| Groundwater | (Environmental Engineering) Water which is contained in geologic strata. Also properly written as two words, ground water. |
| Nitrification | (Environmental Engineering) The biological oxidation of ammonia and ammonium sequentially to nitrite and then nitrate. It occurs naturally in surface waters, and can be engineered in wastewater treatment systems. The purpose of nitrification in wastewater treatment systems is a reduction in the oxygen demand resulting from the ammonia. |
| 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. |
| Primary treatment | (Environmental Engineering) Treatment which includes all operation prior to and including primary treatment, e.g., bar screening, grit removal, comminution, and primary sedimentation. |
| Abstraction - | (Software Engineering) (1) the level of technical detail of some representation of software; (2) a cohesive model of data or an algorithmic procedureAction (also called Software engineering action) - |
| Basis path testing - | (Software Engineering) a white box test case design technique that used the algorithmic flow of the program to design tests |
| Change control authority (CCA) - | (Software Engineering) the person(s) who have responsibility for deciding whether a change is to be made |
| Cyclomatic complexity - | (Software Engineering) a measure of the logical complexity of an algorithm, used in white-box testing |
| Detail design - | (Software Engineering) a design activity that focuses on the creation of an algorithm |
| Modular design - | (Software Engineering) a design approach that stresses modularity |