Water quality testing

Drinking water guidelines

MidCoast Water Services has a comprehensive testing regime to ensure that water quality meets the required standards.

We use standards set out in the Australian Drinking Water Guidelines, which are based on drinking water guidelines developed by the World Health Organisation. We also cooperate with NSW Health in our management of water quality. Testing is carried out regularly at water supply sources such as rivers and weirs, storage areas such as dams and reservoirs and from customers' garden taps.

This testing regime helps to build up a history of water quality and identify any problems within the system. Common tests include E. coli and total coliforms bacteria, pH, temperature, colour, turbidity, fluoride, chlorine, aluminium, iron, manganese, disinfection byproducts and hardness.

Water quality testing

Water quality results in the table below contain a summary of water testing undertaken at customers' taps during the last three months.

Drinking water quality test results summary - 1 July 2018 to 30 September 2018

Water Quality Parameter

 E. coli  Turbidity pH
Australian Drinking Water Guidelines criteria At least 98% samples contain no E. coli bacteria Less than 5 NTU 6.5-9.2* pH units
Water Supply System % of results complying % of results complying/average result % of results complying/average result
Manning 100% 100%                 0.16 100%                     7.69
Tea Gardens 100% 100%                 0.13 100%                     7.69
Bulahdelah 100% 100%                 0.25 100%                     7.74
Stroud 100% 100%                 0.23 100%                     8.05
Gloucester 100% 100%                 0.22 100%                     8.27
North Karuah 100% 100%                 0.21 100%                     8.09
Criteria based on health or aethetic related value  Health Aesthetic Aesthetic

NTU - nephelometric turbidity units

* Aesthetic guideline of pH  = 6.5 - 8.5. A value up to 9.2 may be tolerated, provided monitoring indicates no deterioration in microbiological quality as stated in Australian Drinking Water Guidelines.

For more details please see our Drinking Water Quality Management System - DWQMS - Annual Report Summary 2016-17

If guidelines for E. coli and total coliforms bacteria are not met MidCoast Water Services will issue a boil water alert to affected customers.


Water hardness

The 'hardness' of water is something that is of interest when it comes to new appliances. Often new washing machines or dishwashers have specific settings for various levels of water hardness. As a guide, water with less than 60mg/litre is considered 'soft', up to 200mg 'good quality', between 200mg and 500 mg 'hard' and more than 500 mg is 'very hard'.

Our Manning supply is considered 'good quality' and the Bulahdelah, Stroud, Gloucester and Tea Gardens supplies are considered 'soft'.

The actual details are provided below.


Total hardness units Manning (Manning/ Taree and Forster/ Tuncurry) Bulahdelah Stroud Gloucester Tea Gardens North Karuah
mg/L CaCO3/L (ppm) 61 40 54 30 47 71
mmol/L (millimol per litre)
0.61 0.4 0.54 0.3 0.47 0.71
German degrees 8.54 5.6 7.56 4.2 6.58 9.94
French degrees 15.25 10 13.5 7.5 11.75 17.75


For more information on the use of flouride in our water supplies, follow this link to NSW Health's fact sheet on water fluoridation in NSW