Every community, no matter how big or small or where they are located, needs to have an effective method of safely disposing of sewage to prevent environmental contamination, and to prevent people, animals and insect pests from coming into contact with human waste and spreading disease.
When untreated or inadequately treated wastewater is released into the environment it can have significant environmental, human health and socioeconomic impacts.
Domestic sewage consists of household wastewater (from sources such as bathing/showering, dishwashing, laundry, toilet flushing, etc) and human waste which can contain a wide range of chemical contaminants, as well as pathogenic microorganisms that can cause parasitic intestinal infestations and communicable diseases such as giardiasis, cholera, typhoid, dysentery and diarrhoea.
Domestic wastewater often contains a wide range of dissolved and suspended chemicals originating from detergents, as well as pharmaceuticals, cosmetics and personal care products — collectively known as ’emerging contaminants’.
In addition, many soaps and household cleaning products contain high levels of nitrogen, potassium and phosphorus, which are plant nutrients that can cause an ecological imbalance if they accumulate in the environment.
The inadequate treatment and disposal of human waste can lead to soil, groundwater and surface water bodies becoming contaminated. Inadequately treated sewage is not only unsightly, it can also be odorous.
Health Threats
According to a United Nations report, domestic wastewater can contain high levels of excreted pathogens, many of which can cause gastroenteritis. It is estimated that 1.45 million people die every year from diarrhoea, with children under the age of six being most vulnerable.
Fifty-eight per cent of these deaths are attributed to limited access to clean water and poor sanitation and hygiene.
People can become infected if they come into direct contact with untreated wastewater, or indirectly if they swim in contaminated freshwater or coastal waters, or if they consume food or drinking water that has been contaminated by wastewater.
Filter feeders such as shellfish are particularly prone to contamination and can make a person very ill if they are consumed.
Some species of fish can accumulate toxins in their tissues, which become more and more concentrated over the course of their lifetime.
Environmental impacts
In addition to the human health risk, inadequately treated wastewater can have significant ecological impacts too.
Studies have shown that pharmaceuticals released with human wastewater can disrupt the endocrine system of aquatic animals such as fish and frogs, feminising males, which upsets the ecological balance and threatens biodiversity.
Nutrient loading can strip oxygen from the water, leading to hypoxic conditions in freshwater lakes and coastal bays, known as dead zones, that cannot support life. High nutrient loads also adversely affect the ability of coral reefs to withstand or recover from coral bleaching.
An abundance of phytoplankton limits light penetration and provides a food source for the larvae of the predatory crown of thorns starfish and filter feeding organisms, allowing them to thrive to the detriment of corals. In addition, flourishing algae, stimulated by the influx of nutrients, can outcompete and smother coral, inhibiting its ability to grow or recover.
Socioeconomic impacts
A reduction in biodiversity in both freshwater and marine ecosystems can adversely affect commercial fisheries, which in turn can lead to loss of income or job losses.
Artisan and subsistence fisheries may also be affected, resulting in the loss of a staple food source for communities that rely on seafood as their main source of protein.
Degradation of habitat, such as coral reefs and freshwater lakes, that support recreational activities can lead to a drop in tourism, resulting in economic losses as well as job losses in both the tourism sector and industries/businesses that support these activities.
Sewage treatment options for remote locations
Due to the lack of infrastructure at remote locations, sewage is usually treated on-site. Commonly used on-site sewage treatment options include composting toilets and septic tanks.
However, because sludge removal is not available at remote locations, disposal remains a problem.
Typically, a septic tank system with a soak pit is employed, but contaminants can still leach through soils to pollute groundwater and freshwater bodies, and ultimately coastal waters. A more efficient solution is required, particularly in areas that are ecologically sensitive.
One such solution is a pre-fabricated, on-site, turn-key sewage treatment system.
The Hydroflux Epco RoadTrain® is a self-contained sewage treatment plant that is specifically designed for use in remote locations. These plug and play micro sewage treatment plants are available in a variety of capacities and process options.
While sewage treatment may not be a top priority in sparsely populated areas, it shouldn’t be overlooked.
The risk of groundwater contamination is the same as anywhere else, and the environmental, health and socioeconomic impacts may be much higher.
Hydroflux Epco, a member of the Hydroflux Group, is a water and wastewater business with over 1000 references dating back to 1961.
This partner content is brought to you by the Hydroflux Group. For more information, visit www.hydroflux.com.au
