Common use of Observation Xxxxx Clause in Contracts

Observation Xxxxx. a) This work shall consist of installing observation xxxxx full depth in those test holes determined by the Drill Inspector. The Drill Inspector will determine the observation well design requirement. The installation of the observation xxxxx will be performed by a “resource protection well operator” as licensed by the Washington State Department of Ecology (WAC 173-162). b) Riser pipe shall consist of Schedule 40, 1-inch, 2-inch, and 2.5-inch I.D. PVC pipe. All pipe joints shall be secure and leak proof in accordance with industrial standards and purchaser approval. c) Each screened interval shall have slot size of 0.01 inch and have three rows of slots space at 120 degrees with slot spacing about four slots per inch. The bottom shall be plugged and have a 2 foot unslotted sump. The Drill Inspector will determine screened interval length and depth. d) The sand pack for the observation xxxxx shall consist of Colorado Silica Sand, or Purchaser approved equivalent. Sand shall be clean, hard, and durable. Drill cuttings shall not be used. e) The bentonite chips used to form the seal for the observation xxxxx will be 3/4-inch minus, or Purchaser approved equivalent. f) The method for installing observation xxxxx shall be as follows: 1. Upon completion of the boring, clean water shall be circulated until the overflow is clear and free of soil particles or drilling fluid, for a minimum of 15 minutes. 2. Insert screened interval and riser pipe through the casing. 3. As the casing is being withdrawn, the annular space between the wall of the boring and the screened interval shall then be filled with a sand pack. 4. Contractor shall exercise caution in the extraction of the casing to maintain sand within the casing at all times. 5. However, an excessive height of sand within the casing will not be allowed, as it could cause binding against the riser pipe and/or screened interval resulting in lifting the observation well within the casing. g) Observation well pipe height, unless directed otherwise by the Drill Inspector, shall be a minimum of 2 feet above the ground surface so to ensure a sufficient height to prevent any overflow of groundwater into the well, unless a flush mount is required by Purchaser. h) The top of each observation well shall be provided with a cap in which an air hole has been drilled. The Contractor shall provide a locking steel monument case, in accordance with Department of Ecology requirements (WAC 173-160). i) The Drill Inspector shall inspect and approve each section of observation well pipe and screened interval prior to its installation in the test hole. All pipe joints shall be secure and leak proof in accordance with industrial standards and Purchaser approval. j) The unit contract price per linear foot, (as recorded in the Drill Hole Log) for “Observation Xxxxx’’ shall be full compensation for furnishing all equipment, tools, labor, materials, sand pack, PVC pipe, PVC screened interval, bentonite seal(s), and monument cases, necessary or incidental to complete the work as specified and in accordance with Department of Ecology Standards. k) Contractor shall include installation of vibrating wire piezometer/grout in place at a price per foot of installation when requested by Purchaser. Purchaser will provide all vibrating wire unit(s) to Contractor for installation.

Observation Xxxxx. (a) This work shall consist of installing observation xxxxx full depth in those test holes determined by the Drill Inspectorinspector. The Drill Inspector inspector will determine the observation well design requirement. The installation of the observation xxxxx will be performed by a “resource protection well operator” as licensed by the Washington State Department of Ecology (WAC 173-162). (b) Riser pipe shall consist of Schedule 40, 1-inch, 2-inchinches, and 2.5-inch inches I.D. PVC pipe. All pipe joints shall be secure and leak proof in accordance with industrial standards and purchaser approval. (c) Screened Interval diameter shall be 1-inch, 2-inches, and 2.5-inches I.D. Each screened interval shall have slot size of 0.01 inch and have three rows of slots space at 120 degrees with slot spacing about four slots per inch. The bottom shall be plugged and have a 2 foot unslotted sump. The Drill Inspector will determine screened interval length and depth. (d) The sand pack for the observation xxxxx shall consist of Colorado Silica Sand, or Purchaser approved equivalent. Sand equal, sand shall be clean, hard, and durable. Drill cuttings shall not be used. (e) The bentonite chips used to form the seal for the observation xxxxx will be 3/4-inch minus, or Purchaser approved equivalentequal. (f) The method Method for installing observation xxxxx shall be as follows: 1. : ▪ Upon completion of the boring, clean water shall be circulated until the overflow is clear and free of soil particles or drilling fluid, for a minimum of 15 minutes. 2. ▪ Insert screened interval and riser pipe through the casing. 3. ▪ As the casing is being withdrawn, the annular space between the wall of the boring and the screened interval shall then be filled with a sand pack. 4. ▪ Contractor shall exercise caution in the extraction of the casing to maintain sand within the casing at all times. 5. However, an ▪ An excessive height of sand within the casing will not be allowed, as it could cause binding against the riser pipe and/or screened interval resulting in lifting the observation well within the casing. (g) Observation well pipe height, unless directed otherwise by the Drill Inspectorinspector, shall be a minimum of 2 feet above the ground surface so to ensure a sufficient height to prevent any overflow of groundwater into the well, unless a flush mount is required by Purchaser. (h) The top of each observation well shall be provided with a cap in which an air hole has been drilled. The Contractor shall provide a locking steel monument case, in accordance with Department of Ecology requirements (WAC 173-160). (i) The Drill Inspector shall inspect and approve each section of observation well pipe and screened interval prior to its installation in the test hole. All pipe joints shall be secure and leak proof in accordance with industrial standards and Purchaser approval. (j) The unit contract price per linear foot, (as recorded in the Drill Hole Logdrilling log) for “Observation Xxxxx’’ shall be full compensation for furnishing all equipment, tools, labor, materials, sand pack, PVC pipe, PVC screened interval, bentonite seal(s), and monument cases, necessary or incidental to complete the work as specified and in accordance with Department of Ecology Standards. (k) Contractor shall include installation of vibrating wire piezometer/grout in place at a price per foot of installation when requested by Purchaser. Purchaser will provide all vibrating wire unit(s) to Contractor for installation.