ATU - Advanced Treatment Unit.
This is additional wastewater treatment after conventional septic treatment, and something now required by California law as part of many septic systems in our neighborhood. These units are large secondary tanks that require power and continuous monitoring. Also referred to as STS - Supplemental Treatment System.
STS - Supplemental Treatment System. Often used interchangeably with ATU.
OWTS - Onsite Wastewater Treatment System. Official acronym referring to self-hosted methods of dealing with wastewater including both conventional septic systems and aerobic systems that include an ATU. Typically aerobic systems that include an ATU are called NOWTS, see below.
NOWTS - Non-conventional Onsite Wastewater Treatment System. Essentially a privately-owned sewage treatment plant. These include aerobic systems with an ATU.
LAMP - Local Area Management Plan. Developed by SLO county to manage septic systems and all types of wastwater within the county, as required by California law.
ADU - Accessory Dwelling Unit. a self-contained residential unit located on th same parcel as a single-family or multi-family hone, sometimes called in-law units, granny flats, backyard cottages.