NR 664.0193(4)(4) Secondary containment for tanks shall include one or more of the following devices: NR 664.0193(5)(5) In addition to the requirements of subs. (2) to (4), secondary containment systems shall satisfy the following requirements: NR 664.0193(5)(a)1.1. Designed or operated to contain 100% of the capacity of the largest tank within its boundary. NR 664.0193(5)(a)2.2. Designed or operated to prevent run-on or infiltration of precipitation into the secondary containment system unless the collection system has sufficient excess capacity to contain run-on or infiltration. The additional capacity shall be sufficient to contain precipitation from a 25-year, 24-hour rainfall event. NR 664.0193(5)(a)4.4. Designed and installed to surround the tank completely and to cover all surrounding earth likely to come into contact with the waste if the waste is released from the tank (i.e., capable of preventing lateral as well as vertical migration of the waste). NR 664.0193(5)(a)5.5. Provided with an impermeable interior coating or lining that is compatible with the stored waste and that will prevent migration of waste into the concrete. NR 664.0193(5)(b)1.1. Designed or operated to contain 100% of the capacity of the largest tank within its boundary. NR 664.0193(5)(b)2.2. Designed or operated to prevent run-on or infiltration of precipitation into the secondary containment system unless the collection system has sufficient excess capacity to contain run-on or infiltration. The additional capacity shall be sufficient to contain precipitation from a 25-year, 24-hour rainfall event. NR 664.0193(5)(b)3.3. Constructed with chemical-resistant water stops in place at all joints (if any). NR 664.0193(5)(b)4.4. Provided with an impermeable interior coating or lining that is compatible with the stored waste and that will prevent migration of waste into the concrete. NR 664.0193(5)(b)5.5. Provided with a means to protect against the formation of and ignition of vapors within the vault, if the waste being stored or treated meets any of the following: NR 664.0193(5)(b)6.6. Provided with an exterior moisture barrier or be otherwise designed or operated to prevent migration of moisture into the vault if the vault is subject to hydraulic pressure. NR 664.0193(5)(c)1.1. Designed as an integral structure (i.e., an inner tank completely enveloped within an outer shell) so that the outer shell contains any release from the inner tank. NR 664.0193(5)(c)2.2. Protected, if constructed of metal, from both corrosion of the primary tank interior and of the external surface of the outer shell. NR 664.0193(5)(c)3.3. Provided with a built-in continuous leak detection system capable of detecting a release within 24 hours, or at the earliest practicable time, if the owner or operator can demonstrate to the department, and the department concludes, that the existing detection technology or site conditions would not allow detection of a release within 24 hours. NR 664.0193 NoteNote: The provisions outlined in the Steel Tank Institute’s (STI) “Standard for Dual Wall Underground Steel Storage Tanks” may be used as guidelines for aspects of the design of underground steel double-walled tanks.
NR 664.0193(6)(6) Ancillary equipment shall be provided with secondary containment (e.g., trench, jacketing, double-walled piping) that meets the requirements of subs. (2) and (3) except for all of the following: NR 664.0193(6)(a)(a) Aboveground piping that is visually inspected for leaks on a daily basis, except for flanges, joints, valves and other connections, which must have secondary containment unless they are identified in and comply with pars. (b) to (d). NR 664.0193(6)(b)(b) Welded flanges, welded joints and welded connections, that are visually inspected for leaks on a daily basis.