Drinking water supplied in Suðurnes
HS Veitur hf owns and runs water distribution systems in Reykjanesbær, Garður, Hafnir, along with running the water distribution on Keflavík airport, Sandgerði, Grindavík and Vogar, whom all receive their drinking water from Hitaveita Suðurnesja although they run their own distribution systems. The main drinking water reserve for Hitaveita Suðurnesja is a crater in the molten rock in Lágum, it is there where freshwater floats above the subterranean sea water, just like oil on water, in this area. The freshwater is approximately 40 meters thick and reaches a depth of 58 meters. From there a 10-15 meter thick mixture layer has formed, which has a higher salt content deeper down in the earth. At a depth of around 70 meters the water is immensely salty.
The pumping station in Lágum is built over a crevice full of rocks and and pebbles, which were put there after five steel pipes were laid down in the crevice. Each pipe is about 18.5 meters in length. There are three pumps in the station that produce around 100 liters per second. The water needs of Reykjanesbær and the airbase were estimated as being about 140 – 160 liters per second.
Calculations that were made at the time estimated that only pump needed to be running non-stop; the second would pump during parts of the day, with the third one acting as a back up pump. With the increased water usage additional pumps could be added, still the maxium flow rate of the system was designed for only 400 liters per second. The main converying water tanks are Grænás, with a compacity of 2000 cubit meters, and Keflavík with one 800 cubic meter water tank and another 700 cubic meter water tank functioning as a back up tank.
Near the Grænás tank is the main pumping station of Keflavík airport, which pumps water from the Grænás tank into the distribution system of Keflavík airport and a water tank with 1900 cubic meter compacity. This tank is the main water tank for Keflavík airbase. In addition it is also possible to pump water, with a dated system, from a 2800 cubic meter water tank. Water is pumped into this 2800 cubic water tank from the so called Patterson area from four holes that combined can produce 42 liters per second. Garður receives its water from pumping two drill holes. The two conveying tanks in the system are 100 and 600 cubic meters each. Hafnir receives its water from two drilling holes as well; although these drilled holes are near the highway about 0.6 kilometers from town limits. The salt content of this water is extremely high, to counterbalance these effects there is special equipment that sifts the salt from the drinking water. The pressure is kept in the system with pumps. The usage is around 3-5 liters per second. The main control station is in Svartsengi, however Keflavík air base has an independent control station due to historical reasons.
Vestmannaeyjar, drinking water
The drinking water of Vestmanneyjar arrives from land in South Merki below Eyjafjall. The water is led from there, travelling a distance of 22 kilometers, into a pumping station that then pumps the water to Vestmannaeyjar through two 13 kilometer long underwater pipes. The water spring is located 210 meters above sea level. The water which flows directly into the pipes flows at a rate of 23 liters per second. Although, if the water flows at a faster rater then the 5000 cubic meter water tank “back-up” water tank in Vestmanneyjar decreases in volume; when the water level in the tank drops below a certain level, pumps then automatically turn on that fill the tank back up. The first underwater pump was laid down in 1968, the second one in 1971. Before then no freshwater was available in Vestmanneyjar. Another special aspect to Vestmanneyjar is that the drinking water is sold though meters – even to homes. This is done to ensure there is no unnecessary waste of water. There were plans to lay a third pipe in 1990, although the meters were installed to delay such construction. Other water distribution plants have set up such water meters to decrease water waste and to save on distributional construction costs. The water distribution system of Vestmannayjar is unique in Iceland, additional construction to the system been around 1.5 billion krónur – which was a staggering expense for the inhabitants whilst construction stood over.