The original sewage treatment plant for the area was built in Olympia by the city to meet its own wastewater needs. Construction of the plant was authorized by the City Commission in 1949 and primary treatment went on-line in 1952. The City of Tumwater and the Olympia Brewing Company contracted with Olympia for wastewater treatment service in 1954 and were both connected to the system in 1955. Later, in 1969, Lacey also contracted with Olympia for service and connected to the system.
To qualify for state and federal grants, an interlocal agreement between the three cities and the county was signed in 1976. It provided for cooperative use and development of the Olympia Treatment Plant, established jointly funded major sewer lines and initiated an intergovernmental planning process for a major upgrade of the treatment plant. The resulting 1983 upgrade provided secondary treatment of wastewater.
The treatment plant was further upgraded in the early 1990s to add nitrogen removal and ultraviolet disinfection and upgrade the plant's outfall into Budd Inlet. Those new systems came on-line in 1994.
As the result of a major Inflow and Infiltration Study conducted from 1992-1994, the LOTT partners learned their treatment plant could reach capacity as soon as 2001 during wet weather. In September 1995, they began a four-year long-range planning process, resulting in the Wastewater Resource Management Plan. A new Intergovernmental Agreement was approved by the four LOTT partners (Lacey, Olympia, Tumwater, and Thurston County) in January 2000 to restructure LOTT and implement the plan.
In 2004, the first upgrade under the new plan occurred at the Budd Inlet Treatment Plant, with the addition of a sand filter system to produce reclaimed water. The same year, construction began on the Martin Way Reclaimed Water Plant, which began operation in 2006. LOTT now produces Class A Reclaimed Water at both locations, and the water is used by LOTT’s partner cities – Lacey, Olympia, and Tumwater – for a variety of non-drinking purposes.
LOTT opened its Regional Services Center building in 2010, located on the Budd Inlet Treatment Plant campus. The building is LEED Platinum certified to minimize its footprint and energy use. It includes the WET Science Center, public meeting spaces, and an expanded water quality laboratory. And, in 2013, new primary sedimentation tanks were added to the Budd Inlet Treatment Plant.