Illinois Administrative Code › Title 41 - FIRE PROTECTION › Part 175 - TECHNICAL REQUIREMENTS FOR UNDERGROUND STORAGE TANKS AND THE STORAGE, TRANSPORTATION, SALE AND USE OF PETROLEUM AND OTHER REGULATED SUBSTANCES › Subpart F - RELEASE DETECTION › Section 175.630 - Methods of and Requirements for Release Detection for Tanks

Current through Register Vol. 48, No. 28, July 12, 2024
Owners and operators of petroleum USTs shall provide release
				  detection on tanks. Only one approved method of primary release detection is
				  required for each tank although multiple methods are acceptable. If present,
				  secondary release detection systems must be maintained. No method of release
				  detection shall be used unless that method has been approved by OSFM. USTs must
				  be monitored at least every 30 days for releases using one or more of the
				  methods listed below:
a) Manual Tank
				Gauging
1) Only tanks of 600 gallons or less
				nominal capacity may use the method described in this subsection (a). All
				owners or operators using manual tank gauging methods must conduct a monthly
				reconciliation and maintain those reconciliation records. The requirements for
				this type of release detection shall adhere to requirements listed in this
				subsection for the specific tank sizes noted:
Requirements
Nominal tank capacity
Whether use of manual tank gauging for release
							 detection is allowed
Time limit on use of manual tank gauging for
							 release detection
600 gallons or less
Allowed as sole method of release detection
Allowed indefinitely
601-2,000 gallons
Not allowed
Not allowed
Over 2,000 gallons
Not allowed
Not allowed
2)
				Standards
A) In order to be eligible to
				continue to use manual tank gauging alone (tanks 600 gallons or less only), the
				following standards regarding maximum variation between beginning and ending
				product level measurements shall be adhered to:
Standards
Nominal tank capacity
Weekly standard (one test)
Monthly standard (average of 4 tests taken once
							 weekly over a 4-week period)
600 gallons or less
10 gallons
5 gallons
B) A
				leak is suspected and subject to the requirements of 41 Ill. Adm. Code
				176.300
				through
				176.360
				if the variation between beginning and ending measurements exceeds the weekly
				or monthly standards as listed in this subsection (a). Weekly inventory
				records, monthly reconciliation records, and related records shall be
				maintained for 2 years in order to continue to be eligible to continue to use
				manual tank gauging.
3)
				Manual tank gauging shall also meet the following requirements:
A) Tank liquid level measurements are taken
				at the beginning and ending of a period of at least 36 hours during which no
				liquid is added to or removed from the tank;
B) Level measurements are based on an average
				of 2 consecutive stick readings at both the beginning and ending of the
				period;
C) The equipment used is
				capable of measuring the level of product over the full range of the tank's
				height to the nearest 
				1/8
				inch;
D) The measurement of any
				water level in the bottom of the tank is made to the nearest 
				1/8 inch at least
				once a month; and
E) All personnel
				involved in performing manual tank gauging measurements, recordkeeping and
				related performance must be knowledgeable in that performance and
				activities.
4) Manual
				tank gauging cannot be used as a method of release detection for any tank that,
				after passing only a noninvasive tank integrity assessment, was upgraded using
				the cathodic protection method.