This product summarises surface water quality information in the Namoi river basin. Surface water quality parameters which may be impacted by current and potential coal and coal seam gas (CSG) development include electrical conductivity, turbidity and temperature, suspended solids, pH, concentration of heavy metals and presence of hydrocarbons.
Electrical conductivity (proxy of salinity), turbidity and temperature data are available through the NSW Office of Water’s continuous monitoring network. There are 22 gauging stations measuring water quality in the Namoi river basin. Twelve gauging stations are currently measuring some of these water quality parameters, six are reported as measuring all parameters, and three of these have records covering less than three years. There is one gauge (Goangra), with long continuous records for electrical conductivity (EC) and temperature, located on the Namoi River below current and potential coal and CSG development.
A previous monitoring study, the Namoi Water Quality Project (NWQP), conducted from 2002 to 2007, suggested that the water quality in the Namoi River and its tributaries was generally acceptable for irrigation and other farming activities, although electrical conductivity and turbidity values exceeded the trigger set for the protection of aquatic ecosystems. Electrical conductivity values at Goangra during 2010–11 also exceeded the trigger values for most of the year but were similar to those reported in the NWQP study.
There is no routinely conducted surface water monitoring of heavy metals, trace elements and hydrocarbons. Groundwater is not routinely monitored for hydrocarbons and some trace elements.
Based on the salinity of groundwater in the Namoi subregion, groundwater is generally suitable for drinking and irrigation purposes, with small pockets of higher salinity groundwater.