In a letter to a letter to NSW premier Mike Baird, the group said that greenhouse gases produced from the combustion of coal are significantly affecting underground water and soil and contributing to dangerous changes in environment.
The letter stated: "The health of the community and the social and environmental values of the Hunter Valley are being damaged by the increasing coal production in the region.
"It is time to begin to phase out coal production in the Hunter Valley and begin a transition to a safer, healthier, and secure economic future."
The illnesses and deaths associated with air pollution are said to cost taxpayers millions of dollars each year.
Estimates by Economists at Large in a report by Climate and Health Alliance showed that $600m was being spent annually on health damages caused by Hunter Valley’s five coal-fired power stations.
Hunter Valley, which accounts for around two-thirds of NSW coal production, currently has 31 coal mines and five coal-fired power stations.
Coal from the region is estimated to produce around 348 million tons of carbon dioxide equivalents each year.
