The county government has barred residents from mining gold at Rosterman, citing health and environmental concerns.
Defending the decision, Environment Executive Robert Sumbi said noise pollution was another reason for the ban.
The public complained to the National Environment Management Authority (Nema) that the excavation was too noisy, especially at night.
"Mercury being used in the excavation is hazardous and if handled unprofessionally, it can have harmful effects on the nervous, digestive and immune systems, lungs and kidneys, and may be fatal at the long run," Mr Sumbi said.
The miners argued that they were in possession of temporary licences allowing them to excavate for three years.
"The area was agricultural but it has now been turned to a mining zone," said Sumbi.