Specifications include, but are not limited to: A. Provide all design, labor, equipment and materials necessary to control, convey, and dispose of groundwater, surface runoff, and any other water that may be encountered during performance of the Work. B. Groundwater conditions are described in the GER. The Contractor shall be responsible for design and selection of methods and equipment for control-of-water systems appropriate for the groundwater conditions described in the GER and within the criteria provided. C. Design shall include the monitoring and recording of flow rate, pressure, duration, and volume of water discharged. D. Design a groundwater control system, compatible with requirements of Federal Regulations 29 CFR Part 1926, to produce the following results: 1. Effectively reduce the hydrostatic pressure affecting: a. Excavations. b. Tunnel shaft excavations. 2. Effectively provide a dry and stable subgrade sufficient for the performance of subsequent operations within all tunnel shafts, open cut sections, and structure excavations. 3. Preclude damage to adjacent properties, buildings, structures, utilities, installed facilities, and other work. 4. Prevent the loss of fines, seepage, boils, quick condition, or softening of the foundation strata. 5. Maintain stability of sides and bottom of excavations. E. Provide for arrangement, locations and depths of water control systems to accomplish the Work and satisfy requirements specified. F. Based on Contractor's proposed excavation means and methods, and as required, provide pumped wells, wellpoints and sumps with suitable filters and well screens of adequate size and screen opening to prevent removal of fines from soils. G. Make available equipment, machinery and piping, including standby power and pumps in good working condition and of adequate capacity, to continue operations in an emergency in accordance with submitted and approved Contingency Plan. H. Dispose of water in closed conduits in accordance with permits of jurisdictional authorities. Do not damage public or private property or create a nuisance or health hazard. I. Groundwater control systems may include single-stage or multiple-stage vacuum wellpoint systems, pumped wells, or combinations of these equipment types. J. Provide drainage of seepage water and surface water, as well as water from any other source entering the excavation. Excavation drainage may include placement of drainage materials, such as crushed stone and filter fabric, together with sump pumping. K. Provide ditches, berms, pumps and other methods necessary to divert and drain surface water from excavation and other work areas. L. Sumps or drainage trenches are not to be used unless the groundwater table or potentiometric surface has been lowered to less than 3 feet above subgrade using pumped wells or vacuum wellpoints. M. Locate groundwater control and drainage systems so as not to interfere with utilities, construction operations, adjacent properties, or adjacent water wells. N. Assume sole responsibility for groundwater control systems and for any loss or damage resulting from partial or complete failure of protective measures and any settlement or resultant damage caused by the groundwater control operations. 1. Modify groundwater control systems or operations if they cause or threaten to cause damage to new construction, existing site improvements, adjacent property, or adjacent water wells, or affect potentially contaminated areas. 2. Repair damage caused by groundwater control systems or resulting from failure of the system to protect property as required.
