Solid waste policy in the United States produce large amounts of waste in small areas. For example, EPA reports that a single dairy cow produces approximately 120 pounds of wet manure per day equaling to that of 20-40 people. The main problems of animal waste mismanagement are environmental, especially water pollution. Industrial waste consists of a significant amount of solid waste. EPA reported that each year United States industrial facilities generate and dispose of approximately 7.6 billion tons of industrial solid waste based on 1980s figures. This figure includes waste generated from 17 industrial manufacturers of organic chemicals, inorganic chemicals, iron and steel, plastics and resins, stone,
Per-unit system as base values; power and voltage are typically chosen. All quantities are specified as multiples of selected base values. For example, the base power might be the rated power of a transformer, or perhaps an arbitrarily selected power which makes power quantities in the system more convenient. The base voltage might be the nominal voltage of a bus. Different types of quantities are labeled with the same symbol (pu); it should be clear whether the quantity is a voltage, current, or other unit of measurement. There are several reasons for using a per-unit system: The per-unit system was developed to