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5 C. Preliminary Monitoring Well Design 1. Up to three piezometers may be installed in the reamed test hole with a combination of intermediate and surface seals as shown conceptually on the preliminary design. The piezometer assemblies will be equipped with appropriate centralizers to ensure that the screen intervals are adequately spaced from the borehole wall. 2.A graded gravel envelope, a fine sand transition seal, and a cement sanitary seal will be placed in each well via the tremie pipe method. 3. The monitoring well will be housed in above-grade vaults. D. Local and State Standards 1. All drilling and well construction activities shall comply with local and State standards. If a conflict arises between the Technical Provisions and regulatory requirements, the Contractor shall immediately notify the Engineer and not proceed until the Engineer resolves the conflict. 2. It is the Contractor's sole responsibility to satisfy the well permitting requirements. 1.2.2 LOCATION AND LOCAL CONDITIONS The subsurface geology consists of unconsolidated Quaternary fluvially deposited alluvium (gravel, sand, silt, and clay). 1.2.3 DRILLING FLUID CONTROL PROGRAM A drilling fluid program shall be employed by the contractor in accordance with the following general conditions. 1.A drilling fluid control program shall be prepared by a qualified,professional drilling fluids engineer and submitted to the Engineer for approval. Selection and use of the drilling fluid materials shall be a part of this agreement. The Contractor shall be responsible for maintaining the quality of the drilling fluid to assure protection of water bearing and potential water bearing formations exposed in the borehole, and the ability to obtain reliable representative samples of the formation materials. 2. Material used by the Contractor to prepare the drilling fluid shall be composed of water from an assigned source and drilling additives processed to meet or surpass the specification in the American Petroleum Institute"Std. 13-A for Drilling Fluid Materials". All drilling fluid additives will comply with recognized industry standards and practices and they shall be used as prescribed by the manufacturer. Toxic and/or dangerous substances shall not be added to the drilling fluid. 3. The drilling fluid for the rotary construction shall be made up of high grade bentonite clays or organic polymer additives in common drilling usage in the water well industry, and shall possess such characteristics as required to condition the walls of the borehole to prevent caving of formations and excessive loss of circulation, facilitate removal of the cuttings, and produce an easily removed thin filter cake.