Bright Simons writes: Brown rivers may be due to more than galamsey

A browning of rivers, apparently due to "galamsey" is sinking hearts in Ghana.

Still, excessive turbidity in water bodies isn't only caused by aluvial panning by illegal miners searching for gold. It can also be caused by soil erosion into the water body, runoff due to landsliding banks, & algal growth & microflora, etc. I believe this is elementary.

It would thus be helpful if Ghana's water scientists can be more exact and emphatic in quantifying the exact contribution of illegal mining to the browning and clouding of waters the country is witnessing. Evidence from serious research should help.

In Tibet (China), for instance, river turbidity levels have doubled since 2000. The effect has been blamed on climate change. BASED ON RESEARCH.

Recent United States Geological Survey studies show an increasing pattern of turbidity in parts of the Delaware River Basin, where about 90% of New York City's potable water is said to originate. Various factors including the erosion of sediments from stream banks have been blamed. THIS IS BASED ON RESEARCH.

In 2006, Ghana's CSIR blamed the high turbidity trends witnessed in the Densu basin mainly on "poor farming practices", and not mining. THIS WAS BASED ON RESEARCH.

In 1977, Letitia Obeng attributed increased turbidity in some water bodies in the Volta Basin to dam construction effects. In that same year, government of Ghana passed a law ("executive instrument") creating a large buffer around the Weija lake due partly to high turbidity levels already being witnessed. Needless to say, that law has never been properly enforced. Lack of buffer management also accounts for the death of River Aboabo in the Kumasi area, away from any mining activity.

Studies by Dr Gbedze and collaborators in 2022 in Asutifi North did identify mining as an important factor in the high turbidity being seen in the Ankobrah basin (as indeed have other studies before and after) but they also highlighted the role of farming.

Unfortunately, it is not clear the exact extent to which mining is responsible for the trends across most of the water basins across the country versus other causes because a holistic survey has yet to be done. And responses so far rarely consider multiple factors.

What is even more interesting is how the sight of the "brownness" of the water elevates concern even though turbidity due to sand and clay sedimentation is actually cheaper to treat with filters and less dangerous than contamination by carcinogenic (cancer-causing) chemicals.

Some mining practices (like dredging) actually use far less chemicals than some intensive farming practices. For example, when Dr. Fianko tested fish from the Densu River two decades ago, every single specimen was contaminated by pesticides due to runoff of agricultural soils into the water.

Obviously, there can be no tolerance of mining so close to water bodies for all manner of reasons. However, where there are multiple causative factors, focusing on just one without fully understanding the whole picture can lead to poor policy choices. More importantly, it will make it impossible to know when progress is being made in one or more dimensions of the problem because of lack of categorisation.

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