Ranger mine monitoring data

Magela Creek monitoring data 2014-2015

The graphs on this web page show the key chemical indicators for the 2014-2015 wet season plus flow rate of the creek at the compliance point gauging station (MG009). Data from previous wet seasons can be found at Magela Creek grab sample monitoring data 2002 - 2010 and Magela Creek monitoring data 2010-14.

The Supervising Scientist's interpretation of the data in these charts, along with supporting information, is available at:

Chemical Indicators

Conductivity in Magela Creek

The conductivity limit of 42 µS/cm was ecotoxicologically derived and applies to exposure durations of 72 hours or greater. The Supervising Scientist has developed an interpretive framework to enable assessment of potential impacts arising from exposure durations that are less than 72 hours. FurthEcotoxicological Electrical Conductivity-Magnesium Pulse Framework page.

Magela Creek continuous conductivity monitoring data from the 2014-15 wet season

Turbidity in Magela Creek

The turbidity guideline of 26 NTU was determined statistically from historical weekly grab sampling data. This guideline may be exceeded occasionally due to natural events but should not be exceeded due to mining activities.

Magela Creek continuous turbidity monitoring data from the commencement of the 2014-15 wet season.

pH in Magela Creek

The pH guidelines of 5.0-6.9 were determined statistically from historical weekly grab sampling data. These guideline values may be exceeded occasionally due to natural events but should not be exceeded due to mining activities.

Magela Creek continuous pH monitoring data from the commencement of the 2014-15 wet season.

Uranium in Magela Creek

The uranium limit of 6 µg/L has been derived using local ecotoxicological data in accordance with the Australian Water Quality Guidelines to protect 99% of the species present. The limit must not be exceeded. Please note that the limit is far above the range shown on the charts.

Magela Creek continuous conductivity and uranium data 2014-15 from the commencement of the wet season.

Manganese in Magela Creek

The manganese limit 75 µg/L was ecotoxicologically derived and is only applicable when the total to creek flow is greater than 5 cumecs (m3/s). This guideline may be exceeded occasionally due to natural events but should not be exceeded due to mining activities.

Magela Creek continuous conductivity and manganese data 2014-15 from the commencement of the wet season. Please note that the manganese Limit of 75 µg/L is not shown on the chart.

Magnesium in Magela Creek

The magnesium limit of 3 mg/L was ecotoxicologically derived and applies to exposure durations of 72 hours or greater. The Supervising Scientist has developed an interpretive framework to enable assessment of potential impacts arising from exposure durations that are less than 72 hours. Further details on this framework and its implementation  can be found on the Ecotoxicology Electrical Conductivity-Magnesium Pulse Framework page.

Magela Creek continuous conductivity and magnesium data 2014-15 from the commencement of the wet season.

Sulfate in Magela Creek

There is no specific guideline for sulfate in Magela Creek. Conductivity is strongly correlated to sulfate so the guideline for conductivity is referred to when interpreting sulfate data. For comparison, the drinking water standard with taste as the criterion for sulfate is 250 mg/L.

Magela Creek continuous conductivity and sulfate data from the commencement of the 2014-15 wet season.

Total Ammonia Nitrogen (TAN) in Magela Creek

The interim total ammonia nitrogen guideline of 0.7 mg/L was derived using international ecotoxicological data. The Supervising Scientist is in the process of developing site specific ecotoxicologically derived trigger values using aquatic species endemic to the Alligator Rivers Region.

Magela Creek continuous conductivity and total ammonia nitrogen (TAN) data from the commencement of the2014-15 wet season.

Radium-226 in Magela Creek

The limit or total 226Ra activity concentration in creek water was derived specifically for protection of human health. The median 226Ra activity concentration measured at the upstream site is subtracted from the median measured at the downstream site. This difference value, called the ‘wet season median difference’, should not exceed 10 mBq/L.

Magela Creek radium-226 data from the commencement of the 2014-15 wet season.