LaRoche Industries, Inc. — Hazardous Materials Safety Interpretation

Page 1of Transportation U.S. Department 400 Seventh St., S.W. Washington, D.C. 20590 Special Programs Research and Administration JUL 2 7 2000 Mr. Cariton W. Hendrix Ref. No. 00-0184 DOT Compliance Manager LaRoche Industries, Inc. 1100 Johnson Ferry Road Atlanta, Georgia 30342 Dear Mr. Hendrix: This responds to your letter, dated June 21, 2000, concerning loading and unloading requirements for cargo tanks under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you ask for a definition of "liquid discharge system"as used in § 177.834()(2). The liquid discharge system of a cargo tank consists of those components downstream of the tank that are used for unloading the tank. Thus, the liquid discharge system includes the valve at the product discharge outlet and all piping, flanges, valves, hoses, fittings, and connections downstream of the product discharge outlet. On MC 330, 331, and non-specification tanks authorized under § 173.315(k), the liquid discharge system also includes the primary discharge control system and components used for emergency discharge control, in addition to the valve at the product discharge outlet and all piping, flanges, valves, hoses, fittings, and connections downstream of the product discharge outlet. (See § 178.337-1(g) for definitions of "emergency discharge control" and "primary discharge control system.") On chlorine cargo tanks, the liquid discharge system includes the internal excess flow valve and the external stop, or angle, valve, in addition to all piping, flanges, valves, hoses, fittings, and connections downstream of the product discharge outlet. I hope this information is helpful. If you have further questions, please do not hesitate to contact this office. Sincerely, orn I Allo Thomas G. Allan Senior Transportation Regulations Specialist Office of Hazardous Materials Standards 000184 177.834#

Page 2LA ROCHE INDUSTRIES INC. 1100 JOHNSON FEARY ROAD, N.E. ATLANTA, GA 30342-1708 (404) 851-0300 Gorsky 3177.834 June 21, 2000 00-0184 Mr. Thomas G. Allan Senior Transportation Regulations Specialist Office of Hazardous Materials Standards U.S. Department of Transportation 400 Seventh Street, S.W. Washington, D.C. 20590 Dear Mr. Allan: I have been reviewing the general requirements found in 49 CFR, 177.834 for cargo tank loading and unloading. 49 CFR 177.834 (i) (2) uses the term "liquid discharge systems" and I am unable to find a definition for this terminology. I contacted the HazMat information line and they were unable to assist me. Part of my uncertainty about this term comes from the difference in the parameters for cargo tanks with a capacity less than or equal to 3500 water gallons and those cargo tanks with a capacity greater than 3500 water gallons. Please assist me by providing a clear definition of what constitutes a "liquid discharge system" on the different cargo tanks. Sincerely, Cautton lo, Hendex Carlton W. Hendrix DOT Compliance Manager#