Cannabis growers in Illinois face strict new standards for energy and water usage. The Cannabis Regulation and Tax Act, signed into law in June by Governor J.B. Pritzker, legalized the cultivation and sale of adult use cannabis. It also placed limits on the amount of electricity and water cannabis growers can use, and on water runoff and wastewater associated with cannabis grow operations.

Industry observers describe the Illinois energy and environmental rules governing cannabis cultivation as the strictest in the nation. State Rep. Kelly Cassidy, a lead sponsor of the Cannabis Regulation and Tax Act, described the legislation as ushering in “a new, smarter era of cannabis regulation in our state.”

The energy conservation rules target indoor cannabis production, which is how the majority of U.S. growers cultivate cannabis, according to a 2018 report from New Frontier Data. Indoor cannabis growing demands a lot of energy. Last year, for example, cannabis growers in Denver accounted for about 3% of the city’s total electricity usage, according to city officials. New Frontier Data forecasts that energy consumption by legal cannabis growers nationwide could jump 162% by 2022

“This is a high-resource-use industry and it doesn’t have to be,” Rep. Cassidy, a Democrat from Chicago, said in a report aired on St. Louis public radio. “Illinois can show the way to do it in a better way.”

Illinois cannabis growers must employ automatic watering systems, and limit production of runoff water. Cannabis growers in the state also must install equipment to collect and filter wastewater for future use.

The law also limits energy consumption. A grower in Illinois can use no more than 36 watts per square foot to cannabis light plants, and they must use approved high-efficiency lighting.