What Is In Wastewater Anyway?
Nitrate: Beginning in the septic tank, organic nitrogen compounds are broken down (mineralized) and inorganic ammonium (NH4+) is released. Ammonium is soluble in water but is weakly retained in soil by attraction to negatively charged soil surfaces. Under aerobic conditions inorganic ammonium is rapidly oxidized to nitrate (NO3-) through a microbial process called nitrification. Nitrate as an ion is very soluble in soil solution, and is often leached into the ground water. Nitrate poisoning of infants caused the establishment of drinking water standards for this substance. The increased use of breast feeding and liquid infant formula concentrates have almost eliminated reported cases of Methemoglobinemia in the United States. However, nitrate will continue to be an important indicator of subsurface pollution because it is associated with many other harmful substances that can pollute drinking water. According to a 1995 US Department of the Interior study in central Washington State, 30
