Orange County NC Website
Browse       Search
chips or compressed sodium bentonite pellets with largest dimension <br /> of at least one-fourth inch but not greater than one-fifth of the width of <br /> the annular space into which they are to be placed. Bentonite chips or <br /> pellets shall be hydrated in place. Bentonite chips or pellets may only <br /> be used in accordance with the manufacturer's written instructions. <br /> f. Specialty grout shall consist of a mixture of non-organic, non-toxic <br /> materials with characteristics of expansion, chemical-resistance, rate <br /> or heat of hydration, viscosity, density or temperature-sensitivity <br /> applicable to specific grouting requirements. Specialty grouts may not <br /> be used without prior approval by the Health Director. Approval of the <br /> use of specialty grouts shall be based on a demonstration that the <br /> finished grout has a permeability less than 10-6 centimeters per second <br /> and will not adversely impact human health or the environment. <br /> 2. With the exception of bentonite chips or pellets, the liquid and solid <br /> components of all grout mixtures shall be blended prior to emplacement <br /> below land surface. <br /> 3. No fly ash, other coal combustion byproducts, or other wastes may be used in <br /> any grout. <br /> History Note: Substitute for NCAC 02C.0107 <br /> Eff. March 25, 2020 <br /> F. GROUT EMPLACEMENT <br /> 1. Casing shall be grouted to a minimum depth of 20 feet below the land surface. <br /> 2. In addition to the grouting by this Rule, the casing shall be grouted as <br /> necessary to seal off all aquifers or zones that contain contaminated or other <br /> non-potable water so that contamination of overlying and underlying aquifers <br /> or zones shall not occur. <br /> 3. Bentonite slurry grout may be used in that portion of the borehole that is at <br /> least three feet below land surface. That portion of the borehole from land <br /> surface to at least three feet below land surface shall be filled with a concrete <br /> or cement-type grout or bentonite chips or pellets that are hydrated in place. <br /> 4. Grout shall be placed around the casing by one of the following methods: <br /> a. Pressure. Grout shall be pumped or forced under pressure through the <br /> bottom of the casing until it fills the annular space around the casing <br /> and overflows at the surface; <br /> b. Pumping. Grout shall be pumped into place through a hose or pipe <br /> extended to the bottom of the annular space which can be raised as the <br /> grout is applied. The grout hose or pipe shall remain submerged in <br /> grout during the entire application; or <br /> c. Other. Grout may be emplaced in the annular space by gravity flow <br /> way to ensure complete filling of the space. Gravity flow shall not be <br /> 23 <br />