water and industrial chemicals

[kering]

What actually could be the cause of river waters turning green especially in river Athi.Through mere observation, the water appear to have threadlike substance but we cannot define what it is.Could you please assist.

[ugly_bob]

Sounds like some sort of weed

[drestie]

I know nothing about this particular river, but it sounds like some sort of macroalgae. Many river and lake waters turn green as a result of eutrophication, which is basically the addition of nutrients (often from sewage dumping or agricultural runoff). This results in an overgrowth of algae and can be very harmful to all of the organisms in the body of water.