The term “water quality” describes the physical, chemical and microbiological characteristics of water. These properties collectively determine the overall water quality and the fitness of the water for a specific use. These properties are either intrinsic to the water or are the result of substances that are dissolved or suspended in the water. Water quality is only meaningful when evaluated in relation to the use of the water. The reason is that water of a certain quality may be fit for a specific use, but completely unfit for another use. For example, water that is fit for human consumption may not be fit as boiler feed water because the dissolved inorganic salts that are acceptable in drinking water, are not tolerated in boiler feed water, since they may precipitate and cause blockages in the boiler equipment. Water that is fit for domestic use (drinking water) must comply with specific requirements. The most important requirement is that it must be safe to drink.