| Aromatic | (Environmental Engineering) A form of bonding in which ring compounds share electrons over more than two atoms. The electrons are delocalized. This leads to unusual ring stability. |
| Biosynthesis | (Environmental Engineering) Catabolism, the production of new cellular materials from other organic or inorganic chemicals. |
| Catabolism | (Environmental Engineering) The production of energy by the degradation of organic compounds. |
| Chemical fixation (or stabilization/solidification) | (Environmental Engineering) A term for several different methods of chemically immobilizing hazardous materials into a cement, plastic, or other matrix. |
| Chemotroph | (Environmental Engineering) Organisms which obtain energy from the metabolism of chemicals, either organic or inorganic. |
| Coagulation | (Environmental Engineering) Particle destabilization to enhance agglomeration. |
| Maximum contaminant level (MCL) | (Environmental Engineering) The maximum allowable concentration of a given constituent in potable water. |
| Metabolism | (Environmental Engineering) The processes which sustain an organism, including energy production, synthesis of proteins for repair and replication. |
| NPDES | (Environmental Engineering) The National Pollutant Discharge Elimination System. The discharge criteria and permitting system established by the U.S. EPA as a result of the Clean Water Act and its subsequent amendments or the permit required by each discharger as a result of the Clean Water Act. |
| Reactive waste | (Environmental Engineering) A waste which; 1) reacts violently with water, 2) forms potentially explosive mixtures with water, 3) is normally unstable, 4) contains cyanide or sulfide in sufficient quantity to evolve toxic fumes at high or low pH, 5) is capable of exploding if heated under pressure, or 6) is an explosive compound listed in Department of Transportation (DoT) regulations. One of EPA's four hazardous waste properties. |