Drinking Water Report

Why is this a potential issue?

Where alum is used as a coagulant in water treatment, post-flocculation effects can occur if the soluble aluminium concentration in drinking water exceeds 0.2 mg/L. Depending on pH, a whitish gelatinous precipitate of aluminium hydroxide can be formed in the distribution system which may result in customer complaints about ‘milky coloured’ water. There is public concern over the possible health effects of aluminium, however, no health-based guideline is set for aluminium. Intake of aluminium from food and beverages is approximately 5–7 mg/day. Drinking water contributes less than 2% of the total daily intake. Exceedances of the aesthetic threshold of aluminium occasional occur in the region.

What can be done?

Aluminium concentrations in drinking water can be reduced using the conventional water treatment practices of flocculation and filtration. A well-operated water filtration plant (even using aluminium as a flocculant) can achieve aluminium concentrations in the finished water of less than 0.1 mg/L.

Why is this a potential issue?

What can be done?

Why is this a potential issue?

The level of iron in drinking water is generally an aesthetic issue as elevated levels affect the taste of the water and can cause precipitation of iron from solution. The concentration of iron in drinking water should not exceed 0.3 mg/L. No health-based guideline value has been set for iron. Exceedances of the aesthetic threshold for iron occasional occur in the region.

What can be done?

Iron salts can be effectively removed by the standard water treatment processes of coagulation followed by filtration. Groundwater supplies with a high iron content can be treated to form iron precipitates using aeration, oxidation with chlorine, pH adjustment or lime softening.

Why is this a potential issue?

The level of manganese in drinking water is generally an aesthetic issue as elevated levels affect the taste of the water. Based on aesthetic considerations, the concentration of manganese in drinking water should not exceed 0.1 mg/L, measured at the customer’s tap. At concentrations exceeding 0.1 mg/L, manganese imparts an undesirable taste to water and stains plumbing fixtures and laundry. Even at concentrations of 0.02 mg/L, manganese will form a coating on pipes that can slough off as a black ooze. Manganese would not be a health consideration unless the concentration exceeded 0.5 mg/L. Exceedances of the aesthetic threshold occasionally occur in the region.

What can be done?

Manganese concentrations in drinking water can be lowered by converting soluble forms to insoluble precipitates, followed by filtration.

Why is this a potential issue?

The total hardness of drinking water is an issue as elevated levels cause a build-up of scale in hot water systems and hard water requires more soap than soft water to obtain a lather. Hardness is caused primarily by the presence of calcium and magnesium ions. Public acceptance of hardness can vary considerably among communities and is generally related to the hardness that the consumer has come to expect, which in turn is due to the source of the water.

What can be done?

Hardness can be readily reduced by treatment, for example using lime softening; however, this is rarely practised for Australian drinking water.

Why is this a potential issue?

Turbidity is a measure of the light-scattering property of water caused by the presence of fine suspended matter such as clay, silt, plankton and other microscopic organisms. The turbidity of drinking water can be used as a measure of the efficiency of the filtration and disinfection processes of water treatment and is also an aesthetic issue to consumers. Based on aesthetic considerations, the turbidity should not exceed 5 NTU at the consumer’s tap. Exceedances of this level of turbidity occasionally occur in the region giving drinking water a cloudy or muddy appearance. These exceedances have not been a health concern.

What can be done?

Turbidity has an impact on the aesthetic acceptability of water. Many consumers relate the appearance of water to its safety, and turbid or coloured water is interpreted as being unsafe to drink. Councils attempt to maintain turbidity as low as possible to the point of supply to customers.

Why is this a potential issue?

Where alum is used as a coagulant in water treatment, post-flocculation effects can occur if the soluble aluminium concentration in drinking water exceeds 0.2 mg/L. Depending on pH, a whitish gelatinous precipitate of aluminium hydroxide can be formed in the distribution system which may result in customer complaints about ‘milky coloured’ water. There is public concern over the possible health effects of aluminium, however, no health-based guideline is set for aluminium. Intake of aluminium from food and beverages is approximately 5–7 mg/day. Drinking water contributes less than 2% of the total daily intake. Exceedances of the aesthetic threshold of aluminium occasional occur in the region.

What can be done?

Aluminium concentrations in drinking water can be reduced using the conventional water treatment practices of flocculation and filtration. A well-operated water filtration plant (even using aluminium as a flocculant) can achieve aluminium concentrations in the finished water of less than 0.1 mg/L.

Why is this a potential issue?

What can be done?

Why is this a potential issue?

The level of iron in drinking water is generally an aesthetic issue as elevated levels affect the taste of the water and can cause precipitation of iron from solution. The concentration of iron in drinking water should not exceed 0.3 mg/L. No health-based guideline value has been set for iron. Exceedances of the aesthetic threshold for iron occasional occur in the region.

What can be done?

Iron salts can be effectively removed by the standard water treatment processes of coagulation followed by filtration. Groundwater supplies with a high iron content can be treated to form iron precipitates using aeration, oxidation with chlorine, pH adjustment or lime softening.

Why is this a potential issue?

The level of manganese in drinking water is generally an aesthetic issue as elevated levels affect the taste of the water. Based on aesthetic considerations, the concentration of manganese in drinking water should not exceed 0.1 mg/L, measured at the customer’s tap. At concentrations exceeding 0.1 mg/L, manganese imparts an undesirable taste to water and stains plumbing fixtures and laundry. Even at concentrations of 0.02 mg/L, manganese will form a coating on pipes that can slough off as a black ooze. Manganese would not be a health consideration unless the concentration exceeded 0.5 mg/L. Exceedances of the aesthetic threshold occasionally occur in the region.

What can be done?

Manganese concentrations in drinking water can be lowered by converting soluble forms to insoluble precipitates, followed by filtration.

Why is this a potential issue?

The total hardness of drinking water is an issue as elevated levels cause a build-up of scale in hot water systems and hard water requires more soap than soft water to obtain a lather. Hardness is caused primarily by the presence of calcium and magnesium ions. Public acceptance of hardness can vary considerably among communities and is generally related to the hardness that the consumer has come to expect, which in turn is due to the source of the water.

What can be done?

Hardness can be readily reduced by treatment, for example using lime softening; however, this is rarely practised for Australian drinking water.

Why is this a potential issue?

Turbidity is a measure of the light-scattering property of water caused by the presence of fine suspended matter such as clay, silt, plankton and other microscopic organisms. The turbidity of drinking water can be used as a measure of the efficiency of the filtration and disinfection processes of water treatment and is also an aesthetic issue to consumers. Based on aesthetic considerations, the turbidity should not exceed 5 NTU at the consumer’s tap. Exceedances of this level of turbidity occasionally occur in the region giving drinking water a cloudy or muddy appearance. These exceedances have not been a health concern.

What can be done?

Turbidity has an impact on the aesthetic acceptability of water. Many consumers relate the appearance of water to its safety, and turbid or coloured water is interpreted as being unsafe to drink. Councils attempt to maintain turbidity as low as possible to the point of supply to customers.