When Water Stops Working: Rebuilding Biological Function in Ponds, Dams, Waterways and Wastewater
A farm dam turns green. A council pond develops a skin of algae. A stormwater basin begins to smell. Black sludge builds on the bottom of a waterway. An ornamental lake that once looked clear becomes cloudy and stagnant. A wastewater pond starts producing complaints from everyone living downwind.
Usually we attack what we can see.
Kill the algae. Dredge the sludge. Add another chemical. Aerate harder. Spray the weeds. Mask the smell.
But the smell, algae and sludge are often not the original problem. They are signs that the biological processing of nutrients and organic matter is no longer keeping pace with what is entering the system.
Waterways have a workforce too.
Bacteria, fungi, algae, aquatic plants and organisms living around roots and sediments are constantly transforming carbon, nitrogen, phosphorus and organic wastes. Modern constructed wetlands deliberately harness these processes to treat polluted water.
Research now describes microbial activity as one of the central mechanisms responsible for nitrogen transformation, organic matter breakdown and contaminant removal in wetland treatment systems.
Earthfood® approaches troubled water from that direction.
We ask what biological functions have been lost, overwhelmed or disrupted, then look at how those functions can be rebuilt.
Why does a pond suddenly go green?
Algae need nutrients.
Nitrogen and phosphorus enter waterways from fertilisers, soil movement, animal manure, wastewater, grass clippings, decaying vegetation, urban runoff, industry and many other sources.
Australian Government water information recognises excessive nitrogen and phosphorus as important contributors to algal blooms and eutrophication when the physical conditions are favourable.
Then the cycle can feed itself.
Vegetation and algae grow, die and settle. Organic matter accumulates. Microorganisms consume oxygen while breaking it down. Sediments build. Low oxygen conditions change the chemistry occurring at the sediment and water interface. More nutrients can become available for another round of growth.
The answer is therefore not always another algae killer.
Sometimes we need to change who is processing the nutrients and where those nutrients are going.
This is exactly why functioning wetlands are so effective. Plants provide roots, surfaces and carbon compounds. Microorganisms colonise those environments and perform enormous amounts of nutrient transformation.
Modern reviews of constructed wetlands report substantial removal of organic matter, nitrogen and phosphorus through combinations of physical, chemical and biological processes.
Earthfood brings us into that biological part of the conversation.
What Earthfood can do around ponds, dams and waterways
Earthfood contains living functional microorganisms selected for their capacity to work in biological systems.
Used appropriately around a pond, dam, treatment wetland or waterway, the objective is not to sterilise the water. Quite the opposite.
We want biological activity working again.
That can mean improving the processing of accumulated organic material, supporting nutrient cycling around sediments and plant roots, strengthening the microbial communities associated with aquatic vegetation and directing more of the available nutrient load through productive biological pathways rather than leaving an excess available to drive nuisance blooms.
Plants matter here too. Aquatic and wetland vegetation take up nutrients and create enormous root surfaces where microbial communities establish.
Research into constructed wetlands repeatedly shows that the relationship between plants, substrates and microorganisms is central to treatment performance.
It is not simply a case of plants eating the nutrients. In many treatment wetlands, microorganisms perform a major share of the nitrogen transformation work.
That distinction matters because Earthfood is not an aquatic fertiliser.
We are interested in the workforce.
For the homesteader, small farmer or property owner
That ugly green dam at the bottom of the paddock may be telling you something about the entire catchment feeding it.
What runs into it after rain? Fertiliser? Manure? Organic debris? Soil? Septic seepage? Nutrient-rich garden runoff?
What is sitting on the bottom? How deep is the sludge?
Does the water smell when it turns over?
Are aquatic plants growing, or has one species taken over?
Does the problem explode during warm weather?
Before reaching for something designed simply to kill the visible algae, look at what is feeding it.
For a domestic pond, farm dam, billabong, large water feature or constructed wetland, Earthfood may form part of a biological restoration approach that includes controlling the nutrient source, restoring suitable plants, improving circulation or oxygen where needed and rebuilding microbial activity.
The goal is not a chemically empty body of water.
The goal is a water system capable of processing what enters it.
Now scale that thinking up to a council
Across Australian towns and cities are thousands of stormwater detention basins, constructed wetlands, ornamental lakes, park ponds and urban waterways receiving runoff from roads, gardens, sporting fields, shopping centres and industrial estates.
Queensland's own stormwater framework recognises grassed swales, bioretention basins and constructed wetlands as part of the treatment train used to reduce suspended solids, phosphorus and nitrogen from developed urban areas.
But these systems themselves can deteriorate.
Sediment accumulates. Organic loading increases. Water movement changes. Plants disappear or become dominated by inappropriate species. Anaerobic zones develop. Algae arrive. Odour follows.
Eventually a piece of water infrastructure that was supposed to treat pollution becomes another maintenance problem.
This is where I believe biological augmentation deserves much more attention.
A 2026 review of microbial remediation in constructed wetlands found that microorganisms are a core pollutant-removal mechanism and reported that microbial bioaugmentation improved pollutant removal in reviewed studies, although performance varied and successful establishment of introduced organisms remains an important challenge.
That qualification matters.
You cannot pour biology into any body of water and expect miracles.
Temperature, oxygen, pH, contaminant load, hydraulic retention time, plants, sediment, carbon sources and the existing microbial community all influence what happens next.
That is why a council, industrial estate or large property should not begin with a truckload of product.
It should begin with a site. Measure it. Understand it. Treat an area. Keep a comparison area where possible. Measure again.
That is how we turn biological restoration from a good idea into evidence.
Industrial estates may be one of the most interesting applications
An industrial estate can concentrate everything we do not want moving directly into a creek.
Hydrocarbons from parking areas and workshops. Nutrients from landscaped areas. Sediment from construction. Organic waste. Metals. Detergents. Various chemicals carried by stormwater.
The detention pond or constructed wetland at the end of that catchment becomes the receiving point.
Some contaminants can be biologically transformed. Others can be immobilised, adsorbed, accumulated in biomass or captured in sediments. Others should never be treated as though microbes alone are the answer.
That distinction is essential.
Microbial bioremediation of hydrocarbon contamination, for example, is a well-established field because particular bacteria and fungi can use petroleum hydrocarbons as carbon and energy sources.
Research also shows why field performance depends heavily on having the right organisms and environmental conditions.
Earthfood's opportunity here is not to claim that one standard bottle magically removes every industrial contaminant.
It is to build biological function into a properly designed treatment system and, when a particular contamination problem demands it, develop or add task-specific biological capability following assessment. Our microbes are carnivorous and nitrifying - they do the heaving lifting of change work. And not necesarily in the water - it can be beside the waterways where changes to the landscape need oxygen, aeration, exhumation of pathegons and toxic nano particles of metals and chemistry. That is their job.
That is a very different proposition.
And then there is smell
Anyone who has lived near a failing sewage system knows that water can announce a biological problem long before anyone sees it.
Many offensive wastewater odours arise when organic matter is being processed under anaerobic conditions. Hydrogen sulphide, the familiar rotten-egg smell, is one of the major compounds associated with sewage and wastewater odour. NSW EPA guidance identifies anaerobic decomposition as an important source of treatment-plant odours, while current research recognises biological treatment as one of several effective approaches to odour control.
Microorganisms are already widely used industrially to remove odorous compounds. EPA Victoria, for example, describes biofilters, bio-scrubbers and bio-trickling filters as living treatment systems in which microorganisms break down pollutants and odorous compounds.
That opens a serious area for Earthfood investigation.
Sewer pump stations, rising mains, public amenities, wastewater holding ponds and organic processing systems can develop microbial communities dominated by processes producing offensive compounds.
The biological question becomes whether conditions can be shifted toward organisms and pathways that process those organic materials differently.
Earthfood can be assessed as part of that treatment strategy, particularly at the source where organic loading and odour generation begin.
For commercial wastewater systems, however, this must be measured. Biochemical oxygen demand, chemical oxygen demand, suspended solids, dissolved oxygen, pH, nutrients, sludge volume and relevant odour compounds give us something far more useful than somebody standing beside a pond saying, “It smells better.”
Could biology also reduce sludge?
Potentially, and this is another area worth properly trialling.
Sludge is partly the accumulated result of suspended solids, microbial biomass and organic material that has not been completely broken down.
If biological treatment increases the conversion of biodegradable organic matter before final settling, there is a reasonable basis for investigating whether sludge production, settling characteristics or dewatering behaviour can be improved.
But this is exactly where Earthfood needs numbers.
Before treatment: sludge depth, settled sludge volume, dry solids, organic fraction, BOD and COD.
After treatment: measure them again.
Then we know.
For councils and wastewater operators, a documented reduction in sludge generation or removal frequency could have enormous commercial value because sludge handling, transport, dewatering and disposal all cost money.
Mining and heavily contaminated water are another category again
Mine water, acid and metalliferous drainage, hydrocarbon contamination and tailings require site-specific amended soil biology. - that is Earthfood's job again.
Our standard Earthfood biological system may help establish broader nutrient cycling, carbon processing, rhizosphere function and soil development around rehabilitation areas. More difficult contamination can require specialised organisms and carefully designed conditions. We amend ours to do the work required for the remediaiton.
Hydrocarbon degraders may be used where diesel and petroleum contamination are present. Sulfate-reducing microbial systems can have applications in acid and metalliferous drainage. Other organisms may be selected for metal transformation, immobilisation, mineral weathering or highly saline and alkaline environments.
That is bioremediation, not magic.
And it is exactly why Earthfood is developing its environmental remediation capability around characterisation, specialist biological design, controlled trials, monitoring and validation rather than simply selling drums.
Water should not have to be chemically beaten into submission
There is a bigger idea here.
We have become very good at responding to ecological breakdown by adding another treatment.
Sometimes treatment is essential. Some pollutants must be physically removed. Some toxic discharges must be contained. Some waterways require dredging, aeration, engineering or chemical intervention.
But there is another question we should be asking much earlier:
What biological work has stopped happening here?
Because a pond is not simply a hole containing water. A wetland is not landscaping. A sewage lagoon is not merely a tank without a roof. They are biological processing systems.
When that processing system fails, we see the consequences as algae, odour, sludge, nutrient accumulation, oxygen depletion and contaminated water leaving one place to become somebody else's problem.
Earthfood's role is to put biology back into that discussion.
For the homesteader, that might begin with a dam.
For a farmer, it could begin with a runoff pond or constructed wetland.
For a council, it might be a suburban lake that turns green every summer.
For an industrial park, it could be the stormwater basin receiving everything that washes off the estate.
For a wastewater operator, it may begin at the pump station that neighbours can smell before they can see it.
And for a mine, the work may continue for decades after extraction has stopped.
Different water. Different problem. Different treatment design. But the same starting question.
What living functions are missing, and can we put them back to work?
That is a question worth testing. And Earthfood intends to.
Note Earthfood has been used on end of life mining sites, an industrial park waterway in Logan Council region of southern Brisbane, large industrial grade plantations of monsoonal rains and rotting water in the humidity of PNG.
Bronwyn Holm, Founder, Earthfood®
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