Foam in rivers, creeks and canals
On many occasions, a yellow-brown foam has been observed in rivers, creeks and canals in many areas across Queensland.
Scientific examination of this foam has revealed the presence of vegetable material, such as grass clippings, leaves and twigs which has presumably been blown or washed into the waterways during stormy weather. Microscopic examination has shown undifferentiated algal, vegetable and diatomaceous debris and some filamentous organisms, namely iron bacteria. The iron bacteria are typically associated with brown fibrous material washed out of storm water systems.
Bacteria examination has shown faecal coliform levels to be within the guidelines for recreational water, as described by the National Health and Medical Research Council, namely less than 200 faecal coliforms per 100mL of sample.
Chemical tests have also shown no increases in ammonia or phosphate concentrations above background levels. The low faecal coliform, ammonia and phosphate results indicate that the foam is not due to sewage contamination.
The foam appears to be formed by the action of wind and waves on the proteinaceous by-products of decaying vegetable matter, causing entrapped air to persist as a foam.
If you’ve seen a slimy brown residue in your local waterway or drain- it could be iron bacteria, a naturally occurring microorganism.
While it may be unsightly there is no evidence to suggest that it is harmful to our health.
Iron bacteria have been present in natural waterways for over a million years.
Iron bacteria feed on iron. When the bacteria are ‘feeding’ they may leave slimy rust-coloured deposits suspended in our creeks, lakes, canals and rivers.
If you live near a waterway you may notice this condition worsens after heavy rainfall. This is a result of iron rich soils leaching into the waterways.
When oxygen, water and iron mix together they can create the right conditions for iron bacteria to bloom.
Iron bacteria need to oxidise (change their compound structure) to fulfil their energy requirements. This involves changing ferrous iron (Fe2+) into ferric iron (Fe3+).
This process makes the iron insoluble and produces the rust-coloured slimy deposit you may have noticed.
Spotting iron bacteria
Iron bacteria are typically rust coloured, slimy and have an oily appearance on the water’s surface.
The bacteria can also break up when disturbed.
Council officers use simple test kits for quick identification or a water sample can be taken for further analysis under the microscope.
Mobile cleaning and trade businesses
Run-off from roads, drains and gutters causes poor waterway quality and can be harmful to fish and wildlife. Mobile cleaning and trade businesses can help stop pollutants like detergents, oils and pesticides entering our stormwater system.
This information will help you if you operate:
- pet hydro bath or mobile dog washing units
- car washing
- carpet cleaning
- steam and high-pressure cleaning
- brick and paver cutting
- aggregate driveway laying
- roof cleaning or recoating.
Ways your business can help
- Where wastewater consists only of soil and organic matter (no oil or chemicals) it is suitable to dispose of waste water into a garden or grassed area.
- Wastewater containing any oil or chemicals must be collected by an appropriate regulated waste company. For permanent situations, approval from your water authority must be obtained for waste to be disposed of via the sewer system under a Trade Waste permit.
- Use sandbags or a portable bund to prevent waste water from entering drains.
- Sweep up all waste material rather than hosing down.
- Avoid using detergents, oils, pesticides or chemicals near drains, gutters and waterways.
- Work on a grassed or gravelled area away from drains, roadside gutters and waterways.
- Use a bucket to collect waste water for reuse or proper disposal.
- Store all detergents, solvents, oils or any other chemicals in a secure area.
- Collect all waste and use a licensed recycling operator or disposal facility.
- Clean up spills or leaks using dry absorbent materials such as kitty litter, rags or a bund.
- Use as little water as possible, or use trigger hoses where necessary.
- Ensure all staff are aware of their environmental responsibilities.
Under the Environmental Protection Act 1994, allowing polluted wastewater to enter stormwater drains and roadside gutters and waterways is an offence and may attract a fine to the value of 15 penalty units (individual) or 75 penalty units (corporation). See the penalty unit fact sheet for more information about penalty units.
Stormwater is not treated before entering our local creeks, rivers and waterways. Everyone has a responsibility to keep our waterways clean and healthy.
Roof cleaning and restoration
Wastewater from roof cleaning can flow directly into our creeks, rivers and waterways.
Stormwater pollution – the effects of roof cleaning
Roof and gutter downpipes connect directly to roadside gutters, stormwater drains and into our waterways. This means wastewater run-off from roof cleaning ends up in our creeks, rivers and the ocean. Pollutants, such as oxides, algae, paint flakes, concrete and sediment can kill seagrass, aquatic plants and marine life. By taking some simple precautions when cleaning and restoring roofs, you can help protect our waterways.
Allowing polluted wastewater to enter stormwater drains, roadside gutters or waterways is an offence under the Environmental Protection Act 1994 and may attract a fine to the value of 15 penalty units (individual) or 75 penalty units (corporation), or prosecution for multiple offences. See the penalty unit page for more information about penalty units.
In addition, using water blasters on asbestos cement roofs is illegal. Cleaning a fibro roof with a high pressure water blaster is illegal as it can destroy the roof surface, cause cement debris or asbestos to spray into the air, and result in widespread contamination.
Protecting the environment
We all share the responsibility of keeping our waterways clean and must ensure only clean water enters out stormwater systems. Below are some options that you could use when cleaning:
- if possible, disconnect downpipes and redirect wastewater to the garden, or to a holding tank for disposal by a licensed liquid waste disposal contractor
- if disconnecting downpipes is not possible, block the downpipe and feed the wastewater onto lawns or gardens
- hole may be drilled in the gutter or downpipe, the downpipe blocked (below the hole) and water diverted to garden beds. When complete, the hole can be plugged with a grommet
- use sandbags or a portable bund (a barrier to contain water) in the roadside gutter to protect stormwater drains from accidentals spills and runoff.
Other helpful tips
- Always keep a spill response kit, including a shovel, broom and rags, to clean-up residues nearby. Do not wash or hose remaining waste material into the stormwater drain.
- Keep cleaning times to a minimum.
- Be aware that wastewater from some houses may drain directly into a nearby waterway or subsurface stormwater pipe (not to a roadside gutter). In this case, downpipes must be disconnected and the water drained to a soakage area, such as, the garden or lawn.
- If wastewater does accidently drain to the stormwater gutter, remove all captured wastewater as soon as possible using a vacuum or bilge pump and direct to lawns or gardens, making sure no wastewater flows into the stormwater drain.
- Sandbags and portable bunds in the roadside gutter will capture accidental spills and runoff. They are not designed to hold wastewater from a full roof clean.
- For business owners, please ensure all of your staff are aware of these requirements.
Subtropical climates provide warm and sunny conditions.
These conditions can assist Trichodesmium to bloom in our waters.
Trichodesmium are cyanobacteria (blue-green algae) that appear naturally in tropical and subtropical ocean waters and are commonly known as sea sawdust, whale sperm, whale food and sea scum.
Trichodesmium is a member of the phytoplankton family, and plays an important role in the aquatic food chain.
Normally Trichodesmium are barely visible to the naked eye, but in water that has been calm for long periods it begins to float like sawdust on the surface.
Combinations of calm conditions, northerly currents and warm water temperatures can increase growth and even discolour the water.
What to look for
Blooms are most common between August and December.
You may have noticed a bloom washed up on a beach, or where a river meets the sea. There may also be an unpleasant ‘fishy’ smell. Wind and current conditions often cause large amounts of Trichodesmium to group together.
Trichodesmium blooms can cause water to appear rust-coloured but traces of grey, green and purple streaks can also be visible.
In stagnant conditions, Trichodesmium blooms can release a clear toxin that changes the blooms’ colour from rust brown to green and also releases a pigment that colours the water pink.
The concentration of the toxin in a natural system, like the ocean, is generally not high enough to be harmful to human health.
However to be certain it is best to avoid affected areas.
Blooms generally disappear in a few days.
Please remember if you have come in contact with Trichodesmium it can easily be rinsed off the skin.
Complaints and enforcement
Council only has jurisdiction to act on certain complaints, and shares the responsibility of water pollution issues with other government bodies. Please refer to the information below which outlines authorities for various water pollution types.
Acid sulfate soils
- Occurring on residential land and some commercial land - Contact Council for further clarification.
- Occurring on residential land and some commercial land - Contact Council for further clarification.
- Local road or waterway - Occurring on residential land and some commercial land - Contact Council for further clarification.
- Main road, highway or motorway - Contact your local office of the Department of Transport and Main Roads.
- Major waterway (e.g. river, broadwater, ocean, bay) - Contact your local office of Maritime Safety Queensland.
- Less than 50 fish - Contact Council for further clarification.
- 50 or more fish - Contact your local office of the Department of Environment and Heritage Protection.
Release of contaminants
- Rubbish, cement, oil, paint etc. - Contact Council for further clarification.
- Bilge water (boat) - Contact your local office of Maritime Safety Queensland.
- Soil and sediment from a building or development site – Contact Council for further clarification. In addition to responsibilities under the Environmental Protection Act 1994, property developers and contractors are subject to the Planning Act 2016. They may have conditions on their approval about sediment and erosion control.
- Soil and sediment from a State Government or Council development site – Contact the Department of Environment and Heritage Protection.
Regulation (Inspection process)
Legislation requires Council to respond to complaints received. This response will depend on the complaint history, current compliance status and the risk of the alleged offence. Actions taken by Council may include:
- sending an advisory letter and fact sheet to both the alleged offender and the complainant
- conducting an onsite investigation.
Council is legally required to enforce water pollution issues. If you have difficulty complying with the legislative requirements, contact Council for assistance or advice.
Failure to comply with requirements, may result in one or more of the following enforcement actions:
- a letter being issued requiring action or work to be conducted
- a legal notice being issued requiring action to be taken or work to be conducted
- issuing of a Penalty Infringement Notice (also known as a PIN or on-the-spot fine)