Many manufacturing processes require large amounts of water to provide cooling. Most notable of these are electric power generation plants for steam, oil refining, and petro-chemical manufacturing. In any process where water is used as a coolant, it can contain micro-organisms that interfere with the heat exchangers. These micro-organisms tend to attach themselves to the wall of the heat exchanger tubing forming a layer that decreases the heat transfer efficiency. Another common occurrence is the formation of tubercles. These formations create scale on tube walls and liberate gases (CO2, H2S) which corrode the tube wall.