Ormiston Associates Ltd are specialists in on-site wastewater treatment and disposal system investigation and design. Projects range from individual dwellings to restaurants, hotels, apartments, and subdivision community schemes.

Associated with the larger projects has been the preparation of submissions to the Regional Councils for consent to discharge wastewater into the ground and providing expert evidence services for clients at the Environment Court. More recently, Sandy Ormiston has been part of a small team reviewing and revising the Auckland Regional Council Technical Publication TP58 “Guidelines for on-site wastewater disposal from households and institutions”.

The company is also retained by the Auckland Regional Council to review and process resource consent applications for on-site wastewater treatment & disposal.