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. e EXHIBIT A DESCRIPTION OF THE PROJECT LA PORTE FACILITIES 1. BLOWDOWN SYSTEM Project No. A-43 PURPOSE: To provide caustic scrubbing systems capable of absorbing phosgene and hydrochloric acid from various sources in the La Porte Site and destroy- ing them by chemical reaction. PROCESS DESCRIPTION: The project consists of five complete, independently operated, scrubber systems located at appropriate locations in the La Porte Site. Each system consists of two caustic solution feed tanks, two knockout drums, two absorption columns, two heat exchangers and ten (10) pumps. One dispersion stack will service all scrubbers. Phosgene and hydrochloric acid from pressure relief devices or from equipment clearing systems are transferred by pipeline through one or two knockout drums and then through an absorption column containing a circulating, dilute caustic solution. Here the phosgene and hydro- chloric acid are first absorbed and then reacted with sodium hydroxide and water to produce sodium chloride, sodium carbonate, carbon dioxide and water. Heat liberated by the absorption and reaction process is removed by a heat exchanger in the caustic solution stream circulating about each column. Fresh caustic solution is made up on demand to each column from 24,000 gallon storage tanks which are maintained at constant level by diluting a 50% solution. Vents from each scrubber system are passed by pipeline to an air injected dispersion tower and exposed to an ammonia/stream environment before release to the atmosphere. The spent caustic and ammonia solu- tions released from the scrubber systems or vent stack are collected by pipeline and passed through an existing wastewater treatment system before discharging to the La Porte Site outfall. A-I