(a) Sample points. Sampling points must be identified in the engineering report. A design must include a sufficient number of sampling points to:(1) allow an operator to monitor the disinfection system for process control; and(2) allow monitoring of permitted effluent limits.(b) Dissolved Oxygen Requirements. A wastewater treatment facility must be designed with the ability to add post-aeration if needed to meet effluent limits for dissolved oxygen in the wastewater permit. If the wastewater permit requires a minimum dissolved oxygen of 5.0 milligrams per liter or greater, the engineering report must include calculations that demonstrate how the post-aeration system will maintain the minimum dissolved oxygen level.