In 2014, the engineering team at General Motors' Detroit-Hamtramck Assembly plant recognized that storm water discharge fees were consuming around 14 percent of the plant's utility bill costing the plant millions. To combat this loss, the team decided to invest in a massive storm water retention pond with the capacity of 47 million gallons. GM then worked out a deal with Detroit Water and Sewage Department (DWSD) that would either redirect water that would normally be sent to DWSD or retain the storm water until DWSD's system had a chance to return to dry-weather mode after a storm.
Originally, the plan was to use the new retention pond solely for the purpose of holding onto the water until the DWSD was ready, but engineers then began considering other ways to reuse the water themselves.
The result of these considerations is 3,600 feet of pipe that links the ponds to the plant's warehouse. Water is then pumped into large storage tanks and is initially used to feed the plant's cooling towers, but it doesn't stop there. After further purification, the water is used in the plant's sludge system and phosphate system used to prepare and treat metals used in their vehicles. Eventually, the remaining water is likely to be used to power other Detroit businesses.
This water renewal system is just one of the many different initiatives used by General Motors to stay environmentally sustainable. This plant has installed a six-acre solar power array on top of many other smaller initiatives, some as small as simply turning off the lights during lunch hours.
Alone, this project will benefit both the company and the environment by saving 2.3 million dollars per year and reducing the plant's water usage by 20 percent.