Encouraging signs of ecological recovery in a river polluted with coal mine wastes within the Blue Mountains world heritage area

![CDATA[Coal mine wastewater is discharged to the Wollangambe River, located within the Greater Blue Mountains World Heritage area of New South Wales (NSW) Australia. Degradation of water quality and river ecology within the Wollangambe River has been recorded in past research. Since these studies, the NSW EPA have enforced updated environmental regulation of coal mine wastes. To quantify water quality and river ecology, measures of salinity, metals such as nickel, zinc, as well as total abundance and richness of macroinvertebrate families were collected. Comparing current data to past data has showed improvements of water quality and signs of ecological recovery in the Wollangambe River 20km past the wastewater discharge. Levels of contaminants in the water column such as salinity, nickel, and zinc have reduced while macroinvertebrate abundance and richness has increased. Changes to discharge limits of coal mine wastewater to match the ANZECC guideline values for ecosystem protection can promote the recovery of water quality and river ecology in polluted streams. Environmental regulation of many coal mine waste discharges can be improved to reduce water pollution impacts in streams.]]