Water and Wastewater Treatment

The chemicals you use for water and wastewater treatment are controlled by the Hazardous Substances and New Organisms (HSNO) Act 1996. These types of chemicals are generally under a Group Standard Approval for Water Treatment Chemicals.

These are some of the typical chemicals that might be used for water or wastewater treatment

  • Chlorine gas
  • Calcium hypochlorite
  • Sulphuric acid
  • Hydrochloric acid
  • Sodium hydroxide
  • Aqua ammonia
  • Hydrogen peroxide
  • Potassium permanganate

If you use some of these substances, you may require one of the following test certificates:

Location Test Certificates

You will need a Location Test Certificate if you are using and/or storing particular chemicals above certain quantities. These quantities depend on the hazards of the particular chemicals you have on your site (refer to the Hazardous Substances Class 1-5 Control Regulations or contact a Test Certifier)

For more information about obtaining Location Test Certificates, please refer to the Quick Guide - Location Test Certificates

Approved Handlers

An Approved Handler must make sure that certain chemicals are handled safely, that they do not harm people, nor damage the environment.

The table below shows you which chemicals commonly used will need an Approved Handler. Note that not all employees handling these hazardous substances will have to be Approved Handlers, as long as they are working under the guidance of an Approved Handler. However, an Approved Handler must be present at the location and be available to provide assistance.

How to get Test Certificates

You can obtain your certificates from a Test Certifier. To find your nearest Test Certifier, check the register or call ERMA New Zealand for a list of Test Certifiers to be posted to you.

Tracked chemicals

The most hazardous chemicals need tracking, and you will need an Approved Handler in order to use them. To buy them your supplier will need to confirm you are an Approved Handler, and that you have a Location Test Certificate if needed. The table at the end shows which chemicals are tracked.

At a glance

The following is an overview of some of the substances that require Approved Handlers, Location Certificates and Tracking. Note: these are for the pure substances.

Water/Wastewater Treatment Test Certificates
Chemical Name Location Approved Handler Tracking
Ammonia, up to 50% solutions in water No No No
Calcium hypochlorite Yes >500 kg No No
Chlorine Yes >150 kg Yes (any quantity) Yes
Hydrochloric acid, solutions in water No No No
Hydrogen peroxide, 20-60% solutions in water* Yes >500 litres Yes >500 litres No
Potassium permanganate Yes >500 kg No No
Sodium hydroxide, including solutions in water No No No
Sulphuric acid, solutions in water No No No

* If you have hydrogen peroxide outside the 20-60% solutions in water range, different requirements for Location Certificate, Approved Handler and Tracking will apply. Ask your Test Certifier.

NOTE: If you have more than one substance that requires a Location Test Certificate it is the total quantity of all those substances that will determine whether a test certificate is needed. Please contact a Test Certifier for advice.

What must I do now?

Not all the chemicals you use, distribute, or store are listed in this leaflet, but please be aware that all hazardous chemicals are controlled by the HSNO Act.

You should:

  • check your chemicals to see if they include any of the hazardous chemicals listed in this brochure
  • identify and obtain Test Certificates for Locations and/or Approved Handlers for those substances that require them
  • contact a Test Certifier if you have any queries about what is required for a particular chemical.

Contact ERMA New Zealand

Information on HSNO compliance is also available from ERMA New Zealand. Contact our Hazardous Substances Compliance Line:

Phone: 0800 376 234, or
Email: hsinfo@ermanz.govt.nz

Or contact us at:

ERMA New Zealand
PO Box 131
Wellington