MEC&F Expert Engineers : CHLORINE CYLINDER LEAK AT AN OWENSBORO MUNICIPAL UTILITIES WATER PLANT IN KENTUCKY

Wednesday, March 4, 2015

CHLORINE CYLINDER LEAK AT AN OWENSBORO MUNICIPAL UTILITIES WATER PLANT IN KENTUCKY






MARCH 4, 2015

OWENSBORO, KENTUCKY

Owensboro firefighters dressed in HazMat suits prepare Tuesday morning to enter a portion of Owensboro Municipal Utilities' William Cavin Water Treatment Plant on Kentucky 144 near the Elmer Smith Station. 

Owensboro Fire Department's hazardous materials team along with other emergency personnel were called to the treatment plant in response to a small chlorine leak in a 1-ton cylinder that had just been delivered to the plant from Henderson. 

OMU workers detected the leak after noticing discoloration on one of the cylinder's safety plugs. 

Fire department personnel covered the plug with a special kit and the cylinder was returned to the supplier, according to Kevin Frizzell, OMU director of production. 

OMU operates two water treatment plants — the Cavin plant and Plant A on East Fourth Street near Daviess County Middle School. 

Photo by Jenny Sevcik, Messenger-Inquirer/jsevcik@messenger-inquirer.com, 691.7294 

WATER PLANT A

OWENSBORO MUNICIPAL UTILITIES

Water Plant A produces drinking water for the citizens of Owensboro, Kentucky. The plant has a capacity of 20 million gallons of finished water per day. It has one RMP covered process - chlorination of the drinking water for microbiological control. The Plant is subject to the OSHA Process Safety Management requirements and is therefore a RMP Program Level 3 process.

OMU takes its role in the safety and well being of the community seriously and goes to great lengths to ensure that its facilities and operations do not impact its neighbors adversely. Emergency response plans and procedures are in place to ensure that employees and neighbors of our facilities will not be exposed to harmful releases.

The Process
The plant uses gaseous chlorine to disinfect the drinking water produced. Chlorine is stored in 2000 pound cylinders with a maximum on site at any one time of 8 cylinders. The entire process takes place in a totally enclosed building which is monitored continuously for chlorine leaks. In the event of a significant leak, a scrubber system will activate to neutralize the chlorine before it can be released from the building.

Worst Case Release Scenarios
The RMP requires that the "Worst Case" release scenario be addressed. For Water Plant A, the worst case is a failure of a cylinder which releases all of the gas (2000 pounds) in a ten minute period. This case assumes no scrubbing and no containment from the chlorine building. In this case, the chlorine could affect receptors within a three mile radius of the plant. It is estimated that this could affect 42,839 persons.

An alternate "worst case" scenario reviewed is if there is a severe piping leak. In this case, the scrubber would be in service and the potential radius affected is 0.40 miles. It is estimated that this could affect up to 1,890 persons.

It is emphasized that these are "worst case" conditions. 

Release Prevention
OMU has a program in place at the plant to prevent situations that could lead to a release of chlorine. Some elements of this program are: employee training; equipment maintenance; equipment inspection program; and contractor management. These are designed to provide that the system is well maintained and that employees and contractors are aware and informed of the risks and proper procedures for working on and around the chlorine system.

OMU also has in place continuous monitoring and controls such as the enclosed building and scrubber for minimization of the possibility of chlorine escaping from the facility. 

Five Year Accident History
We have had three (3) minor chlorine releases in the previous five years.

Emergency Response Program
OMU has an emergency response program that is coordinated with the local Emergency Management Agency and police and fire departments.

Planned Improvements
The chlorine facilities are new and well designed and there are no plans for modifications. OMU will continue to review its training program and procedures and make improvements where possible.