Redstone Arsenal Water Treatment Plant #1 - Executive Summary
Executive Summary |
Redstone Arsenal (RSA) is located in Madison County, southwest and adjacent to the city of Huntsville, Alabama (Figure 1-1). RSA currently comprises 37,910 acres (including special-use permit land) located on an approximately six-mile wide by ten-mile long site (U.S. Army Missile Command, 1995). Approximately 29,000 government and contractor personnel are employed at RSA. Prior to acquisition by the Army, the land comprising the present day Arsenal was primarily used for producing cotton, corn, hay, small grain crops, and livestock.
The primary activity at the RSA water treatment plants (covered processes) is to treat water collected from the Tennessee River to industrial and Federal and State drinking water standards. Collection operations include pumping, storage, solids reduction, and bacteria and virus removal. Water is drawn from the Tennessee River at Plant #1 through intakes located approximately fifteen feet below the surface. Approximately 10-12 mill
ion gallons of raw water is processed through the Water treatment Plant #1 system per day. It is pumped through the rapid mix area into 3 settling basins. Two of the basins are for industrial water and hold 1.5 million gallons each. The third basin is used for domestic water and holds up to 800,000 gallons.
After being pumped from the river, the industrial water passes through a rapid mix chamber where the raw water is treated to 2-ppm chlorine and to 24-ppm aluminum sulfate. It is then sent to flocculators for one hour and 30 minutes total time and remains in the settling basin for 4-6 hours. The water goes over weirs on the take-off side and sodium hydroxide is added to adjust pH to a range of 6.9-7.0. It is then pumped into a 250,000 gallon clear well before being released into the industrial water system.
The domestic water comes off the top of settling basin #3 and is passed though sand and gravel filters. At this point, caustic soda, fluoride and phosphate are added and
the chlorine is adjusted to a chlorine residual of 2-ppm. The rest of the water from settling basin #3 is sent to the industrial water.
This Risk Management Program (RMP) plan was prepared to cover one regulated chemical (chlorine) at Water Treatment Plant #1 located on Redstone Arsenal (RSA). Chlorine is used to treat the water to drinking water standards by reducing the quantities of bacteria and viruses in the water to acceptable levels.
Water Treatment Plant #1 has a maximum inventory of 20,000 pounds of chlorine stored on site in one-ton cylinders. This is above the threshold quantity of 2,500 pounds and 1,500 pounds under OSHA's Process Safety Management (PSM) program. This requires that the RMP meet Program Level 3 requirements. The chlorine cylinders are stored on their side in an open area where they are easily accessible, but covered to reduce the amount of rainfall that might reach them.
These processes were determined by conducting a thorough review of RSA's Tier
II reports and a site inspection of each site where we expected to find RMP chemicals. A table was prepared and is included in the written RMP plan that details the results of this inspection.
Accident records were reviewed for the covered processes. No known accidents have occurred in the past five years from operations involving the covered processes.
An off-site consequence analysis was conducted of the two processes. The layout of the chlorine cylinders is such that when one cylinder is emptied, the second comes on line. It was therefore determined that the maximum amount that could be released was two one-ton cylinders, or 4,000 pounds. The worst-case scenario was modeled using the RMP-Comp program. The model assumed that the processes were in a rural setting. The modeling reveals that an evacuation radius of 4.2 miles results around water treatment plant #1.
The release radii were drawn on USGS 7.5-minute topographic maps and the census data compared. A worst-case re
lease from Water Treatment Plant #1 would impact a population of 8,000. A worst-case release from Water Treatment Plant # 1 would impact the Wheeler National Wildlife Refuge, NASA's Marshall Space Flight Center and the nearby community of Triana.
Alternative release events were modeled based upon the document "Compliance Guidance and Model Risk Management Program for Water Treatment Plants" published by the American Water Works Association Research Foundation and the USEPA, ISBN No. 0-89867-965-6. Release scenarios CLA 3, CLA-4 and CLA-5, as described in Table 5-5 of the above referenced guidance document, were modeled using RMP-Comp. The scenario that resulted in the largest release radius was scenario I.D. CLA-5. The resulting radius was 0.6 miles.
Because of the determination that the process is subject to Program 3 prevention plan requirements, the site's OSHA PSM program was reviewed and modified to comply with the Program 3 requirements. When completely implemented, the i
nstallation will be in complete compliance with the OSHA PSM requirements and as a result, the EPA RMP requirements.
The prevention plan consists of the following documents:
? Risk Management Procedures Manual
? PSM/RMP Program Manual
The Risk Management Procedures Manual establishes the RMP management system, the requirements for controlling documents, controlling records, and developing documents and procedures and the controlling confidentiality. Subsections of this document include the following:
? RMP Management System
? RMP Management Responsibility
? Numbering and Indexing
? Controlling Confidentiality
? Developing Policies, Procedures and Instructions
? Controlling Documents
? Controlling Records
? Establishing and Maintaining Libraries
? Controlling Nonconforming Conditions
? Managing Corrective & Preventive Action
The PSM/RMP Procedure Manual presents the specific procedures for the RMP program, such as the process hazard analysis procedures, training, employee parti
cipation, mechanical integrity, etc. The subsection headings include the following:
? Employee Participation Procedure
? Process Safety Information Procedure
? Process Hazard Analysis Procedure
? Operations Personnel Training Procedure
? Operating Procedures
? Contractor Procedures
? Pre-startup Safety Review Procedure
? Mechanical Integrity Procedure
? Hot Work Permit Procedure
? Management of Change Procedure
? Incident Investigation Procedure
? Compliance Audits Procedure
RSA's emergency response plans and programs were reviewed and modified to comply with the RMP requirements. A section was added that specifically addresses releases of chlorine. This section was added as an addendum to RSA's Spill Prevention, Containment and Countermeasure (SPCC) plan and the Installation Spill Contingency Plan (ISCP). Where possible, references to existing sections of the SPCC and ISCP were made and new information was added and has been incorporated into the site-training program.