Surge Control Tanks: What are They and How are They Regulated?
Some bulk gasoline terminals and most all pipeline breakout stations have emergency relief tanks that are only used when there is over-pressurization in a pipeline that needs to be relieved. Also known as surge control tanks, these emergency relief tanks typically do not store product very often (if ever), so why are they regulated the same as a gasoline storage tank that receives product from a pipeline? Well, actually they are not regulated the same way.
The gasoline distribution GACT found at 40 CFR Part 63, Subpart BBBBBB defines a surge control tank as a tank or vessel only used for controlling pressure in a pipeline system during surges or other variations from normal operations. Surge control tanks that contain gasoline products are still subject to Subpart BBBBBB but have less stringent requirements. Table 1 to Subpart BBBBBB lists a specific compliance option for facilities with surge control tanks. These facilities are required to:
Equip each tank with a fixed roof that is mounted to the tank in a stationary manner and with a pressure/vacuum cent with a positive cracking pressure of no less than 0.50 inches of water; and
Maintain all openings in closed positions when not in use.
These requirements are much less stringent than the equipment standards for regular gasoline storage tanks. For example, surge control tanks are not required to have a floating roof to control evaporative losses. This is in stark contrast to normal gasoline tanks which are required to have a floating roof as well as specific rim seal and deck fitting configurations.
If the only gasoline tanks at the terminal are surge control tanks, the facility meets a different classification altogether. A pipeline operation used to maintain the desired pressure and flow of product through the pipeline, and not containing gasoline storage tanks other than surge control tanks, is considered a “pipeline pumping station.” Pipeline pumping stations are still subject to Subpart BBBBBB but are not subject to the testing, monitoring, and record keeping requirements like a normal bulk gasoline terminal. On more than one occasion, CFR has had to point out these differences to regulators to avoid imposing unnecessary restrictions on these surge control tanks.
CFR has been working with tank operators for over 30 years and has a long track record of providing support for tank operators in the petroleum and chemical industry. Contact CFR to learn more about we can assist with your storage tank cleaning emissions program.