Feedwater from a municipal source can contain suspended solids and dissolved gases. Dissolved oxygen causes corrosion in the boiler and system. Dissolved CO2 in outgoing steam creates carbonic acid which will dissolve boiler tubes, drain lines, steam fittings/valves and condensate return lines. Dissolved solids will form scale in the boiler, pipes and the equipment using the steam. Boilers can develop hot spots, leaks and pressure failure. A high concentration of impurities can also lead to foaming and carry-over. Foam in steam outlet can cause water hammer in a steam line, erosion in piping and frequent low water issues.