THIS CHAPTER PROVIDES an overview of standard corrosion testing procedures for freshwater systems. Additional information is provided in Chapter 31-Freshwater. Freshwater can be defined simply as water that is not salty; brackish water as defined by the dictionary is water having a somewhat salty taste. A more quantitative definition of brackish water is water with a salinity between 0.5 and 17 parts per thousand [1]. Then freshwater can be further defined as water with a salinity of less than 0.5 parts per thousand. For the purposes of this chapter, freshwater systems include potable water, heating/cooling, steam, condensate, rivers, streams, lakes, and wastewater.