Sewage discharge
Overview of sewage discharge rules
The effects of sewage discharge from one boat may be minor, but the cumulative effects of the whole maritime sector are significant.
The Resource Management (Marine Pollution) Regulations 1998, (the Regulations) set treatment standards that specify where are allowed to discharge sewage to control pollution of the sea from sewage.
What the Regulations cover
In general, you must not discharge untreated sewage:
- within 500 metres of land
- in water less than 5 metres deep.
There are fewer restrictions on the discharge of treated sewage.
To protect the public and the marine environment, the Regulations also prohibit sewage discharge near marine farms, mātaitai (traditional food collection reserves), and marine reserves.
Regional councils may decide that they need more protection. They can increase the areas where treated Grade B and untreated sewage discharges are prohibited. This will be shown in their regional coastal plans which boat operators should check. Note that Fiordland is specifically recognised in the Regulations. Discharge restrictions apply there to treated and untreated sewage.
Southern Ocean restrictions
If you are heading to the Southern Ocean, Marine Protection Rules Part 160 restrict the discharge of sewage in the Antarctic Treaty Area, below 60° south.
Sewage treatment standards
The Resource Management (Marine Pollution) Regulations 1998 (the Regulations) set three treatment standards. Each treatment standard specifies where you can discharge sewage to control pollution of the sea from sewage.
Grade A treated sewage
Grade A treatment systems, defined in Schedule 6 of the Regulations, are usually found on ships.
- These systems often treat wastewater using a bacterial breakdown and disinfection stage before they discharge treated wastewater. Schedule 5 of the Regulations lists certified Grade A treatment systems.
- If your ship has a Grade A treatment system, and you operate and maintain it according to the manufacturer’s specifications, you must not discharge treated sewage within:
- 100 metres of a marine farm
- the internal waters of Fiordland.
Grade B treated sewage
Boat operators can use a Grade B sewage treatment system, listed in Schedule 7 of the Regulations, to reduce the impact of their wastewater discharges on the marine environment.
The treatment process in Grade B systems usually involves mechanical breakdown and disinfection before discharge.
To be effective, treatment systems must be operated and maintained to the manufacturer’s specifications. If you treat sewage to Grade B, you must not discharge treated sewage within:
- 500 metres of a marine farm or a mātaitai, traditional food collection reserve
- areas that regional coastal plan rules prohibit.
Untreated sewage
Untreated sewage is a greater threat to the marine environment and its users than treated wastewater. The Regulations include more restrictions to control untreated sewage discharges.
You must not discharge untreated sewage:
- within 500 metres of land, measured from mean high water springs
- in water less than 5 metres deep
- within 500 metres of a marine farm or mātaitai (traditional food collection reserve)
- within 200 metres of a marine reserve
- within areas that regional coastal plan rules prohibit.
Boat owners and operators without treatment systems can use the following measures to work within sewage discharge requirements:
- encourage crew and passengers to use shore-based toilets before you sail
- install a holding tank so people can use toilets on board in restricted areas
- fit deck valves so holding tanks can be pumped out at marina-based reception facilities
- dispose of waste from portable toilets at land-based reception facilities, particularly if you used a chemical deodorant
- check whether pump out facilities are available and working at your marina before you sail.