides. The ductile cast iron pipes are manufactured with a bituminous coating for protection against corrosive soil and is being extra wrapped by WEB with a 14 mils thick polyethylene tape. The WEB has also used High-density polyethylene (HDPE) pipes for 2 pilot projects. In the near future WEB will be using more HDPE pipes especially in areas with a more aggressive and corrosive (salt) soil.
The total length of transport and distribution lines is listed as of 2008 as approximately 642 km. The length of service connections is not included. It is assumed that each house has a service connection line of 1.5 meters on average and that each house has one connection line independent of how many water meters are installed at the end of the service connection. We have approximately 37 thousand water connections with monthly metering.