River Murray flood
River Murray in flood. Image courtesy of Department for Environment and Water
EPA position on flood mud
The River Murray is a valuable state resource providing a much-loved home for people, flora and fauna alike. It is also a lifestyle and holiday destination for many South Australian families. Everyone affected by the floods can play their part in keeping the river safe from environmental harm for their families, those living downstream and for future generations. It will take committed individuals and communities working together with local, state and Federal governments to ensure we protect this precious asset from unnecessary harm.
The EPA appreciates that the recent floods have had wide-reaching impacts on communities across the River Murray basin. The clean-up as the water recedes is an immense undertaking that requires a coordinated effort. One of the key elements related to these efforts is the removal and disposal of ’flood mud’.
Flood mud is the wet clay, soil and sand that settles on the ground after flood waters recede. The Environment Protection (Water Quality) Policy 2015 prescribes clay, soil and sand (whether wet or dry) as pollutants. Under this Policy, a pollutant must not be released into any waterways, including the River Murray.
Depositing flood mud into the river causes the water to become cloudy, which significantly reduces the amount of light reaching the riverbed. This can result in significant harm to plant and aquatic life, which impacts the recovery of the river’s delicate ecosystem. To protect the river, any activity (either directly or indirectly) that may cause soil, clay or sand to enter the river must not be undertaken.
All reasonable efforts should be taken to remove soils and mud using either mechanical or manual means while cleaning up roads, paths and hard surfaces to avoid these pollutants entering the river.
If water from low-lying areas needs to be pumped back to the river, all reasonable efforts should be taken to avoid stirring up and pumping any mud that might have settled out in those areas.
How to dispose of flood mud
Flood mud can be properly disposed of by:
- Spreading it across land and property: this may have benefits to the ground area as the mud is nutrient rich.
- If there is no capacity or capability to do this, large quantities can be stockpiled (separate from other waste or litter) for collection by Green Industries waste contractor. This will be offered as a free service.
For further information please contact the relief information hotline on 1800 302 787.
- Latest information and advice from agencies across government on current flooding along the River Murray
- River Murray water and animals, PIRSA
- River Murray water quality, SA Water
- Flows and water levels, Department for Environment and Water
- Flood waste management and disposal will be overseen by Green Industries SA with advice from the EPA
- River Murray water and human health, SA Health
Flood-affected materials and orphaned wastes
The EPA provides advice on disposal of flood-affected materials or orphaned wastes from flood events and other waste management issues.
Animal carcasses must be removed without compromising the more pressing needs of farmers, residents and emergency services. The EPA will render assistance to farmers and emergency services to undertake this necessary activity while protecting water resources.
The EPA and PIRSA recommend that affected farmers and residents contact their insurers prior to disposal of stock.
This information will assist farmers and emergency services in the initial review of the safe and appropriate disposal of animal carcasses under local conditions, and should be read in conjunction with PIRSA advice.
Preferred method of disposal
Isolated carcasses located throughout a property in the order of 10 per hectare (10/Ha) can be left to decompose naturally on site.
Dry rendering at an abattoir is the usual preferred method of carcass disposal, but this may not be a viable option. Burial is the preferred option for disposal of larger numbers of carcasses.
For information on the handling and removal of asbestos, refer to the guideline Wastes containing asbestos – removal, transport and disposal and the Asbestos disposal fact sheet.
For more information on the management of flood-damaged asbestos, see the Asbestos SA website.
CCA treated timber
The chemicals and heavy metals present in CCA-treated timber poses a risk to ground and surface water quality, human and animal health, and soil quality.
Do not dispose of CCA treated timber by burning or burying on site.
For further information on how to manage and dispose of CCA timber waste, please see the Guideline on copper chromated arsenate (CCA) timber waste—storage and management.
Contaminated water in rainwater tanks
After a flood, water in rainwater tanks may contain contaminated water and debris. Residents may wish to drain and discard the water to a watercourse and clean the tank.
SA Health has advised that in most cases, potable mains water will remain safe. Check out this fact sheet to ensure that your rainwater supply is suitable for drinking.
When handling flood-affected, unlabelled or damaged chemicals and their containers, appropriate personal protective equipment should be worn to avoid contact and inhalation. This includes but is not limited to wearing impermeable gloves, eye protection, protective face mask/dust mask, clothing with long sleeves/pants and suitable enclosed footwear.
Stock, pets and children should be excluded from affected areas to prevent contact, inhalation and ingestion of harmful chemicals.
Storage and disposal
If flood-affected, unlabelled or damaged chemicals and their containers are to be stored/stockpiled prior to disposal, storage should occur in a bin or container which can contain any leakage.
Alternatively, such items can be stored on an impermeable surface such as concrete, paving or bitumen and be covered to prevent leaching and further dispersal of chemicals to the surrounding environment.
A licensed waste transporter (listed in the Yellow Pages) should be used to transfer chemical wastes safely to an appropriate landfill site.
Dredging and excavation of soils
Dredging and excavation of soils may be required to reinstate vessel channels, boat mooring/launching areas, or remove sand/soil that has subsided from river banks. Spoil may be contaminated and therefore any stockpiles must be located at an appropriate distance from waterways so they are not likely to re-enter waterways.
For further information on how to undertake dredging and manage excavated soils, please refer to the Dredge guideline.