Potential Environmental Impact of Operating Facilities

Transcription

1 Potential Environmental Impact of Operating Facilities Learning Outcome When you complete this module you will be able to: Discuss the impacts that operating facilities may have on the environment and some methods of dealing with those impacts Learning Objectives Here is what you will be able to do when you complete each objective: 1. List the types of impacts that operating facilities can have on the environment. 2. Discuss how plant personnel are alerted to the environmental problems of operating facilities. 3. Discuss the overall noise implications of operating facilities. 4. Discuss and give examples of the importance of "attitude" in limiting the environmental impact of operating facilities. 5. Describe the issues associated with long-term, hazardous waste treatment strategies. 6. Describe the general considerations associated with the decommissioning and abandonment of operating facilities. 1

2 INTRODUCTION This module will discuss the impacts of an operating industrial facility. Some points to be addressed are covered in detail in other modules. An operating facility may adversely impact the environment as a result of several different operational characteristics, such as: - Incomplete combustion. - Planned or unplanned vapor release. - Hazardous or contaminated liquid release. - Airborne particulate matter. - Solid waste. - Noise generation. - Odour. - Surface disturbance. These excursions have immediate and long-term effects on the environment. Incomplete combustion, for example, discharges an excessive amount of CO, which affects the atmosphere. Also, unless dealt with, a form of NO x is produced during all combustion processes. Under certain conditions, this NO x will produce ozones, visible as a brown haze in the atmosphere. When combined with rain, CO and NO x form acids, which may be harmful to the soil and waters upon which they fall. Noise pollution, on the other hand, will have a more immediate effect. Not only is it an annoyance; over a period of time, personnel without proper protection will experience hearing loss. Pollution in the liquid form has the potential for long-term soil contamination as well as groundwater contamination. Sustained pollution over a long period of time may render the soil hazardous and unproductive. Contamination of groundwater could introduce excessive levels of undesirable components into drinking water or irrigation streams. During the normal course of operation, or when an excursion occurs which releases material to the atmosphere, a very distinct and far-reaching odour may result. For example, the odours of hydrogen sulphide, mercaptans or C 5 + streams are very noticeable. These products may or may not be harmful, depending on the concentration level; however, the presence of any of these products in the atmosphere raises a concern for the public exposed to the odours. Care must be taken in handling any material which may produce odours. For example, when injecting mercaptan into a load of propane, or offloading mercaptan, ensure adequate measures are taken to minimize the chance of a release. 2

3 RECOGNITION Different methods may be employed to alert operators to the existence of a problem. For example, instrumentation may be used to indicate a change in level, flow, or pressure, or incomplete combustion. Other equipment may be used to monitor for seal leaks, the integrity of critical equipment, or for contaminated sewers. The operating and maintenance personnel probably provide the most effective means of recognition of problems. Through frequent and comprehensive checks, early recognition of spills, leaks or any unplanned condition can minimize the impact. It is important that all employees know the characteristics of the materials they are dealing with in order to spot excursions, and protect themselves and the environment. As a person becomes intimately familiar with the facility they work in, various sights, sounds, and smells become standard or normal. One way to detect possible trouble is to recognize conditions which are different from normal. Does your area have an unusual sound? Should that vapor plume be there? What is the source of the different odour? If any of these questions surface during the execution of duties, make sure the cause is followed to the source. The Workplace Hazardous Material Information System (WHMIS) is a valuable resource in this monitoring process. Familiarity with the facility which one operates and maintains makes it possible to identify design deficiencies and seek alternate methods of doing the job to ensure that current methods address the problem of environmental impact. Some facilities use gaskets or valve packing with asbestos fibers. In the new, undamaged state, these are not hazardous; however, as they wear, some asbestos fibers may be exposed. During the changeout of this material, ensure that this hazard is recognized. Establish procedures for the removal and disposal of this material to ensure that asbestos fibers are not released into the atmosphere. NOISE Application for new permanent facilities, or for modifications to existing permanent facilities will, where there is a reasonable expectation of continuous noise generation, require a noise impact statement. Facilities such as compressor stations, pumping stations, gas processing plants and batteries with compressors are examples of installations for which a noise impact statement would be required. 3

4 The noise impact statement should specify the design sound level at the nearest or most impacted permanently or seasonally occupied dwelling. The noise impact statement is intended to encourage applicants to consider possible noise impacts before a facility is constructed or in operation. Since the cost to retrofit may be significantly more than if noise mitigation measures are incorporated into the design of a facility, operators should discuss noise matters with residents during the design and construction phases of an energy facility. While residents, particularly in rural areas, would generally prefer no increase in sound levels resulting from energy-related developments, it is sometimes not possible to completely eliminate these increases. However, if proper sound control measures are incorporated into facility design, increases in sound levels can be kept to acceptable minimums. Sound levels are generally considered to be acceptable when overall quality of life or indoor sound levels for residents are not adversely affected. This does not guarantee that a resident will not hear sounds from a facility; rather it aims for a situation in which the sound level increases will be kept to acceptable minimums and that indoor sound levels will not be adversely affected. Even for facilities with no dwellings within 3 km, uncontrolled sound generation will not be allowed. Therefore, reasonable measures should be taken to moderate potentially bothersome sound generation even though no sound level criteria are specified. Retrofit may be required if a residence is built close enough to a facility that it can no longer be considered to be remote. For drilling and servicing rigs, the responsibility for sound control belongs to the well licensee. Compliance for drilling and servicing rigs is enforced on a complaint basis only, because of the large number of variables at each location. It is expected that all parties will act quickly to remedy any complaints. While noise impact from energy facility-related heavy truck traffic is not specifically mentioned, it should be noted that its impact is not excluded from the Permissible Sound Levels regulations. It is expected that every reasonable measure will be taken by industry to avoid or at least minimize the impact of heavy truck traffic in any given area. 4

5 ACTIONS The action taken by the operations personnel is critical in minimizing the impact of an unplanned excursion. An action may be as simple as the adjustment of air flow to ensure complete combustion. Other more complex situations may require the isolation of equipment and containment of a release. For example, suppose a pump seal fails, and releases liquid hydrocarbon to grade. Prompt isolation of the pump will reduce the amount of material spilled. Containment to prevent the release from entering storm sewers, etc. will aid in minimizing the damage caused. Perhaps the most beneficial and effective action in the reduction of environmental impacts is attitude. No longer can actions be taken just because They were always done like that!. One must be conscious of the impact of any actions taken. Questions, such as Is there a better way?, should be asked to raise awareness and thus potentially reduce the environmental effects. Can the transmitter that has always been blown to grade be routed to a collection system; e.g., to a flare or contaminated sewer? How about the flange or packing leaks that have been there for a while and don t seem to be getting worse. These fittings should be tightened if possible, or placed on a scheduled maintenance list. If they are chronic problems perhaps a preventive maintenance schedule is necessary. When isolating and preparing equipment for maintenance or other activities, care should be taken to minimize the release of material. Where possible, liquids should be back pressured into the system and vapors purged to a contained system. Plans must be put in place to deal with the residual material such as trapped liquids or sludge deposits. Plans for containment and disposal of materials, and regulations governing the use of correct personal protective equipment are necessary. When an action is taken, whether it be in normal routine duties or in response to some unplanned event, other problems that may arise as a result of that action should be considered. Often the most probable scenarios are identified, and procedures, whether normal operating or emergency, are written to address these situations. However, during the execution of these activities a thought process should be instilled which prompts the employee to ask why each step is being carried out and what the impact of the procedure is likely to be. As a facility ages certain aspects of the original design may no longer address the operating parameters. Changes will occur that require the addition of equipment, or the retrofitting of existing equipment to deal with environmental concerns. It is the responsibility of each worker within a facility to identify and act on these concerns as they become apparent. 5

6 Each step in a change of design or of operating methods should be evaluated to assess the consequence of the change. Normally a hazard analysis and risk assessment is included in the design stage to identify, minimize and control any hazardous situation. Prior to commissioning or operating a design change, an additional hazard and operability study should be conducted to address the potential effects of any modifications. Let us examine three types of actions that can be taken when a problem area is identified. Permanent action is the most desirable since it deals with and eliminates the root cause. A vessel is purged through an atmospheric vent on a frequent basis. A permanent action would be to vent the vessel into a closed flare system. The second type of action is interim action which allows you to live with the effects of a problem while making definite plans to address the cause at the earliest opportunity. To ensure that this action is effective, it is critical to assign responsibility and establish a time frame for follow up. A section of pipeline ruptures and spills oil. An interim action would be to repair the rupture. Responsibility would then be assigned to test and replace any suspect areas by a certain date. The third category is adaptive action which allows the plant to operate with the condition indefinitely. A transmitter has been blown down to grade twice a day since the facility started up. It is impractical to route the drains to a collection system. In this case the frequency of blowdown can be addressed and the transmitter may only be blown down on an as-required basis. By recognizing and analyzing the operation, the blowdown frequency may be reduced. The ability to deal with abnormal conditions in a timely and efficient manner will significantly reduce adverse environmental impacts. Questioning, and developing contingency plans for the occasions when something goes wrong will assist in achieving this. Companies will generally have identified the most likely cases and have established emergency plans. 6

7 The following answers to If something goes wrong, how am I going to handle it? help to establish emergency procedures: - Know the material you are dealing with. - Know the isolation points in the process. - Identify what is required to contain a release and protect yourself. - Identify what other problems to the environment or process an upset may cause. - Inform other people in your area of what you are doing so they may assist if needed. - Discuss the what ifs of an occurrence with others to gain their experience in dealing with unusual occurrences. DECOMMISSIONING AND ABANDONMENT When an existing facility is shut down and decommissioned, the site must be left in a condition suitable for alternate uses. It must pose no future threat to public health or the environment, nor create any future liability for the company. A condition of approval for a new facility requires that an acceptable development and reclamation plan be prepared prior to construction. It will be necessary to remove from the soil all hydrocarbon contamination resulting from on-site waste management and the inevitable spills and leaks that occur in operating a facility. This may involve actual removal or cleansing of the soil, depending on the levels and types of contaminants present. The highest practical reclamation standards must be established and met. The public must be provided with a full disclosure of all reports and data generated during the reclamation project. Before the closure is announced anticipated environmental impacts must be identified and appropriate remedial plans formulated. The plans should address such details as closure, dismantling, site evaluation and reclamation procedures. Even before shutdown, the process of determining the history and location of potential sources of past contamination, such as tank leaks, process spills, and landfills, can proceed through a history and records search and discussion with long term employees. As areas are abandoned periodically over the life of the facility, the site and equipment can be dismantled and cleaned. It must be recognized that while these steps are helpful in initiating the cleanup, the full scale of the project may expand as the shutdown phases progress. 7

8 The cost of reclamation can be greatly influenced by the activities of the operations personnel. If people operate a facility in an environmentally conscious manner, there will be far less work to do in returning the site to a condition suitable for alternate uses. LONG-TERM IMPACTS Long term environmental impacts are greatly influenced by the manner in which companies and facilities manage the hazardous waste generated. The most proficient principle of hazardous waste management is to avoid the generation of the waste in the first place. Recovering and reducing the amount of hazardous material is to be preferred to the necessity of its treatment or destruction. If the hazardous material cannot be eliminated it must be securely contained and monitored to protect people and the environment. Long-term storage of hazardous material should be avoided where commercial treatment or disposal facilities exist. When an outside contractor is used for hazardous waste disposal some key points must be checked: 1. Ensure that the transportation of hazardous waste conforms with the Transportation of Dangerous Goods (TDG) legislation. 2. Conduct periodic assessments of the disposal company to ensure the methods used comply with all required legislation. Hazardous material that may migrate, leak or accumulate from storage or operating facilities must be dealt with. The most common approach is to deal with these as they occur; however, some residual material will accumulate during the life of the facility. When a contaminated area is identified the boundaries must be defined. This will involve core sampling of the soil to determine the circumference and depth of the area affected. Once this is established the contaminated soil is removed, placed in sealed containers, and removed for disposal/destruction. The void created by the contaminated material removal would then be replaced by fresh fill. Another area that may be cause for concern is the disposal of samples that are taken within a facility. If the samples contain hazardous material they should be disposed of in a careful, responsible manner. This may mean collecting in appropriate containers and removing to in-plant contaminated sewer facilities or off-site disposal facilities. The samples should never be poured or released to a sanitary or storm sewer system where water or soil contamination may occur. 8