Sec. 26.13.05.10-4. Containment and Detection of Releases

A. Except as allowed for in §F of this regulation and Regulation .10-5 of this chapter, an owner or operator shall provide secondary containment that meets the requirements of this regulation by the following deadlines:

(1) For all new tank systems or components, before their being put into service;

(2) For all existing tank systems used to store or treat EPA Hazardous Waste Nos. F020, F021, F022, F023, F026, and F027 that are:

(a) Underground tanks that cannot be entered for inspection, by January 12, 1987;

(b) Underground tanks that can be entered for inspection, within 2 years after July 1, 1993; or

(c) Not underground tanks, within 2 years after July 1, 1993;

(3) Existing underground tank systems that cannot be entered for inspection and that are a known and documented age, within 2 years after January 12, 1987, or when the tank system becomes 15 years old, whichever comes later;

(4) Existing tank systems of a known and documented age that are not underground or are underground tanks that can be entered for inspection, within2 years after July 1, 1993, or when the tank system becomes 15 years old, whichever comes later;

(5) Existing underground tank systems that cannot be entered for inspection, and for which the age cannot be documented:

(a) Within 8 years of January 12, 1987, if the age of the facility is 7 years or less; or

(b) If the age of the facility is greater than 7 years, within 2 years after January 12, 1987, or the time the facility becomes 15 years old, whichever comes later;

(6) Existing tank systems that are not underground tanks, or are underground tanks that can be entered for inspection, and for which the age cannot be documented:

(a) Within 8 years of July 1, 1993, if the age of the facility is 7 years or less; or

(b) If the age of the facility is greater than 7 years, within 2 years after July 1, 1993, or the time the facility becomes 15 years old, whichever comes later;

(7) Tank systems that are used to store or treat materials that become regulated as hazardous wastes after July 1, 1993, within the time intervals required in §A(1)-(6) of this regulation, except that the date that a material becomes a hazardous waste is substituted for January 12, 1987 or July 1, 1993, whichever is applicable.

B. The owner or operator shall ensure that secondary containment systems provided in accordance with §A of this regulation:

(1) Are designed, installed, and operated to prevent any migration of wastes or accumulated liquid out of the system to the soil, ground water, or surface water at any time during the use of the tank system;

(2) Are capable of detecting and collecting releases and accumulated liquids until the collected material is removed;

(3) Are constructed of or lined with materials that are compatible with the waste or wastes to be placed in the tank system;

(4) Have sufficient strength and thickness to prevent failure owing to pressure gradients, including static head and external hydrological forces, physical contact with the waste to which it is exposed, climatic conditions, and the stress of daily operation, including stresses from nearby vehicular traffic;

(5) Are placed on a foundation or base capable of providing support to the secondary containment system, resistance to pressure gradients above and below the system, and capable of preventing failure due to settlement, compression, or uplift;

(6) Are provided with a leak-detection system that is designed and operated so that it will detect the failure of either the primary or secondary containment structure or the presence of any release of hazardous waste or accumulated liquid in the secondary containment system within 24 hours, or at the earliest practicable time if the owner or operator can demonstrate to the Secretary that existing detection technologies or site conditions will not allow detection of a release within 24 hours; and

(7) Are sloped or otherwise designed or operated to drain and remove liquids resulting from leaks, spills, or precipitation.

C. The owner or operator shall remove spilled or leaked waste and accumulated precipitation from the secondary containment system within 24 hours, or, if the owner or operator can demonstrate to the Secretary that removal of the released waste or accumulated precipitation cannot be accomplished within 24 hours, in as timely a manner as is possible to prevent harm to human health and the environment.

D. The owner or operator shall use one or more of the following devices in providing for secondary containment for tanks:

(1) A liner, external to the tank;

(2) A vault;

(3) A double-walled tank; or

(4) An equivalent device as approved by the Secretary.

E. The owner or operator shall ensure that:

(1) External liner systems are:

(a) Designed or operated to contain 100 percent of the capacity of the largest tank within the boundary of the liner system;

(b) 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 and the additional capacity is sufficient to contain precipitation from a 25-year, 24-hour rainfall event;

(c) Free of cracks or gaps; and

(d) 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 or tanks (that is, capable of preventing lateral as well as vertical migration of the waste);

(2) Vault systems are:

(a) Designed or operated to contain 100 percent of the capacity of the largest tank within the boundary of the vault system;

(b) 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, and the additional capacity is sufficient to contain precipitation from a 25-year, 24-hour rainfall event;

(c) Constructed with chemical-resistant water stops in place at any joints;

(d) Provided with an impermeable interior coating or lining that is compatible with the stored waste and that will prevent migration of waste into the material of construction of the vault;

(e) 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 the definition of ignitable waste under COMAR 26.13.02.11, or meets the definition of reactive waste under COMAR 26.13.02.13, and may form an ignitable or explosive vapor; and

(f) Provided with an exterior moisture barrier or are otherwise designed or operated to prevent migration of moisture into the vault if the vault is subject to hydraulic pressure;

(3) Double-walled tanks are:

(a) Designed as an integral structure, with an inner tank completely enveloped within an outer shell, so that any release from the inner tank is contained by the outer shell;

(b) Protected, if constructed of metal, from both corrosion of the primary tank interior and of the external surface of the outer shell; and

(c) 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 Secretary, and the Secretary concludes, that the existing detection technology or site conditions would not allow detection of a release within 24 hours.

F. The owner or operator shall provide ancillary equipment with secondary containment such as a trench, jacketing, or double-walled piping that meets the requirements of §§B and Cof this regulation except for:

(1) Above-ground piping, exclusive of flanges, joints, valves, and other connections, that is visually inspected for leaks on a daily basis;

(2) Welded flanges, welded joints, and welded connections, that are visually inspected for leaks on a daily basis;

(3) Seal-less or magnetic coupling pumps and seal-less valves, that are visually inspected for leaks on a daily basis; and

(4) Pressurized above-ground piping systems with automatic shut-off devices, such as excess flow check valves, flow metering shutdown devices, or shut-off devices actuated by loss of pressure, that are visually inspected for leaks on a daily basis.

G. The owner or operator of a tank system, until such time as secondary containment that meets the requirements of this regulation is provided, shall comply with the following:

(1) For nonenterable underground tanks, conduct at least annually a leak test that meets the requirements of Regulation .10-2B(3)(e)(i) of this chapter, or other tank integrity method as approved or required by the Secretary;

(2) For other than nonenterable underground tanks, either conduct a leak test as in §G(1) of this regulation, or develop a schedule and procedure for an assessment of the overall condition of the tank system by an independent, qualified, registered professional engineer;

(3) Ensure that assessments of the overall condition of the tank system performed instead of a leak test satisfy the following requirements:

(a) The schedule and procedure for the assessment is adequate to detect obvious cracks, leaks, and corrosion or erosion that may lead to cracks and leaks;

(b) Stored waste is removed from the tank, if necessary, to allow the condition of all internal tank surfaces to be assessed; and

(c) The frequency of the assessment is based on the material of construction of the tank and its ancillary equipment, the age of the system, the type of corrosion or erosion protection used, the rate of corrosion or erosion observed during the previous inspection, and the characteristics of the waste being stored or treated;

(4) For ancillary equipment, conduct at least annually a leak test or other integrity assessment as approved by the Secretary;

(5) Maintain on file at the facility a record of the results of the assessments conducted in accordance with §G(1)-(4) of this regulation; and

(6) Comply with the requirements of Regulation .10-6 of this chapter if a tank system or component is found to be leaking or unfit for use as a result of the leak test or assessment performed in accordance with §G(1)-(4) of this regulation.