Wekiva Hunt Club WWTF/WTP - Executive Summary
SANLANDO UTILITIES - WEKIVA HUNT CLUB WWTF/WTP
The intent of the Executive Summary of the U.S. Environmental Protection Agency (EPA) Risk Management Program (RMP) is to provide complete and accurate information concerning the Sanlando Utilities Wekiva Hunt Club Wastewater/Water Treatment Facility to the community. This document will be available to the public and shall include information pertaining to the following:
* Wastewater/Water Treatment Facilities
* Hazard Assessment
* Prevention Program
* Emergency Response/Action Plan
Wastewater/Water Treatment Facilities
The Wekiva Facility stores the chlorine gas for both its Water Treatment Plant (WTP) and its Wastewater Treatment Plant (WWTP) in the same room. Chlorine is used for disinfection purposes at both Facilities. At the WTP, chlorine is added primarily to destroy pathogenic organisms in the water to safeguard against water-borne illnesses in the water supply system. At the WWTP, chlorine is
added to the treated effluent to destroy any remaining pathogenic microorganisms in the treated wastewater. At this facility, the effluent is also dechlorinated, using sulfur dioxide, to remove the chlorine from the effluent before it is discharged to the environment.
The chlorine gas is stored in one ton cylinders of chlorine, which are fabricated to FDOT standards (106A500X). The average container has a capacity of one short ton (2000 pounds), an outer diameter of 30 inches and an overall length of 82 inches. The heads on each end of the cylinders are convex inward and forge welded to the barrel of the cylinder. The sides are crimped inward at each end to provide a grip point for lifting beams.
All one ton cylinders are equipped with six fusible metal plugs, three on each end. The fusible plugs serve as overpressure relief devices. The fusible metal is designed to melt between 158 (F and 165 (F to relieve pressure and prevent rupture of the container in case of fire or overheati
ng. The ton-container is designed around a maximum hydrostatic pressure of 500 psig.
The cylinders are stored outdoors in a three-sided building that provides ventilation and keeps the cylinders above the natural grade of the site. Two chlorine ton cylinders are stored on a ton-cylinder scale and are operational via a vacuum feed. The remaining back-up cylinders are supported and spaced using trunnions. This allows for the proper orientation of the outlet valves. Also, in case of a leak, the ton-cylinder can be rotated so that the chlorine escapes as a gas rather than as a liquid.
The chlorination system at the Wekiva Facility injects the chlorinegas into a water solution that is used for disinfection purposes. Chlorine is fed from the ton cylinders through a device called a "chlorinator". The chlorination system includes a vacuum regulator check unit that mounts directly to the upper gas valve of the ton-cylinder by means of a lead gasketed positive yoke assembly, and an ejector.
The feed system from the container through the chlorinator and to the ejector is operated under a vacuum, so any small leaks pull in air instead of releasing chlorine. The chlorinator feed rate ranges from 0 to 500 lb/day.
The chlorinator is equipped with a small 25 watt heating element. Therefore, as chlorine is drawn into the chlorinator from the ton-cylinder, it is deflected down into a drip-leg where any liquid chlorine is vaporized, permitting only gas to enter the regulating portion of the chlorinator. A vent/relief valve is provided with the chlorination unit to vent chlorine gas to the atmosphere at a remote location.
The Hazard Assessment was performed in compliance with the requirements of the EPA standards. The Off-Site Consequence Analysis (OCA) of worst-case and alternate-case releases of chlorine was estimated, and a five year accident history was evaluated. The OCA assessment includes dispersion models, identification of the area that is above the
toxic end point criteria, and the estimated affected population and environmental receptors.
The OCA was performed using the RMP*Comp( model. The RMP*Comp( model was supplied by the EPA and developed by NOAA, and it takes into account variances in wind speed, temperature, humidity, surface roughness (urban or rural setting), and release rate.
Worst-Case Release Scenario
Analysis of the worst-case release scenario of chlorine was performed utilizing the parameters provided in 40 CFR 68.22. The worst-case release scenario selected for the Wekiva Facility's off-site consequence analysis is the release of the contents of an entire one-ton chlorine cylinder from the chlorination process in a period of 10 minutes. This yields a release rate of 200 lbs/min. The radius of influence in this worst-case scenario was determined by the RMP*Comp( model to be 1.3 miles.
In accordance with 40 CFR 68.22, the population within the area of influence was determined, and other public and environmen
tal receptors were identified. The population was based on census track data obtained using the Landview III program, which is available on the Internet at www.rtk.net. The information regarding public receptors was gathered using a combination of street maps and USGS maps. The information gathered is presented in Table 1.
Table 1. Worst-Case Area of Influence Receptors
Alternate-Case Release Scenario
Analysis of the alternate-case release scenario of chlorine was performed in accordance with 40 CFR 68.22 as well, but the scenario is modeled in a more realistic setting. This model assumed a release rate of 10.5 lbs/min for a duration of 60 minutes. The distance to the chlorine toxic end point was determined by the RMP*Comp( model to be less than 0.1 mile. Within this area of influence, there are 98 residents and no other receptors, according to the census track data i
n the Landview III program.
The Wekiva Facility has had no releases of chlorine reported in the last five years that have resulted in on-site or off-site death, injury, evacuation, sheltering-in-place, property damage, or environmental damage.
Prevention Program 3
Sanlando Utilities stresses the importance of safety to all their employees. Programs have been developed for standard operating procedures, process safety training, and process technology for employees at all levels. The programs are in accordance with both OSHA PSM and EPA RMP Prevention Program 3.
Sanlando Utilities developed and implemented a training program that complies with 29 CFR 1910.119. Within the first week, all new employees, who work with or are exposed to chlorine are given orientation safety training. The Area Manager will review with each employee, upon initial assignment, parts of the Emergency Action Plan (EAP) that he or she must know to protect him/herself in an emergency. Contract
ors and visitors will be briefed on the EAP and actions they must take in an emergency as well.
In addition to the EAP orientation, each employee is trained in the standard operating procedures for the smooth operation of the Facilities. This program is developed to train the employee in basic operational procedures such as initial startup, normal operation, temporary operations, emergency shutdown, emergency operations, and normal shutdowns. It is also intended to prepare employees for minor troubleshooting.
As a policy, employees are tested to ensure that they have retained the training and process safety information. Refresher courses are periodically required to maintain the smooth operation at the Wekiva Facility.
A copy of the Process Safety Management Program is located at the Wekiva Facility for easy access and quick reference by all employees.
Emergency Response Plan
Sanlando Utilities is committed to the safety of their employees as well as the surrounding community. Th
e Utility coordinates with the local emergency responders, the Seminole County HazMat Team and the Police Department, to implement an Emergency Response Program. The Program is set up in accordance with the provisions of 29 CFR 1910.38(a) and includes procedures for handling small releases.
The Wekiva Facility is included in the community emergency response plan. In the event of a major chlorine release, the facility operating procedure is to evacuate the site upwind of the release and call 911 to report the incident. The Seminole County HazMat Team and the local Police Department will coordinate to contain the release and provide first aid, evacuation, and sheltering-in-place as necessary.
In the event of a minor leak, the operators will don a self-contained breathing apparatus (SCBA) and attempt to stop the leak. Standard procedure is for one operator to fix the leak while a second operator observes from a distance to provide back-up. If the leak cannot be stopped, the major chlor
ine release procedures will be followed. This documentation is collated in a binder, identified as the "Sanlando Utilities Emergency Action and Management Plan Manuals". One binder is kept at the Wekiva Facility for reference.
Sanlando Utilities strictly adheres to the OSHA and EPA standards, relating to the Emergency Planning and Response. Each facility employee is provided with an overview of the emergency action and response plan to assure that he/she knows what action to take in an emergency and can perform the tasks safely and in accordance with the outlined plans.
Sanlando Utilities - Wekiva WWTF/WTP Executive Summary 5