San José scored 71.57 in total , and comes fifth for lifestyle and policy . It also ranks 12th for energy sources , 13th for environment and 21st for transportation . Its Environmental Sustainability Plan builds on its already decade-old ‘ Green Vision .’ The city is currently working on recycled water projects due to severe droughts common in the area . Advanced filtration technologies are being used to make wastewater potable and to replenish the groundwater system . In terms of sustainable growth , the city ’ s ‘ smart growth ’ policies are working to reduce sprawl , traffic congestion and greenhouse gases and to preserve the green hillsides which are at risk as San José from the sprawling suburbanisation of the Bay Area .

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