Whitestone Pumping Facility - Executive Summary
THE FACILITY AND THE REGULATED SUBSTANCES HANDLED |
The Saginaw-Midland Municipal Water Supply Corporation, hereinafter referred to as the SMMWSC, is a non-profit municipal authority owned jointly by the two cities of Midland and Saginaw, Michigan. It is an example of a partnership for the common good. The SMMWSC was formed to supply unfiltered Lake Huron water to these two cities as high quality raw water for their public drinking water supplies. The only treatment given the water as it is taken from Lake Huron and pumped to the two cities at the SMMWSC's Whitestone Pumping Facility is the addition of chlorine. The purpose of the chlorination is for disinfection of the water prior to transmission. The maximum inventory of liquid chlorine at the facility is 12 one-ton containers.
The Whitestone Pumping Facility is remotely located on Michigan's northeastern shoreline of Lake Huron on a large parcel of land. It is situated eight miles north of the nearest town, AuGres, Michigan (
Population 838). The facility operates continuously with a total of 9 full time shift operators, maintenance, and supervisory employees working at the facility.
FIVE-YEAR ACCIDENT HISTORY
The water system, which was formed in 1946, began operations in 1948. It has operated continuously for more than fifty years without a serious chemical release incident. The facility has had no reportable off-site chemical releases in the past five years.
THE GENERAL ACCIDENTAL RELEASE PROGRAM AND CHEMICAL-SPECIFIC PREVENTION STEPS
The SMMWSC has had an ongoing safety program in compliance with the Process Safety Management (PSM) regulations of OSHA. To attain compliance with the RMProgram, it was decided to treat it as an entirely new program. A consultant was engaged to assist the SMMWSC 's limited staff with the implementation of the RMProgram. The Risk Management Program guidance manual published by the American Water Works Association Research Foundation was used as a primary referen
ce. Other informational materials and manuals from USEPA and the Chlorine Institute supplemented it. Since the process was already regulated by PSM (OSHA), the SMMWSC 's management determined that the chlorination process came under Program 3 of the regulation.
A seven person RMP Team was formed to help implement the RMProgram. The Team consisted of the facility's most experienced and knowledgeable staff in the chlorination process. Included were a senior operator, the maintenance supervisor, an electrical division representative and the production supervisor. The other Team members were the manager, the administrative secretary, and the consultant.
A mission statement was developed and distributed at the first meeting, along with a description of the objectives and goals of the RMP Team together with an organization chart showing RMP responsibilities. The Team met at varying intervals over a five-month period between January 1999 to June 1999. Minutes were maintained of the Te
am meetings by the administrative secretary and are a part of the SMMWSC 's RMP records.
Separate smaller teams were used to conduct the PHA and the Compliance Audit portions of the program. However, because of the water system 's limited staffing, it was necessary to use some members of the RMP Team for these functions.
THE ACCIDENTAL RELEASE PREVENTION AND EMERGENCY RESPONSE POLICIES
Fourteen new RMP policies, which were recommended in the AWWA guidance manual as model policies, were adopted to implement the RMProgram.
As part of the Hazard Assessment requirement in the RMP regulation, an Off-site Consequence Analysis (OCA) was conducted using the RMP*Comp software, Version 1.06. Population estimates were made for the Worst Case and the Alternate Case using the LandView III software.
As part of the SMMWSC 's Prevention Program, a new Process Hazard Analysis (PHA) was conducted in accordance with the policies, new Operating Procedures (OP) and Maintenance Procedures (MP) were
developed and adopted, and the facility's Emergency Action Plan (EAP) was revised and updated.
A WORST CASE SCENARIO
The RMP regulation requires the facility to investigate an assumed situation in which the entire contents of a full chlorine container is released over a ten-minute period. For the Whitestone Pumping Facility this scenario would be a one ton container releasing its contents of 2000 pounds of chlorine in ten minutes outside in the open air. The computer analysis indicated the gas would be diluted to below a level-of-concern beyond a distance of 1.3 miles from the release point. The LandView computer model indicated that a population of 223 persons might be effected in this scenario.
AN ALTERNATE CASE SCENARIO
Since the situation described above as the Worst Case is not likely to ever happen, the regulation provides for an alternate scenario to be reported, which would be more likely to occur. The regulation requires that the alternate scenario selected must r
esult in a chemical release extending beyond the facility property boundaries. Since there are numerous preventative, detection, and mitigating devices in place inside the facility, which will prevent an off-site release, no situations inside the chlorine building could be found that would result in an off-site release.
The alternate case selected, which was most likely to happen and result in an off-site incident, was for an automobile in the parking lot to leak gasoline from its tank. A flame would have to ignite the gasoline, the resulting fire to spread across the parking lot to the chlorine container storage area, where the contents of a one-ton chlorine container would become heated to 158 degrees Fahrenheit and a fusible temperature relief plug would melt releasing liquid chlorine. This scenario would have a level-of-concern endpoint 0.3 miles from the release point. The LandView computer model indicated that a population of 9 persons might be affected by this scenario.
THE EMERGENCY RESPONSE PROGRAM
The facility is unable to provide adequate Emergency Response from its very limited staff. Local responders (voluntary fire department) do not have the training or equipment to safely respond to a chlorine release. However, arrangements have been made for a CHEMTREC team from Midland, Michigan to respond to that need, when called. An Emergency Action Plan has been adopted and implemented which provides for facility staff to be "sheltered in place" in the main pumping building, which is a separate building from the chlorination process building. The plan includes the necessary emergency notification and contact numbers. It provides that local responders will provide public notification. A warning siren will aid in notification of the public in a chemical release emergency. The facility is equipped with multi-channel portable radios having the frequencies of all of the local responder and law enforcement units for communication.
The SMMWSC manage
ment is a member of and regularly attends meetings with the Arenac County Local Emergency Planning Committee to help coordinate community local response for notification and evacuation, should it ever be necessary.
IMPROVEMENTS FOR SAFETY
1. Automatic Chlorine Shut-off Valves-
A new system of automatically controlled, air-operated, shut-off valves located at the chlorine containers has been installed in the process system. When chlorine is detected in the atmosphere in the chlorine process building, all valves close.
2. Additional Chlorine Monitoring -
A new perimeter chlorine detector monitoring system is being installed to monitor the outdoor chlorine storage area.
3. Corrosion -Resistant Container Connectors-
New connectors have been installed to connect the containers to the process piping. The new connectors are less subject to corrosion and provide an extended life expectancy.
4. Parking Restrictions-
Modifications have been made to the vehicle parking in the vici
nity of the chlorine storage area. These changes are a direct result of the Alternate Case OCA studies. Vehicle parking has been moved further away from the storage area.
5. Warning Siren-
A manually activated warning siren is being installed at the facility to advise local residents of an off-site chlorine release.
6. Improved building air quality-
A new air handling and purification system is being installed to pressurize the main pumping facility building with high quality air during a chlorine release emergency. This system will assure the safe "sheltering-in-place" of facility personnel and will reduce the adverse effects of chlorine on the electrical and mechanical equipment within.
A public meeting is planned for the summer of 1999 to communicate the Risk Management Program with the local residents in the vicinity of the plant site. This time was selected because a large percentage of local residences are cottages, which are only occupied in sum