Cover Image

PAPERBACK
$62.00



View/Hide Left Panel

CHAPTER SIX

Steps Toward a “Best Practices” Protocol

THE IMPORTANCE OF CONSIDERING THE ADOPTION OF BEST PRACTICES

This report has shown that induced seismicity may be associated with the development of different energy technologies involving fluid injection and sometimes fluid withdrawal (see, e.g., Chapter 3). Furthermore, despite an increased understanding of the basic causes of induced seismicity (Chapter 2), these kinds of energy development projects will retain a certain level of risk for inducing seismic events that will be felt by members of the public (see Chapter 5). While the events themselves are not likely to be very large or result in any significant damage, they will be of concern to the affected communities and thus require both attention before an energy project involving fluid injection gets under way in areas of known seismic activity (whether tectonic or induced) and management and mitigation of the effects of any felt seismic events that occur during operation.

This chapter outlines specific practices that consider induced seismicity both before and during the actual operation of an energy project and that could be employed in the development of a “best practices” protocol specific to each energy technology. The aim of any eventual best practices protocol would be to diminish the possibility of a felt seismic event from occurring, and to mitigate the effects of an event if one should occur. The committee views the ultimate successes of any such protocol as being fundamentally tied to the strength of the collaborative relationships and dialogue among operators, regulators, the research community, and the public (see also Chapter 4). Indeed, protocols, when properly developed and understood, can serve to protect and benefit the various parties involved both directly and indirectly in energy project development.

The chapter begins with a few examples of induced seismicity “checklists” and protocols in the literature that have been developed for the purpose of management of induced seismicity for specific energy projects. The chapter then discusses some of the key components of these checklists and protocols and develops two induced seismicity protocol “templates,” one for enhanced geothermal systems and another for wastewater injection wells. The chapter includes discussion of the incorporation of a “traffic light” system to manage fluid injection and concludes with a discussion of the role and importance of public outreach and engagement prior to and during development of energy projects involving fluid injection. The committee acknowledges that this kind of preemptive management approach



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 151
CHAPTER SIX Steps Toward a “Best Practices” Protocol THE IMPORTANCE OF CONSIDERING THE ADOPTION OF BEST PRACTICES This report has shown that induced seismicity may be associated with the development of different energy technologies involving fluid injection and sometimes fluid withdrawal (see, e.g., Chapter 3). Furthermore, despite an increased understanding of the basic causes of induced seismicity (Chapter 2), these kinds of energy development projects will retain a certain level of risk for inducing seismic events that will be felt by members of the public (see Chapter 5). While the events themselves are not likely to be very large or result in any significant damage, they will be of concern to the affected communities and thus require both attention before an energy project involving fluid injection gets under way in areas of known seismic activity (whether tectonic or induced) and management and mitigation of the effects of any felt seismic events that occur during operation. This chapter outlines specific practices that consider induced seismicity both before and during the actual operation of an energy project and that could be employed in the devel­ opment of a “best practices” protocol specific to each energy technology. The aim of any eventual best practices protocol would be to diminish the possibility of a felt seismic event from occurring, and to mitigate the effects of an event if one should occur. The committee views the ultimate successes of any such protocol as being fundamentally tied to the strength of the collaborative relationships and dialogue among operators, regulators, the research community, and the public (see also Chapter 4). Indeed, protocols, when properly developed and understood, can serve to protect and benefit the various parties involved both directly and indirectly in energy project development. The chapter begins with a few examples of induced seismicity “checklists” and protocols in the literature that have been developed for the purpose of management of induced seis- micity for specific energy projects. The chapter then discusses some of the key components of these checklists and protocols and develops two induced seismicity protocol “templates,” one for enhanced geothermal systems and another for wastewater injection wells. The chapter includes discussion of the incorporation of a “traffic light” system to manage fluid injection and concludes with a discussion of the role and importance of public outreach and engagement prior to and during development of energy projects involving fluid injec- tion. The committee acknowledges that this kind of preemptive management approach 151

OCR for page 151
INDUCED SEISMICITY POTENTIAL IN ENERGY TECHNOLOGIES embodied in any best practices protocol for induced seismicity can be complicated by the challenges of determining whether any seismicity felt in a region with injection wells is induced or is due to natural, geologic causes (see Chapter 1). However, we suggest that the benefit of the collective dialogue and establishing best practices in the event of a felt seismic event is in itself constructive, with few or no negative consequences. EXISTING INDUCED SEISMICITY CHECKLISTS AND PROTOCOLS Induced seismicity does not fall squarely in the sole purview of any single govern- ment agency and, in fact, requires input and cooperation among several local, state, and federal entities, as well as operators, researchers, and the public (see Chapter 4). Because of these shared interests and potential responsibilities, the committee suggests that the agency with authority to issue a new injection permit or the authority to revise an existing injection permit is the most appropriate agency to oversee decisions made with respect to induced seismic events, whether before, during, or after an event has occurred. In many cases this responsibility would fall to state agencies that permit injection wells. In areas that are known by experience to be susceptible to induced seismicity, a best practices protocol could be incorporated into the approval process for any proposed (new) injection permit. In a ­ reas where induced seismicity occurs, but was not anticipated in a particular area, existing injec­ ion permits relevant to that area could be revised to include a best practices protocol. t Two Checklists to Evaluate the Potential for Induced Seismicity and the Probable Cause of Observed Events Checklists can be convenient tools for government authorities and operators to discuss and assess the potential to trigger seismic events through injection, and to aid in determin- ing if a seismic event is or was induced. Two checklists, one to address each of these two circumstances—the potential for induced seismicity and the determination of the cause of a felt event—were developed nearly two decades ago by Davis and Frohlich (1993) to address each of these circumstances (summarized in the sections that follow). Their work recommends a list of ten “yes” or “no” questions to quantify “whether a proposed injection project is likely to induce a nearby earthquake” and a list of seven similar questions to quantify “whether an ongoing injection project has induced an earthquake.” Will Injection Induce Earthquakes: Ten-Point Checklist The ten-question checklist evaluates four factors related to possible earthquake hazards: historical background seismicity, local geology, the regional state of stress, and the nature of the proposed injection. Table 6.1, modified from Davis and Frohlich (1993), compares 152

OCR for page 151
Steps Toward a “Best Practices” Protocol TABLE 6.1  Criteria to Determine if Injection May Cause Seismicity NO Texas Denver APPARENT CLEAR City, Tracy, RMA, Question RISK RISK Texas Quebec Colorado Background Seismicity 1a Are large earthquakes (M ≥ 5.5) NO YES NO YES YES known in the region (within several hundred km)? 1b Are earthquakes known near the NO YES NO YES NO? injection site (within 20 km) 1c Is rate of activity near the injection NO YES NO NO NO site (within 20 km) high? Local Geology 2a Are faults mapped within 20 km of NO YES YES YES NO? the site? 2b If so, are these faults known to be NO YES NO NO NO active? 2c Is the site near (within several NO YES NO? YES YES hundred km of) tectonically active features? State of Stress 3 Do stress measurements in the region NO YES NO NO? YESa suggest rock is close to failure? Injection Practices 4a Are (proposed) injection practices NO YES NO? YES YESa sufficient for failure? 4b If injection has been ongoing at the NO YES NO N.A. N.A. site, is injection correlated with the occurrence of earthquakes? 4c Are nearby injection wells associated NO YES NO N.A. N.A. with earthquakes? TOTAL “YES” ANSWERS 0 10 1 5 4 a Assumes stress measurements completed prior to survey. NOTE: RMA, Rocky Mountain Arsenal. SOURCE: Davis and Frohlich (1993). 153

OCR for page 151
INDUCED SEISMICITY POTENTIAL IN ENERGY TECHNOLOGIES the answers of this ten-point criteria list for three injection wells. The wells listed include an existing injection well located in Texas, a proposed injection project in Quebec, and the injection well located at Rocky Mountain Arsenal in Denver with questions answered “as if injection had not yet taken place.” The authors note, “In actuality, if one were to propose injection at a site near Denver today, the existence of the earthquake activity between 1962 and 1972 would alter the profile, and there would be six or more ‘yes’ answers” (p. 214). The authors go on to say, “At the Tracy, Quebec site we find five ‘yes’ answers. . . . We would thus conclude that the situation is more similar to Denver than the Texas Gulf Coast” (p. 214). Did Injection Induce the Observed Earthquake(s): Seven-Point Checklist The list of seven questions from Davis and Frohlich (1993) again evaluates four factors related to possible cause: background seismicity, temporal correlation, spatial correlation, and injection practices. In Table 6.2 the seven questions are listed and are specifically phrased so that a “yes” answer would indicate underground injection induced the earthquake(s) and a “no” answer would indicate the earthquake(s) were not caused by injection. Two injection wells are evaluated in Table 6.2. The well in Denver, Colorado, was the injection well at the Rocky Mountain Arsenal, which was definitely shown to be the cause of induced earthquakes in the mid-1960s. The Painesville, Ohio, well, also known as the Calhio well, which was injecting liquid waste from agricultural manufacturing, was investigated as a cause of earthquakes and revealed ambiguous results; the scientists who examined the data could not make a certain correlation between the injection well and the earthquakes, in part due to historical (natural) seismic activity in the area.1 An Example Best Practices Protocol for Induced Seismicity Associated with Enhanced Geothermal Systems As an example of a protocol used in projects expected to result in induced seismicity, the Department of Energy (DOE) has published a best practices protocol for addressing the potential of induced seismicity associated with the development of enhanced geo­ ­ thermal systems (EGS) (Majer et al., 2012). The steps that a developer might follow in that protocol are summarized in Box 6.1. The DOE states that this protocol is not intended as a proposed substitute to existing local, state, and /or federal regulations but instead is intended to serve as a guideline for the systematic evaluation and management of the anticipated effects of the induced seismicity that are expected to become related to the development of an EGS project. 1  For example, see www.dnr.state.oh.us/geosurvey/earthquakes/860131/860131/tabid/8365/Default.aspx. 154

OCR for page 151
Steps Toward a “Best Practices” Protocol TABLE 6.2  Seven Questions Forming a Profile of a Seismic Sequence Earthquakes Earthquakes I II Clearly NOT Clearly Denver, Painesville, Question Induced Induced Colorado Ohio Background Seismicity 1 Are these events the first known NO YES YES NO earthquakes of this character in the region? Temporal Correlation 2 Is there a clear correlation between NO YES YES NO injection and seismicity? Spatial Correlation 3a Are epicenters near wells (within NO YES YES YES? 5 km)? 3b Do some earthquakes occur at or NO YES YES YES? near injection depths? 3c If not, are there known geologic NO YES NO? NO? structures that may channel flow to sites of earthquakes? Injection Practices 4a Are changes in fluid pressure at NO YES YES YES well bottoms sufficient to encourage seismicity? 4b Are changes in fluid pressure at NO YES YES? NO? hypocentral locations sufficient to encourage seismicity? TOTAL “YES” ANSWERS 0 7 6 3 SOURCE: Davis and Frohlich (1993). Using this protocol as a foundation, the committee has adapted the protocol’s set of seven steps in Table 6.3 to illustrate a set of parallel activities, with steps 2 through 7 under­ aken essentially concurrently, as opposed to sequentially, to help manage and miti- t gate induced seismicity from injection associated with EGS. Viewing a protocol as a set of parallel activities is useful not only for general project management but also for the ability it provides to reassess the protocol through time as circumstances of an energy project change and more data are acquired. This resulting matrix form can be used as a template to develop an appropriate protocol to mitigate the potential to induce seismicity in other 155

OCR for page 151
INDUCED SEISMICITY POTENTIAL IN ENERGY TECHNOLOGIES BOX 6.1 The Department of Energy Protocol for Addressing Induced Seismicity Associated with Enhanced Geothermal Systems The elevated downhole fluid pressures used in EGS induce fracturing that can result in a level of induced seismicity that is felt at the surface and that in some cases has caused serious concern among those living nearby (see Chapter 3). To attempt to avoid the repeated occurrence of such results, while encouraging the future use of geothermal resources, a protocol has evolved to serve as a guide for EGS developers within the United States as well as internationally. The most current protocol, developed by the Department of Energy (Majer et al., 2012), “outlines the suggested steps that a developer should follow to address induced seismicity issues, implement an outreach campaign and cooperate with regulatory authorities and local groups.” This sequence of seven steps can be summarized as follows: STEP 1. Perform Preliminary Screening Evaluation. Assess the feasibility of the proposed project as to its technical, socioeconomic, and financial risks in order to provide an initial measure of the project’s potential acceptability and ultimate success. Review local regulatory conditions, the level of natural seismicity, and the probable impacts of the project on any nearby communities and sensitive facilities. STEP 2. Implement an Outreach and Communication Program. Before operations begin, implement a public relations plan that describes the proposed operations, determine the resulting concerns, address those concerns, and then periodically meet with the locals to explain the upcoming operations and the results of the work done to date. STEP 3. Review and Select Criteria for Ground Vibration and Noise. Identify and evalu- ate local environmental and regulatory standards for induced vibration and noise. Develop appropriate acceptance criteria for an EGS project. STEP 4. Establish Local Seismic Monitoring. Collect baseline data on the regional seismicity that exists before operations begin. Install and operate a local seismometer array to monitor the project’s operations. STEP 5. Quantify the Hazard from Natural and Induced Seismic Events. Estimate the ground shaking hazard from the natural seismicity to provide a baseline to evaluate the additional hazard from the induced seismicity. STEP 6. Characterize the Risk of Induced Seismic Events. Characterize the expected induced ground motion and identify the assets and their vulnerability within the area likely to be influenced by the project. STEP 7. Develop a Risk-Based Mitigation Plan. If the level of seismic impacts becomes u ­ nacceptable, direct mitigation measures are needed to further control the seismicity. A “traffic light” system can allow operations to continue as is (GREEN), or require changes in the operations to reduce the seismic impact (AMBER), or require a suspension of operations (RED) to allow time for further analysis. Indirect mitigation may include community support and compensation. 156

OCR for page 151
Steps Toward a “Best Practices” Protocol energy technologies. The committee has done this exercise for induced seismicity associated with injection wells used for oil and gas development (Environmental Protection Agency [EPA] Underground Injection Control [UIC] Class II wells) or with carbon storage (EPA UIC Class VI wells) and has developed an example of the primary elements that might be included in a best practices protocol matrix (Table 6.4). THE USE OF A TRAFFIC LIGHT CONTROL SYSTEM The protocols described in Box 6.1 and Tables 6.3 and 6.4 refer to a “traffic light” con- trol system for responding to an instance of induced seismicity. Such a system, although rarely employed in energy technology projects with active cases of induced seismicity,2 a ­ llows for low levels of seismicity but adds additional monitoring and mitigation require- ments when seismic events are of sufficient intensity to result in a concern for public health and safety. The preferred criterion to be used for such a control system has been the level of ground motion observed at the site of the sensitive receptor, be it a public or private facility. Seismic event magnitude alone is generally insufficient as the only criterion because of the nature of attenuation (absorption or loss of energy) with increasing distance from an event location to a sensitive receptor site. Zoback (2012) provides a summary of a traffic light system for the purpose of managing potential induced seismicity from wastewater disposal. As an example, the Bureau of Land Management (BLM) recently issued as its “Con- ditions of Approval”3 for a proposed EGS project the specific procedures to be followed in the event that induced seismicity is observed to be caused by the proposed stimulation (hydraulic fracturing) operation. The specific procedures included the use of the traffic light control system that allows hydraulic fracturing to proceed as planned (green light) if it does not result in an intensity of ground motion in excess of Mercalli IV (“light” shaking with an acceleration of less than 3.9%g), as recorded by an instrument located at the site of public concern. However, if ground motion accelerations in the range of 3.9%g to 9.2%g are repeatedly recorded within one week, equivalent to Mercalli V (“moderate” shaking), then the operation is required to be scaled back (yellow light) to reduce the potential for the further occurrence of such events. And finally, if the operation results in a recorded accelera­ ion of greater than 9.2%g, resulting in “strong” Mercalli VI or greater shaking, then t the active operation is to immediately cease (red light). The authority for the permitting of Class II injection well location varies by state and is discussed in Chapter 4. Well permits of Class II injection wells in Colorado, for example, are reviewed by the Colorado Geological Survey (COGCC, 2011). During a geologic review, 2  To the committee’s knowledge, the traffic light system has been applied only at the Berlin geothermal field in El Salvador (Majer et al., 2007) and at Basel, Switzerland. 3  R.M. Estabrook, BLM, Conditions of Approval for GSN-340-09-06, Work Authorized: Hydroshear, The Geysers, January 31, 2012. 157

OCR for page 151
TABLE 6.3  Primary Elements of a Protocol for Addressing Induced Seismicity in EGS Technologies Adapted as a Series of Parallel Activities 158 Extending over the Lifetime of the Operation Initial Screening Assess the local hazard potential from natural seismicity; the local, state, and federal regulations; the nearness of the to Determine the project to population centers; the probable magnitude of induced events; and the probable risks of potential damage Feasibility of the from both natural and induced events. If the proposed EGS project appears to be feasible based on this initial EGS Project screening assessment, then the Essential Activities of the EGS project as listed below are recommended to proceed in the manner described within each of the five sequential stages of project development as identified herein. Category of PREPARATION DRILLING STIMULATION OPERATIONS COMPLETION Essential Activities STAGE STAGE STAGE STAGE STAGE Public and Identify the local Meet with and Meet with and Meet with and Meet with and Regulatory people and inform the public, inform the public, inform the public, inform the public, Communications organizations to be regulators, and regulators, and regulators, and regulators, and met with. Hold an media as to the media as to the media as to the media as to the initial public meeting, drilling schedule. stimulation schedule operations schedule project completion. explain the planned Upon completion and results. and results. project, identify their meet and explain the concerns. drilling results. Criteria for Install ground motion Report to the public, Report to the public, Report to the public, Report to the public, Ground Vibration and noise monitoring regulators, and regulators, and regulators, and regulators, and and Noise instrumentations. media the monitoring media the monitoring media the monitoring media the monitoring results. results. results. results. Seismic Determine areal size Continue to monitor Add and/or Add and/or Continue to record Monitoring and sensitivity needed the seismicity reposition array’s reposition array’s and report on the for local array. Install recorded and seismometers as seismometers as induced seismicity and operate the publically report the needed to follow needed to follow as long as needed seismic recording results. and characterize the and characterize the to describe the local array and allow induced events. induced events. conditions. INDUCED SEISMICITY POTENTIAL IN ENERGY TECHNOLOGIES timely public access to results.

OCR for page 151
Hazard Evaluate the potential Review and reassess Review and reassess Review and reassess Report to the public, Assessment additional hazard the potential for the potential for the potential for regulators, and to be expected from damage based on damage based on damage based on media on any actual the locally induced local observations. local observations. local observations. hazards observed. seismicity. Risk Assessment Develop a Revise the Risk Assessment as appropriate, based on any physical Report to the public, probabilistic risk damage, nuisance, and/or economic losses attributed to the project regulators, and analysis to estimate operations. media on the actual the probability of risk results experienced. (monetary loss) to be expected. Direct Mitigation Develop a plan to If needed, implement the control system to cause the drilling, Report to the public, Plans control the level and stimulation, or continuing operations to be temporarily reduced or regulators, and impact of locally suspended until the level of the locally induced seismicity has been media on the actual induced seismicity. returned to an acceptable level, as determined by the regulatory results experienced. agencies. Indirect Mitigation Provide local jobs, support local community facilities, and provide compensation if appropriate. Continue indirect Plans mitigation activities as long as needed. Steps Toward a “Best Practices” Protocol 159

OCR for page 151
TABLE 6.4  Summary of the Primary Elements of a Protocol for Addressing Induced Seismicity Associated with Injection Wells Used for Oil 160 and Gas Development (EPA UIC Class II wells) or Associated with Carbon Sequestration (EPA UIC Class VI wells) Additional UIC Permitting After Drilling and Prior to Monitoring Requirements During Requirements Injection (A Second Look) Injection Public and Regulatory Operator should identify local Operator should notify Operator should provide periodic Communications residents and cities and counties appropriate regulatory agencies updates to appropriate regulatory that could be affected by induced and the local public and provide agencies and the local public on seismicity and hold public updated information and analysis the locations and extent of their meetings to explain project and based on any new information injection operations and the locally identify concerns. obtained during drilling observed seismic activity. operations. Hazard Assessment Evaluate the potential additional Review and reassess the potential Report to the appropriate hazard to be expected from for induced seismicity based regulatory agencies and the public locally induced seismicity. on any additional information on any actual hazards observed obtained during drilling and during injection activity. completion of the injection well. Risk Assessment Develop a probabilistic Revise the risk assessment as Revise the risk assessment as risk analysis to estimate the appropriate based on any appropriate based on additional probability of risk to be expected. additional information obtained information obtained during during the drilling and completion injection activity. of the injection well. Criteria for Ground Determine areal size, sensitivity, Vibration and appropriate instrumentation needed for local array. INDUCED SEISMICITY POTENTIAL IN ENERGY TECHNOLOGIES

OCR for page 151
Seismic Monitoring Install and operate the seismic recording array to obtain baseline seismic data and record seismic events due to injection activity. Mitigation Plans Develop a plan to control the level Revise mitigation plan as Continuously review and assess and impact of locally induced appropriate based on any mitigation plan to determine seismicity based on the hazard additional information obtained effectiveness. and risk assessment and baseline during the drilling and completion seismic data. of the injection well. NOTE: The entire protocol would apply to injection wells proposed in areas where induced seismicity has actually occurred. In areas where induced seismicity was not expected but later occurred, the shaded requirements would apply as revisions to the original injection permit. Steps Toward a “Best Practices” Protocol 161

OCR for page 151
INDUCED SEISMICITY POTENTIAL IN ENERGY TECHNOLOGIES the historical earthquake data near the well are closely examined, along with any published fault maps in the area. Additional data regarding fault information, such as that available from three-dimensional (3D) seismic images or other geological information from the well operator may be requested if the well appears to be sited in a high-risk area. MITIGATING THE EFFECTS OF INDUCED SEISMICITY ON PUBLIC AND PRIVATE FACILITIES The best practices protocols appropriately include an emphasis on establishing a public relations plan to inform the public as well as the appropriate regulatory agencies of the purpose of the proposed or existing project, the intended operations, and the expected impacts on the nearby communities and/or facilities. Public acceptance begins with an under­ tanding of what is expected to transpire and what contingencies exist for dealing with s the unexpected. Inherent in any public information and communication plan is the idea that a developer regularly meets with the local public to explain the schedule and activities of each upcoming stage of operations, as well as the results of the operations performed to date. During the committee’s information gathering session in The Geysers in Northern California and at the associated workshop in Berkeley, we had an opportunity to discuss the 50-year history of induced seismicity at The Geysers geothermal field and meet with the operators, regulatory authorities, researchers, and the local residents from Anderson Springs and Cobb, nearest to The Geysers operations, and subject to the effects of ground shaking due to induced seismicity (see Appendix B—meeting agenda). The discussions we had with these individuals provided some interesting lessons (Box 6.2) regarding the value and potential success of constructive public engagement, for all parties, when induced seismicity may be or becomes an issue in an energy development project. The committee found several very important points to consider regarding the value of successful public outreach, using this example from The Geysers: 1. Time. Public engagement, even if begun early in a project’s planning processes, is a process that occurs over a long time and not a goal in itself. As a process, public engagement requires dedicated and frequent communications among industry, the public, government officials, and researchers. 2. Information and education. Although the initial burden to supply information and to educate local residents lies with the operator and government authorities, residents, too, have a responsibility to become informed and to be constructive purveyors of data and information back to those responsible for operations to allow constructive dialogue to take place. 3. Managed expectations through transparency. Coupled to the sharing of infor- mation and education is the idea of managing expectations. Each group involved 162

OCR for page 151
Steps Toward a “Best Practices” Protocol BOX 6.2 The Geysers: Toward Mitigating the Effects of Induced Seismicity About 40 years ago researchers at the U.S. Geological Survey (USGS) and elsewhere began report- ing that induced seismicity was associated with the geothermal production and injection operation at The Geysers (e.g., Hamilton and Muffler, 1972). At first, the causes of the seismicity in this area, where natural seismic activity has a long history, were unclear to the seismologists and to the local operators. Following the installation of additional seismometers to increase the accuracy of locating the events, it became evident that the earthquakes were primarily associated with the injection wells associated with The Geysers and, indeed, essential for continued operation of the field to produce electricity (see Chapter 3; Box 3.1). Conse- quently, when a pipeline project was proposed 15 years ago to deliver wastewater for increased injection at The Geysers to maintain and enhance power generation, the Environmental Impact Report required the establishment of a Seismic Monitoring Advisory Committee (SMAC) to monitor and report on the production and injection, and seismic activities. The committee includes representatives of the Bureau of Land Management and California state regulatory agencies, county government, the USGS and Lawrence Berkeley National Laboratory, the local communities, and the operators of the geothermal facilities. Real-time results of the seismic monitoring are continuously available to all at the Northern California Seismic website, and the semiannual meetings of this committee provide a forum for all the stakeholders to compare the locations and magnitudes of the reported seismic events to the locations of the reported production and injection activities. Despite the benefits of establishing the SMAC, the geothermal operators were still viewed by some local residents as not having taken sufficient responsibility for mitigating the effects of the clearly increased numbers of induced seismic events being felt within the local communities (see Box 3.1), and a petition was filed to declare the situation as being a public nuisance. The county government established two sub­ ommittees to deal c directly with the residents of the two local communities of Anderson Springs and Cobb. Each sub­ ommittee c has representatives of its local community, the local operators, and the local county super­ isor. Ground motion v recording instruments were installed in each community, and the resulting information is available in near real time at an independently controlled website. This information allows anyone with Internet access to compare the recorded time of an observed ground motion with the reported times of the separately reported local seismic events in order to determine the location of the apparent source that caused the observed ground motion. The members of each subcommittee have developed a system of receiving, reviewing, and approving damage claims attributed to the local induced seismicity. Over the past 6 years the geothermal operators have reimbursed the homeowners for their costs to have their home damages repaired, at a total expense of less than $100,000 while contributing funds far in excess of this for improvements to the common facilities in the local communities. In addition the county government has continued to contribute to these communities part of the mitigation funds it receives as redistributions of the royalty payments made to the federal govern- ment by the local geothermal operators. This system of coordinating the use of the combined resources of both industry and local government has much improved the mitigation of the effects of the locally induced seismicity, and it is now resulting in much improved and mutually satisfactory relationships among the parties. SOURCES: DOE (2009); J. Gospe, Anderson Springs Community Alliance, 2011, “Man-Made Earthquakes & Anderson Springs,” DVD, June 30; see also www.andersonsprings.org/. 163

OCR for page 151
INDUCED SEISMICITY POTENTIAL IN ENERGY TECHNOLOGIES in an energy development project has different goals and expectations. Mutual understanding of other groups’ goals and expectations is fundamental to developing strong and constructive communication. Transparency regarding these goals and expectations is important to their management. REFERENCES COGCC (Colorado Oil and Gas Conservation Commission). 2011. COGCC Underground Injection Control and Seismic- ity in Colorado. January 19. Denver, CO: Department of Natural Resources. Available at cogcc.state.co.us/Library/ InducedSeismicityReview.pdf (accessed February 2012). Davis, S.D., and C. Frohlich. 1993. Did (or will) fluid injection cause earthquakes? Seismological Research Letters 64(3-4):207-224. DOE (U.S. Department of Energy). 2009. Appendix J—Statement of Compliance with DOE Seismicity Protocol. ­ eysers G Power Company’s Enhanced Geothermal System Demonstration Project, Northwest Geysers Geothermal Field, So- noma County, California (DOE/EA 1733). Available at www.eere.energy.gov/golden/NEPA_FEA_FONSI.aspx (ac- cessed February 2012). Hamilton, R.M., and L.J.P. Muffler. 1972. Microearthquakes at The Geysers geothermal area, California. Journal of ­Geophysical Research 77:2081-2086. Majer, E.L., R. Baria, M. Stark, S. Oates, J. Bonner, B. Smith, and H. Asanuma. 2007. Induced seismicity associated with enhanced geothermal systems. Geothermics 36:185-222. Majer, E.L., J. Nelson, A. Robertson-Tait, J. Savy, and I. Wong. 2012. Protocol for Addressing Induced Seismicity Associated with Enhanced Geothermal Systems. DOE/EE-0662. U.S. Department of Energy. Available at www1.eere.energy. gov/geothermal/pdfs/geothermal_seismicity_protocol_012012.pdf (accessed April 2012). Zoback, M.D. 2012 (April 2). Managing the seismic risk posed by wastewater disposal. Earth Magazine 38-43. Available at nodrilling.files.wordpress.com/2012/02/zoback-earth.pdf (accessed April 2012). 164