4.18 Other discharges of contaminants
Introduction
The following provisions apply to discharges of contaminants onto or into land or water that are not otherwise covered by the plan, and that are identified as occurring or needing to occur for recognised purposes. Discharges directly to the CMA are addressed in other parts of the Unitary Plan.
1. Activity table
The following table outlines the activity status for activities that result in a discharge of contaminants to land or water. Refer to other provisions in the Unitary Plan for the activity status of the related land use activity.
[rp]
 Activity Activity Status
Discharge of wastewater or washwater from any of the following activities:
- concrete/asphalt laying for reworking and other road construction
- drilling – excluding bore development and testing
- mobile cleaners
- washing vehicles, plant or machinery
- cleaning, maintenance and preparation of surfaces of buildings, and associated that do not border, or span or otherwise extend over any water body
- road construction activities
- construction, installation, maintenance, alteration, removal or upgrading of any component of the stormwater or wastewater network that does not border, span or otherwise extend over any water body
- installation, repair, maintenance, alteration or removal of network utility infrastructure that does not border, span or otherwise extend over any water body
- quay cranes operated by Ports of Auckland
- dust suppression
- emergency services response training activities
  P
Discharge of water from:
- testing or emptying of pipelines, tanks or bunds
- swimming pools, other than saltwater pools and filter backwash water,
- bore development, testing or purging (dewatering), except for contaminated groundwater
- temporary and permanent discharge of diverted uncontaminated groundwater
- water used for freshwater fish farming ponds, tanks or other containment structures operating without chemical additives on a continuous flow-through basis
- trenches or other sites
  P
Swimming pool filter backwash to land in a manner that does not result in runoff into surface water  P
Discharges of potable water for the purpose of draining pipelines or water reservoirs for inspection, repair or maintenance excluding scouring water from any water supply reservoir and backwash water from water treatment plants
  P
Discharges for the purpose of dewatering trenches or other excavations  P
Discharge of dye or tracer material for investigative purposes  P
The discharge of geothermal water from any site in Parakai or Waiwera thermal aquifer management areas (as shown in Figures 1 and 2)  P
Any discharge from a New Zealand Defence Force weapons system to land within areas designated for defence purposes
  P
Discharge of dye or tracer material for investigative purposes that does not meet the permitted activity conditions  C
The discharge of wastes as a result of wet or dry abrasive blasting activities is that does not comply with the permitted activity conditions
  C
Discharge of wastewater or washwater from:
a. cleaning, maintenance and preparation of surfaces of buildings, and associated structures
b. installation, repair, maintenance and removal of network utility infrastructure
c. construction, installation, alteration, removal or upgrading of any component of the stormwater or wastewater network
that do not meet the permitted activity conditions		  C
The discharge of geothermal water from any site at Parakai or Waiwera thermal aquifer management areas as shown in Figures 1 and 2 that does not comply with the permitted activity conditions  C
The discharge of geothermal water from any site at Parakai or Waiwera thermal aquifer management areas as shown in Figures 1 and 2, that does not comply with the controlled activity controls
  RD
Any discharge of geothermal water outside of Parakai and Waiwera thermal aquifer management areas as shown in Figures 1 and 2
  D
Any discharge of water or wastewater not otherwise authorised by a rule in the Unitary Plan  D
Discharge of contaminants associated with hydraulic fracturing onto or into land or water  D
2. Controls
2.1 Permitted activities
A permitted activity that does not comply with the controls below is a discretionary activity.
2.1.1 General
1. The discharge must not, after reasonable mixing, give rise to:
a. the production of any conspicuous oil or grease film, scum or foam, or floatable or suspended materials; or
b. any conspicuous change in the colour or visual clarity; or
c. any emission of objectionable odour; or
d. the rendering of freshwater unsuitable for consumption by farm animals; or
e. a change the natural temperature of the receiving water by more than 3 degrees C; or
f. a change in the natural pH of the water by more than 1pH unit.
2. The contaminant discharged must not either by itself or in combination with other contaminants after reasonable mixing exceed the greater of the 95 per cent trigger values for freshwater (groundwater) specified in the Australian and New Zealand Guidelines for Fresh and Marine Water Quality 2000, or the natural background level.
3. The discharge must not enter into any water supply catchment, Wetland, Natural Lake or Natural Stream Management Area.
4. The discharge must not cause erosion or scouring at the point of discharge or alter the natural course of the water body.
2.1.2 Discharge of water from testing or emptying of pipelines, tanks or bunds
1. As far as practicable, welding residues or other debris contained within a pipeline must not be discharged to the receiving water.
2.1.3 Discharge of water from swimming pools
1. Swimming pool water must be discharged:
a. into a reticulated wastewater system where available and connection is approved by network utility operator; or
b. if wastewater reticulation disposal is not available the swimming pool must be left uncovered and shall not be dosed with chemical additives for at least 14 days before the discharge occurs.
2.1.4 Discharge of potable water for draining pipelines or water reservoirs for inspection, repair or maintenance
1. The discharge, after reasonable mixing, must result in a free available chlorine concentration g/l in the receiving water of less than or equal to 13.
2. If the discharge is to a tidally influenced environment, the discharge must occur during the upper half of the tide unless the discharge occurs directly into open water without disturbing sediment.
2.1.5 Discharges for dewatering of trenches or other excavations
1. The origin of the discharge must be limited to surface water and/or groundwater.
2. Appropriate sediment control measures must be implemented to ensure that the discharge does not result in any of the effects listed in the generally permitted activity control in clause 2.1.1.1 above.
3. The discharge must meet all other relevant permitted activity controls of the Unitary Plan, including those relating to land disturbance and contaminated land.
2.1.6 Discharge of dye or tracer material for investigative purposes
1. Notice of the intended discharge must be given to the council at least 12 hours prior to the discharge occurring.
2. The dye or tracer must be of a type designed for use in natural water and must be used in accordance with manufacturer’s recommendations and any recognised standards and practices.
2.1.7 Discharge of geothermal water from any site in Parakai and Waiwera Thermal Aquifer Management Areas
1. Any discharge of backwash water must only take place from pools with a volume of less than 10m3.
2. Discharges other than backwash water must comprise geothermal water only and must contain not residual added chemicals.
3. The temperature of the discharge must be less than 35 degrees C.
4. The discharge must be less than 100m3 per day and must not cause erosion, overland flows or nuisance to neighbouring properties.
5. The discharge must not be directly into any water body.
6. Approval must be obtained from council for any discharge to public stormwater reticulation.
2.1.8 Any discharge from New Zealand Defence Force weapons system to land within areas designated for defence purposes
1. Any unexploded munitions must be located and destroyed as soon as practicable.
2. Any metallic debris must be removed from site where practicable.
3. The discharge must not result in the contamination of other land not designated for defence purposes.
4. The discharge must not result in the contamination of groundwater used by other parties.
5. The discharge must not lead to contamination of surface water.
2.2 Controlled activities
2.2.1 Discharge of wastewater or washwater
1. Discharges from the following activities must not enter any Wetland Management Area, Natural Lake Management Area or Natural Stream Management Area:
a. the cleaning, maintenance and preparation of surfaces of buildings, associated structures e.g. driveways and garages bridges and other structures
b. installation, repair, maintenance and removal of network utility infrastructure
c. construction, installation, alteration, removal or upgrading of any component of the stormwater or wastewater network.
d. wet or dry abrasive blasting activities.
2.2.2 Discharge of geothermal water from any site in Parakai or Waiwera thermal aquifer management areas (as shown in Figures 1 and 2)
1. The discharge must comprise geothermal water, with or without the addition of pool chemical treatments.
2. The discharge must not contain any filter backwash water.
3. The contaminant discharged must not either by itself or in combination with other contaminants exceed the 95 per cent trigger values for freshwater (groundwater) specified in the Water Quality Protection Guidelines (ANZECC, 2001).
4. The temperature of the discharge must be less than 35 degrees C.
5. The discharge after reasonable mixing must not change the natural temperature of the receiving water by more than 30 degrees C.
6. The discharge after reasonable mixing must not change the natural pH of the water by greater than 1pH unit.
7. The discharge must not cause erosion or scouring at the point of discharge or cause downstream channel erosion or alter the natural course of the water body.
8. The discharge must not result in significant flooding.
3. Assessment - Controlled activities
3.1 Matters of control
The council will reserve its control to the matters below for the activities listed as controlled in the activity table. 
1. General
a.the volume of discharge and level of contamination
b.the method of discharge and effects arising from the method chosen
c.the provision and adequacy of equipment for the collection, treatment and disposal of any discharge
d.specific requirements for monitoring the consent.
2. Discharge of wastes from wet or dry abrasive blasting activities
a.the duration of the discharge
b.notification of affected parties prior to work starting.
3. Discharge of geothermal water at Parakai or Waiwera thermal aquifer management areas (as shown Figures 1 and 2)
a.the quality of any discharge including methods for the treatment and disposal of contaminants, including pool treatment chemicals and filter backwash water
b.the location of any discharge point
c.the rate and frequency of any discharge.
4. Assessment - Restricted discretionary activities
4.1 Matters of discretion
The council will restrict its discretion to the matters below for the activities listed as restricted discretionary in the activity table. 
1.The discharge of geothermal water from any site at Parakai or Waiwera thermal aquifer management areas as shown in Figures 1 and 2, that does not comply with the controlled activity controls
5. Aquifer management areas
Figure 1: Parakai thermal aquifer management area
Figure 2: Waiwera thermal aquifer management area