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3. Embankment Material <br />Soils from 5 to 17 feet below surface in the area of excavation of the reservoir have been identified as <br />PREFERRED EMBANKMENT AND LINER MATERIAL by the Engineer and as referenced in the EEC report. <br />These preferred materials are identified as "Bulk 7 9.0" and `Bulk 10 5.0" in the EEC report and are classified as <br />Lean CIay or Lean Clays with Sand. The reservoir embankment and liner shall be constructed of this material and <br />any variance from the soil types referenced shaII not be used. Soils used shall be free of foreign material such as <br />vegetation, organic matter, trash, brush, fallen trees or other objectionable material. Stones over two (2) inches in <br />diameter shall be removed from the fill material. <br />4. Embankment Construction <br />After stripping vegetation and organic matter in the embankment footprint, the in -situ soils shall be scarified to a <br />- minimum depth of nine (9) inches and compacted to 95% of the soil's maximum dry density and moisture <br />adjusted to -1% to +3% of optimum moisture. The embankment fill shall be placed in horizontal layers (lifts) not <br />to exceed six (6) inches in compacted thickness. The fill shall be added and compacted to achieve the final <br />elevations and grades shown on the construction plans. Each lift shall be compacted with a standard sheepsfoot <br />roller, or other equivalent methods which must be approved by the Engineer. Roller feet or cleats should have <br />sufficient length to penetrate the loose lift to the underlying compacted lift in order to achieve good bonding at the <br />lift interface. The sheepsfoot roller should not "walk out" as the lift becomes more compact, i.e., 1 to 2 inches of <br />the lift being compacted should be left reasonably loose to allow the subsequent lift to effectively bond with the <br />lift placed. The placement of lifts shall be accomplished such that there are no lenses or streaks of material. The <br />use of smooth drum rollers is not acceptable. <br />Water will need to be added to the fill material to achieve the proper moisture content for compaction. Water is <br />available at the site for moisture control of the liner installation process. Water is typically applied using truck <br />mounted tanks equipped with spray bars. The amount of water to be added should be sufficient to bring the <br />moisture level of the soil mixture to somewhat wet of minimum. Immediately after application, the water should <br />be thoroughly mixed into the embankment material to eliminate surface ponding and enable the mixing equipment <br />to operate without excessive loss of traction. The preferred method to add and mix moisture is to apply water <br />using spray trucks to the soil to be excavated or to add water as the lift is being place, then mix the material using <br />a disc to create a homogeneous mixture. <br />Upon completion, all embankment walls shall be stabilized to minimize erosion and to maintain moisture <br />conditions. Rock riprap is specified herein as erosion control for the interior western portion of the reservoir and <br />a 12 -inch thick soil blanket is specified for the interior eastern portion of the reservoir. These erosion control <br />methods are included on the Earthwork Construction Plans. All exterior slopes of the reservoir shall be vegetated <br />as specified herein to minimize erosion. <br />5. Embankment Construction Testing <br />Each compacted six -inch lift shall be tested by a geotechnical laboratory for compaction and moisture content. A <br />minimum of one test per 600 cubic yards (tight) placed per lift shall be recorded (or one test every approximately <br />200 feet). Each embankment lift shall be compacted to 95% of Standard Proctor at optimum moisture content ( -I <br />to +3 %). Results of all moisture /density testing shall be included in the Geotechnician's report. The <br />Geoteclmieian present on -site will notify the Contractor of any failing tests and the Contractor will make all <br />necessary reparations to correct those areas failing field density and moisture testing. The Contractor and <br />Engineer shall coordinate regarding elevation control of each lift to ensure the correct number of density and <br />moisture tests are collected (and that meet the specification). <br />6. Embankment Stabilization <br />Once the embankment has been constructed, exterior slopes shall be seeded as per Section 32 90 00. <br />310000 -2 <br />