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Raw sewage

Untreated wastewater and its contents.

Raw water

Intake water before any treatment or use.


River Basin Management Plan.

Receiving water

Inland and coastal water receiving treated effluent to which pollution control legislation applies generally.

Recharge Area

An area where rainwater soaks through the ground to reach an aquifer.

Reclaimed wastewater

Treated wastewater that can be used for beneficial purposes, such as irrigating certain plants.

Recycled water

Water that is used more than one time before it passes back into the natural hydrologic system.

Red list

List of potentially dangerous substances whose discharge to watercourses is controlled under integrated pollution control.


Putting the desired counter-ion back on the ion exchanger, by displacing an ion of higher affinity with one of lower affinity.


A natural or artificial holding area used to store water.

Reverse Osmosis process

The Reversed Osmosis (RO) process uses a semi-permeable membrane to separate and remove dissolved solids, organics, pyrogens, submicron colloidal matter, viruses, and bacteria from water. The process is called 'reverse' osmosis since it requires pressure to force pure water across a membrane, leaving the impurities behind.


The part of precipitation water that runs off the land into streams or other surfacewater.

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