Section 258.26 - Run-on/run-off control systems(a) Owners or operators of all MSWLF units must design, construct, and maintain: (1) A run-on control system to prevent flow onto the active portion of the landfill during the peak discharge from a 25-year storm;(2) A run-off control system from the active portion of the landfill to collect and control at least the water volume resulting from a 24-hour, 25-year storm.(b) Run-off from the active portion of the landfill unit must be handled in accordance with § 258.27(a) of this part.56 FR 51016, Oct. 9, 1991; 57 FR 28627, June 26, 1992