BIF Metal Spiking Safety Considerations & Training
|Jim Woodford||David Constans|
|Operations Consultant||Vice President|
|Gossman Consulting, Inc.||Air Compliance Technologies|
In February of 1991 the USEPA promulgated the Burning of Hazardous Waste in Boilers and Industrial Furnaces (BIF) regulations. These regulations officially regulate cement kilns and boilers involved in hazardous waste activities under the Resource Conservation and Recovery Act (RCRA). The storage and handling of the waste materials burned in these devices was already governed by RCRA.
These additional regulations require that specific metals going into a cement kiln (industrial furnace) be monitored so that metal emission limits will not be exceeded. The specific metals are antimony, arsenic, barium, beryllium, cadmium, chromium, lead, silver, mercury and thallium.
A Compliance Test must be conducted and a report submitted by August 21, 1992. The feed rates used during the test automatically become the upper limits for each respective kiln. Consequently, kilns will be trying to maximize the input of their feed streams so as not to establish unrealistically low limits. This paper addresses the safety aspects associated with the metals spiking necessary to maximize metals input during the Compliance Test.
The Technical Implementation Documentation for EPA's Boiler and Industrial Furnace Regulations issued in March of 1992 provides general guidelines for metals spiking in section 220.127.116.11 and is partially cited as follows: "Metals should be spiked in a form which matches as closely as possible the form of the metals in the waste." Towards that end, metals which are metalic ions in liquid form, attached to long chain hydrocarbons, have been chosen. These metals are generally soluble in waste fuels. The balance of the metals can be crystals or powders soluble in water. These materials are fed into the waste fuel line just prior to the injection point into the kiln. As a safety consideration, it is important to choose materials that are not substantially more toxic than the metal itself.
Pre-Set Up Safety
Interaction with plant management initiates the discussion about how much metals bearing materials will be required. This is determined by closely examining feed rates and metals emission limits. Depending upon the Compliance Test needs, metal bearing materials may eventually be delivered in drums and/or tankers. Suitable on site storage space will need to be made available for these materials. This area will need to be roped off for authorized personnel only.
General safety training is recommended at this point so that these materials can be safely handled on-site by plant operations people. These training classes are normally conducted by representatives of the metal spiking company. Copies of the Material Safety Data Sheets (MSDSs) are made available to the operators. General safety precautions are covered and a sign off sheet is completed at the end of the classroom session.
Set Up Safety
Set up is primarily accomplished by represenatives of the metals spiking company. Any shelter and/or containment materials are purchased locally and/or put together prior to actual set up of the spiking equipment (i.e. running required electrical service to this area). This normally occurs before the metals spiking company arrives on-site and includes the selection of a pumping site and chemical handling area.
Set up safety precatuions follow:
- carefully clear the pumping area of all debris
- construct the pumping containment area, making sure that the dimensions are sufficient to contain at least 55 gallons
- make sure that all site workers are aware of the importance of maintaining the containment area integrity throughout the Compliance Test
- construct the pump support mainframe(s), making sure of sturdiness and operational flexibility (this includes fork lift overhead considerations)
- use appropriate chemically compatible pump and pump accessory materials to insure proper pumping conditions and reduce the possibility of failure
- carefully run individual metal feed lines and hook into feeder header
- test the individual pumps and header with water
- connect the header to the waste fuel feed line once the pumping system checks out
The metals spiking system is now ready for the Compliance Test. Since all of these materials are toxic and some of them carcinogenic, make sure that all fork lift drivers have received safety training. As solids, the primary hazards are inhalation and skin contact. As liquids, the primary hazards are inhalation of mists and skin contact.
Appropriate safety gear for most pumping activities during the Compliance Test consists of:
- hard hat
- safety glasses
- steel toed shoes
- cotton shirt and pants
- "rain suit" top and bottom (chemically resistant overalls will serve as a substitute)
- chemically resistant gloves
- chemically resistant inner gloves
- half face respirator with organic/acid vapor cartridges plus particulate protection
- full face splash shield for potential splash situations
Any activities requiring more stringent safety precautions (e.g. supplied air) would be performed exclusively by the metals spiking company. It is important that appropriate safety precautions are adhered to and not allowed to become lax as familiarity increases.
Compliance Test Safety
Multiple metals spiking occurs during the Compliance Test. This can involve as many as five individual drum pumping stations and one or more 7000 gallon tanker(s). Once the system is actually pumping metal bearing solutions, it runs almost maintenance free. The system must be frequently inspected for leaks as there are numerous connections per pumping station. Something as simple as blowing a pressure gauge can result in leaking material.
Drum changes are also potential material spill/leakage situations. Given proper guidance, experienced fork lift operators help insure that drum changes go smoothly and without incident. Drums are designed to maintain structural integrity as long as the bungs are snug. Never move drums unless bungs are securely in place. Another activity which could result in material spills is switching tankers. Only one person can be in charge of the pumping area at any given time and this must be agreed to in advance of any activity. Tanker switching is a multiple step activity and of such a nature that the person orchestrating the switching cannot be in question. Simply stated, that person's word is the law in the pumping areas.
A spill of any size would be handled within the normal spill control procedures at a given facility. Familiarity with plant spill control procedures is important to the metal spiking crew.
Additional Safety Precautions
There are additional safety concerns which may be a factor during metals spiking. One in particular is interruption of waste fuel pumping. Since the metals bearing material is being input into the waste fuel line, any anticipated shut off of the waste fuel must be communicated to the metals pumping area in a timely fashion.
Weather is also a concern, in particular, rainy weather. Electrical equipment must be protected from rain and footing can become slippery under rainy conditions.
Electrical fires are also a very real possibility. Electrical interrupt switches, a safe but short distance from the actual pumping area, are required. An ABC fire extinguisher should be available in this area.
The final additional safety concern which merits attention is the heat given off by the kiln. This heat raises a number of areas of potential concern:
- heat stress
- vapor generation from metal bearing materials
- pump cavitation
- pumps may overheat
- an increase of potential chemical reactions
Safety considerations are important throughout the metals spiking planning and implementation process. By emphasizing safety from the beginning, it becomes very clear that safe operations are important. Additionaly, emphasizing safety helps establish a level of trust and confidence with the kiln management and their employees.
- Jointly choose an area that is as isolated as possible from regular plant traffic.
- Choose metal bearing materials that are not substantially more toxic than the metal itself.
- Stress safety issues in pumping area construction prior to the Compliance Test. This includes the storage area for the metal bearing solutions.
- Insure that site employees have received proper MSDS safety training prior to any chemicals arriving on site. Make MSDSs available on site.
- Follow established safety guidelines when setting up the metals spiking area. Double check the system.
- Make sure that proper safety guidelines are followed throughout the entire metals spiking time period (usually 24 to 48 hours).
- Monitor the metals spiking system and be on the alert for any unusual conditions which might impact safe and effective metals spiking activity.