# COMAR Title 26 — Department of the Environment

## Subtitle 10 — Oil Pollution Control and Storage Tank Management

### Chapter 05 — UST Systems: Release Detection

#### Regulation .04 Inventory Control.

*COMAR 26.10.05.04*

A. Inventory Variations.

  (1) An owner and an operator of a UST system shall review the reconciled inventory records required by COMAR 26.10.04.01 for the following:

    (a) Inventory variations exceeding 1 percent plus 130 gallons of the metered quantity of a regulated substance each calendar month; and

    (b) Daily inventory records that show 7 consecutive days of shortage totaling 80 gallons or more.

  (2) An owner and an operator of a UST system shall conduct a review of reconciled inventory records at the following frequencies:

    (a) Review inventory variation as required under §A(1)(a) of this regulation monthly; and

    (b) Review daily inventory records as required under §A(1)(b) of this regulation daily.

  (3) Reporting and Investigating Inventory Variations.

    (a) An operator of a UST system shall report a variation or shortage as described in §A(1) of this regulation to the owner of the UST system;

    (b) Upon discovery of an inventory variation, an owner and an operator of a UST system shall immediately investigate the cause of the variation or shortage;

    (c) If the investigation required under §A(3)(b) of this regulation reveals no indication of a discharge or release from a UST system, an owner and an operator of a UST system shall state the cause of the inventory variation or shortage in the daily inventory records; and

    (d) If the investigation required under §A(3)(b) of this regulation reveals a discharge or release from a UST system, an owner and an operator of a UST system shall follow the procedures established under COMAR 26.10.08.

B. The Department may require an owner and an operator of a UST system to perform a precision tightness test of the UST system:

  (1) If the owner and the operator fail to reconcile daily inventory records as specified in COMAR 26.10.04.01 and review the reconciled records in accordance with §A of this regulation;

  (2) If the owner and the operator fail to comply with monthly release detection requirements of Regulation .05 of this chapter; or

  (3) For any other good cause as determined by the Department.

C. The Department may require an owner and an operator of a UST system to perform a precision tightness test of the UST system and install monitoring wells or conduct a site assessment if there is reason to believe there is or may have been a discharge or release of a regulated substance from the UST system.