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b)Those portions of a single aquifer where contamination occurs in separate and <br /> definable layers within the aquifer. <br /> 7. The well construction materials shall be compatible with the depth of the well and any <br /> contaminants to be monitored or recovered. <br /> 8.The well shall be constructed in such a manner that water or contaminants from the <br /> land surface cannot migrate along the borehole annulus into any packing material or <br /> well screen area. <br /> 9. In monitoring wells, packing material placed around the screen shall extend at least <br /> one foot above the top of the screen. Unless the depth of the screen necessitates a <br /> thinner seal;a one foot thick seal, comprised of chip or pellet bentonite or other <br /> material approved by the Department as equivalent, shall be emplaced directly above <br /> and in contact with the packing materials. <br /> 10. In monitoring wells, grout shall be placed in the annular space between the <br /> outermost casing and the borehole wall from the land surface to the top of the <br /> bentonite seal above any well screen or to the bottom of the casing for open end <br /> wells. <br /> 11. If the well penetrates any water-bearing zone that contains contaminated or saline <br /> water,the well shall be grouted within one day after the casing is set but in no case <br /> shall any well remain ungrouted for more than seven days after the casing is set. <br /> 12.All monitoring wells, including temporary wells, shall be secured with a locking well <br /> cap to ensure against unauthorized access and use. <br /> 13. All monitoring wells shall be equipped with a steel outer well casing or flush-mount <br /> cover, set in concrete, and other measures sufficient to protect the well from damage <br /> by normal site activities. <br /> 14.Any well that would flow under natural artesian conditions shall be valved so that the <br /> flow can be regulated. <br /> 15. In monitoring wells, the well casing shall be terminated no less than 12 inches above <br /> land surface unless all of the following conditions are met: <br /> a)Site-specific conditions directly related to business activities, such as vehicle <br /> traffic, would endanger the physical integrity of the well; and <br /> b)The well head is completed in such a manner so as to preclude surficial <br /> contaminants from entering the well. <br /> 16. Each monitoring well shall have permanently affixed an identification plate.The <br /> identification plate shall be constructed of a durable waterproof, rustproof metal, or <br /> other material approved by the Department as equivalent and shall contain the <br /> following information: <br /> a)Well contractor name and certification number; <br /> b) Date well completed; <br /> 34 <br />