Both recreational and medical cannabis growers in Illinois will have to meet high standards for their energy and water use.

A state law signed by Gov. J.B. Pritzker in June places limits on the amount of water and electricity growers can use, as well as setting requirements for water runoff and wastewater.

“This is a high-resource-use industry, and it doesn’t have to be,” said state Rep. Kelly Cassidy, D-Chicago. “Illinois can show the way to do it in a better way.”

The legislation’s sustainability requirements for growers is among the strictest in the nation, according to Sam Milton, a consultant at Climate Resources Group, which helps businesses, regulators and other organizations pursue climate-friendly business practices.

“It definitely puts Illinois at or near the top in terms of state policies for energy and environmental performance for cultivation facilities,” he said.

Illinois growers must use automatic watering systems and limit how much runoff water they produce, according to the new state law. They also have to collect and filter wastewater so that it could be used to water their plants in the future.

In terms of energy consumption, a grower can use no more than 36 watts per square foot for lighting the plants. That standard is similar to one in Massachusetts, but the Illinois law goes further.

Cultivators also must use high-efficiency lights approved by the DesignLights Consortium, a nonprofit organization that pushes for the use of high-performing commercial lights.

The regulations target indoor production, where the majority of growers in the U.S. say they cultivate, according to a 2018 report from New Frontier Data.

Indoor growing uses a lot of energy. Marijuana businesses represented nearly 4% of Denver’s power use in 2018. The same New Frontier Data report estimates energy use in cannabis legal states would jump 162% by 2022, if growers do not change their practices.

Illinois lawmakers observed how much energy and water the cannabis industry used in other states around the country and saw a chance to become the standard for the country, Cassidy said.

“This bill was an opportunity to set a high bar for how this industry will grow in Illinois,” she said. “We were looking to take the lead here.”

Illinois’ efforts on energy efficiency is drawing praise from many environmental groups.

“It is the best in terms of sustainability regulations of any cannabis regulation in the country,” said Jennifer Walling, executive director of the Illinois Environmental Council.

The environmental council represents more than 80 environmental groups in Illinois and pushes for stronger environmental laws and policies at the state capitol. Those groups were concerned about the energy consumption from marijuana cultivation and distribution, Walling said.

“We want to be bringing the state towards 100% clean, renewable energy,” she said. “If we’re having a new industry enter into Illinois that creates a lot of pollution or uses a lot of energy, that’s not going to protect Illinoisans.”

Illinois enters the recreational cannabis market years after Colorado, Washington and other early adopter states. Waiting that long let the state take a different approach to regulating its new industry.

“I think they learned from some of the mistakes of Colorado, Washington and Oregon,” Milton said. “A lot of states have ignored the fact that these facilities are very energy intensive.”

Being more energy efficient ultimately saves money, which Milton said will make Illinois growers more competitive as the cannabis market eventually expands nationally.