Building Control Technology Requirements

Section 742.1210  Building Control Technology Requirements a)         Natural attenuation, access controls, and point of use treatment shall not be considered building control technologies. b)         For purposes of determining compliance with remediation objectives under Tier 1, building control technologies are not recognized. c)         The following building control technologies are recognized for purposes of pathway exclusion under Section 742.312. 1)         Sub-slab depressurization (SSD) systems meeting the following requirements: A)        A suction pit is installed that is at least  two cubic feet and extends at least 6 inches below the slab (larger suction pits may be excavated as needed to achieve the performance criteria in subsection (c)(1)(B)); B)        A PVC pipe of at least 3 inches in diameter extends from the suction pit to the intake side of an in-line fan capable of achieving a static vacuum of at least 0.25 inches water column (wc) at the suction point and measureable vacuum at the farthest edges of the area served by the suction pit under worst case conditions (all exhaust fans and heating systems running, during cold weather) as determined by a differential pressure reading of at least -0.003 inches wc below the slab or visible downward flow of air at test holes using chemical or smoke sticks; C)        All visible cracks and joints in the slab (including the place where the pipe exits the slab) and foundation walls are sealed; D)        The pipe exhausts outside the building at least 10 feet above ground and at least 10 feet from any door or window; and E)        Additional suction pits meeting the requirements of subsection (c)(1)(A) shall be installed as necessary to achieve measureable vacuum below the slab in all areas, including in any area where subsurface or foundation conditions (e.g., a sub-slab grade beam) prevent adequate suction field extension. 2)         Sub-membrane depressurization (SMD) systems meeting the following requirements: A)        A non-woven geotextile is installed on the exposed earthen material; B)        A cross-laminated polyethylene membrane liner at least 0.10 mm (or 4 mil) thick is placed over the geotextile and sealed to foundation walls using a low volatile adhesive that is recommended by the liner manufacturer (e.g., acrylic latex adhesive); C)        A 3 inch diameter PVC pipe extends from a hole cut in the liner to the intake side of an in-line fan capable of achieving a static vacuum of at least 0.25 inches water column (wc) at the riser pipe and measureable vacuum at the farthest edges of the liner under worst case conditions (all exhaust fans running during cold weather) as determined by a differential pressure reading of at least -0.003 inches wc below the liner or visible downward flow of air in test holes using chemical or smoke sticks; D)        The pipe is sealed to the liner; E)        The pipe exhausts outside the building at least 10 feet above ground and at least 10 feet from any door or window; and F)         No leaks based on smoke stick tests along the entire perimeter of the liner (i.e., at all sealed edges) with the fan running.  Where leaks are identified, appropriate repairs are undertaken and smoke stick testing repeated until no leaks are detected. 3)         Membrane barrier systems when placed below concrete slabs meeting the following requirements: A)        The membrane is impermeable to volatile chemicals and is not less than 1.5 mm (or 60 mil) thick; B)        The membrane is sealed to foundation walls and any penetrating pipes according to membrane manufacturer/installer recommendations; C)        The membrane is installed in accordance with the manufacturer's requirements and by an applicator trained and approved by the manufacturer; D)        A smoke test of the membrane system (where smoke is injected below the installed liner prior to slab installation), in accordance with the manufacturer's requirements, is performed to ensure no leaks exist.  Where leaks are identified, appropriate repairs are undertaken and smoke testing repeated until no leaks are detected; E)        The membrane is puncture resistant to slab installation construction activities and protected by sand layers or geotextiles as recommended by the manufacturer; and F)         Construction activities following membrane installation do not damage, puncture or tear the membrane or otherwise compromise its ability to prevent the migration of volatile chemicals. 4)         Vented raised floors meeting the following requirements: A)        An interconnected void system below the slab sufficient to allow free movement of air and communication of negative pressures to all points below the slab; B)        Sealing of all construction joints, open cracks, and penetrations through the slab (e.g., for utilities and riser pipes) with a low volatile caulk; and C)        At least one 3 inch diameter riser pipe venting to the atmosphere above the roof line (at least 10 feet from any doors or windows) for each 5000 square feet of membrane area, with the capability of converting passively vented floor systems to actively vented or SSD systems meeting the performance requirements of subsection (c)(1).