White Slough Water Pollution Control Facility - Executive Summary

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EXECUTIVE SUMMARY 
 
1. Accidental Release Prevention and Emergency Response Policies 
 
The City of Lodi White Slough Water Pollution Control Facility handles chlorine and sulfur dioxide which are considered hazardous materials.  The properties of chlorine and sulfur dioxide make it necessary to observe safety precautions in handling chlorine and sulfur dioxide to prevent human exposure, and to reduce the threat to the facility's workers and nearby members of the community.  It is the facility's policy to adhere to all applicable Federal and State of California rules and regulations.  Safety depends upon the safe procedures used to handle chlorine and sulfur dioxide; the safety devices and systems designed and constructed into the facility; and the training of the pertinent personnel. 
 
2. Stationary Source and Regulated Substances Handled 
 
The facility is a 8.5 million gallons per day treatment plant for wastewater from domestic and industrial sources.  The plant design has parallel treat 
ment systems for domestic and industrial wastewater.  The domestic portion of the flow is treated in an activated sludge system.  The industrial wastewater is treated in aerated ponds.  Effluent from both systems is reclaimed by irrigation on adjacent City-owned agricultural land.  Storage ponds for winter industrial flows are included for use when conditions are too wet for land disposal.  Domestic effluent is discharged to the Delta waterway at times when irrigation needs have been met and during non-irrigation seasons. 
 
Disinfection and dechlorination of the wastewater is performed prior to discharge.  The effluent leaving the secondary clarifiers contains large numbers of biological organisms.  Some of these may be pathogenic (disease causing) organisms.  The effluent is disinfected to protect the public health by the use of a chlorine solution produced at the plant by mixing chlorine gas and water.  Some residual chlorine is present after disinfection and represents a toxid hazard 
to the aquatic life in the Delta waterway.  The chlorine is neutralized to remove this threat by the addition of sulfur dioxide (dechlorination). 
 
There is a daily maximum of 26,000 lb of chlorine and 26,000 lb of sulfur dioxide at the facility. 
 
3a. Worst Case Release Scenario 
 
The Worst Case release scenario for interconnected equipment must consider the largest quantity of a regulated substance handled on site in a single vessel at any time, taking into account administrative controls as per the CCR Title 19 Division 2 Chapter 4.5 Article 2 Section 2750.3(b). 
 
The 2700 gal bulk tank of chlorine is the largest vessel in the chlorine feed system.  This tank is, at most, filled with 25,000 lb of chlorine which is 79% of tank capacity.  The Worst Case release scenario for the bulk tank of chlorine is the release of the 26,000 lb of chlorine at the rate of 2,600 lb/min for 10 minutes. 
 
The distance to the endpoint of 3 ppm for the Worst Case scenario will extend beyond the boundaries of 
the stationary source. 
 
3b. Alternative Release Scenario 
 
The Alternative Release scenario for the chlorine bulk tank is complete failure and separation of the one inch hose feeding liquid chlorine to the 2,700 gal storage tank close to the bulk tank connection during the bulk tank filling operational procedure.  Chlorine liquid loss will occur from the bulk tank and the truck tank.  The truck tank will experience a large increase in flow rate and the slide check valve will sense the excess flow and will quickly close, cutting off the liquid chlorine flow from the truck tank.  The liquid chlorine loss from the truck tank and hose is calculated to be 21 lb of liquid chlorine.  The loss from the bulk tank will continue until the liquid contents left in the tank solidify due to the withdrawal of the Heat of Vaporization by the escaping chlorine vapor.  The 21 lb loss from the truck tank is neglected in comparison the large loss from the bulk tank. 
 
The distance to the endpoint of 3 ppm f 
or the Alternative Release scenario for the chlorine bulk tank will extend beyond the boundaries of the stationary source. 
 
The Alternative Release scenario for the sulfur dioxide bulk tank is complete failure and separation of a one inch hose feeding liquid sulfur dioxide to the 2,700 gal storage tank close to the bulk tank connection during the bulk tank filling operational procedure.  Sulfur dioxide liquid loss will occur from the bulk tank and the truck tank.  The truck tank will experience a large increase in flow rate and slide check valve will sense the excess flow and will quickly close, cutting off the flow from the truck tank.  The loss from the truck tank and hose is calculated to the 20 lb of liquid sulfur dioxide.  The loss from the bulk tank will continue until the liquid contents left in the tank solidify due to the withdrawal of the Heat of Vaporization by the escaping sulfur dioxide vapor. 
 
The distance to the endpoint of 3 ppm for the Alternative Release scenario for  
the sulfur dioxide Risk will extend beyond the boundaries of the stationary source. 
 
3c. Administrative Controls 
 
Administrative control to limit the distances for each reported scenario exists to restrict the amount of chlorien and sulfur dioxide released to a minimum, if a release were to occur; and preferably to not have a release occur.  This administrative control is inherent in the operational procedures for the chlorine system, the sulfur dioxide system, and the training provided to the chlorine system and sulfur dioxide operators. 
 
4 General Accidental Release Prevention Program and Chemical Specific Prevention Steps 
 
The facility complies with all applicable federal and state codes and regulations.  There are safety meetings and safety training.  The Process Safety Management (PSM) program implemented at the facility for the chlorine and sulfur dioxide related activities and equipment represnets one of the facility's main active commitments to an accidental release prevention  
program. 
 
5 Five Year Accident History 
 
There has been no accidental release of chlorine or sulfur dioxide. 
 
6. Emergency Response Program 
 
The Emergency Response Program is based upon the alerting of personnel at the facility to evacuate the facility and await the arrival of responders from the San Joaquin County Fire Department at the evacuation assembly location if a release occurs that causes the evacuation to be initiated.  The County of San Joaquin - Office of Emergency Services incorporates this response into the County Area Plan for the Region 4 Local Emergency Planning Committee. 
 
7. Planned Changes To Improve Safety 
 
There are commitments made under the Risk Management Plan for the State of California's Accidental Risk  Prevention (CalARP) program that has been implemented at this time.  Current applicable codes and regulations are being reviewed to determine if other commitments need to be made to achieve increased operational safety for the chlorine and sulfur dioxide syste 
ms.
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