City Of Indianola Public Works Department - Executive Summary

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I. General Facility and Regulated substance Information 
The City of Indianola Public Works Department provides potable water and sanitary sewer service to its customers through its water distribution system, sewer collection system and wastewater lagoon. The facility has two regulated processes which use chlorine gas and qualify for program 2 regulations for EPA's Risk Management Plan. The first process includes the wastewater lagoon disinfection system which uses gaseous chlorine in 1-ton containers.  The total quantity maintained at the facility is 6000 pounds.  The second process is the storage of 150 pound cylinders for use in the water supply system.  Theses cylinders are stored in public works building No. 1.  The maximum amount stored is 44 cylinders or 6600 pounds. 
II. Worst Case Scenario and Alternate Release Scenario 
The worst case scenario presented in this report is for a 1-ton chlorine container located at the wastewater lagoon assuming a catastrophic failure due to cor 
rosion, impact or construction defects.  It is assumed that 2000 pounds are released at 200 lb./min over a 10-minute duration.  This scenario affected the greatest distance (2.63 miles) and the greatest number of public receptors (an estimated 12,900 people based on 1990 census data).  The ALOHA(R) model was used assuming an outdoor release case.  No passive mitigation measures were considered for this scenario.  The alternative scenario considered was a 1-ton chlorine container with gas feed assuming a tubing failure resulting in the release of gas through a 5/16 inch diameter valve body opening.  It is assumed that 312 pounds is released at a 10.5 lb./min release rate for a 60-minute duration. The total distance to end point is 0.56 miles.  Again the ALOHA(R) model was used and passive mitigation measures were not considered for this scenario. 
III. Program 2 -Prevention Program 
The release and prevention program is based on Program 2 regulatory requirements.  Up-to-date safety 
rmation related to gaseous chlorine processes and equipment has been compiled and will be maintained by the City of Indianola Public Works Department.   
Prevention steps include a hazard review of the chlorine processes and procedures.  This review is performed by applying a checklist based on The Chlorine Manual , Chlorine Institute Pamphlet 1, 6th Edition, January 1997.  Operating and maintenance procedures and instructions have been reviewed and compiled and are maintained at the facility.  These procedures provide clear instructions and steps for safely conducting activities associated with each covered process.  All employees presently operating processes involving chlorine have been properly trained or tested competent in the operating procedures that pertain to their duties. Any employees newly assigned to these duties will be properly trained and tested prior to beginning those duties involving chlorine. 
Compliance audits will be performed at least every three years in accord 
ance with 40 CFR part 68.58.  These audits will be conducted to ensure that the employees are properly implementing the program on an ongoing basis and to provide a measure of its effectiveness.  The audits will be conducted by at least one person knowledgeable in the process and will be documented in the form of a Compliance Audit Checklist. 
IV. Five-Year Accident History 
There have been no reportable accidents that have occurred at this facility within the last five years. 
V. Emergency Response Plan 
The City of Indianola Public Works Department is included within the written Sunflower County Emergency Response Plan.  All measures for public notification and alert systems are included within that plan.  Emergency contact numbers and evacuation procedures are readily available at the facility and all employees are familiar with the notification procedures.
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