Hazardous spills

Tlie area, A, in tliis equation is tlie entire surfrce area of the vessel, not the wetted surface area wliich maybe used in related equations. However, tlie error introduced by tliis difference in tlie calculation for a full tank is small. 

For water spray protection over tlie entire surfece area of tlie tank designed witli a density of 0.25 gpiii/fl or more F=0.3. For an approved fire resistant installation, F=. 3. For an underground or buried tank, F=0.3. For water spray witli good drainage F=0.15. 

Tlie gas discliarge rate from tlie relief valve, G , can tlien be calculated using tlie following foniiula  

A detailed discussion of tlie fonnulas used in NFPA Codes can be found in Appendix B of tlie Flanunable and Combustible Liquids Code Handbook. API RP520 recoimnends a similar foniiula applicable to pressurized storage of liquids at or near tlieir boiling point where tlie liquids liave a liigher molecular weight tlian tliat of butane. 

All of tlie recoimnended heat flux equations in API 520 and NFPA Codes tliat are used to design relief valve assmne tliat tlie liquids are not self-reactive or subject to runaway reaction. If tliis situation arises, it is necessary to include tlie heat of reaction and tlie rate of the reaction into account in sizing the relief device. 

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This chapter addresses the potential for hazardous air emissions from environmental remediation sites. These emissions can occur at hazardous spill locations, at undisturbed remediation sites, and during cleanup of remediation sites under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) or the Superfund Amendments and Reauthorization Act (SARA). Air emissions may pose a potential health risk at these sites. 

Hazardous Spills Emergency +1 800 478-9300 after hours Fax +1 907 465-5097 E-mail website envircon.state.ak.us Web site www.state.ak.us/dec... 

Accidents such as fires, explosions, toxic emissions, and hazardous spills, are dealt with in Uie next cliapter. Tlie decision to include Uiese in a separate chapter was not as easy as one would expect since the topics of both chapters could be classified as accidents. However, in order to treat the accidents in a cause and effect marmer, it was felt Uiat fires, explosions, etc., could well be considered an effect arising from Uie generic accidents discussed in Uiis cliapter. 

Fires, Explosions, Toxic Emissions, and Hazardous Spills... 

The next two sections discuss accidents tiiat result in the release of a toxic emission or a liazardous spill. In general, a to.xic emission can be considered to be either continuous or instantaneous. In tliis section only tlie atmospheric effects of toxic emissions are considered. Hower cr, hazardous spills (ne 1 section) usutilly denote a liquid contamination of either soil or water systems in addition a liazardous chemical spill may lead to tlie release of toxic emissions. 

Huibregtse, K.R. and Kastman, K.H., Development of a System to Protect Groundwater Treatment by Hazardous Spills on Land, U.S EPA, Edison, NJ, 1979. 

A water spray protection system around vessels is recommended to prevent this type of failure. These water spray protection systems, commonly called deluge systems, are designed to keep the vessel cool, flush away potentially hazardous spills, and help to knock down gas clouds.13 Deluge systems can also provide enough time to transfer material out of a storage tank into another (safe) area. 

The accomplishment of these objectives involved two different research grants Grant No. R 805 466010, "Collection and Treatment of Wastewater Generated by Pesticide Applicators", from the Oil and Hazardous Spills Branch, U.S. Environmental Protection Agency and "Removal of Five R-PAR and Near R-Par Herbicides from Wastewater", from North Central Regional Pesticide Impact Assessment Program. 

If a small quantity of an acid or a base is spilled in a laboratory, you can use a neutralization reaction to minimize the hazard. To neutralize a basic solution spill, you can add solid sodium hydrogen sulfate or citric acid. For an acidic solution spill, you can use sodium hydrogen carbonate (baking soda). Note that you cannot use a strong acid or base to clean up a spill. This would result in another hazardous spill. As well, the neutralization reaction would generate a lot of heat, and thus produce a very hot solution. 

In the same vein, certain waste-handling procedures, even those performed intermittently, can result in very serious contaminant exposure without proper precautions. Workers need to be instructed in the proper procedures for cleaning up spills and accumulated debris. Spilled materials can become airborne and pose an inhalation hazard. Spills and chemical process wastes may end up in the waste-water treatment facilities where they again can be volatilized into the air and result in unexpected worker exposure. 

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