Often it is useful to have a record of the visual appearance or movement of a discharge, or as a record of compliance with resource consent conditions about how a site is operated.
The Council uses a time lapse video unit to monitor a variety of effects. A record of the number and duration of smoke events from different chimneys on a factory, the quantities of dust blowing from an asphalt plant and its yard, the formation of clouds or a plume of water vapour from large cooling tower systems, and the movement of a plume of discoloured effluent and surface slick from a marine outfall, are examples of how the unit has been used.
Elsewhere in New Zealand and overseas, digital cameras are now being used to send pictures directly back to Council staff. These are useful for monitoring changes in beach or river profiles, and volcanic activity.