Determining dams containing hazardous waste - EM1612 (PDF, 62K

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Department of Environment and Heritage Protection
www.ehp.qld.gov.au ABN 46 640 294 485
Information sheet
Mining
Determining dams containing hazardous waste
The purpose of this document is to provide information on how an environmental authority applicant can determine whether
their activities will require regulation as a dam containing hazardous waste.
Introduction
This information sheet outlines the steps to determine if a dam contains hazardous waste directly associated
with mining activities. The steps include (i) what constitutes a hazardous waste; (ii) whether the dam is a high
hazard dam; or (iii) whether the dam is a low hazard dam. For clarification and definitions of terms please see
the notes on definitions section at the end of this information sheet. This information sheet should be used when
preparing and lodging an application form for an environmental authority for a mining activity.
Background
The Water Act 2002 transferred responsibility to the administering authority 1 for dams containing hazardous
waste. These dams are primarily used for storing process water, recycling treatment liquors and for tailings
disposal. The definition of hazardous waste for the purpose of regulating dams is defined in the ‘Code of
Environmental Compliance for Environmental Authorities for High Hazard Dams Containing Hazardous Waste
(EM1698)’ as ‘any substance whether liquid, solid, or gaseous, derived by or resulting from, the processing of
minerals that tends to destroy life or impair or endanger health’. The code can be found on the administering
authority website at .
The administering authority has categorised dams according on the basis of environmental risk. To determine
which category a dam falls into, there are three questions an applicant must satisfy. These include:
1. Does the dam contain hazardous waste?
2. Is the dam a high hazard dam containing hazardous waste?
3. Is the dam a low hazard dam containing hazardous waste?
1. How to determine if a dam contains hazardous waste
A dam contains hazardous waste only if the dam’s contents (either actual contents or predicted contents)
exceeds any of the criteria in Table 1, or in the case of pH, does not comply with the limits stated in Table 1.
This includes waste produced by gravity separation or washing processes.
1
The Department of Environment and Heritage Protection is the administering authority under the
Environmental Protection Act 1994.

Table 1 - Acceptance criteria
Information sheet
Determining dams containing hazardous waste
Parameter 2 Liquor 3 4 5
Total solids
Arsenic 1.0 mg/L 500 mg/kg
Boron 5.0 mg/L 15 000 mg/kg
Cadmium 10 µg/L 100 mg/kg
Cobalt 1.0 mg/L 500 mg/kg
Copper 1.0 mg/L 5 000 mg/kg
Lead 0.5 mg/L 1 500 mg/kg
Mercury 2 µg/L 75 mg/kg
Nickel 1.0 mg/L 3 000 mg/kg
Zinc 20 mg/L 35 000 mg/kg
Chloride 2 500 mg/L —
Fluoride 2.0 mg/L —
Sulphate 1 000 mg/L —
Cyanide 10 mg/L 2 500 mg/kg
pH Between 4 and 8 Net acid generation of pH

Information sheet
Determining dams containing hazardous waste
1. In the event of dam failure or overflow, the dam’s content would have one of the more of the following
actions:
a) flow to a sensitive or commercial place;
b) flow to a riverine area containing permanent water;
c) contaminate a water supply for human consumption; or
d) contaminate a water supply for stock.
2. The dam is located within a:
a) declared catchment or sub artesian area; or
b) watercourse and the dam’s surface area exceeds 1ha.
3. The dam has a surface area greater than 2ha.
3. How to determine a low hazard dam
A low hazard dam is one that contains hazardous waste, poses a lower risk to the environment and
consequently, the regulation is less rigorous than that of a high hazard dam.
The dam containing hazardous waste is a low hazard dam if it does not fall within the category of a high hazard
dam containing hazardous waste.
Notes on definitions
“commercial place” means a work place used as an office or for business or commercial purposes, which is
not part of the mining activity and does not include employee’s accommodation or public roads.
“dam failure” includes the uncontrolled release of the contents of a dam through collapse of the dam or some
part of it, failure to prevent excessive seepage or failure to contain hazardous substances.
“mining activities” refer to s. 147 of the Environmental Protection Act 1994.
“sensitive place” means;
a) a dwelling, residential allotment, mobile home or caravan park, residential marina or other
residential premises;
b) a motel, hotel or hostel;
c) an educational institution;
d) a medical centre or hospital;
e) a protected area under the Nature Conservation Act 1992, the Marine Parks Act 1992 or a World
Heritage Area; or
f) a public park or gardens.
“watercourse” means a river, creek, or stream in which water flows permanently or intermittently in a visibly
defined channel (natural or artificially improved) with:
a) continuous bed and banks;
b) an extended period of flow for some months after rain ceases; and
c) an adequacy of flow that sustains basic ecological processes and maintains biodiversity.
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Further information
Advice and support are available:
Information sheet
Determining dams containing hazardous waste
� through a statewide network of regional offices of the administering authority and the Department of
Natural Resources and Mines;
on the administering authority website at ; and
� by contacting Permit and Licence Management within the administering authority on 13 QGOV (13 74
68).
Disclaimer
While this document has been prepared with care it contains general information and does not profess to offer
legal, professional or commercial advice. The Queensland Government accepts no liability for any external
decisions or actions taken on the basis of this document. Persons external to the Department of Environment
and Heritage Protection should satisfy themselves independently and by consulting their own professional
advisors before embarking on any proposed course of action.
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