City of Edmond Water Treatment Plant - Executive Summary |
|
EXECUTIVE SUMMARY The City of Edmond has adopted this Program in order to implement 40 CFR 68, the federal requirements regulating Risk Management of Highly Hazardous Chemicals. This program will help prevent the occurrence of, or minimize the consequences of, catastrophic release by stating our policies and guidelines for the management of process hazards in start-up, operation, inspection, maintenance and the other matters addressed in the federal standard. Our program calls for maximum employee participation and includes all elements of the employee participation provisions of the federal standard. We shall, at a minimum: (1) consult with employees and their representatives on the conduct and development of the process hazard review and other elements of the risk management plan, and (2) provide to our employees and their representatives access to the process hazard review and all other information required to be developed under that standard. Accidental Release Prevention and Emergency Response Policies The City of Edmond believes that preventative maintenance is the key to minimizing the potential for accidental releases. Standard Operating Procedures have been reviewed and revised to enable the employees to perform their work in a safe and efficient manner. The City of Edmond has chosen to be a non-responding facility in the event of an emergency. Responsiblity for emergency response to an accidental release has been given to the Edmond Police and Fire Departments and the State and Local Emergency Planning Committee. Stationary Source and Regulated Substances The Water Treatment Plant (WTP) utilizes chlorine for disinfection of treated water. The maximum inventory and threshold quantities for chlorine is shown below: Chemical Maximum Inventory (lbs.) Threshold Quantity (lbs.) Chlorine 12,000 2,500 Worst-Case and Alternative Release Scenari os The Offsite Consequence Analysis (OCA) was conducted for a worst-case release and an alternative release scenario. A dense gas dispersion model (SLAB) was used to determine endpoint distances for both scenarios. The population data was estimated using the Landview block uniform density group method. The model input parameters and assumptions fulfilled 40 CFR 68 requirements and are submitted in the following table along with modeling results: SLAB Input Parameters Worst-Case Scenario Alternative Scenario Endpoint Concentration (mg/l) 0.0087 0.0087 Windspeed (m/s) 1.5 3.0 Atmospheric Stability Class F D Temperature (F) 77 77 Humidity (%) 50 50 Height of Release (m) 0.01 0.01 Surface Roughness (m) 1.0 1.0 Impact Radius (miles) 4.2 0.8 Affected Population (persons) 3,300 80 The WTP is located in a predominantly rural area near Lake Arcadia. Sensitive receptors identified within the worst-case scenario circle of impact are residences, churches, schools and a public recreation area. Only residences are located in the alternate scenario circle of impact. General Accidental Release Prevention Program The WTP has acquired knowledge regarding process safety and hazard assessment. Under Program Level 2, the WTP has used this information to implement policies and procedures related to operations, training, mechanical integrity, incident investigations and compliance audits in order to create a safe w orkplace. Chemical Specific Prevention Steps The completion of the Hazard Assessment resulted in the recognition of preventive steps to eliminate or minimize the possibility for accidental releases and employee exposure to chemical risk. Five-Year Accident History In the last 5 years there have not been any accidental releases from the chemical process that resulted in deaths, injuries, evacuations, sheltering-in-place, property damage, or environmental damage. |