The performance of package plants can be improved by sizing the components conservatively. In general, the careful selection of the right process should lead to an adequate plant for small isolated communities requiring sewage treatment. A plant such as the one using an "Extended Aeration Activated Sludge" process should produce a good effluent quality, have low sludge yield and be easy to operate.

There are now a large number of package plants in the market using a variety of equipment. Uncontrolled selection of plants can lead to problems with operational knowledge and supply of spare parts. Hence, some form of regulation for the use of these plants will be employed to ensure overall industry efficiency.

Further, market forces have driven the manufactures to make optimistic claims for the treatment capacity of small package plants, leading to plants designed in the high rate activated sludge mode in order to reduce the capital cost of construction. This often leads to high operational, maintenance and operator costs due to the need for high operator involvement to keep the plants running within the design parameters.