Do you know of any activity which may be polluting this water source?

(N/A) The activities that may be polluting water sources include:
$1$. Disposal of garbage or untreated sewage from cities,towns,and residential areas into water bodies.
$2$. Discharge of industrial effluents containing toxic chemicals and heavy metals.
$3$. Release of hot water from industries (thermal pollution),which increases water temperature and decreases the dissolved oxygen level,thereby disturbing the $BOD$ (Biochemical Oxygen Demand) and aquatic life.