ENGINEERING WATER DISTRIBUTION

WATER SOURCES: CONCLUSION OF FINDINGS

     Having investigated the current usage and potential of aquifer wells, water reclamation and desalination plants, we understand that they all have merits and disadvantages. Aquifers are a very reliable source of water and are both relatively cheap and simple to construct and run. However, if used too excessively, they can cause the water table levels to drop. Contamination of aquifers is also regular in LEDCs, which can cause outbreaks of dangerous and life threatening water-borne diseases such as cholera.

 Reclaimed water also carries a risk of containing disease causing organisms or other contaminants if not properly treated before human contact; however, strict guidelines and processes often mean that reclaimed water is more pure (containing less contaminants) than normal ground and surface level water. The extensive processing required to purify and filter the waste water means that this is a costly technique; there is no option to cut corners here as full filtering is essential if it is to produce water fit for human consumption.

   However, we think that, while unsuitable for providing drinking water on a mass scale due to combined safety and cost issues, reclaimed water is perfect for a variety of non-potable uses such as irrigation and cooling water for oil refineries and power plants. Depending on how close a human contact there would be to the water, we think that it would be possible to avoid stage three of the filtration and purification process for non-potable water, which would save on cost. This also saves potable water for drinking, and reduce the chance of drought as we would need to use less of the water supply from underground sources. As reclaimed water often contains higher levels of nutrients such as nitrogen, phosphorus and oxygen, it even acts as a fertilizer which could benefit crop production if used in agriculture.

    In our opinion, the best solution for a long term source of drinking water is through desalination. This process is hugely advantageous in that it is totally independent of precipitation levels, whereas aquifers rely on discharge and recharge zones from rainfall and so would eventually dry out if over used. However, 97% of the world’s water supply is saline, and is mostly untapped, and I strongly believe that this is the way forward if we are to provide sufficient clean drinking water to our growing world population. Using desalination is an excellent option for arid countries near the sea, which is the case for many developing countries, especially in Africa. Currently, however, this option is only utilised on any grand scale on MEDCs; especially in the Middle East. This could be due to the expense of current processes or a lack of infrastructure in those countries which is discouraging foreign companies from building desalination plants there.

      However, new developments such as low temperature thermal distillation are allowing pure water to be produced from saline using less energy and so at lower costs, which will hopefully make this technology more accessible to those in the developing world in the coming years. The investment in engineering technology to produce fresh, potable water would allow governments in LEDCs, especially in sub-Saharan Africa, to become more stable and consider more long term options, as they would no longer have to worry about the devastating consequences of unexpectedly low precipitation causing drought, which is often followed by famine, disease and both civil and international unrest.