W.C. Water-Fall

3. Sedimentation basin and filter discharge channels.
5. A pipe with several branches/fittings to allow water or gas to be discharged.
9. A device that removes oxygen or air from a liquid.
10. Metal arm attached to the centre column in a multiple hearth incinerator that moves material around each hearth.
12. Type of inclined plate settler.
14. Process of particles in solution starting to adhere together after addition of a coagulant.
16. Visible by the eye without the aid of a microscope.
18. The boundary between adjacent drainage basins.
19. The rate at which atmospheric temperature decreases with altitude.

1. A front-end loader used to load trucks with material from excavations.
2. An approximate measurement of the diameter of a pipe.
4. A group of atoms, acting as a single atom, that goes through chemical reactions without change.
6. A line from which heights and depths are calculated or measured.
7. An instrument for measuring pressure.
8. Biologically harmful.
11. Mineral name for the black, mixed ferrous-ferric iron solid.
13. Act of returning a multimedia filter bed to its stratified condition.
15. Resistant to decomposition or decay by biological means or by chemical means.
17. Film of water left around each grain of water-bearing material after gravity water is drained off.