This paper presents the development of a method of performing Management Systems Audits of Environmental, Health and Safety (EH&S) programs in upstream oil and gas companies. It describes how the results from the compliance auditing system presented in SPE Paper 25955, "Initiating an Audit Program: A Case History" were combined with a system categorizing EH&S activities into several management systems defined by regulations and good operational practices, and used to perform short term "Pareto-style" audits (e.g., 80% of the value from 20% of the time). A comparison is made of this type of audit model with the classic accounting audit model. Examples from Management System Audits Of ARCO's foreign and domestic operations are used. Included are discussions of the economic benefit of performing EH&S Audits and the benefit of developing a method of auditing considering the new ISO 14000 standard for environmental auditing and the proposed ISO safety auditing standard.
The conclusions presented are that auditing by experienced personnel using an auditing template developed exclusively for upstream operations provides benefits to the company in the areas of compliance, management systems development and education of first line operations personnel as well as resulting in an overall reduction in the cost of an audit. A further conclusion will be that trends in international standardization appear to be mandating an EH&S auditing program for those companies planning to do business outside the United States.
In 1990, ARCO Oil and Gas Company, then the domestic exploration and production (E&P) unit of Atlantic Richfield Company (ARCO), established an audit team responsible for monitoring compliance with all applicable environmental, health and safety (EH&S) regulatory requirements. This group was charged with completing a full cycle of compliance audits within three years. A detailed account of how the program was established and implemented is contained in SPE Paper 25955, "Initiating an Audit Program: A Case History". A review of the initial program is necessary in order to fully understand the development of the second generation program for auditing EH&S management systems which has grown from the initial program.
Putting the initial compliance audit program into effect required that many things be accomplished. These included the development of the audit protocols based on all applicable federal, state and local regulations and getting the protocols incorporated into a computer database system. In addition, an audit plan and schedule for auditing all of the 560 properties included in the audit universe had to be developed. Simultaneously, the permanent audit group was staffed with employees with either an EH&S or operating background with no fewer than three to five years of experience. Despite the many activities needed to develop an in-house audit team and its tools and the large number of properties to be audited, the compliance audit of all ARCO Oil and Gas Company facilities was completed before the end of 1993.
At that time, all properties operated by ARCO Oil and Gas Company had been subjected to a wall-to-wall compliance audit, reports had been written documenting each specific item which needed to be corrected and action plans to correct all compliance issues had been agreed to by the audit team and operating areas. As mentioned in SPE Paper 25955, it appeared that recurring compliance findings occurred at facilities covered by the same field management. Although the auditors provided detailed one-to-one training to first line supervisors during the audit field investigation phase, the compliance findings did little to impact the way in which EH&S activities were managed on an areal basis. The press of operating in a low operating cost environment left those responsible for production operations with little time to do anything other than to complete punchlist items. Further, the audit results provided little basis for making adjustments to management techniques that would affect their long term compliance efforts.
Previous assessment of dispersion modelling, toxicity testing, and characterisation of produced formation water (PFW) discharges into Bass Strait indicated a very low environmental risk from PFW to the marine environment. Peak PFW concentrations can exceed the effect levels (EC50 or LC50) measured in 24-96 hr laboratory toxicity tests only within distances of tens of metres from the discharge point. In this assessment, the field monitoring of aromatic hydrocarbons in the water column (which are in low concentrations in PFW) was undertaken to directly assess dispersion and predicted fate mechanisms.
Very low concentrations of both light and heavier aromatic hydrocarbons are likely in any PFW discharge. A high volume absorption sampler was deployed 20 m from the discharge point to continuously sample ocean concentrations of aromatic hydrocarbons for up to one week, providing large volume (1,000 L) water samples. Gas Chromatography/Mass Spectrometry (GCMS) was used to measure aromatic hydrocarbon concentrations.
The concentrations measured with the ocean sampling device provide time integrated samples over approximately one week, and the results showed that the ratio of discharge concentration to ocean concentration was approximately 20,000:1.
Compared to dispersion modelling predictions, the ocean sampler indicates lower environmental risk. This is because dispersion modelling predicts ocean concentrations within the plume whereas the sampler is measuring concentrations at a fixed point over the long term and is exposed to the plume only intermittently, similar to a sessile marine organism. Therefore the ocean concentrations provided by the large volume sampler are more representative of longer term ocean concentrations which can be experienced by marine organisms.
Further assessment of prevailing operational and oceanographic conditions in Bass Strait suggests that there does not appear to be a water column accumulation of PFW aromatic hydrocarbons adjacent to the discharge.
There are currently 12 offshore produced formation water (PFW) discharges from Esso/BHPP's oil and gas production facilities in Bass Strait, Australia (Figure 1). Total volumes of the discharges are approximately 90 ML.d-1. The volumes have increased significantly in the past five years from the minimal discharges in the early 1970s when oil production was brought on-line starting with Halibut in 1970. PFW discharge volumes are likely to increase further as fields mature.
Environmental risk assessment of PFW discharged into Bass Strait suggests the discharges present a low potential for impact on marine organisms due to low acute toxicity and high dilution rates. Terrens and Tait reported discharge plume dispersion modelling predictions where the dilution of a typical PFW discharge in Bass Strait was 30:1 within 10 m of the discharge point, and that acceptable acute toxicity could be obtained with dilution of less than 4:1. The dispersing discharge plume is spatially limited as a narrow band, and mobile due to local tidal conditions. The length of any water column organism's exposure to concentrations in excess of acute effect levels measured in laboratory toxicity tests would be less than about 30 seconds for median current conditions, a period much less than that of the 24 hr or 96 hr acute toxicity tests.
Shell companies have their own separate identity. In this paper the collective expressions 'Shell' and 'Group' and 'Royal Dutch/Shell Group of Companies' may be used for convenience where reference is made to the companies of the Royal Dutch/Shell Group in general. Those expressions are also used where no useful purpose is served by identifying the particular company or companies.
A desire to implement HSE Management Systems including HSE Cases in all Shell companies operations prompted the development of a relational data base software package (THESIS) to provide a structured way of preparing an HSE Case. The software includes features which facilitate the management of "Keeping the Case Alive", enabling the dissemination of tasks and hazard information to the workplace.
During the software development it was recognised that a significant reduction could be made in the resources which would be required to prepare an HSE Case for each and every operation by the building of "Generic HSE Cases" addressing specific activities which were repeated across the Company's operations. This was recognised to be particularly valid for the smaller Single String Venture type of operations. The activities selected for the initial Generic HSE Case development include Land Drilling Operations, Land Seismic Acquisition, and Land Transport.
To establish the Generic HSE Case, the THESIS data base is populated with data for a generic operation, identifying all the hazards and activities associated with that operation including all the associated controls, with established formats for the textual sections. In effect, the Generic Case defines the standards required for that type of operation. To generate an operation specific HSE Case, the Generic Case thereafter requires to be modified/adapted so that it represents the actual situation in the operation which it defines. This process includes itemisation of all the operation specific details, and may involve the inclusion/deletion of any additional/existing activities or hazards together with their associated controls.
Through the use of THESIS and the Generic Drilling HSE Case which has been developed, it has been established that a local specific Drilling HSE Case may be produced within two months by a small dedicated team; a significant reduction when compared with to the early Cases, which demanded man years of effort.
The Cullen Inquiry Report (1990) on the Piper Alpha accident recommended that operators should be required to submit Safety Cases for each installation to demonstrate that a Company's SMS was adequate to ensure safety: It was assumed that SMS already existed, but recommendations on minimum requirements were given, for example that they should follow the principles of Quality Management contained within ISO 9000, BS5750.
The Shell Group followed up on this initiative in 1991, leading to the development of Safety Management Systems and Safety Cases within Shell E&P Companies. Corporate guidance was issued in an attempt to achieve uniformity in the application of the new SMS and Safety Case concepts and techniques.
Early efforts at compiling Safety Cases within the Shell Group of Companies were undertaken primarily in the larger "Operating Companies" who were obliged to meet the new regulations. The Cases tended to be focused at the Operator business activity / departmental level, addressing programming and planning. These Cases were supplemented to a varying degree by contributions from the "sharp end" work-force (e.g. the Drilling Contractor).
Following the completion of the early Safety Cases it was soon recognised that their subsequent use was limited;
Many areas in the United States are not in attainment of the National Ambient Air Quality Standard for ozone, These areas include some with petroleum production operations, such as Kern County, California. In addition, major OCS development and production sources in the Western Gulf of Mexico are located offshore of the Houston and Beaumont/Port Arthur nonattainment areas. EPA requires that states implement a planning (SIP) process to develop strategies to achieve the federal ozone standard. These plans have the potential to result in significant control requirements for the production facilities. Potential impacts from different source types can be assessed through use of photochemical modeling of ozone precursor emissions (hydrocarbon and nitrogen oxides) from all anthropogenic (man made) sources. This modeling information can be used to: 1) identify whether specific types of sources contribute to the ozone nonattainment problem, and 2), develop a set of control measures to reduce ambient ozone levels.
This paper will examine two photochemical modeling case studies which assessed the impact of petroleum productions sources in the Bakersfield and Houston nonattainment areas, The San Joaquin Valley SIP modeling showed that additional controls of NOx emissions from heaters, boilers and internal combustion engines located on the west side of the Valley were not necessary to meet the federal ozone standard by 1999. In the case of the assessment of OCS impacts on Houston, modeling showed that at times and locations where the federal ozone standard was exceeded, OCS contributions were minimal, This finding not only removes the probability of controls, but also greatly limits any probability of transfer of jurisdiction for OCS air quality from Minerals Management Service to EPA.
Recommendations on how to develop and implement a modeling assessment program will be presented to aid those who may be involved in similar planning processes in the future.
This paper will present two case studies in which decisions about the need for controls of air emissions from petroleum productions sources were based on air quality modeling. Unlike simple permit modeling, the assessments were made for multiple sources and used sophisticated photochemical models The paper will describe how air quality monitoring and modeling programs were implemented in a cooperative fashion with the appropriate regulatory agencies. This resulted in all parties having a vested interest in the success of the program. As important, it allowed all parties to accept the results of the assessment. In both cases, no new or additional controls were required, and the avoided costs to the petroleum industry were estimated at $ 50,000,000 and $ 100,000,000 respectively.
In 1990, the U. S. Congress passed the federal Clean Air Act Amendments (CAAA). Major changes were made with respect to requirements to attain the ozone National Ambient Air Quality Standards (NAAQS). This standard is set at 12 parts per hundred million (pphm), averaged over one hour, It is not be exceeded more than once annually, averaged over three years. Title I of the Act mandated that those states which contained areas not yet in attainment with the ozone NAAQS submit a State Implementation Plan (SIP) by November 1994. The SIP was required to demonstrate that the areas in question would attain the standard by the applicable deadline.
Shell companies have their own separate identity. In this paper the collective expressions 'Shell' and 'Group' and 'Royal Dutch/Shell Group of Companies' may be used for convenience where reference is made to the companies of the Royal Dutch/Shell Group in general Those expressions are also used where no useful purpose is served by identifying the particular company or companies.
Shell International Exploration and Production (SIEP) commenced a programme of Health Safety and Environmental (HSE) auditing in its Operating Companies (Opcos) in the late 1970s. Audits in the initial years focused on safety aspects with environmental and occupational aspects being introduced as the process matured. Part of the audit programme is performed by SIEP auditors, external to the Opcos. The level of SIEP-led audit activity increased linearly until the late 1980s, since when a level of around 40 audits per year has been maintained in roughly as many companies. For the last 15 years each annual programme has included structured audits of all facets of EP operations.
The frequency and duration of these audits have the principle objective of auditing all HSE critical processes of each Opco's activity, within each five-year cycle. Durations vary from 8-10 days with a 4 person team to 18-20 days with a 6-8 person team.
Each audit returns a satisfactory or unsatisfactory rating based on analysis of the effectiveness of the so-called eleven principles of Enhanced Safety Management (ESM) required to be applied throughout the Group.
Independence is maintained by the SIEP audit leader, who carries ultimate responsibility for the content and wording of each report, where necessary backed-up by senior management in SIEP.
These SIEP-led audits have been successful in the following areas:
- Provision of early warning in areas where facilities' integrity or HSE management was likely to be compromised.
- Aiding the establishment of an internal HSE auditing process in many Opcos.
- Training, through participation in audits, not only auditors, but also prospective line managers m the effective management of HSE.
With the recent introduction of HSE Management Systems (HSE-MS) in many Opcos, auditing is now in the process of controlled evolution from ESM to HSE-MS based. The evolutionary process includes restructuring the standard report contents list and questionnaires, reviewing the rating methodology and the production of revised guidelines. Full HSE-MS based auditing, scheduled to be achieved by end 1997, is expected to lead to further improvement and structure in Opco internal auditing, with an eventual reduction in the need for audits led by SIEP staff. The ultimate level of SIEP-led auditing has not been established and will depend on the achievements by, and confidence in, the Opcos.
SIEP activities are conducted in 37 countries around the world through the Opcos. Each Opco is individually responsible for its business, but SIEP seeks through its policy, which requires foremost attention for health and safety of employees and other persons, and conservation of the environment, the implementation of common standards by the Opcos, where possible. P. 389
Soetjiptono, T.E. (PT Caltex Pacific Indonesia) | Nugraha, S. (PT Caltex Pacific Indonesia) | VanDerZanden, D.F. (Chevron Research & Technology Company) | Petersen, L.P. (Chevron Research & Technology Company) | Verstuyft, A.W. (Chevron Research & Technology Company) | Schievelbein, V.H. (Texaco Exploration and Production Technology Department) | Rabideau, C.G. (Texaco Exploration and Production Technology Department) | Gilmer, L.K. (Texaco Exploration and Production Technology Department) | Comey, K.R. (Texaco Exploration and Production Technology Department)
T.E. Soetjiptono, and S. Nugraha, PT Caltex Pacific Indonesia, D.F. VanDerZanden, L.P. Petersen, and A.W. Verstuyft Chevron Research & Technology Company, and V.H. Schievelbein, SPE, C.G. Rabideau, L.K. Gilmer, and K.R. Comey, Texaco Exploration and Production Technology Department
The Caltex Pacific Indonesia production field located in Duri, Indonesia, is the world's largest steam flood. Because of the large scale of these operations, there is an interest in understanding the emissions into the atmosphere from the various sources in the field as well as the possible impact on the air quality resulting from these emissions. To be proactive and to fulfill this need, a study was done to inventory emissions from the facilities in the field and to use air dispersion models to estimate impacts on the air quality using the inventory results. This paper will discuss methods and procedures used in the study to quantity the emissions from the following sources in the Duri field: process vents, production impoundments and wastewater canals, roads, fugitive emissions, storage tanks, and combustion sources. Emissions of the following compounds were addressed in the study: non- methane hydrocarbons (NMHC) and aromatic hydrocarbons (BTEX), hydrogen sulfide, nitrogen oxides, sulfur oxides, particulate matter (PM), and carbon monoxide. Because of the diverse nature of the sources in the field, a wide range of emission estimating procedures were used including direct measurement methods, empirical methods based on mass transfer principles, and standard emission factors or procedures available from the United States Environmental Protection Agency (U.S. EPA). To quantity and track the emissions data generated, a computerized emissions inventory was developed. This paper will also discuss the dispersion modeling methods that were used to estimate the ground level concentrations in the surrounding areas using the data developed in the emission inventory. These discussions are based upon the results of a preliminary study which is limited to a portion of the Duri production field.
Emission inventories have been commonly used by many industries, especially in developed countries, to estimate the emissions of compounds from their operations. Inventories provide information that is useful in determining the relative magnitude of emissions between sources. The data developed in the emission inventory can be used in a dispersion model to estimate the worst case scenarios of the ground level concentrations in the surrounding areas.
This paper describes the methodologies and procedures used in an emission inventory and dispersion modeling study developed for a portion of the steam flood project located in the Duri oil field in Indonesia. The overall goal of this study is to identify which of these sources have the most significant influence on the surrounding air quality. This will provide a basis for developing Company strategy in dealing with air quality issues.
The following paragraphs describe the methodology for estimating the emissions from each source. It is divided into sections by source type. Each section describes the source and emission estimating procedures. The application of air dispersion models for estimating air quality is also described. Air Emission Inventory
Emissions were calculated using a combination of direct measurements and published emission factors. Emission factors are combined with other operating parameters (such as fuel consumption) to calculate emissions. The emissions were quantified from the following sources in the Duri field: process vents, production impoundments and wastewater canals, roads, fugitive emissions, storage tanks, and combustion sources (steam generators, turbines, and engines). P. 239
Hibernia is an offshore oilfield located 315 km east southeast of St. John's, Newfoundland, off Canada's east coast. The field will be produced from a single concrete platform standing in 80 m of water on the Grand Banks ( Fig. 1). There will be a double loop export line and offshore loading system for dedicated, double hulled tankers ( Fig. 2).
The field is expected to come into production in late 1997. It has taken just over 5 years to construct the platform. While four of the five Topsides modules of the platform were built at yards in Italy and Korea, the Gravity Base Structure (GBS ) or caisson, the wellhead module, and several topsides mounted structures were built in Newfoundland. The platform will be assembled and completed at the Newfoundland site prior to towout to the Grand Banks for production operations.
A small cove on Newfoundland's northeast coast was selected as the construction site ( Fig. 3 ). The site is unique as it is being used for both base and topsides construction, assembly and mating. The deepwater site for completing construction of the base and for mating is only 300 m from the shore site with water depths of over ISO metres.
Great Mosquito Cove, the construction and assembly site, is located within a Fjord named Bull Arm at the bottom of 90km long Trinity Bay (Fig. 4). Sunnyside is the only community on Bull Arm with two other fishing communities 14 km distant by water, Chance Cove and Bellevue.
Bull Arm, like every other part of the Newfoundland coastline is used by inshore fishermen. Sunnyside crews fish only in Bull Arm from 18 - 32 foot open boats. They use several varieties of fixed gear: lobster pots, flounder nets, gill nets, bar seines, longlines, caplin traps, cod traps, squid traps and jiggers. Crews from nearby communities typically have larger vessels, about 34 feet in length, and search throughout Bull Arm and other areas of Trinity bay for pelagic species such as herring. mackerel and caplin using purse seines and bar seines as well as using a variety of fixed gear similar to that used by Sunnyside fishermen, with the addition of crab traps.
Before Platform Construction Began
As soon as the construction site was selected in late fall 1989, two main initiatives were started to ensure that the concerns of the local area fishermen were identified and addressed during all planning and construction activity.
Bid packages that went out to bidders for site and subsequent platform construction contained background development information on the inshore fishery and also instructions to prepare a specific commercial fishery Environmental Protection Plan. The resulting plans were reviewed by HMDC, government and the general public.
Hibernia also began the information gathering and discussions with the local area fishermen which would lead to the two - part Project Fisheries Agreement, consisting of a Code of Practice, addressing safety matters, and a compensation policy and program.
At first it was very difficult to persuade many of the area fishermen to participate in the development of a working relationship between themselves and the project. For many, the reaction to the selection of Bull Arm as the platform construction site was that the fishery was finished and that they should simply be paid off and their gear abandoned: others felt that "Big Oil" would simply do whatever it wanted no matter what they said. The cynicism and pessimism had some basis: over the years the inshore fishery had been managed by means of a very large number of government rules, regulations and policies which rarely, if ever, included input from the fishermen themselves. It was only after many, many discussions with the fishermen about the project - how big it will be, exactly what area will we use, what will go in the water, will there be pollution safeguards, what will be left behind when the platform is finished -and some time on the water with the fishermen seeing the area from their point of view, that specific concerns of the fishermen, and suggestions as how to address them, began to emerge.
The Shell Petroleum Development Company is operating in southern Nigeria in the delta of the Niger River. This delta covers an area 70,000 square km of coastal ridge barriers, mangroves, freshwater swamp forest and lowland rain forests. Over the past decades considerable changes has occurred through coastal zone modifications, upstream urban and hydrological infrastructure, deforestation, agriculture, fisheries, industrial development, oil operation, as well as demographic changes.
The problems associated with these changes are:
1. over-exploitation of renewable natural resources and breakdown of traditional management structures;
2. impact from industry such as pollution and physical changes, and
3. a perception of lack of social and economic equity.
SPDC has taken a three-pronged approach to counter these problems:
1. its long-standing environmental programme addresses the problems related to its operations;
2. a community affairs programme, with an outgoing attitude, showing commitment to support the communities through training, provision of school, hospitals, etc., and agriculture and fisheries extension programmes, and
3. the initiation of an independent and objective study, the Niger Delta Environmental Survey, which will provide the environmental framework in the wider sense for SPDC's operations.
This Survey has as its mission to undertake, in concert with communities and other stakeholders, a comprehensive environmental survey, in order to establish the causes of ecological and socioeconomic change over time and to induce corrective action and encourage relevant stakeholders to address specific environmental and related socioeconomic problems identified in the course of the Survey.
Shell Petroleum Development Company of Nigeria (SPDC) is operating in southern Nigeria in the delta of the Niger River, the main oil producing area of Nigeria.
The Niger Delta covers an area of some 70.000 square km and consists of a number of distinct ecological zones which are characteristic of a large river delta in a tropical region: coastal ridge barriers, saline mangroves, freshwater swamp forests and lowland rain forests.
The economy of the region is based on agriculture - which now has taken most of the dry land rain forest - and fisheries, with the oil and gas industry as the major industrial activity. Port Harcourt and Warri are the main urban centres.
A series of trials have been conducted on a range of offshore helicopter types during the past three years, which have aimed to examine the ability of passengers, during a simulated ditching and capsize, to use the prescribed emergency exits and procedures. As a result of the trials, in which problems of egress were identified under worst case conditions, immediate limitations were advised to Shell Group companies on the cabin capacity of specific helicopter types by Shell Aircraft Limited, pending significant cabin configuration changes which have included enlarged and push-out windows, and changes in seating.
Cabin safety in fixed wing aircraft is an area where regulatory authorities have spent considerable time and effort in recent years to enhance standards. However, until recently, the same could not be said for helicopters, particularly those operating in the offshore environment. Whilst the design requirements for medium to large helicopters specify emergency exits required for surface evacuation, they do not address the underwater escape problem. The Westland's study investigated 98 civil helicopter water impacts over a 20 year period; approximately 50% resulted in fatalities. In accidents where the cause of death could be established, 56% of fatalities were the result of drowning. In a similar study of military helicopter water impacts, it was found that 82% of fatalities were due to drowning.
It was this background, and knowledge of recent accidents (in the North Sea area) that led Shell Aircraft Limited in 1992 to initiate a series of trials on a range of offshore helicopter types. These trials aimed to examine the ability of passengers to escape during a simulated ditching and capsize. As a result of the trials, in which problems of egress from an inverted submerged cabin were identified, immediate limitations were recommended to the Shell Group of Companies, on the cabin capacity of specific helicopter types on contract, pending cabin configuration changes which have included enlarged and push-out windows and changes in seating.
The Escape Environment
Captain Brooks highlights the problem of the helicopter ditching, inverting and sinking. With water rushing in through cockpit windows, aircrew and passengers have to overcome inherent bouyancy to make their escape from a flooded compartment through cargo doors, access doors, windows or the windshield. They may even be thrown out through a split in the cabin if the impact is severe. Even if the crew and passengers are uninjured, escape is difficult with loss of vision, disorientation, the requirement to hold breath under water against the gasp reflex and the extreme terror created by the catastrophe. Occupants whose passage is blocked by entanglement with debris, who cannot release their lap straps or who are injured, commonly perish.
Brooks concluded that the crew and passengers of a helicopter flying over water generally have less than one minute of warning of a ditching before they find themselves in the water. The helicopter is unstable in water and will frequently capsize if struck by a breaking wave. While some of the accidents he reviewed were survivable, he concluded that little had been done to reduce contact or acceleration injuries by introducing basic crash-worthiness principles into the helicopter. However if the crew and passengers did survive the initial impact, then the greatest threat to survival was the potential for drowning.
Brooks also pointed out that crew and passenger survival was enhanced if they had a good pre-flight briefing, were sports or professional divers and, most important of all, had practical professional training in under-water escape and the correct crash position to adopt. He also argued that for current in-service helicopters, redesign of parts of the helicopter structure would reduce fatalities, particularly the introduction of crash-worthy seats and four-point restraint for everyone on board. In addition, increasing the number of escape hatches, adding hatching in the deck, lengthening hatches to floor level, shortening the distance to travel from seat to escape hatch, simplifying hatch or window release mechanisms, making each window a push-out window, adding an underwater Braille system that would guide survivors to the escape hatch by touch, and incorporating good under water lighting would all improve the survival rate. He noted also that further opportunities for survival could be achieved by the addition of an under water breathing apparatus and the fitting of externally mounted self-stabilising multi-seat life rafts that jettisoned automatically on ditching.
Produced water discharges are monitored under the National Pollutant Discharge Elimination System (NPDES) program, and one of its provisions limits oil and grease concentration in the water. This paper summarizes the results of studies conducted by EPA and API to compare results obtained using different solvents (Freon or n-hexane) in the gravimetric technique for EPA reporting as specified in Method 413.1 (current compliance method, Freon extraction) and Method 1664 (proposed new method, n-hexane extraction) and discusses the impact of the new method. The outline of an ongoing API project on techniques for measuring oil and grease content of produced water for overboard disposal will also be discussed.
Produced water and waste water discharges are regulated under the National Pollutant Discharge Elimination System (NPDES) program in the US, and one of its provisions is that the concentration of oil and grease in produced water for overboard discharge be below 29 mg/L or 42 mg/L (daily or monthly mean respectively) using the 1979 EPA Method 413.1. This method is now specified in over 10,000 different NPDES Permits in 25 different industry classifications. This method involves the liquid-liquid extraction of hydrocarbons from the water samples using Freon-113 (1,1,2-trichloro-1,2,2-trifluoroethane) as the solvent, followed by evaporation of the solvent itself from that phase and determination of the oil and grease content by weighing the residue (gravimetric analysis). Freon is an excellent solvent for this purpose because of its solvent power for oil and grease and because of its volatility, where the latter makes it easy to evaporate from the oil and grease analyte.
The United States is one of the many signatories to an international treaty known as the Montreal Protocol, which calls for the reduction of use of substances which will deplete the ozone layer in the upper atmosphere. The compounds which fall into this class are for the most part the chlorofluorocarbons, often known by the trade name Freon. One of these compounds is the Freon-113 specified in Method 413.1 for the analysis of Oil and Grease in discharged water. Thus, the Environmental Protection Agency has been faced with the need to change the regulatory specified method to replace Freon as the solvent.
This paper will: 1) Summarize recent events in the selection of a new method that would replace Freon, 2) Summarize the replacement Method 1664, and 3) Comment on the implications for NPDES Permit Compliance.
Selection of a Replacement Method/Solvent
In considering a change to a new method, both the EPA and the industry are aware of the fact that the total recoverable oil and grease as described in EPA 413.1 (and consequently used for permitting purposes) is a "method defined parameter". As noted by the EPA, this means that "the result depends totally on how the measurement is made" and that "changes to the specific analytical protocols have the potential of changing the numerical value of the results for a given sample." The industry was obviously concerned that a change in method could cause a change in results and thereby in the status of permit compliance.