When the overall treatment objective has been established, the appropriate level of preapplication treatment should be determined. For SAT, the minimum preap-plication treatment is primary sedimentation or the equivalent. For small systems a short detention-time pond is recommended. Long-detention-time facultative or aerobic ponds are not recommended because of their propensity to produce high concentrations of algae. The algae produced in stabilization ponds will reduce infiltration rates in SAT systems significantly. If facultative or stabilization ponds are to be used with SAT, it is recommended that an aquatic treatment or constructed wetland system be used between the pond and the SAT basins to reduce TSS levels.
Was this article helpful?