Promising early results for potential water source

Hunter Water has been investigating the potential for a new water source deep under the Tomago Sandbeds in an ancient riverbed known as the Hunter Palaeochannel.

We are excited to confirm our investigations have produced promising results.

Monitoring wells – small-diameter bores – installed in 2020 confirmed the presence of the gravel and sand aquifer, its thickness and the quality of the water.

This meant Hunter Water could proceed to sink three, full-scale bores to test the capacity of the aquifer and its viability as a water source.

Since October our contractor, Water Resources Drilling, has worked steadily through difficult drilling conditions and Covid-19 challenges to sink the 273mm-diameter bores with the third finished last week.

All full-scale bores were drilled to depths of between 44 metres and 82 metres, well below the limits of the upper sandbeds.

In good news for the investigations and for future work, two of the three bores are showing promising early results.

Under initial tests to prove capacity, one of the bores was able to produce water at a rate of up to 50 litres per second or four million litres per day (4ML/day).

The third bore, which we finished drilling last week, produced at a rate of seven litres a second.

The other bore did not produce consistently.

These results confirm we can tap into the palaeochannel aquifer, but more investigations and data analysis are needed.

Hunter Water has been consulting closely with the Natural Resource Access Regulator and NSW Health to ensure water samples are tested and results assessed thoroughly.

To confirm how the palaeochannel aquifer recharges and its possible supply characteristics, Hunter Water will assess the data with industry experts and regulators to decide the best approach to further investigate how the source can sustainably be used to supply suitable quality water.

Although the process of investigating this option is low risk, Hunter Water is taking a careful, step-by-step approach to minimise any risk from drilling into this new and relatively unknown water source.

This project has formed part of Hunter Water’s draft Lower Hunter Water Security Plan, which is due for release in the early part of this year.