A process using extremely
short wave-length light that can kill micro-organisms (disinfection) or cleave
organic molecules (photo oxidation) rendering them polarized or ionized and
thus more easily removed from the water.
waters for which no classification has been assigned and which have not been
identified in Appendix A of 31 Texas Administrative Code, Chapter 307.10 of
Title 31 (relating to definitions).
occurring earth formations that have not been lithified. Alluvium, soil, gravel,
clay, and overburden are some of the terms used to describe this type of formation.
Undercurrent: A current below
the upper currents or surface of a fluid body.
Underdrain: A concealed drain
with openings through which the water enters when the water table reaches the
level of the drain.
Underflow: Movement of water
through subsurface material.
A tank located all or partially
underground that is designed to hold gasoline or other petroleum products or
Undertow: The current beneath
the surface that sets seaward or along the beach when waves are breaking on
Underwater: Under the surface
of the water; lying, growing, performed, worn, or operating below the surface
of the water, as underwater caverns, underwater operation of a submarine.
Unit surcharge: A surcharge imposed
for all water use above a threshold level for excess consumption established
based on average per capita or per-household consumption.
Unloading: The release of
the contaminant that was captured by a filter medium.
Zone: The area
above the water table where soil pores are not fully saturated with water.
Upflow: An upward flow.
Upwater: Ultra pure water
creation demands a specialised way of working. A number of techniques are used
amongst others; membrane filtration, ion exchanges, sub micron filters, UV and
ozone systems. The produced water is extremely pure and contains none to very
low concentrations of salts, organic/ pyrogene components, oxygen, suspended
solids and bacteria.
Urban runoff: Storm water from
city streets and adjacent domestic or commercial properties that may carry pollutants
of various kinds into the sewer systems and/or receiving waters.
USGS: United States
Utility: Public water
UV: Ultra Violet.
Radiation that has a wavelength shorter than visible light. It is often used
to kill bacteria and destroy ozone.