Only tanks of 1,000 gallons or less capacity may use manual tank monitoring as the sole method of release detection. Tanks of 1,001 to 2,000 gallons, inclusive, may use manual tank monitoring in place of manual inventory control, but require tank tightness testing in accordance with § 74:56:01:26. Tanks of greater than 2,000 gallons may not use manual tank monitoring to meet the release detection requirements.

1. (onetest) of test

2. (averageoffourtests) 550 gallons or less

   10 gallons

   36 hours

   5 gallons

   551-1,000 gallons

   9 gallons

   44 hours

   4 gallons

   1,001-2,000 gallons

   26 gallons

   36 hours

   13 gallons

   1,000 gallons (if tank

   12 gallons

   58 hours

   6 gallons

   is 48" x 128")

Tank liquid level measurements shall be taken at the beginning and end of the time period specified in the table in this section, during which no liquid may be added to or removed from the tank. The level measurements shall be based on an average of two consecutive stick readings at both the beginning and end of the period. The equipment used must be capable of measuring the level of product over the full range of the tank's height to the nearest one-eighth of an inch.

A leak shall be suspected if the variation between beginning and ending measurements exceeds the weekly or monthly standards set forth in the following table:

Weekly standard

Minimum duration

capacity

Source: 18 SDR 62, effective October 10, 1991; transferred from § 74:03:28:11.06, July 1, 1996.

General Authority: SDCL 34A-2-93 , 34A-2-99.

Law Implemented: SDCL 34A-2-98 , 34A-2-99.