Rule 19 water treatment plant wastes
The discharge from water treatment plants into or onto land of:
(1) supernatant and other waste water;
(2) coagulant wastes and admixtures containing coagulant wastes mixed with soil, aggregates, or other naturally occurring materials;
is a Controlled Activity, and shall comply with the standards and terms below.
Standards and terms
(a) the discharge shall occur no less than 20 metres from any surface water body, from any bore used for drinking water supply, irrigation or stock water or from the coastal marine area;
(b) the base of the disposal area shall be no less than 1.5 metres above the highest level of the water table; and
For a discharge to a dedicated disposal site (i.e., a site which only receives coagulant wastes), the following standard shall apply:
(c) coagulant waste shall be physically stable to the extent necessary to ensure that the discharge site does not constitute a greater hazard with respect to landslip or subsidence than existed at the site prior to waste disposal.
The Wellington Regional Council will exercise control over:
(1) the water content of the coagulant waste;
(2) the manner in which the discharge occurs, including requirements to engineer the site to standard which ensures (c) above is met;
(3) rehabilitation of the discharge site;
(4) monitoring requirements;
(5) the duration of the consent;
(6) administrative charges;
and where coagulant waste is to be applied as a soil amendment or landscaping material, or where supernatant is to be applied to land;
(7) the rate of application.
Explanation. Rule 19 applies to waste generated during water treatment and includes both liquid waste (e.g., from backwashing of filters) and coagulant wastes. The standards and terms address soil and water quality concerns.
For the avoidance of doubt, a consent is not required to dispose of coagulant waste to a landfill which already holds the appropriate consents.