Md. Code Regs. 26.10.17.07

Current through Register Vol. 51, No. 22, November 1, 2024

Section 26.10.17.07 - Secondary Containment

A. An owner, an operator, and a person in charge of an AST system with a shop-fabricated AST shall surround the AST system with a continuous secondary containment dike that meets the requirements of this regulation if:

(1) The shop-fabricated AST is a single-walled AST with a capacity of 10,000 gallons or greater;

(2) The shop-fabricated AST is a double-walled AST with a capacity of 10,000 gallons or greater, unless the double-walled shop-fabricated AST meets the conditions in §B of this regulation; or

(3) The Department determines that the AST system poses a water pollution hazard due to its size, nature, or location.

B. An owner, an operator, and a person in charge of an AST system with a double-walled shop-fabricated AST is exempt from the requirement to install a secondary containment dike around the double-walled shop-fabricated AST provided the AST system:

(1) Has overfill prevention equipment in accordance with Regulation .08 of this chapter;

(2) Has a method of release detection in accordance with Regulation .09 of this chapter;

(3) Is located within a secured area; and

(4) Meets one of the following conditions:

(a) The AST system is part of a motor fuel dispensing facility, has a storage capacity not greater than 12,000 gallons, and stores a Class I liquid;

(b) The AST system is part of a motor fuel dispensing facility, has a storage capacity not greater than 15,000 gallons, and stores a Class II liquid; or

(c) The AST system is not part of a motor fuel dispensing facility, has a storage capacity not greater than 20,000 gallons, and stores a Class II liquid or Class III liquid.

C. Compliance Schedule.

(1) An owner, an operator, and a person in charge of an AST system with a shop-fabricated AST that has a new secondary containment dike shall meet the requirements in §§D-J of this regulation upon installation of the secondary containment dike.

(2) Unless otherwise provided in this regulation, an owner, an operator, and a person in charge of an AST system with a shop-fabricated AST that has an existing secondary containment dike shall meet the requirements in §§D-J of this regulation not later than:

(a) 2 years after June 13, 2022; or

(b) Another time period approved by the Department.

D. An owner, an operator, and a person in charge of an AST system with a shop-fabricated AST required under §A of this regulation to have a secondary containment dike shall ensure the secondary containment dike:

(1) Can contain a spill, release, or discharge from an AST and connected piping within the secondary containment dike surrounding the AST until the spill, release, or discharge is detected and removed;

(2) Is designed by a professional engineer;

(3) Is approved by the Department;

(4) Is designed with consideration given to the soil and groundwater conditions at the oil storage facility or oil handling facility;

(5) Prevents movement of oil into, near, or in an area likely to pollute waters of the State;

(6) Provides safe ingress and egress for an individual;

(7) Prevents water accumulation at an AST foundation;

(8) If the secondary containment dike surrounds two or more ASTs, is subdivided in accordance with NFPA 30 "Flammable and Combustible Liquids Code";

(9) If the secondary containment dike is exposed to precipitation, is designed and constructed to effectively hold 110 percent of the maximum capacity of the largest AST in the area enclosed by the secondary containment dike; and

(10) Is constructed so that the secondary containment dike, upon testing, meets one of the following permeability criteria:

(a) A permeability of less than 10^-4 centimeters per second; or

(b) A product level drop rate of less than 1 centimeter per 3 hours.

E. Within 90 days of conducting a permeability test on a secondary containment dike or another time period approved by the Department, an owner, an operator, and a person in charge of an AST system with a shop-fabricated AST shall repair or replace a secondary containment dike that does not meet one of the permeability criteria listed in §D(10) of this regulation.

F. An owner, an operator, and a person in charge of an AST system with a shop-fabricated AST that has an earthen secondary containment dike shall conduct permeability testing on the earthen secondary containment dike according to the following requirements:

(1) For an existing earthen secondary containment dike that has not been previously tested for permeability, test the existing earthen secondary containment dike for permeability using an industry standard approved by the Department not later than 1 year after June 13, 2022;

(2) Test a new earthen secondary containment dike for permeability using an industry standard approved by the Department upon completing the construction of the earthen secondary containment dike and prior to placing the AST in-service; and

(3) Submit the results of the permeability testing to the Department not later than 60 days after the test.

G. An owner, an operator, and a person in charge of an AST system with a shop-fabricated AST that has a secondary containment dike shall maintain written verification that the secondary containment dike meets the applicable requirements in §§D-F of this regulation in accordance with Regulation .14 of this chapter.

H. An owner, an operator, and a person in charge of an AST system with a shop-fabricated AST that has a secondary containment dike shall ensure a drain valve installed in the secondary containment dike is:

(1) Not a flapper-type valve; and

(2) Except when being used to drain trapped water in accordance with §I of this regulation, kept completely closed and locked at all times.

I. When draining trapped water from a secondary containment dike, an owner, an operator, and a person in charge of an AST system with a shop-fabricated AST that has the secondary containment dike shall:

(1) Ensure the drainage leaving the secondary containment dike does not have any visible evidence of oil sheen;

(2) Designate a representative to supervise, monitor, and document each drainage event from the secondary containment dike;

(3) Keep a log that includes the following information for each secondary containment dike drainage event:

(a) The name of the employee supervising, monitoring, and documenting the drainage;

(b) The date of drainage event;

(c) The time the drainage event started and ended;

(d) The estimated volume of water drained; and

(e) A description of the water quality, such as the presence of an oil sheen; and

(4) Maintain the log required by §I(3) of this regulation in accordance with Regulation .14 of this chapter.

J. An owner, an operator, and a person in charge of an AST system with a shop-fabricated AST that has a secondary containment dike shall maintain the secondary containment dike clear and free of:

(1) Vegetation; and

(2) Flammable and combustible materials, including oil.

Md. Code Regs. 26.10.17.07

Regulation .07 adopted effective 49:12 Md. R. 642, eff. 6/13/2022