City of Thomasville Wastewater Treatment Plant - Executive Summary
City of Thomasville |
The City of Thomasville has implemented a comprehensive program to safely manage chlorine at its water and wastewater treatment plants located in the City of Thomasville. There have been no chlorine incidents in the most recent Five-Year history period.
In 1997, a Process Safety Management (PSM) program was initiated at the Plants with the assistance of Operations Excellence Consulting, Inc., a safety consulting firm. A PSM Implementation Manual was edited to be site specific and issued to the Wastewater Treatment Plants. With this step, approximately 50% of PSM requirements were met.
Key items included in the manual were:
- Written site-specific procedures for Employee Involvement, Management of Change, Incident Investigation, Pre-Startup Reviews and Self-Audits.
- Chlorine safety information as required by the regulations
Next, these additional steps were implemented to bring the PSM program to full compliance:
on PSM and its key components including Management of Change, Mechanical Integrity and Incident Investigation.
-Conducting Process Hazards Analyses for the two chlorine processes
-Developing Standard Operating Procedures for safe Chlorine Management
-Developing a Maintenance Program for the chlorine systems at each plant
-Developing an initial Emergency Response Plan
-Training in support of the certification of operators
The superintendent, city safety manager and several plant operators meet several times per year to review and update procedures and to maintain compliance with all aspects of the PSM regulation.
In addition to PSM compliance, the plants have implemented a number of programs to improve the safe handling of chlorine.
- The chlorine delivery system at the wastewater plant was upgraded to a full vacuum system in February 1999. This new process has proven to significantly improve chlorine safety by placing most of the cylinder system under vacuum. Any lea
k will result in air leaking into the system as compared to chlorine escaping the system.
- The chlorine emergency response plan has been upgraded at both plants. The services of a professional hazardous material response team have been obtained to response to all chlorine incidences.
- Both plants have reduced inventories allow all chlorine to be stored inside. The storage building will act to contain and significantly reduce the impact of any release. They also improve site security.
Future projects will evaluate alternatives to chlorine for disinfection.
To further understand chlorine risks, Operations Excellence Consulting, Inc., a safety consulting firm was contracted to conduct "Offsite Consequence" Modeling Analysis, as required by EPA's Risk Management Program. Both "Worst Case" and "Alternative Case" chlorine release scenarios were studied for each site.
The results showed that the risk of chlorine exposure varies depending on the plant's location:
- The Wastewater Treat
ment Plant is located on the southwest side of the City of Thomasville at 110 Optimist Park Road. The plant is located on a gentle hill, which slopes to the west. The North Fork of Hamby Creek is at the base of the hill. The creek also wines to the north of the plant. There is heavy vegetation at the base on the banks of the creek. Given the heavier-than-air property of chlorine, with wind from the southwest, south, southeast or east or with little or no wind, a chlorine release will flow to the creek and dissipate. However, a wind form the northwest, north or northeast can carry a chlorine release into the adjacent ballpark and several homes beyond the ballpark.
- The Water Treatment Plant is located in the west side of Thomasville 200 Old Lexington Road. The plant is a area of the city that slops gently to the west. In a low and no wind scenario, a chlorine release will be directed to the west. Otherwise, a release will be directed by the prevailing winds
In addition to Process
Safety Management, the organization has an active safety program. The City of Thomasville has had an active Safety Committee. The committee meets monthly with representatives from each function and each site. The committee's duties include reviewing new safety procedures, accident investigations, safety surveys and safety communications.
Within the Utilities Department, there are monthly safety meetings conducted by each plant. There is a review on an OSHA subject or a discussion on a specific water or wastewater safety issue.
The Utilities safety program involves the following activities:
- Conducting accident reviews for prevention/minimization;
- Conducting safety inspections for all facilities;
- Disseminating safety information to Utilities staff;
- Preparing and conducting safety training program including such topics as hazard communication, personal protective equipment, confined space and lockout/tagout;
- Verifying performance of training programs;
- Addressing safety
- Identifying mandatory regulatory agency-required safety training needs;
- Recognizing exemplary safety performance
As a result of our programs, the plants have had a strong safety record with no loss time accident over the past six years. We plan to continue our emphasis on safety to maintain and improve our safety performance.
City of Thomasville, North Carolina