Coastal Water Authority (Lynchburg Pump Station) - Executive Summary
Coastal Water Authority |
Lynchburg Pump Station
RISK MANAGEMENT PROGRAM PLAN
Accidental Release Prevention and Emergency Response Policies
The accidental release prevention and emergency response policies at Coastal Water Authority's Lynchburg facility are engrained in the fundamentals of our prevention program.
At our Lynchburg pump station, we presently handle two chemicals, which is considered hazardous by the Environmental Protection Agency (EPA). The same properties that make these chemicals valuable for making drinking water safe also make it necessary to observe specific safety precautions. These safety precautions are exercised in the operation and maintenance of our chlorination system and ammonium hydroxide system to control human and environmental exposure in an effort to reduce the overall threat to our workers as well as the surrounding communities.
It is Coastal Water Authority's policy to adhere to all applicable federal, state and local rules
and regulations. However, the safe handling of hazardous chemicals is paramount at CWA and we often exceed standards and recommended practices governing the safe handling of hazardous chemicals to ensure that we have obtained a reasonable level of risk reduction
We believe that accountability for safety reaches throughout all levels of management at CWA. Senior management's commitment and dedication to continued safe-operating practices is clearly evident in our organization structure and employee empowerment.
Facility Description and regulated substances handled
The Lynchburg pump station covers approximately 220 acres, including reservoirs. It is located at 908 South Lynchburg Road, Houston, Texas in Harris County. Our facility treats a maximum of 315,000,000 gallons of water per day.
There is a maximum of twenty (20) full-time employees at the plant site at any one time. In addition, our plant has two residences located onsite.
We presently handle only two chemicals, whi
ch are considered hazardous by the EPA. These substances are present in quantities greater than their threshold quantities identified by the RMP regulation. Therefore they are included in our risk management program.
X Ammonium Hydroxide - This is also known as aqua ammonia. It is used as a water treatment chemical at the plant. It is received by tanker truck into the plant and stored in one of two atmospheric tanks onsite. A concrete dike protects these tanks. It is designed to hold the entire contents of either tank. Each tank can hold a maximum of 18,000 gallons, however administrative controls at the plant limit the capacity of the tanks to 15,000 gallons each.
X Chlorine - Chlorine is used as a water treatment chemical at the plant. It is received into the plant in one ton containers. These containers are standard DOT and Chlorine Institute specified containers. Deliveries of chlorine are received at the plant every two weeks. The plant may have a maximum invento
ry of 72,000 pounds of chlorine onsite at any one time, however, only three containers (6,000 pounds) are being used at any one time.
Offsite Consequence Analysis (worst-case & alternate-cases)
The RMP rule requirements for identification and selection of a worst-case hazard scenario are prescriptive. These requirements negate most safety systems designed to mitigate an incidental release that would typically be used in the event that an incident occurred. Based on EPA defined Offsite Consequence Analysis (OCA) Guidance, CWA has one worst-case hazard scenario for the toxic material handled onsite. This scenario is estimated to create the greatest distance in any direction to an EPA defined concentration (endpoint) resulting from an accidental release.
Our worst-case toxic scenario involves chlorine. Chlorine is used as a water treatment chemical at the plant. It is stored under its own vapor pressure in standard one ton containers located under a protective open-sided shed. T
he scenario uses the EPA's theoretical assumption that a container may catastrophically fail and release chlorine to the atmosphere. It completely negates any mitigation attempts and assumes that all 2,000 pounds of chlorine can be dispersed within 10 minutes to form a toxic vapor cloud that drifts offsite into the surrounding community.
Using the EPA's Offsite Consequence Analysis Guidance Document, dated October 1998, to determine the greatest downwind distance, it was determined that a chlorine vapor cloud may extend 1.30 miles from the plant. This calculation was based on the EPA recommended guide for chlorine.
The EPA rule also requires that alternate or more likely accident scenarios involving regulated chemicals be identified. Other more likely scenarios were assessed for chlorine and ammonium hydroxide, using parameters prescribed in the RMP regulation. The analysis of the alternate scenarios could include mitigation affects from both passive and active safety systems.
CWA conducted an iterative assessment of several alternate or more likely scenarios. From the various scenarios assessed, CWA selected the following two as a representative example of alternative scenarios:
X Inadvertent mishandling of a chlorine shipping container during delivery results in complete separation of the container's valve. This failure assumes that 251 pounds per minute of chlorine is released. Dispersion of the chlorine gas could result in the formation of a vapor cloud extending 0.27 miles (1,426 feet) from the plant.
X During offloading of ammonium hydroxide from a tank truck the truck's offloading hose inadvertently uncouples. The emergency devices on the truck and actions of standby personnel are considered to control the spill within a maximum of 10 minutes. This failure modeled the release of 247 pounds per minute of ammonium hydroxide. Evaporation of the liquid pool may result in the formation of a vapor cloud extending 0.2 miles (1,056 feet) from the pla
Accidental release program & chemical-specific prevention steps
Coastal Water Authority contracted with an outside engineering firm to assist in the development of a prevention program tailored exclusively to water treatment operations. This prevention program was designed around mechanical integrity and training aspects. The primary objective being to ensure complete containment of chlorine and ammonium hydroxide through safe operation and maintenance of the water treatment systems.
Although newly developed, the prevention program has been designed with the following objectives:
X Enhancement of the mechanical integrity of all chlorine and ammonium hydroxide equipment and piping,
X Compilation of safety information to improve hazard awareness, and
X Training to increase hazard recognition
Five year accident history
CWA has a very comprehensive Incident Reporting and Investigation procedural process. This process is defined and explained by CWA-008. Basically, an incid
ent occurs when a deviation from expected performance is experienced.
Formal investigations are required to be conducted by appointed teams knowledgeable in operations or equipment being investigated. Root cause and corrective actions are also required in order to determine incident prevention steps. Progress regarding corrective action on all investigated incidents is required to be tracked through to completion.
Coastal Water Authority's Lynchburg pump station has not had an accidental release of EPA regulated chemicals within the past five years that resulted in an onsite injury or affected the community adversely.
Emergency response program
At CWA we handle two regulated toxic substances (chlorine and ammonium hydroxide) over threshold quantities. We have made a concise decision to not respond to catastrophic releases of chlorine at the Lynchburg pump station. Our employees have been instructed to notify the Baytown Fire Department and LEPC and to evacuate in the event
of such a catastrophic incident.
In accordance with the requirements of the Risk Management Program rule, CWA is included in the Baytown, Texas local emergency response plan under the Emergency Planning and Community Right-to-Know Act (EPCRA).
Planned improvements to reduce risk
Investigation of inherently safer technologies, chemical inventory reduction through usage studies and administrative limits, and fail safe design applications are a few of the continuous improvements occurring at CWA. Safety depends upon our management commitment, the manner in which we handle chlorine and ammonium hydroxide, the safety devices inherent to our water treatment systems, our operating procedures and philosophies, and the training of our employees.