Accessibility. Skip to main content.

How the National Environmental Standards deal with electricity transmission activities (9 of 12)

These pages set out aspects of the NES that Transpower and councils need to consider for transmission activities.

  1. Summary of the NES
  2. Operation of existing transmission line and use of access tracks
  3. Overhead conductors and adding overhead circuits
  4. Earthwires and telecommunications cables
  5. Work on underground conductors / Taking existing overhead transmission lines underground
  6. Increasing voltage or current rating / Electric and magnetic fields
  7. Transmission line support structures — alteration, relocation, and replacement / Temporary / Removal
  8. Telecommunications and signs / Devices / Signs
  9. Discharges
  10. Trimming, felling, and removing trees and vegetation
  11. Earthworks
  12. Noise and vibration from construction activity

Discharges

Discharges from blasting and applying protective coatings to transmission line support structures

Regional plans currently control or permit discharges to air, water and land that can occur from cleaning, surface preparation and applying protective coatings to transmission line support structures. The relevant existing rules in regional plans are replaced by regulation 25, regulation 26 and regulation 27 for these activities. These are discharges under section 15 of the RMA, and are a regional council matter.

Explanation: discharges from cleaning permitted

Wet and dry abrasive blasting (referred to collectively as 'blasting' in the NES) is permitted - regulation 25.

Conditions require that blasting is done more than 50 metres from a water body or public road, and more than 100 metres from an occupied building - regulation 25(3) and (4).

The free silica content of the abrasive material used is limited to 5% - regulation 25(5). The conditions also require that deposited material (for example larger debris) is collected and removed from the site where practicable - regulation 25(6). Restrictions are imposed on the chemicals that can be used for surface preparation - regulation 25(9).

Grit from dry abrasive blasting can travel further than grit from wet abrasive blasting, so conditions limit it to no more than 1 metre above ground level, and require screening to keep the grit and dust from blowing around - regulation 25(7).

Where a tower coated with lead-based paint is cleaned, conditions require that the debris be collected on mats and removed, to prevent lead entering the environment - regulation 25(8).

Explanation: applying protective coatings to support structures and foundations permitted

Hand-painting of a transmission support structure is a permitted activity with no specific conditions, as the effect of hand-painting is minimal. Tower foundations can be spray-coated as a permitted activity provided that it is done no more than 1 metre above the ground - regulation 25(10). Screening is not required – spray-coating is done under much lower pressure than blasting and the spray drift is not likely to be a problem.

If the conditions are not met, a consent will be required. Where the effects of the activity can be controlled by imposing additional conditions, then the activity is controlled. If the council would need to have the discretion to decline the consent in order to control of the effects, the activity is restricted discretionary.

Explanation: controlled and restricted discretionary activities

If applying surface coatings does not meet the conditions listed above, the activity will be controlled.

If blasting does not meet the permitted conditions, it will be controlled unless it is done over a water body or the coastal marine area - regulation27(1)(a), the silica content is greater than 5% - regulation 25(4), or dry abrasive blasting is done without screens or more than 1 metre above the ground - regulation 25(7).

The only exception is if the activity does not meet condition (2) or (5): any blasting within the specified distances from roads, water bodies and occupied buildings; or any dry abrasive blasting undertaken more than 1 metre above ground level or without the use of screens, are restricted discretionary. This is because the council may have to decline the consent to prevent adverse effects. 

For controlled activities, control is reserved over the:

  • effects on water quality and ecologically-sensitive receiving environments
  • effects on occupied buildings
  • risk of contamination of soil
  • effects on health.

For restricted discretionary activities, the local authority has discretion to take account of any of the matters listed above; it can also consider the effects on the use of public roads in determining whether to grant the consent, and in setting conditions.

Refer to regulation 25, regulation 26 and regulation 27.

Discharges to water

Explanation: discharges to water permitted

Under regulation 28, regional councils can permit discharges to water that have minor effects. A discharge will be permitted if it meets the conditions in regulation 28 that after reasonable mixing, the discharge must not:

  • produce conspicuous —
    • films of oil or grease
    • scums or foams
    • floatable or suspended materials
  • create a conspicuous change in colour or visual clarity
  • emit an objectionable odour
  • make fresh water unsuitable for farm animals to drink
  • have adverse effects on aquatic life that are more than minor.

Explanation: discharges to water controlled

If the permitted activity conditions in regulation 28 are not met, discharges to water are controlled by regulation 29. Control is reserved over:

  • the effects on water quality
  • the effects on aquatic life.

|

Last updated: 18 January 2010