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Marginal Wastewater Resources

Cooling Tower
A cooling tower is a heat rejection device that extracts wasted heat to the atmosphere though the cooling of a water stream. The type of heat rejection in a cooling tower is termed "evaporative" in that it allows a small portion of the water being cooled to evaporate into a moving air stream to provide significant cooling to the rest of that water stream.

Common applications include cooling circulating water used in oil refineries, chemical plants, power stations and air conditioning systems. The smallest cooling towers are designed to handle water streams of only a few gallons of water per minute while the largest towers cool hundreds of thousands of gallons per minute.

Waste water from cooling towers can be collected and used for other purposes, such as toilet flushing, garden watering or other industrial processes.

Air Conditioning

Water consumption can be reduced by recycling condensation water from air conditioning systems.  When using water cooling air conditioning the water is obtained from the plumbing system. The wastewater must go down a drain or it may be collected and reused for watering the garden, filling a swimming pool etc.

If homes and commercial buildings could collect waste water from installed air conditioning systems, millions of liters of water could easily be collected each and every year.

Rainwater Harvesting

Rainwater harvesting is a technology used to collect and store relatively clean rain water from roof tops or hillside run-off water. This water would typically be disposed by the drainage system or naturally dissolve into the ground. The water is generally stored in a rainwater tank or directed into mechanisms that can recharge groundwater. Rainwater harvesting can provide drinking water, domestic water, water for livestock, water for small irrigation and a way to replenish ground water levels. Rainwater harvesting has been practiced in arid and semi arid areas. It has become an integral part of societies in remote places where piping water and reliance on wells is not an option.

Rainwater harvesting can also provide supplemental water for the city's requirement, it can increase soil moisture levels for urban greenery. In urban areas harvested rainwater can be used for flushing toilets and washing laundry. Indeed in hard water areas it is superior to mains water. It can also be used for showering or bathing.

Green Roofs

Green roofs or disconnected garden developments involve the creation of a "contained" green space on top of a man-made structure. This green space could be below, at or above ground level, but in all cases the plants are not planted directly into the "natural earth".

Water collected via the drains from Green roof systems or disconnected gardens can be returned to the garden after undergoing the necessary treatment. This solution is both practical and cost effective when addressing the lack of pure drinking water in many regions but the desire to maintain vegetation growth in a practical and cost effective way.