City of Lawton Wastewater Treatment Plant - Executive Summary
This document represents the Risk Management Program (RMProgram) and Risk Management Plan (RMP) for the City of Lawton, Waste Water Treatment Plant (WWTP) at Lawton, Oklahoma. After all Program elements described throughout this document are implemented, the City of Lawton, WWTP will be in compliance with current RMP regulations for the management of Highly Hazardous Chemicals.
The City of Lawton operates a WWTP that uses chlorine gas in the tertiary treatment process and is stored inside and outside of the Chlorine Building, out of direct sunlight, with overhead protection. The chlorine gas is contained in 1-ton cylinders (2000lb) of which there is at most 12 full cylinders on hand. Because the WWTP does not meet the criteria for the Process Safety Management (29 CFR 1910 .119) it becomes mandatory to manage the process under Program 2 requirements of the Accidental Release Prevention Provisions.
The City of Lawton, WWTP uses sulfur dioxide (SO2) gas to
actively remove the chlorine gas from the treated water prior to discharging as effluent into 9 mile creek. The SO2 used for this process is stored on wedges in the SO2 Room and on the ground out of direct sunlight outside the SO2 Building with overhead protection. Under the current operations of the WWTP, there are at most 14 full 1-ton cylinders of SO2 at the site.
Chlorine gas at the City of Lawton, WWTP is fed directly from four (4) 1-ton containers. Under normal operations, two (2) cylinders are attached to the chlorination system for back up or potential use and two (2) cylinders are attached to the chlorination system at the same time for actual use. As a result, the maximum potential chlorine inventory at this plant is 12, 1-ton cylinders or 24,000 lbs of chlorine gas.
The four (4) cylinders attached to the chlorination system are maintained at a constant temperature between 60 and 80 degrees F by a heating and ventilation system. The temperature of the chlorination are
a should never reach the critical temperature for chlorine gas (290 degrees F). However, at these temperatures chlorine will only exist in the gaseous phase. In order to allow for this case, all chlorine gas cylinders are equipped with fusible plugs designed to relieve extremes in pressure caused by elevated temperatures.
SO2 gas at the City of Lawton, WWTP is fed directly from four (4) 1-ton containers. Under normal operations, two (2) cylinders are attached to the SO2 system for back up or potential use and two (2) cylinders are attached to the SO2 system at the same time for actual use. As a result, the maximum potential SO2 inventory at this plant is 14, 1-ton cylinders or 28,000 lbs of SO2 gas.
The four (4) cylinders attached to the SO2 system are maintained at a constant temperature between 60 and 80 degrees F by a heating and ventilation system. The temperature of the SO2 area should never reach the critical temperature for SO2 gas (290 degrees F). However, at these temp
eratures SO2 will only exist in the gaseous phase. In order to allow for this case, all SO2 gas cylinders are equipped with fusible plugs designed to relieve extremes in pressure caused by elevated temperatures.
WORST-CASE RELEASE SCENARIO
According to the RMP guidelines, a worst case scenario would involve a rupture of a full 1-ton (2000 pound) cylinder of chlorine or SO2 with a release time of 10 minutes. The entire contents of the cylinder would be evacuated with a release rate of 200 pounds per minute. As a result of the pressure of the released gas, the building fails and all 2000 pounds of gas are released into the environment. Using the data provided above, the air dispersion modeling software calculated a total plume distance for the worst-case scenario of 3.5 miles.
ALTERNATIVE RELEASE SCENARIO
Dispersion modeling was also performed to estimate the effective areas for at least one alternative release scenario for each regulated substance in a regulated process. Alte
rnative release scenarios were evaluated and the final calculation was for 0.6 miles downwind.
Well-trained operators are integral to prevention and mitigation of the effects of accidental chemical releases.
The City of Lawton, Assistant Director of Public Works and the RMP team are responsible for maintaining the written Employee Training Program and associated training materials and training records.
The WWTP Superintendent is responsible for ensuring that all personnel involved in the handling of Chlorine and SO2 at the plant complete and maintain all training requirements for his or her position, and that all supporting documentation is filed. The WWTP Superintendent plans classroom training for all personnel and periodically reviews training records to ensure that all employees receive the required training. The City of Lawton, WWTP encourages employee participation and input in maintaining a safe work environment through an Employee Participation Plan.
The City of Lawton, WWTP Chlorine and SO2 Manuals will be used as the primary guidance during initial training. They emphasize health and safety hazards associated with the chemicals, operating procedures, and relevant safe work practices. Initial training for new operators will include both classroom and on-the-job (i.e., hands-on) training. New employees to the WWTP are shown the process of maintenance and equipment testing by trained personnel using demonstration and hands-on methods. City of Lawton, WWTP maintenance personnel perform on-site maintenance and equipment testing on all chlorination/Sulfanation equipment. All personnel are instructed that repairs are replacements in kind, where only the same manufacturer's equipment is used and no retrofitting occurs.
All current operations and maintenance personnel receive initial RMProgram training. New personnel will receive initial program training prior to commencing work. Topics to be covered during initial traini
ng include the following:
-Overview of the RMProgram describing all elements.
-The Chlorine/SO2 process operation and hazards and the approximate schedule for implementing the required RMProgram tasks.
-The entire Employee Participation Procedure with emphasis on employee rights and on procedures to obtain access to program information.
The intent of refresher training is to ensure operators and maintenance personnel understand and follow the most up-to-date procedures for a process. At a minimum refresher training is provided to operators and maintenance personnel every 3 years. All information covered in initial training is included in refresher training with additional emphasis placed on current operating procedures and safety information and a review of the City of Lawton, WWTP Emergency Preparedness Plan. Maintenance personnel will be given additional training specific to maintaining Chlorine/SO2 equipment.
The policy of Ci
ty of Lawton, WWTP is to involve its employees in the development and implementation of the EPA RMProgram elements at the process and storage areas which are subject to risk management regulations. The City of Lawton, WWTP Employee Participation Plan addresses involving employees in PHAs and other process safety management program elements, communicating employees right-to-access RMP information, and documenting employee participation. The City of Lawton, WWTP communicates the following information to all operations/ maintenance personnel:
-Content of the RMP and requirement for employee participation.
-Employees' right to access PHAs and all process safety management information required to safely perform their duties.
-Procedures for obtaining access to this information.
The environmental Compliance Official for the WWTP has overall responsibility for maintaining and implementing this procedure.
EMPLOYEE ACCESS TO RMPROGRAM
The City of Lawton, WWTP and contract employees oper
ating or maintaining a chlorine or SO2 area have direct, routine access to the information included in the City of Lawton Chlorine or SO2 Manual, which is maintained in the WWTP Chlorine Room, SO2 Room, and WWTP Administration Building:
-Material Safety Data Sheets (MSDS) sheets
-Current Operating Procedures
-Operator Training Manuals
-Emergency Response Procedures
In addition, the City of Lawton, WWTP and contract employees have access to the PHA and other program information required to safely perform their duties. Employees verbally request access to this information through the WWTP Superintendent, who provides timely access to approved requests during normal working hours.
The City of Lawton, WWTP will perform audits to self evaluate the design and effectiveness of its RMProgram and compliance with EPA RMP regulations. Whenever necessary, recommendations will be developed from the audit to address program deficiencies. Compliance audits must be performed
at least every 3 years at the regulated process areas at the City of Lawton, WWTP.
An incident investigation ensures that all incidents at the City of Lawton, WWTP that resulted in or could have reasonably resulted in a release of chlorine or SO2 are promptly investigated (within 48 hours). The purpose of the incident investigation procedure is to identify the underlying causes of an incident and to implement corrective actions to prevent the incident from reoccurring. These incident investigation procedures cover EPA RMP-regulated processes at the City of Lawton, WWTP. The procedures apply to all incidents that result in chlorine or SO2 releases and all "near-miss" incidents that could result in chlorine or SO2 releases. These procedures do not replace City of Lawton, accident investigation procedures.
INVESTIGATION INITIATION PROCEDURES AND TEAM
Following an incident that resulted in or could have possibly resulted in a release of chorine or SO2, th
e affected/responding operators will immediately notify the Compliance Manager or the WWTP Superintendent of the incident. The Compliance Manager and the WWTP Superintendent will report any release and initiate an investigation as soon as possible and no later than 48 hours after the incident.
If the incident resulted in an injury to an operator and/or contractor, the Compliance Manager and the WWTP Superintendent are responsible for notifying the City of Lawton, Safety Director. This additional member is responsible for documenting the incident in accordance with his respective procedures.
The WWTP Superintendent and the Compliance Manager review incident investigation reports with all affected operators and maintenance personnel during monthly safety meetings. In addition, incident investigation findings are communicated to all contract employees if relevant to their job tasks. All City of Lawton, WWTP personnel informed of investigation results must sign and dat
e an attendance sheet supplied by the WWTP Superintendent for documentation purposes.
EMERGENCY RESPONSE PROGRAM
The purpose of this procedure is to ensure that the City of Lawton, WWTP maintains an up-to-date, complete, written Emergency Preparedness Plan (EPP) and effective response capabilities for the two regulated process areas. A comprehensive EPP, when combined with emergency response training, is instrumental in minimizing the impact of an accidental release by ensuring proper and quick facility response. This plan is subject to the following regulatory requirements:
-OSHA 1910.38 (Emergency Action Plan)
-OSHA 1910.120 (HAZWOPER)
-Clean Water Act/SPCC
-RCRA (Resource Conservation and Recovery Act, 40 CFR Section 264)
-EPCRA (Emergency Planning and Community Right-to-Know Act)
The City of Lawton, WWTP RMP-team is responsible for reviewing and updating the EPP annually. The WWTP Superintendent is responsible for ensuring that updated copies are distributed to the appropri
ate locations throughout the City of Lawton.
EMERGENCY RESPONSE PROCEDURES
In the event of an accidental release of chlorine or SO2 gas at the WWTP or the Chlorine/SO2 cylinder storage area, WWTP employees are capable of responding in a timely and organized fashion.
MAINTAINING THE EPP
The current update to the EPP includes response procedures, emergency PPE and equipment, and training topics specific to chlorine and SO2 gas. It is important that changes in facility layout or personnel or changes in operating procedures that may alter the release scenarios significantly be included in future revisions to the EPP.