Water Purification Plant - Innovation in Hermanus

Keeping at the forefront of problem-solving, the Overstrand Municipality built the first water purification plant of its kind in South Africa - in conjunction with the Department of Water and Sanitation, and the Department of Cooperative Governance and Traditional Affairs (CoGTA).

The Preekstoel Water Treatment Works (WTW), a project that commenced in 2011, was built in the Hemel-en-Aarde Valley to meet the growing demand for water in the Overstrand area. Urbanisation and subsequent increases in housing development and businesses, as well as recent decreases in rainfall, have substantially increased the demand for water.

The Preekstoel WTW processes surface water as well as borehole water, removing high levels of iron and manganese, and blending this water with that supplied and filtered from the De Bos Dam. An innovative bio-filtration system was engineered where good iron and manganese bacteria flourish and consume and reduce the high levels of iron and manganese found in borehole water. The pH and dissolved oxygen content are regulated to promote the growth of these bacteria and produce quality purified water.

The high levels of iron and manganese in borehole water not only stain clothes but also block the water distribution systems. Different kinds of bacteria - not the good ones that are introduced in the bio-filtration system - combine these elements with oxygen-forming "rust" and slimy matter that sticks bacteria to pipes and pumps. 

The demands of water are better met, but how good is the quality of the Overstrand's water?

The Department of Water and Sanitation instated the Blue Drop Report to measure the standard of water across municipalities, and ensure they are supplying quality water and being penalised should they fall short. According to the Blue Drop Report released on the 6th of June 2023, the Overstrand municipality ranked fifth in the Western Cape with a commendable score of 94% on the overall performance indicator for the Preekstoel Water Treatment Works (WTW).

The Overstrand Municipality sets a world-class standard for the community, increasing water supply as well as ensuring the quality is excellent - just another reason that we love to live in Hermanus.

Hermanus' water gets another thumbs up (overstrand.gov.za)