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3 . 3 Weir Operating Procedures During Dredging Once dredging begins and continuing though the completion of placement operations , the contractor remains responsible for operating the weir system as required to maintain effluent turbidity standards without compromising dike stability. The contractor achieves these objectives by adding weir boards and raising the weir crest elevation as required to control water level and ponding depth, and thereby retention time, within the basin . However, as described in Section 3 . 3 .2 , the contractor must not allow the water level within the basin to increase too quickly or the ponding depth to increase beyond the recommended maximum . Either condition could potentially lead to excessive seepage through the dikes, slope instability and , under extreme conditions , dike failure. Obviously, avoiding these conditions remains the one of the contractor ' s primary responsibilities . The remainder of this section presents guidelines that the contractor must follow to complete the required dredging and maintain effluent quality without compromising the integrity of the dike or the weirs . The following basic principles of operation provide a necessary preface to that discussion : • Throughout all phases of dredging operations, the contractor must maintain a qualified operator at the containment facility. As part of the required pre-construction submittals, the contractor must submit the specific qualifications of the designated operator(s ) to the Project Engineer for review and approval . Each operator shall remain in constant radio contact with the dredge plant and shall possess the direct authority to shut down the dredge if required . Each operator shall retain primary responsibility, either through his direct action or through actions of others under his direct supervision, for adjusting the weirs to maintain effluent quality and ensure dike integrity ( Section 3 . 3 . 1 ), for perfornung all inspections related to dike integrity, for documenting the results of those inspections ( Section 3 . 3 . 2), and for ensuring the security of the containment facility and the safety . of all contractor personnel under his or her direct supervision. • Throughout all phases of dredging operations, the contractor must ensure that all three weir stacks remain fully operational . Closing off one or more weir stacks or weir discharge pipelines by inserting bladders or other blockages is specifically prohibited. • Throughout all phases of dredging operations except during short intervals while weir boards are being added or removed from individual weir stacks , the contractor must - 14 -