Producing Cleaner Water for Generations to Come

The Sacramento River flows from the Cascade Mountains, winds along 400 miles of Northern California and empties into the San Francisco Bay. Throughout its journey, there exists a delicate balance between nature and civilisation.

The river significantly affects the livelihood of Californians, serving large-scale farming and mining operations. It’s a major source of irrigation, drinking water, timber, hydroelectric power and recreation, and it’s a habitat for endangered fish species, including salmon, steelhead, delta smelt and green sturgeon.

In 2010, the Central Valley Regional Water Quality Control Board (Regional Water Board), the state agency that regulates wastewater discharge to the river, issued a new permit to Regional San now Sacramento Area Sewer District (SacSewer). The permit included strict conditions that could only be met with new wastewater treatment facilities.

SacSewer, a steward of the river since its inception in 1973, serves 1.6 million residents by treating household, business and industrial sewage. The agency hired us, as part of a joint venture team, to manage major upgrades. The new plant was completed in spring 2023 under budget and on schedule. Now it removes 99 percent of ammonia and 89 percent of nitrogen from the wastewater therefore producing a cleaner water for discharge to the river.

We developed a Program Management Information System and validated various treatment concepts through pilot testing. The new treatment process includes nutrient removal, filtration and enhanced disinfection. These efforts, combined with the optimisation of construction sequencing through 4D/5D modelling and modern visualisation tools, reduced overall program costs by $400 million. The estimated total cost to comply with the National Pollutant Discharge Elimination System permit ranges from $1.5 billion to $2.1 billion, with additional annual maintenance costs.

The EchoWater Project is the largest public works project in Sacramento County’s History

To emphasise the project’s mission, Regional San derived the name EchoWater, describing the process of returning water to its original state, like an echo returning to its source. The newly improved and renamed EchoWater Resource Recovery Facility will resonate throughout the 27,000-square-mile watershed and will improve the state’s Bay Delta ecosystem.