ABSTRACT
INTRODUCTION It would be inappropriate to discuss the various unit operations configured in a water purification system without discussing the impurities present in raw water. The nature, type, and concentration of various impurities should define the water purification system. This is particularly true for USP Purified Water systems and systems used for the production of active pharmaceutical ingredients, where there is limited, if any, definition of water purification, techniques required to produce the desired water quality. Raw water supplies to pharmaceutical water purification systems must, as discussed in chapter 1, meet the National Primary Drinking Water Regulation (NPDWR) as defined by the U.S. EPA or an appropriate similar agency. The requirements for feedwater to a compendial water system are set forth in the current applicable USP Official Monograph. It is important to recognize the myriad of different potential sources of feedwater to facilities. Raw feedwater may be from a municipal (private or public) supply or a dedicated private supply for the facility. It should be obvious that the nature and concentration of various impurities in raw water supplies will be a function of the ultimate “source” of the water. Sources may include reservoirs, lakes, streams, rivers, and groundwater. Groundwater supplies may be influenced by surface water supplies depending on the topography and depth of the aquifer. In the Appendix A of this chapter, general characteristics are presented for various impurities present in surface waters, groundwaters influenced by a surface supply, and groundwaters not influenced by a surface supply.
