Onsite Wastewater Management Systems (OWMS)

The Water New Zealand Onsite Wastewater Management Systems (OWMS) Special Interest Group was established to service the interests of all people involved in small wastewater flows.

Topic areas include research, practice and administration related to onsite wastewater systems. Covering all aspects of on-site domestic wastewater systems through to small community wastewater schemes. Including the use of natural systems such as waste stabilisation ponds, constructed wetlands and land treatment processes in managing small wastewater flows within the environment.


The Water New Zealand OWMS Special Interest Group aims to:

  • Provide a forum for interaction and discussion between participants in the small wastewater and natural systems industry.
  • Facilitate the exchange of information between members and related organisations and agencies.
  • Assist development of provide support for training programs for participants in the small wastewater and natural systems industry.
  • Organise seminars, workshops and other meetings to support the objectives of the group.
  • Promote education and public understanding regarding small wastewater and natural systems issues.


Understanding and taking care of your on-site wastewater management system for domestic wastewater

This brochure has been written to firstly assist owners of an on-site wastewater management service to better understand the physical design of their system and, secondly, to understand the need and the procedures for operation and maintenance of the system.

Choosing an On-site Wastewater Management System, OWMS

For people needing to manage their own household wastewater within the boundaries of their property - an on-site wastewater management service (OWMS). OHMS must comply with the local regulations administered by Regional and Territorial Councils.

Onsite Effluent Treatment National Testing Programme (OSET NTP)

The Onsite Effluent National Testing programme has been put into abeyance. This has previously been governed by an advisory group which included the SWAN group. Further information on the testing centre is available on this webpage .

Onsite Wastewater Management Systems Research Key documents and research completed up to 2019, provided by the New Zealand Land Treatment Collective.


The Onsite Wastewater Management Systems Special Interest Group’s full Terms of Reference are here.


To register your interest in future activities, contact our Group’s coordinator Katrina.Guy@waternz.org.nz

Chair: Gareth Williams

OWMS Committee