Water formed deposits result from naturally occurring minerals precipitating from water to form scale. The most common scales are calcium carbonate, calcium sulfate and silica or silicates. Scale buildup on surfaces can be extremely hard and difficult to remove. Scaling will drastically reduce heat

transfer capacity and system energy efficiency.

Cooling systems are exposed to many types of corrosion, from general electrochemical corrosion, to pitting caused by deposits, electrolysis, or microorganisms. Corrosion can reduce the life-span of equipment by years, requiring expensive replacement. It can lead to costly equipment repairs and production downtime. Corrosion related deposits lead to reduced capacity and wasted energy because of heat transfer efficiency losses.

Fouling occurs when solid materials form or contribute to the formation of deposits on equipment surfaces. They are introduced to the system as suspended solids and may enter by the makeup water, from corrosion by products, or as airborne materials. Examples include mud, sand, silt, clay, oils, debris, organics, microbes, etc. These materials adhere to heat transfer surfaces and reduce heat transfer and water flow.

Microbial problems associated with industrial cooling water systems are caused by algae, fungi, and bacteria.

They cause plugging, fouling, corrosion, and destruction of wooden cooling tower components. Many different bacteria species may exist in cooling water systems. Some of the problems caused include severe bacterial slimes and fouling, sulfuric acid, under deposit corrosion and health hazards.