Onsite wastewater management systems (OWMS)
... and Water Regional Plan (LWRP) and the Building Code, administered by the local council. Your system will require regular maintenance to avoid ponding and odours and to reduce the risk of people getting sick or contamination. ...
https://www.ecan.govt.nz/your-region/your-environment/water/wastewater/onsite-wastewater-management-systems-owms