Admiral Doyle Wastewater Treatment Plant - Executive Summary |
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Executive Summary LDEQ Facility ID Number 30581. This Risk Management Plan has been developed for The City of New Iberia's Admiral Doyle Waste Water Treatment Plant in accordance with 40 CFR part 68. This facility is subject to the requirements of this program due to the usage and storage of chlorine in an amount greater than 2,500 lbs. and sulfur dioxide in an amount greater than 5,000 lbs. The facility is located within the city limits of New Iberia, LA on the corner of Admiral Doyle Dr. and Bank Ave. The area surrounding the facility consists of residents and commercial buildings. The latitude and longitude of the facility was obtained from the USGS Topographic map entitled New Iberia South, LA. The facility treats waste water from the surrounding residential and commercial entities. This treatment includes the chlorination and de-chlorination, with sulfur dioxide, of the water supply prior to being disposed of into the adjacent Commercial Canal. A continuous rate of chlor ine is mixed with water in the injection room. Once the chlorine is injected into the water it is diluted to an amount which is less than 1% chlorine by weight. The chlorine-water mixture is then routed to the contact chamber where the waste water is treated. The part of this process that is subject to the RMP requirements begins with the chlorine supply (6-1 ton cylinders) and ends at the point where it is mixed with the water. The facility uses approximately one cylinder of chlorine every two weeks. The waste water plant stores a maximum of six-one ton cylinders (12,000 lbs.) of chlorine at any one time. For the de-chlorination process a continuous rate of sulfur dioxide is mixed with water in the injection room and the mixed stream is sent to the effluent of the chlorination contact chamber. Once the sulfur dioxide is mixed with water it is diluted to an amount that is less than 1% by weight. The part of the de-chlorination process that is subject to the RMP requirements begins with the sulfur dioxide supply (3-1 ton cylinders) and ends at the point where it is mixed with the water. The facility uses approximately one cylinder of sulfur dioxide every two weeks. The plant stores a maximum of three-one ton cylinders (6,000 lbs.) of sulfur dioxide at any one time. The worst-case release scenario for both chlorine and sulfur dioxide involves the release of the greatest amount from a single vessel as required by 40 CFR part 68.25 (b)-Determination of worst-case release quantity. This type of release may occur as a result of catastrophic natural or other unforeseen disaster. A release of 2,000 lbs. for a duration of 10 minutes results in a 1.3 mile distance to the toxic endpoint for both chlorine and sulfur dioxide. This endpoint, developed by the American Industrial Hygiene Association, is the location where minimal effects of exposure to the toxic substance are likely to occur. This distance encompasses approximately three-fourths of the city of New Iberia from Hwy 329 at Center St. to Main St at Lee St. and from Hopkins St. at Robertson St. to Jefferson Terrace St. just before Hwy 83. According to a January 1999 publication of July 1, 1998 population estimates the population of New Iberia is approximately 33,850. It is estimated that the worst-case circle encompasses 75% of the population (25,388). An alternative case or a more likely release of sulfur dioxide could occur as a result of a valve, regulator seal, or gasket leak. The plant is equipped with a SO2 leak detection system that has sensors located near the cylinders. If a 1 ppm leak of SO2 is detected an alarm will sound and according to facility personnel, it would take less than 1 minute for on-site personnel to respond by closing the flow valve and thus stopping the leak. Although the facility is not equipped with a chlorine leak detection system, the presence of facility employees 24 hours per day prohibits a similar leak from the chlorine cylinders from going unnoticed. Assuming the substance (either chlorine or sulfur dioxide) flashes to the atmosphere at a rate of 0.5 ft3/min for a maximum of 5 minutes (0.5 lbs. of chlorine or 0.4 lbs. of sulfur dioxide) the distance to the toxic endpoint is less than 0.1 mile. The area within 0.1 mile of the facility extends across Admiral Doyle Dr. from Elm St. to Ann St. and covers the southeast corner of Bank Ave Park to 300 feet on the south side of Admiral Doyle Dr. Based on a maximum population density of 8,268 p/mi2, the population within 0.1 mile of the facility is approximately 65. This type of release is only expected to impact those persons in the immediate vicinity of the chlorine or sulfur dioxide cylinders. The facility has not experienced a release which caused on or off site injury, death or property damage within the past five years. Facility employees are properly trained in the operating and maintenance procedures. These procedures are kept on-site within the O & M Manuals. Records of inspections, testing, and maintenance are also kept on file at the facility. Written emergency response procedures are kept on file at the facility. The emergency response procedures describe actions for incidental response for facility personnel in the event of a relatively small leak or release that does not pose an immediate safety or health hazard. If incidental response activities do not halt the release or the release poses an immediate safety or health hazard, specially trained response personnel are contacted to take over response activities. In the event of a toxic leak or release, employees are instructed to assess the situation and to determine if it is safe to discontinue the leak without the help of emergency responders. If there are any doubts as to the safety of the release, the employees are to initiate the written notification procedures. Current safety features installed at the facility include the leak detection system, 24 hr/day on-site personnel, and a metal roll-away cover to protect the cylinders from the heating effects of direct sunlight. Inspections of the process and associated equipment are conducted on a regular basis to avoid failure and detect normal wear and tear of equipment parts. |