Apas Kiri Hot Springs

What is there

The Geological Survey mapped the area in 1989 and labelled the sites Apas 1 to 5. Apas 1 to 4 all lie on the north side of the Apas Kiri 2 river at about 160 to 180 m above sea level, and the surface features cover roughly 3 km².

• Apas 1: a 64°C spring at the foot of a 2 m travertine terrace. Its outflow has built a 2.5 m travertine cliff coated in brown and green algae.
• Apas 2: four springs on low travertine terraces at the river's edge, 41 to 65.5°C.
• Apas 3: a round mud pool about 5 m across, 62°C at its most active outlet.
• Apas 4, the "old steaming ground": a bare patch 75 m long where hot water (50 to 79°C) spouts from travertine cones up to 3.5 m high, between bubbling pools of 40 to 60°C.
• Apas 5: a pear-shaped mud pool about 50 by 40 m, 1.5 km north of Apas 4 on the Apas Kiri 3 river, at 57.5 to 60°C.

A 2000–2001 survey counted fifteen active features between 43 and 78°C, found five new springs and noted one that had dried up.

The water

Unlike the acidic sulphur springs in Tawau Hills Park, the water at Apas Kiri Hot Springs is near-neutral (pH about 6 to 8) sodium chloride water, high in bicarbonate. It is also high in arsenic: 150 to 250 ppm in the spring water, and over 2,400 ppm in travertine from the Apas 4 cones. Don't drink it or wash your face in it.

The geothermal project

Chemical geothermometers put the underground reservoir at roughly 190 to 220°C. AK-1D, described as Malaysia's first geothermal exploration well, was drilled here and reached about 200°C at 1,450 m. In 2016 Tawau Green Energy announced a 30 MW power plant at Apas Kiri. Construction stopped in mid-2016, and in December 2018 Parliament was told the project had been abandoned. We found nothing more recent on the site or on who controls access to it.

Safety

The mud pools look solid and are not. During the 2000–2001 survey the semi-hardened crust at Apas 4 gave way under a researcher, who sank about 1.5 feet into hot mud. Water at the spouts is close to 80°C.

Visiting

There are no facilities, signs or published visiting arrangements. The wider prospect runs from Tawau Hills Park on its northwest edge to oil palm and cocoa estates on the southeast, with the Andrassy Forest Reserve in the middle. A Sabah tourism ministry official, in an undated news clipping kept by UMS, named the "conical spouts" at Andrassy as a volcanic attraction reachable from Tawau town, but gave no access details. Researchers in 2001 proposed a bathing park like Poring here; that never happened.