Ft. Morgan Water Treatment Plant - Executive Summary |
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Introduction The City of Fort Morgan, Colorado operates a 10-million gallon per day treatment plant. This Risk Management Plan (RMP) covers the Section 112r regulated substances maintained at the Fort Morgan Water Treatment Plant, which will be referred to herein as the Plant. Plant Description The Plant maintains only one regulated substance on site: chlorine. The maximum possible chlorine storage is 14,000 pounds, which exceeds the RMP threshold quantity of 2,500 pounds. The storage and management of chlorine is addressed in this RMP. The Plant is located at 14625 Rt. 8, Wiggins, Colorado, which is in a rural area. The surrounding area has very few obstructions. The Worst Case Release Scenario The worst case release scenario for chlorine was calculated as the release of a single one-ton cylinder in accordance with the definition provided in the Environmental Protection Agency guidance for RMP development. The chlorine storage is enclosed, so the buiding acts as a passive miti gation measure for the worst-case release. The conditions of the scenario, such as release time and weather status are those provided in the EPA Off-Site Consequence Analysis Guidance. 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 2.2 miles under the specified weather conditins before despersing in the atmosphere to a harmless concentration. Within that radius of the Plant, it is estimated that 20 people could potentially be affected. There are no public or environmental receptors with this radius. This type of release would only occur if the valve was broken off the cylinder, or the cylinder was breached. The likelyhood of such an incident occurring is minimal. Alternative Release Scenario The alternative release scenario is, by definition, a more likely release scenario than the worst case. The type of system failure se lected for the alternative release was the loss of chlorine due to the rupture of both diaphragms in the vacuum regulator. The chlorine would leak from a 1/2-inch opening. The leak would continue until the chlorine detection alarm sounded and the valve on the cylinder would be closed. The Wiggins Fire Department would respond to the leak. The time for the response was estimated at 15 minutes. The fire response personnel woudl enter the chlorine area in protective clothing and close the valve on the leaking cylinder. The results of the Off-Site Consequence Analysis using RMP*Comp, indicated that the chlorine would travel approximately 0.1 miles under the specified weather conditions in order to disperse in the atmosphere to a harmless concentration. Within that radius of the Plant, it is estimated that 10 people could potentially be affected. Process Hazard Assessment A process hazard assessment was performed on the chlorine system beginning with cylinder unloading and ending w ith the chlorine in solution. A checklist and a modified "What if" analysis were used. General questions regarding the storage and use areas as well as protocols for the management of the chlorination system were answered. Following the checklist, each valve, line, and piece of equipment in the system was assessed from the cylinder to point of chlorine injection 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, potential failures, maintenance and inspection concerns, and standard operating procedures were reviewed for each point in the system. 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 sign ificant training before being allowed to work on the system. At the beginning and end of the daily operating period, 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 operations control area. Personnel are trained routinely on safety concerns and general operation procedures as well as emergency procedures. Emergency Response Plan All leaks requiring the use of a chlorine "B" kit will be managed by the Wiggins Fire Department. The Plant has an agreement with the Fire Department, which is included in this plan. A complete copy of the Emergency Response Plan (Contingency Plan) is also included. Accident History The Plant has had no chlorine releases in the past five years. |