What Happened?
San Diego recently approved a water recycling program that will purify up to 15 million additional gallons of drinkable water per day by 2023. The 20-year program is designed to make better use of available resources while the region continues to battle drought conditions.
Goal
The San Diego City Council approved the Pure Water San Diego program to help provide residents with safe and cost-effective drinking water. The city will use $3.5 billion from various grants to build out the infrastructure to purify and distribute the water over a 20-year period.
By 2023, San Diego expects to purify 15 million more gallons of drinkable water daily than is currently available today. Looking to the long term, San Diego plans to increase drinkable water output to 83 million gallons by 2035, which will account for about 35 percent of the city’s total supply.
Currently, the City of San Diego Public Utilities Department imports about 85 percent of its water. The city has been battling droughts and depleted reserves for a decade, and launched a water-reuse study to see what options it had in recycling water for safe consumption. San Diego then conducted a second study in 2009 that collected research and data through 2013. The findings from each study were used to develop the Pure Water San Diego initiative now in progress.
How It Works
The Pure Water San Diego project involves a three-step purification process that will take place in water purification facilities that are environmentally sustainable. The city conducted more than 9,000 water quality tests to ensure the purified water was free of contaminants once it passes through the multi-barrier water purification process. The major steps include:
- Wastewater is sent to an advanced water purification facility
- Wastewater undergoes several purification processes such as membrane filtration and advanced oxidation
- Water is blended with imported water in an environmental buffer
- Water is sent to a regular drinking water plant for distribution
Over time, San Diego expects the Pure Water program to bypass the environmental buffer – which is the San Vincente Reservoir – to send treated water directly to the final treatment plant for distribution.
Cities Sell Water
Saginaw and Midland, Michigan, jointly own a water supply corporation that recently entered into an agreement to sell raw water to Bay County. The cities decided to start selling raw water to generate significant savings – up to $800,000 in Saginaw alone, Michigan Live reported.
The cities will be able to use a fixed cost over a larger volume to get a high return on investment. Because Bay County will be purchasing up to 22 million gallons per day starting in 2015, Saginaw and Midland could see water costs in their budgets drop drastically. These savings could be reinvested into upcoming capital projects. Saginaw and Midland’s water corporation already has access to assets to collect and distribute the raw water, which limits initial costs. Bay County is also constructing a $60 million treatment plant that will receive raw water from the water corporation and distribute it between 15 municipalities in the Bay Area Water Authority.
Water Projects
Gov1 has kept a close eye on different water projects across the country that focus on conservation and efficiency.