2015/16 – Quilpie (Queensland) – Fluoride, pH, Sodium

2015/16 – Quilpie – Fluoride
2009/15: Quilpie (Queensland) – Fluoride 1.9mg/L (highest detection)
2015/16: Quilpie (Queensland) – Fluoride 1.8mg/L (highest detection)
“Quilpie water quality does not meet the Australian Drinking Water Guidelines due to naturally
occurring high levels of fluoride.”
“Continued monitoring of Quilpie’s water supply have revealed naturally occurring Fluoride in
concentrations that exceed of ADWG, with an average value of 1.75mg/l. Ongoing exposure to
high fluoride levels in drinking water have the potential to cause adverse health impacts. The
effects of fluoride concentrations found in Quilpie’s Drinking water supply include dental fluorosis which has the potential to stain developing teeth in infants. A more serious impact on health caused by high Fluoride levels includes skeletal fluorosis which only occurs in very high levels of fluoride in drinking water, above those levels experienced in Quilpie. Ongoing monitoring of Fluoride in Quilpie’s drinking water supply is one of the highest priorities relating to water quality, close monitoring of these levels will allow the detection of increased health risk in the future….”

Based on health considerations, the concentration of fluoride in drinking water should not exceed 1.5 mg/L.

“Fluoride occurs naturally in seawater (1.4 mg/L), soil (up to 300 parts per million) and air (from volcanic gases and industrial pollution). Naturally occurring fluoride concentrations in drinking water depend on the type of soil and rock through which the water drains. Generally, concentrations in surface water are relatively low (<0.1–0.5 mg/L), while water from deeper wells may have quite high concentrations (1–10 mg/L) if the rock formations are fluoride-rich.” 2011 ADWG.

2015/16 – Quilpie – pH (alkaline)
2015/16: Quilpie (Queensland) – pH 9.31 (highest detection)


Based on the need to reduce corrosion and encrustation in pipes and fittings, the pH of
drinking water should be between 6.5 and 8.5.

New concrete tanks and cement-mortar lined pipes can significantly increase pH and
a value up to 9.2 may be tolerated, provided monitoring indicates no deterioration in
microbiological quality.

pH is a measure of the hydrogen ion concentration of water. It is measured on a logarithmic scale from 0 to 14. A pH of 7 is neutral, greater than 7 is alkaline, and less than 7 is acidic.

One of the major objectives in controlling pH is to minimise corrosion and encrustation in pipes and fittings. Corrosion can be reduced by the formation of a protective layer of calcium carbonate on the inside of the pipe or fitting, and the formation of this layer is affected by pH, temperature, the availability of calcium (hardness) and carbon dioxide. If the water is too alkaline (above pH 8.5), the rapid deposition and build-up of calcium carbonate that can result may eventually block the pipe.

2015/16 – Quilpie – Sodium

2009/15: Quilpie (Queensland) – Sodium 209mg/L (highest detection) Sodium 201mg/L (average detection)

“The concentrations of sodium in Quilpie’s Drinking water supply are consistently above ADWG
aesthetic thresholds, the presence of sodium in water supplies is common in ground water due to the high solubility of sodium salts and the abundance of mineral deposits. The concentrations of sodium in Quilpie’s drinking water supply do not pose a great risk to human health however may be of concern to people suffering from severe hypertension. The concentrations present in the water supply may have an effect on the taste of the water where ADWG advise that taste becomes appreciable at 180mg/l.”
“Based on aesthetic considerations (taste), the concentration of sodium in drinking water
should not exceed 180 mg/L….The sodium ion is widespread in water due to the high solubility of sodium salts and the abundance of mineral deposits. Near coastal areas, windborne sea spray can make an important contribution either by fallout onto land surfaces where it can drain to drinking water sources, or from washout by rain. Apart from saline intrusion and natural contamination, water treatment chemicals, domestic water softeners and
sewage effluent can contribute to the sodium content of drinking water.” ADWG 2011