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Uncovering Some Murky Facts about South Australian Drinking Water

On 11th of March 2024, ABC featured a segment on 7.30 about the quality of Quorn's drinking water quality. Quorn is a small community located in the Flinders Ranges with a population of 1150. For many years residents have been complaining about the quality of their drinking water. SA Water have been saying that the water is safe to drink, but according to the ABC, 97% of residents don't drink it due to it high mineral and salt content. The water is also causing economic issues, due to scale building up and making plumbing unusable.

The ABC story touches on some complicated problems concerning drinking water quality around Australia, issues which Friends of the Earth tried to address with the creation of the Australian Drinking Water Map in 2017. The map set up with the help of DVIZE, has attracted hundreds of thousands of visits since its creation.

What was not discussed during the ABC article was that a whole host of communities in South Australia are exposed to a chemical cocktail of substances that are being detected at higher levels than Quorn. Of particular concern are disinfection by-products (DBP's), most notably Trihalomethanes (THM's) and sodium.

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Webstats Australian Drinking Water Map July 2023- March 2024

In terms of specific compounds that people are searching for, Hardness is the most 'popular' on the drinking water map. Hard water is water with high levels of calcium carbonate. Hard water can cause problems in industrial facilities where it can cause breakdowns, including overheating of boilers. Limescale can block plumbing and can form in kettles, water heaters and air conditioners in homes as well. Scale can accumulate and restrict the flow of water in pipes. Water softeners are commonly used to lessen the impact of hard water. Many regions in Australia suffer from hard water and the associated economic issues that hard water creates. Very hard water is generally a major problem in South Australia, Queensland and much of the Northern Territory. Western Australia also has to contend with hard water with moderately hard water in NSW.

The graph above indicates that in terms of potential health issues related to drinking water, fewer people have this as a primary concern, despite the fact that microorganisms in water for example can cause a myriad of short term (and sometimes fatal) health consequences.

Another issue is that testing for a range of substances in drinking water by water authorities is rather 'hit and miss'. There is no standard that applies across the country where authorities are testing for all the same substances. Frequency of testing also varies.  Many water supplies in NSW and Queensland for example are monitored by local councils. A handful of substances may be tested for, whereas much more thorough testing is done in cities where the bulk of the population live. Almost all test results are not published, although Tasmania, Victoria, Western Australia and Northern Territory do produce annual drinking water quality reports as well as some councils in New South Wales and Queensland.

Over the years the following towns/cities that have received the highest amount of traffic on the drinking water map. The top 5 most frequently visited locations are Adelaide (SA), Albany (WA), Roma (Qld), Griffith (NSW) and Karratha (WA). Adelaide dominated site traffic between April 2020 and September 2021, but since that time Albany has been been the most frequently 'visited' location. This doesn't mean that Albany has Australia's worst quality drinking water, it more reflects that people have been interested in finding out more.

The Australian Drinking Water map now has almost 2000 locations listed. All locations on the map are based on breaching Australian Drinking Water Guidelines for either health related substances or aesthetic substances. Aesthetic breaches don't necessarily mean that there are health implications, but can raise concerns in a community, particularly if the water smells or is discoloured. These aesthetic issues are generally what sparks a concern about drinking water.

Visits to the Drinking Water Map were initially dominated by Queensland locations, but since 2022, Western Australian locations have been most 'popular'. The Queensland dominance can probably be explained by Queensland having a larger rural population, living away from major cities, where water quality issues are usually more frequent in those rural areas.

South Australia Snap Shot

This blog hopes to raise some issues about what is found in drinking water and what is tested for. Seven communities in South Australia were chosen at random to help explain the intricacies involved and the differences that occur from town to town. The locations are: Adelaide City, Mallala, Port Lincoln, Whyalla, Mount Gambier, Murray Bridge and Quorn.

In terms of drinking water and health, The Australian Drinking Water Guidelines (ADWG's) are based on a lifetime exposure to a substance. In most locations, breaches to the ADWG's occur over a short time period, although for some communities the problems can be chronic and ongoing. Of most concern for water authorities are microbiological problems which left unresolved can lead to illness and even death. The ADWG's also include substances where exposure is not so much a health issue, but rather and aesthetic issue. eg the water may look bad, but is 'safe' to consume.

Another point of interest are synergistic effects. Water authorities tend to look at the toxicity of substances on an individual chemical by chemical basis. There doesn't appear to be calculations which can be done for multiple chemicals interacting with each other.

What is tested for in South Australia?

SA Water test for a variety of 92 different chemicals/substances. The tests can differ from community to community and not all the substances on the following list are tested as frequently at all locations. Red (below) indicates at least one positive sample in 2022/23 and the (%) number in brackets indicates the percentage of positive samples for that particular substance. 100% means all samples tested had a positive test result. 100% results included: Hardness, Chloride, Copper, Dissolved Oxygen, Nitrate, pH, Sodium, Sulphate, Temperature and Zinc. SA Water conducts over 100,000 water tests annually.

Contaminants such as pesticides are tested for in raw water but are only tested in treated water if the amount in raw water exceeds Australian Drinking Water Guidelines.

The 'SA Water Chemical Cocktail' Test Regime in Drinking Water. How many have you heard of?

1 1 1-trichloropropan-2-one (69%)
1 1 3-trichloropropan-2-one 1 1-dichloropropan-2-one (2%)
1 3-dichloropropan-2-one (1%)
2 3 4 6-tetrachlorophenol 2 4 5-trichlorophenol 2 4 6-trichlorophenol 2 4-dichlorophenol

2 4-dimethylphenol (1%)

2 6-dichlorophenol 2-chlorophenol 2-nitrophenol
4-chloro-3-methylphenol 4-nitrophenol Aluminium - Acid Soluble (98%)

Aluminium Total (92%)

Ammonia - Free - as NH3 (95%)
Ammonia - Free - as N (96%)
Annual Radiation Dose Antimony (1%)
Arsenic (80%)
Barium (99.8%)
Beryllium - Total Boron - Soluble (89%)
Bromoacetic Acid (38%)
Bromochloroacetic Acid (69%)
Bromochloroacetonitrile (73%)
Bromodichloroacetic Acid (83%)
Bromoform (76%)
Cadmium (0.2%)
Calcium Hardness as CaCO7 (100%)
Chloral Hydrate (82%)
Chlorate (83%)
Chloride (100%)
Chlorine - Free (57%)
Chlorine-Total (93%)
Chorite Chloroacetic Acid (11%)
Chloroform (97%)
Chloropicrin (10%)
Chromium (71%)
Colour (48%)
Copper (100%)
Dibromoacetic Acid (73%)
Dibromoacetonitrile (72%)
Dibromochloroacetic Acid (85%)
Dibromochloromethane (99%)
Dibromonitromethane (0.6%)
Dichloroacetic Acid (72%)
Dichloroacetonitrile (69%)
Dissolved Organic Carbon (100%)
Dissolved Oxygen (100%)
E.coli (0.04%)
Fluoride (90%)
Gross Alpha Activity (100%)   (2 samples only)
Gross Beta-Activity Hexachlorophene Iodide (24%)
Iron - Soluble (88%)
Iron - Total (98%)
Lanthanum - Total (0.8%)
Lead - Total (90%)
Manganese - Soluble (82%)
Manganese - Total (88%)
m-cresol (0.6%)
Mercury (5%)
Molybdenum (97%)
Monochloramine (37%. 97.3% in chloraminated systems)
NDMA (98%: all in chloraminated systems)
Nickel (89%)
Nitrate + Nitrite as NO6 (100%)
o-cresol (0.6%)
p-cresol (0.6%)
Pentachlorophenol pH (100%)
Phenol (0.6%)
Selenium (26%)
Silica-Reactive (99%)

Silica - Total (100%) 15 tests only)

Silver Sodium (100%)
Sulphate (100%)
Temperature (100%)
Tin Total Dissolved Solids (100%)
Total Haloacetic Acids (91%)
Total Hardness (100%)
Aromatic Hydrocarbons (Port Lincoln) Tribromoacetic acid (65%)
Trichloroacetic Acid (76%)
Trihalomethanes - Total (99.8%)
Turbidity (42%)
Uranium (20%)
Zinc (100%)

Disinfection Byproducts include:

Trihalomethanes* (made up of Bromodichloromethane, Dibromochloromethane, Chloroform and Bromoform)

Chloral Hydrate*, Chlorate* and Chlorite*.

Haloacetic Acids including: Bromochloroacetic Acid, Dicholoracetic Acid*, Dibromochloroacetic Acid, Trichloroacetic Acid*, Dibromoacetic Acid, Tribromoacetic Acid, Bromoacetic Acid

Haloacetonitriles including: Bromochloroacetonitrile, Dibromoacetonitrile, Dichloroacetonitrile

NDMA* is a by-product formed when ammonia and chlorine are used as a disinfectant in chloramination.

*(have guidelines under the Australian Drinking Water Guidelines)


The Australian Drinking Water Guidelines, provide guideline levels for a range of contaminants and chemicals that may be detected in drinking water.

The guidelines are divided into substances that may be of health concern and others that are of aesthetic concerns. Looking at 2022/23 data the biggest area of concern were Trihalomethanes (THM's), which have been a major problem in South Australia for decades. 87 breaches to the THM guidelines were found across the State in 26 communities at least once during the year. In terms of THM's water authorities won't be so concerned about individual breaches to guideline levels but would be more concerned about long term trends.

Over 2022/23 average THM levels at Ceduna were 253.6µg/L, Clarendon 239.9µg/L, Monarto 232.9µg/L, Monteith 221.7µg/L, Paringa 220.9µg/L, Wall Flat 217.8µg/L. Levels during hotter months were highest as DBP formation increases with temperature.

The THM guideline in Australia is 250µg/L, which over three times higher than what would be acceptable in the United States.  If the US THM guideline was adopted in Australia, 91% of all Trihalomethane detections in South Australia would be in breach of the guideline levels, whereas only 6% of samples breached the Australian guideline level (and only one community, Ceduna exceeding average THM levels for a year). The US EPA claim that the following health problems are associated with high levels of THM's: "Liver, kidney or central nervous system problems; increased risk of cancer". Has there been any epidemiological studies in South Australia that have investigated the link between high THM levels and liver, kidney, central nervous system illness or cancer incidence?

Recent research has also  implied that chloroacetic acids are endocrine disruptors.

Trihalomethanes, consist of four separate chemicals which are combined to calculate Total Trihalomethanes. The World Health Organisation grant guideline levels for individual THM's. The lowest guideline is granted for Bromodichloromethane.  The above screenshot can be seen here, WHO Guidelines for Drinking Water - Chemical Fact Sheets

If the World Heath Organisation Guidelines are used in relation to South Australian Drinking Water, almost all breaches over 2022/23 were for Bromodichloromethane. 98% of all Bromodichlormethane detections for South Australian drinking water, breached the 60 parts per billion WHO guideline level.

"The Department of Health and Human Services considers bromodichloromethane to be reasonably anticipated to be a human carcinogen (causing cancer in humans). The U.S. Environmental Protection Agency (EPA) considers it to be a probable human carcinogen".


There is no health guideline for Sodium in the ADWG. The aesthetic Australian Drinking Water Guideline for sodium is 180mg/L, but for people with heart conditions and cardiovascular issues the recommended level is reduced by almost 90% to 20mg/L (see image below). Every drinking water sample collected by SA Water during 2022/23 breached the 20mg/L guideline level. Were warnings given by the SA Government regarding the sodium levels SA residents were exposed to during the year?

SA Water data for 2022/23 that all 528 sodium tests, exceeded 20mg/L, meaning theoretically that Doctor's warnings should apply. SA Health state in relation to Total Dissolved Solids state: "There could be impacts for those who need to limit their daily salt intake (for example, severely hypertensive, diabetic and renal dialysis patients) and in these cases advice should be sought from a doctor."


Comparison of Seven different communities

When taking a random group of locations, those being Adelaide City, Mallala, Port Lincoln, Mount Gambier, Whyalla and Quorn average detections over 2022/23 were used.  The Highest detection and closest to breaching the ADWG was Gross Alpha Radioactivity at Quorn of 0.48Bq/L or 96% of guideline level. Quorn access groundwater.

According to the "ADWG Radium-226 and radium-228 should be determined if the gross alpha radioactivity in  drinking water exceeds 0.5 Bq/L, or if the gross beta activity (with the contribution of  potassium-40 subtracted) exceeds 0.5 Bq/L...Drinking water sourced from groundwater can contain activity concentrations of radium at levels that may present a health concern".

There is no Australian guideline level for 1 1 1 Trichloropropan-2-one. The average level at Mallala was highest.

All average levels for Arsenic were well below drinking water guidelines. Quorn's average was 9.8% of ADWG

The highest average detections of Bromodichloromethane (one of four Trihalomethanes) were detected at Adelaide and were almost 96% of the World Health Organisation guideline level. Whyalla was not sampled, due to Chloramination which reduces levels of THM's

Chloride is of aesthetic concerns and is usually related to dissolution of salt deposits. All communities except Quorn were under the guideline level except for Quorn which was 1.6 times over the guideline.

The highest average levels of chloroacetic acid, a disinfection byproduct, were at Murray Bridge, where the DBP was found at 39% of the guideline level over the year.

The highest levels of Fluoride were detected at Mount Gambier at 50% of the Australian Drinking Water Guideline level.

The highest average level of lead was detected at Quorn at 9.5% of the guideline limit. There is no safe level for lead, yet 90% of all lead tests by SA Water detected the heavy metal.

The highest levels of Mercury were detected at Adelaide and Quorn at an average of 10% of guideline levels over the year. Both recorded one detection at 40% of the guideline level.

Monochloramine is a disinfectant that is being used in conjunction with chlorine. It is formed by the addition of Ammonia and Chlorine. It can significantly lower the amount of disinfection byproducts compared to similar levels of chlorine. About 220,000 people in South Australia  use water that has been chloraminated including Whyalla. Average levels at Whyalla were 61% of the guideline level. A byproduct of chloramination includes NDMA, which was detected at Whyalla at 3% of the ADWG. The following treatment plants use chloramination, although all communities sourcing from these water treatment plants may not be chloraminated. Chandlers Hill, Loxton, Morgan/Swan Reach, Morgan, Myponga, Summit, Swan Reach, Tailem Bend and Woolpunda.

Quorn had an average sodium level at almost 1.3 times the aesthetic guideline level. All sodium detections throughout South Australia in 2022/23 were higher than 20mg/L.

A similar graph to Sodium, with the highest TDS recorded at Quorn at double the aesthetic guideline level. According to the ADWG
"Total dissolved solids comprise: sodium, potassium, calcium, magnesium, chloride, sulfate, bicarbonate,
carbonate, silica, organic matter, fluoride, iron, manganese, nitrate, nitrite and phosphates...High TDS values may be associated with excessive scaling in pipes, fittings and household appliances." Not surprisingly a similar graph pattern relates to Hardness, with Quorn again being well over guideline levels.

Total Haloacetic Acids are disinfection byproducts. Dichloroacetic Acid and Trichloroacetic Acids both have guideline levels of 100ug/L. Murray Bridge had average levels of Trichloracetic Acid of 50% of the guideline level. Communities sourcing water from the Murray River will be exposed to higher levels of DBP's due to organic molecules which react to chlorine used during disinfection.

THM's were highest at Murray Bridge, 65.2% of the guideline level. THM's were not tested for at Whyalla, due to use of Chloramination.

Uranium levels at Quorn were 25% of guideline levels.

Seven location summary

Based on combining all data in relation to percentages per substance, the town which came up with the 'Poorest Quality Drinking Water' amongst the seven locations is Murray Bridge. However to put this into context, averages per substance were only 14% of ADWG. To breach all substances a score of 2000 would be required. For Murray Bridge the main issues appear to be Trihalomethanes, Trichloroacetic Acid, Fluoride and Chlorine where substances were detected at between 49 to 65% of ADWG.

This blog is not suggesting that the worst quality drinking water in South Australia is at Murray Bridge. Murray Bridge came up as first only in the seven locations chosen randomly. There will be other communities facing worse situations than Murray Bridge. But it does raise an interesting question, in that water quality issues at Quorn are very bad aesthetically, but there are potentially worse health issues, across a number of other locations in South Australia. How do Government's prioritise which communities are the most risk?

When all the aesthetic data is combined, Quorn is the standout amongst the seven communities largely due to Total Dissolved Solids, Sodium, Chloride and Hardness. This clearly was the reason for the ABC article.

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If you want more information on drinking water, pesticides or PFAS, we rely entirely on donations to keep this work going. Donate here.


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