Excerpts from vah.com:

Fire Chief Lance Harris is proud to announce that the Arlington Heights Fire Department was again approved as an ISO CLASS 1 organization, following a thorough evaluation by the Public Protection Classification Insurance Services Office. Additionally, the Arlington Heights Fire Department received one of the highest scores recorded at 97.21.  This is the fire departments second consecutive evaluation receiving this honor.

ISO ratings are designed to score a fire department’s ability to protect their community, with ISO CLASS 1 ranked as the highest possible class. Currently, out of approximately 40,000 fire departments nationwide, there are just over 400 departments to hold an ISO CLASS 1 rating, with only 29 in Illinois. 

Key factors that contributed to the fire department improving its CLASS 1 rating score were improved record keeping, training, the fire department’s Community Risk Reduction Program, the accredited dispatch agency Northwest Central Dispatch, and the village’s water distribution system in combination with maintenance and testing of the villages fire hydrants.  

thanks Martin