The United States Geological Survey estimates that (as of 2005, the most recent year for which data is available) we withdraw 410 billion gallons of water a day, including both fresh and saline water. Most (80%) of these withdrawals go to thermoelectric power plants (for cooling) and agriculture (for watering crops).
Level 2 is the second darkest hair color level. It is usually used to describe a natural black, and is the natural color of most people who have naturally black hair along with Level 3, soft/light black hair. Refer to the hair color chart. Most drugstore black hair shades are Level 2, medium black. Level 2 hair color is best suited to people whose natural hair color is between Level 2 and Level 3.5.
How Does Ph Affect Hair? Ph in Hair. The natural Ph level of human hair ranges between 4.5 and 5.5 (roughly, 5.0) and is, therefore, more acidic that water or a neutral base. The Ph scale ranges from zero to 14, with zero being the most acidic and 14 being the most alkaline.