and the Manual for Assessing Consequence Categories and Hydraulic Performance of Structures
(ESR/2016/1933) . These inspections must be undertaken by a suitably qualified and experienced
person.
In addition to these inspections, the Heritage Minerals Water Management Procedure provides
standard controls for various Project activities including tailings and water management, chemical and
hazardous material storage, and wastewater management in accordance with environmental best
practice and relevant guidelines and standards.
If the amendment is approved, a tailings management plan will also be developed to provide operational
strategies to be implemented to ensure that the Upper Mundic Gully TSF is safe and stable and does
not cause any further environmental harm through releases.
6.3. Groundwater
6.3.1. Values
As with surface water, groundwater EVs and WQOs within Mount Morgan Mine receiving environment
are outlined within the Callide Creek Catchment Environmental Values and Water Quality Objectives
(DEHP, 2013). The environmental values of the Callide groundwaters (including Dee River) are the
same as surface water with the exclusion of human recreation values. The WQO for aquatic ecosystem
protection states that where groundwaters interact with surface waters, groundwater quality should not
compromise identified environmental values and WQOs for those waters.
Groundwater water quality within the Upper Mundic Gully TSF area has not been previously
investigated. Most monitoring bores installed at the site are located between the sources of
contamination and receiving environment, being the Dee River. Installation of groundwater monitoring
bores in hydrogeological and topographical upgradient locations has not been warranted by either the
State or various EA holders.
Although the groundwater contours show migration of groundwater towards the south east, the
influence of the OCP and the Westen Dump on the Upper Mundic Gully area is not well understood.
The presence of the exposed Western Dump could possibly be contributing to localised impacts to
groundwater in this area, however this would require further investigation to determine, which is
proposed through conditions identified in Section 2.3 of this document.
ARD has severely affected the groundwater at the Mount Morgan Mine, with high levels of dissolved
metals including sulfate, aluminium, iron, magnesium, calcium, copper and zinc (Unger et al., 2003).
Measures of pH have been as low as 2.5 in previous groundwater measurements (Wels et al., 2007).
DSITI (2015) analysed past groundwater quality data recorded from 2008 to derive site-specific set of
water quality triggers. The Mount Morgan Mine was classified as a ‘highly disturbed site’, needing
thresholds developed from historical data to detect and assess groundwater quality changes more
accurately. The bores were divided into zones that reflected their proximity to the OCP, with Zone 1
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Wulguru Technical Services Pty Ltd – Supporting Information to Amend an Environmental Authority
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