One of Boise’s signature utilities is set to be upgraded.

This summer, the city of Boise is putting in $750,000 of extra maintenance into its geothermal system, the largest of its kind in the United States.

City officials tell the Idaho Press, the goal is to fix connections between pipes and other needed maintenance to reduce breaks in the winter months once the system kicks into high gear, heating nearly 6 million square feet of businesses, residences and city buildings in the downtown core.

Work will take place over the summer and be largely coordinated with Ada County Highway District, which is repaving large sections of both Main and Idaho streets.

The geothermal system is a key part of the city’s move to have all residences and businesses in Boise powered by 100 percent renewable energy by 2035.