Water reuse project combats water stress in Chongqing, China
Chongqing, China, where one of our EnerSys facilities is located, is flagged as being a high risk area for water stress.1 As part of our global commitment to the United Nations CEO Water Mandate to advance water stewardship, the EnerSys Chongqing production facility implemented a new water optimization initiative in April 2024, which saves between 15 to 20 cubic meters of water daily compared to the historical baselines within the traditional manufacturing process.
The project – spearheaded by Oliver Huang, the Environmental Health and Safety Manager Asia; designed by Rob Qiao, the Equipment Supervisor; and supported by both Wayne Xu, the Sr. Engineering Manager and Sherry Chen, the Environmental Health and Safety Manager – helps address the water stress in the region while also having a positive ROI for the Chongqing facility. “Improving water efficiency is vital to maintaining our operations and conserving natural resources for our communities,” Oliver emphasized. “It also is better for business… It is important to have processes in place to maximize each drop.”
The project began with an inspection and mapping of the plant’s water piping and metering system to identify opportunities for water reuse. At the Chongqing production facility, reverse osmosis (RO) is used to purify water to a quality standard required for use in paste mixing, paste machine washing, and acid preparation. Despite this reuse, there is still some leftover RO rejected water that is sent for discharge as it is excess to the existing water recycling system.
Through this project, the remaining RO rejected water is collected and stored in an above-ground storage tank and is used to flush nearby toilets and in cooling towers for acid filling machines and for acid preparation machines. These two processes in the plant were eligible for RO rejected water given the water quality requirements, which do not require any additional filtering or quality control of the rejected water.
“Our Chongqing Team has been reusing water for just over a month and a half and given its success we are looking into additional ways to optimize the use of RO rejected water on site,” says Oliver. The amount of water diverted from daily discharge is equivalent to the daily drinking water consumption of approximately 110 individuals in China,2 conserving a valuable portion of the city’s water resource.
Our commitment to sustainability and water stewardship at the Chongqing plant showcases how resourcefulness can produce meaningful environmental benefits. As we strive to meet our water conservation goal to reduce water intensity by 25%3 and improve our operational impact, the ingenuity of our team at Chongqing will continue to inspire other efficiency improvements at various EnerSys locations across the globe.
1 World Resources Institute, Aqueduct Water Risk Atlas
2 China: daily per capita water consumption | Statista
3 per kWh of storage produced by 2030 compared to 2020