Staff Reporter<\/p>\n\n\n\n
NAMWATER is addressing manganese-related water quality challenges experienced in Rehoboth through treatment adjustments, increased monitoring, reservoir cleaning and planned filter refurbishment, with recent testing showing considerable improvement in water quality.<\/p>\n\n\n\n
NamWater Chief Operations Officer Andreas Kok provided an update to the Management Committee of the Rehoboth Town Council, explaining the cause of the manganese-related problem, measures already implemented and improvements recorded through recent water quality testing.<\/p>\n\n\n\n
Kok explained that manganese occurs naturally in rocks and soils in the catchment of the dam and can be carried into the dam through rainfall runoff and river flows. It can enter the water either in dissolved form or attached to soil and sediment particles.<\/p>\n\n\n\n
Over time, these particles settle and accumulate at the bottom of the dam. When oxygen levels in deeper water become low, manganese can be released from the sediment and dissolve into the water.<\/p>\n\n\n\n
Seasonal changes can also cause the deeper and upper layers of water to mix, a process known as dam turnover. This can bring water with higher manganese levels to the point where water is drawn for treatment, resulting in a seasonal increase in manganese in the raw water entering the purification plant.<\/p>\n\n\n\n
According to NamWater, dissolved manganese is generally invisible, meaning the water can initially appear clear. The water can later become brown or black when the dissolved manganese is oxidised and converted into solid particles.<\/p>\n\n\n\n
Kok explained that chlorine, which is added to disinfect the water, can also contribute to the oxidation of manganese, particularly as the water travels through the town\u2019s distribution system.<\/p>\n\n\n\n
The resulting particles can remain suspended in the water, causing the brown or black discolouration, while some particles can settle in reservoirs and pipes and cause further discolouration when disturbed.<\/p>\n\n\n\n
NamWater has begun optimising chemical dosing and treatment conditions to improve manganese oxidation and removal at the purification plant. Sampling and water quality monitoring have also been increased at the plant and at points throughout the town.<\/p>\n\n\n\n
All NamWater reservoirs have been cleaned to remove accumulated manganese deposits, while targeted scouring or flushing of affected sections of the town\u2019s distribution system is planned to remove deposits from the pipes.<\/p>\n\n\n\n
NamWater said it would credit the water used for this flushing.<\/p>\n\n\n\n
Kok said recent water quality results show considerable improvement following the interventions, although manganese deposits may still be present in some parts of the distribution network.<\/p>\n\n\n\n
The replacement of sand in the plant\u2019s filters is also planned, with the first filter scheduled to receive new sand within two weeks. The remaining filters will be refurbished one at a time to allow the plant to continue operating and maintain water supply.<\/p>\n\n\n\n
In the longer term, NamWater plans to upgrade the purification plant to strengthen its treatment performance and improve its ability to manage changing raw water conditions.<\/p>\n\n\n\n
NamWater said the planned upgrade will also support compliance with applicable drinking water quality requirements under the Water Resources Management Act, 2013 (Act No. 11 of 2013), and its regulations.<\/p>\n\n\n\n
On the safety of the water, NamWater said bacteriological results for treated water from the Oanob Purification Plant product water and the Rehoboth reservoir for March to September 2026 showed that all 40 samples were classified as either ideal or acceptable.<\/p>\n\n\n\n
Kok said the results indicate that the water is safe to drink, although he acknowledged that brownish water is aesthetically concerning to residents and can create the impression that it is unsafe.<\/p>\n\n\n\n
NamWater said monitoring will continue to determine whether the improvements are sustained and that it will continue working with the Rehoboth Town Council and the community to address the water quality challenges.<\/p>\n\n\n\n
Picture for illustrative purposes only. Photo: NamWater<\/p>\n","protected":false},"excerpt":{"rendered":"
Staff Reporter NAMWATER is addressing manganese-related water quality challenges experienced in Rehoboth through treatment adjustments, increased monitoring, reservoir cleaning and planned filter refurbishment, with recent testing showing considerable improvement in water quality. NamWater Chief Operations Officer Andreas Kok provided an update to the Management Committee of the Rehoboth Town Council, explaining the cause of the …<\/p>\n","protected":false},"author":10,"featured_media":402059,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24],"tags":[],"class_list":["post-402058","post","type-post","status-publish","format-standard","has-post-thumbnail","category-news"],"yoast_head":"\n