Captor effluent flows into two activated sludge basins for further treatment. The average M.L.S.S. in the aeration basins during the summer months is 1400 to 1600 mg/l and during the winter months is 2200 mg/l. D.O. is maintained at 2.5 to 3.5 mg/l by two direct drive centrifugal blowers with a third blower reserved for backup. Air from the blowers is distributed throughout the basins by high efficiency EPDM membrane diffusers. The sludge age ranges from 5 days to 15 days. The S.V.I. ranges from 100 o 380 depending on the mode of operation.
The performance of the Captor/Activated sludge system after 11 years of operation is shown below.
| Parameter | Inf. Avg. mg/l | Range mg/l | Eff. Avg. mg/l | Range mg/l | Avg. % Removed |
| CBOD | 209 | 146-266 | 5 | 3.7-9 | 98 |
| Sus. Sol. | 211 | 145-290 | 4 | 2-11 | 98 |
| Ammonia | 17 | 6-23 | 2.6 | .5-6 | 84 |