Jet-eductor well system

(1) Scope. The work provided for herein consists of furnishing all labor, material, equipment, and tools to install, develop, and test pump the jet-eductor wells to be installed around the perimeter of the excavation at the locations shown on the drawings and as speci­fied herein.

(2) Design. The jet-eductor wells to be installed on the upper berm around the excavation at elevation 28 to 34 feet are to intercept the seepage from silt, sandy silt, silty sand, and sand strata which are penetrated in some areas by the outer excavation slopes. The pur­pose of the jet-eductor wells is to lower the groundwa­ter table below the slopes of the main excavation and to prevent any detrimental raveling or instability of the slopes caused by seepage. The jet-eductor wells shown on the contract drawings and as specified here­in have been designed to lower the groundwater table in the upper silts and sands to within about 2 or 3 feet of the contact with any underlying impervious stratum where shown on the drawing. However, other reaches of the outer excavated slopes than shown on the drawings may require dewatering or drainage. If observations indicate the need for dewatering other reaches of the outer slopes, the Government will design the supplemental jet-eductor wells and system and furnish the design to the Contractor for installa­tion. The Contractor will be reimbursed for the cost of any supplemental wells, jet-eductor pumps, and piping when completely installed and ready for operation, as an extra, The Contractor shall be fully responsible for controlling the groundwater table and seepage from and below the main excavated slopes as specified herein, and for proper installation, operation, mainte­nance of the specified jet-eductor wells, and any sup­plemental dewatering measures installed for control­ling the groundwater within the excavation.