Sungai Balung Hot Springs

What the surveys found

Balung 1 has six outlets on both banks and in the bed of the stream, about 200 m above sea level. On the left bank the water comes out of boulders of silicified rock 5 to 15 cm above the stream; two more outlets sit higher on the right bank, in weathered dacite. Temperatures measured 50 to 56.1°C with pH 6 to 6.2. The four most active outlets together gave about 0.5 litres a second, and thin films of silica were forming on the boulders.

Balung 2 is about 0.5 km northeast, also at around 200 m. A single outlet a few centimetres above the stream gives 55.6°C water at pH 5.97 and 0.5 litres a second. A warm pool (39°C, 1.5 m across) sits 30 m further northeast, away from the river. Both sites have a strong rotten-egg smell.

One of the Balung spring sites was a new find during the 1989 Geological Survey work.

The water

The water is rich in sulphate (about 1,250 to 1,300 ppm) and calcium, with very little chloride. Geologists class it as acid sulphate water that has been neutralised by cold groundwater on its way up, which is why the pH is close to 6 rather than the pH 4 of the Tawau Hills Park sulphur springs. Both groups sit on the edge of the Maria volcanic complex, the heat source shared with Apas Kiri.

Getting there, in theory

In 2000 the researchers needed about four hours to reach the springs from park headquarters: 1.5 hours by off-road vehicle to the Balung substation, then 2.5 hours on foot along a jungle trail. Sabah Parks still lists a Balung substation on the park's east side, but publishes no trail to the springs. The 2000 researchers thought the Balung springs were warm enough to develop as a bathing spot like Poring. A later push by UMS and the tourism ministry to promote volcano tourism around the park named columnar rock joints along the Balung River as an attraction, but not the springs. We found no sign that a trail or facilities were ever opened to the public.