Olathe Water Treatment Plant No. 1 - Executive Summary |
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EXECUTIVE SUMMARY Introduction The City of Olathe operates two water treatment facilities. Water Treatment Plant Number 1 is a 4-million gallon per day, conventional plant. This Risk Management Plan (RMP) covers the Clean Air Act, Section 112r regulated substances maintained at Water Treatment Plant Number 1, which will be referred to herein as the Plant. Plant Description The Plant maintains two regulated substances on site: ammonia and chlorine. The maximum ammonia storage is 8,380 pounds, which is well below the RMP rule threshold quantity of 20,000 pounds. Chlorine storage is 8,000 pounds, which exceeds the RMP threshold quantity of 2,500 pounds. The storage and management of chlorine is addressed in this RMP. A description of the chlorine system is included in this section. The Plant is located at 600 South Curtis, Olathe, KS, which is in an urban area. The surrounding population includes commercial and residential properties as well as public access sites. The Plant is located 5000 feet west of Interstate 35 and 1500 feet west of the Atchison, Topeka and Santa Fe railroad and 2500 feet north of Old 56 Highway. The Plant is located adjacent to Water Works Lake. The Worst Case Release Scenario The worst case release scenario for chlorine was calculated as the loss of a single one-ton cylinder in accordance with the definition provided in the Environmental Protection Agency guidance for RMP development. Only passive control systems were taken into consideration, such as the containment provided by the building. The conditions of the scenario, such as release time and weather status are those provided in the EPA Off-Site Consequence Analysis Guidance. Determination of the area of potential impact was determined using RMP*Comp, modeling software developed by the EPA. The results of the Off-Site Consequence Analysis indicated that the chlorine would travel approximately 4,750 feet under the specified weather conditions before dispersing in the atmos phere to a harmless concentration. Within that radius of the Plant, an estimated 8,900 persons could potentially be affected. Maps of the area and a list of the types of receptors in the potential impact area are provided in the Off-Site Impact Analysis Section. The list of potential receptors includes: - Kansas School for the Deaf - Nursing homes (3) - Daycare facilities (4) - Salvation Army - County Jail - County courthouse - County administration building - First Christian Church - VoTech school - Elementary school (2) - First Methodist Church - Church of God Holiness - St. Marks Lutheran Church - Olathe Christian Church The likelihood of such an incident occurring is minimal. Historically, there have been no recorded releases of a fusible plug blowout from stationary chlorine tanks (White, 1999 ). Alternative Release Scenario The alternative release scenario is, by definition, a more likely release scenario than the worst case. Engineered controls, such as the chlorine dete ction system and alarm, are considered in the analysis. The type of system failure selected for the alternative release was the loss of chlorine due to failure of the two diaphragms on one of the vacuum regulators. Failure of the diaphragms would allow for loss of chlorine from the cylinder through the vacuum regulator to the atmosphere. The chlorine would be leaked from a one inch line on the vacuum regulator. The leak would continue until the chlorine detection alarm sounded and the system with the defective vacuum regulator could be switched to another of the two tank systems on line. Because chlorine would have leaked into the chlorine room, response would be made by the Olathe Fire Department under their agreement with the Plant. The time for the response was estimated at 15 minutes. Once on site, the fire response personnel would enter the room in protective clothing and manually switch the chlorine feed to the unaffected tank. The results of the Off-Site Consequence Anal ysis using RMP*Comp, indicated that the chlorine would travel approximately 3,200 feet under the specified weather conditions in order to disperse in the atmosphere to a harmless concentration. Within that radius of the Plant, an estimated 4,500 persons could potentially be affected. Maps of the area and a list of the types of receptors in the potential impact area are provided in the Off-Site Impact Analysis Section. Process Hazard Assessment A process hazard assessment was performed of the chlorine system beginning with cylinder unloading and ending with the chlorine in solution. A combination checklist and modified "What if" type of analysis was used. General questions regarding the storage and use areas as well as practices and protocols associated with the management of the chlorination system were answered. A copy of that checklist in included in this plan. Following the checklist, the system was methodically assessed/evaluated from the cylinder to point of chlorine inject ion using a system flow diagram. The valves and other points in the system where chlorine could be released are numbered on the flow diagram. The assessment is formatted in accordance with those numbers. Compliance with code requirements, considerations of potential failure, maintenance and inspection concerns, and standard operating procedures were reviewed for each point in the system. Comments are summarized in the Process Hazard Analysis section. Prevention System The Plant has an operation, maintenance and inspection system designed to review each element of the chlorination system routinely. There are Operation and Maintenance manuals for each major piece of equipment, and personnel receive significant training before being allowed to work on the system. At the beginning of each of the three shifts and as each cylinder is changed, the valves and piping are tested for leaks. There are standard operating procedures (SOPs) for startup, shutdown, normal operation, and emergency operation. The SOPs are written and posted in the appropriate areas. Personnel are trained routinely on safety concerns and general operation procedures as well as emergency procedures. The system is equipped with chlorine detectors and alarms that indicate leaks. The tanks are stored and used inside the building. Ventilation is provided in the chlorine room only when a worker is present. The lack of pressure gas piping significantly reduces the risk of a chlorine leak. Emergency Response Plan Plant personnel are allowed and trained to respond to leaks that can be managed by turning off a valve. Any response requiring entry in a dangerous atmosphere or use of a chlorine repair kit is to be managed by the Olathe Fire Department. The Plant has an agreement with the Fire Department. A complete copy of the emergency plan and the Fire Department Guidelines is included in this plan. Accident History The Plant has had no chlorine releases in the past five years. Tank mounted vacu um regulators were added to the chlorine system a few years ago which eliminated the use of chlorine pressure lines. |