This document shows photos of aeration chambers at a sewage treatment works before and after dosing commenced. The before photo depicts murky water in the chambers while the after photo shows clearer water, indicating the dosing improved water quality after 4 weeks.

2. Humansdorp Sewage Treatment
Works
Aeration Chambers before
dosing commenced

3. Humansdorp Sewage Treatment
Works
4 weeks after
dosing commenced