underground injection control (uic) in ohio

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1 underground injection control (uic) in ohio Comparison of Public Concerns and Related Regulations and Authority PUBLIC CONCERN Pollution Prevention OHIO DIVISION OF OIL & GAS S AUTHORITY THAT ADDRESSES CONCERN Prohibition against the contamination or pollution of the land, surface waters, and subsurface waters (RC (A) and OAC 1501:9-3-04(A)) Prohibition against faulty well construction ( RC (A)) Well construction requirements(oac 1501: and 07) - surface casing set at least 50 feet below deepest USDW - notice given to inspector prior to cementing, placing and removing casing, installation of tubing and packer, and initial injection. - production casing cemented at least 300 feet above the top of the injection zone Surface facility construction: prevent pollution to surface and subsurface soils and water (OAC 1501:9-3-05(A)(6)) Notification of inspector when injection is to commence (OAC 1501:9-3-07(B)) On average unannounced inspections conducted every 11 to 12 weeks Monitoring for mechanical integrity (OAC 1501:9-3-07): - old wells monthly mini-tests or continuously - new wells continuously Automatic shut-off if maximum allowed injection pressure is exceeded (OAC 1501:9-3-07(G)) Surface Water Contamination Or Ground Water Contamination Prohibition against the contamination or pollution of the land, surface waters, and subsurface waters (OAC 1501:9-3-04(A)) Well construction requirements(oac 1501:9-3-05) Surface facility construction: prevent pollution to surface and subsurface soils and water (OAC 1501:9-3-05(A)(6)) Reporting of chemicals used in the drilling of the surface casing and stimulation of an injection well (OAC (A)(9) and (10)) Replacement of water supplies that are substantially disrupted by contamination, diminution, or interruption (RC (F)) Monitoring For Leakage And Integrity Toolbox of tests, including pressure fall-off testing, seismic plan, and any other test deemed necessary (OAC 1501:9-3-06(B)) Continuous monitoring of injection pressures for mechanical integrity (OAC 1501:9-3-07(E)): - old wells monthly mini-tests or continuously - new wells continuously Automatic shut-off if maximum allowed injection pressure is exceeded (OAC 1501:9-3-07(G)) Well construction requirements(oac 1501: and 1501:9-3-07) - notice given to inspector prior to cementing, placing and removing casing, installation of tubing and packer, and initial injection. - production casing cemented at least 300 feet above the top of the injection zone Effects Of Recent Legislation And Regulations Toolbox of tests (OAC 1501:9-3-06(B)): - pressure fall-off testing; - seismic plan and monitoring; - geophysical logs; - radioactive tracer or spinner survey; and - any other test deemed necessary Performance tests or evaluations of proposed injection well (OAC 1501:9-3-06(B)) Monitoring for mechanical integrity (OAC 1501:9-3-07): - old wells monthly mini-tests or continuously - new wells continuously Automatic shut-off if maximum allowed injection pressure is exceeded (OAC 1501:9-3-07(G)) Water sampling within 300 feet of proposed well in urbanized area (RC (A)(8)) Additional Resources Ohio EPA: Penn State Marcellus Center: Frac Focus:

2 The Facts about Hydraulic Fracturing Production of the state s shale gas deposits will help lower Ohio s natural gas costs to consumers and grow our economy? The Facts about Fracking Hydraulic fracturing has been used safely in more than 1 million U.S. wells. The first commercial fracking well was drilled more than 60 years ago in Oklahoma. Hydraulic fracturing has been used for more than 50 years in Ohio to stimulate oil and gas well production. Since 1990, more than 15,000 Ohio wells have used hydraulic fracturing. During that time the Division of Oil and Gas Resources Management has conducted a number of water well investigation complaints none of the investigations revealed problems due to hydraulic fracturing. What is Hydraulic Fracturing? The fracking process enables energy companies to tap into natural gas-rich shale such as the Marcellus and Utica-Point Pleasant deposits in Ohio. This allows natural gas trapped deep in the earth to be released and captured for use in our homes, businesses, and as an alternative fuel for some cars. How deep is a shale gas well? 5,000 to 8,000 feet down (that s more than 1.5 miles, and thousands of feet below freshwater aquifers). How and why is shale fractured? After a well is drilled and secured, a mixture that is approximately 98 percent sand and water, with a small amount of chemical additives, is injected at a very high pressure to fracture the shale. The sand keeps the fractured shale open and serves as a conduit for extracting the natural gas. Can hydraulic fracturing fluid rise to the surface? No. Geologically speaking, the bedrock between the fracked site and the surface is so dense that it makes it impossible for frack fluid to travel upward thousands of feet, or between rock formations and into freshwater aquifers. How much natural gas is currently being produced in Ohio through traditional drilling? In 2009, more than 88 billion cubic feet of natural gas was produced in Ohio. Nearly 100 percent of the natural gas produced in Ohio is used right here at home. Independent study commends Ohio regulations Ohio recently received a positive endorsement of its hydraulic fracturing program by the non-profit, multi-stakeholder organization, the State Review of Oil & Natural Gas Environmental Regulations, Inc. The report, which can be downloaded at ohiodnr.com (use Shale Development link), commended ODNR for its role in revising Ohio s oil and gas laws. Since then, new rules and regulations have been passed to further strengthen groundwater protection. The U.S. Environmental Protection Agency, the Ground Water Protection Council, and the Interstate Oil and Gas Compact Commission* all have found hydraulic fracturing nonthreatening to the environment or public health. U.S. EPA is conducting another study to evaluate potential impacts of hydraulic fracturing on drinking water and groundwater. *U.S. EPA, 2004 study; GWPC, 2009 report; IOGCC, 2002 study Additional Resources Ohio EPA: Penn State Marcellus Center: Frac Focus:

3 Wastewater (Flowback) from Hydraulic Fracturing Hydraulic fracturing (sometimes called fracking) has been used since the 1950s in Ohio as part of the oil and gas drilling process. About 80,000 wells have been drilled in Ohio using hydraulic fracturing. After a well is drilled, a mixture of water, sand and chemical additives is injected under pressure to fracture the shale reservoir, which enhances the flow of oil and gas for collection. Most of the water used in fracturing remains thousands of feet underground, however, about percent returns to the surface through a steel-cased well bore and is temporarily stored in steel tanks or lined pits. The wastewater which returns to the surface after hydraulic fracturing is called flowback. It can take up to 4 million gallons of water to fracture a horizontally drilled shale well, compared to 4-5 million gallons used weekly by an average golf course. Sand helps keep the fractures open which enables the natural gas to migrate through the shale reservoir to the steel-cased well bore to reach the collection point. Chemical additives make up less than one-half of one percent of the water used. Benefits provided by these chemicals include preventing corrosion and eliminating friction. Most additives have other common uses including water treatment and household cleansers. In Ohio, oil and gas operators must either recycle their wastewater or inject the flowback into deep injection wells (called Class II wells) which lay thousands of feet underground below the water table. Permits for these types of wells are closely regulated by ODNR s Division of Oil and Gas Resources Management. An on-site impoundment is one option for temporary freshwater storage prior to fracking. Shale drill sites use a series of stainless steel tanks to collect flowback from hydraulic fracturing. Frack tanks must be hauled by trailer to a disposal location. Additional Resources Ohio EPA: Penn State Marcellus Center: Frac Focus:

4 Environmental Safety at the Well Site A strong regulatory framework enables the Division of Mineral Resources Management to ensure the safety of Ohio s citizens and environment, as well as the safety of drill-site employees. Regulatory Safeguards ODNR s is responsible for regulating: Oil and gas drilling, production and reclamation operations Brine disposal operations Salt solution mining operations Underground injection well operations Can well-site safety be guaranteed? A strong regulatory framework enables the Division of Oil and Gas Resources Management to ensure the safety of Ohio s citizens and environment, as well as the safety of drill-site employees. In 2012, new well construction rules were enacted to accommodate the ever-changing technologies of oil and natural gas drilling. Ohio now boasts some of the most stringent well contruction standards in the country. Regulations, passed in 2010, strengthened the oil and gas drilling inspection process. These rules require energy companies drilling in Ohio to notify the department at three critical phases: Well construction ensure casing is properly placed as permitted Well control testing of blow-out prevention devices, which controls pressure Fluid control monitor the company s handling of the fluid Division inspectors place a high priority on witnessing these critical phases. Protection of groundwater resources During drilling, steel casings are inserted into the well bore. The casing makes sure that the fluid to be pumped through the well, as well as the oil and gas collected, remains isolated from groundwater and never enters the water supply. Additional groundwater protections include cementing the casing(s) in place. The casing-cement specifications and cementing process are based on the American Petroleum Institute s highest standards. Division inspectors place a high priority on witnessing this critical phase to make certain of proper installation. Once the cement has set, the drill hole (wellbore) is continued from the bottom of the first cemented steel casing to the next depth. This process is repeated using smaller steel casings each time until the oil and gas bearing reservoir is reached. Under new state law, operators are required to use four to six casing layers. Casing program Ohio s freshwater aquifers were mapped in the 1980s; the deepest are located about 1,000 feet underground. Using the mapping information, the division s permitting staff design a steel-and-cement casing program that protects public health and groundwater resources from contamination. Disposal of hydraulic fracturing fluid and brine (production fluid) Oil and gas operators must dispose of hydraulic fracturing fluid through Class II deep injection wells the safest, most environmentally friendly method of disposal. Through a partnership with the U.S. Environmental Protection Agency, Ohio s injection wells are regulated by the. Additional Resources Ohio EPA: Penn State Marcellus Center: Frac Focus:

5 Deep Injection well disposal According to the U.S. Environmental Protection Agency (EPA), as of 2010, there are about 144,000 Class II deep injection wells in the United States? What are deep injection wells? These deep, subsurface wells also known as Class II injection wells are drilled into porous formations of limestone or sandstone. Often these wells have been drilled specifically for injection disposal; however, some are exploratory wells that never produced or were once active but now no longer produce natural gas or oil. The average Class II well is about 4,000 feet. All injection wells are strictly regulated in Ohio by the Ohio Department of (ODNR), and the United States Environmental Protection Agency (U.S. EPA). Safety first! Class II injection well disposal is the safest, most environmentally friendly method of disposal and has been used in Ohio since the 1960s. According to the U.S. EPA, it is the best way to ensure that underground sources of drinking water are not contaminated by fluids produced from the drilling, stimulation, and production of oil and gas. New law signed by Governor Kasich in 2012 added additional testing requirements and reporting standards to further strengthen regulations related to Ohio s Class II injection wells. What is being injected into these deep wells? The natural gas and oil drilling process creates oil-field wastes, often referred to as brine, fracturing fluid or flowback. As defined by the U.S. EPA, only oil-field wastes may be transported from drilling sites and injected into Class II wells, which are specifically designed for this type of waste disposal. How is our groundwater protected during disposal? Class II injection wells require four layers of protective steel piping and cement, which safeguards underground water aquifers. The injection zone is always below a layer of impermeable rock or clay, which keeps the fluids trapped deep in the porous formations below. The drilling and construction of Class II deep injection wells and surface casings are witnessed by inspectors. All aspects of the drilling and construction of Class II wells and surface casing are witnessed by an inspector. After deep injection begins, inspectors continue to monitor the well on a regular basis for mechanical integrity. Each well is inspected about once every weeks. Nearly 30 years of responsible management Managed by ODNR since 1983, the state s Underground Injection Control Program has successfully injected large volumes of oilfield wastes, protecting underground sources of drinking water and our ecosystem. Fees raised by injection wells support permitting, certification and inspection of wells and service operations. Additional Resources Ohio EPA: Penn State Marcellus Center: Frac Focus:

6 GLOSSARY OF COMMON TERMINOLOGY Annual Report Report filed by owner/operator that lists the volumes and pressures from the previous year Annular space The space between casing strings or between casing and borehole wall Area of Review A ½ or ¼ mile radius around a proposed injection well location that is reviewed for any wells that penetrate the proposed injection formation. Brine All saline geological formation water resulting from, obtained from, or produced in connection with exploration, drilling, well stimulation, production of oil and gas, or plugging of a well Brine Hauler Truck that hauls oilfield fluid waste from the production site to the injection site. These haulers are regulated by ODNR-DOGRM. Casing Steel pipe placed in an oil/gas well to prevent borehole collapse and unwanted fluid movement Class II Injection Well Injection wells related to oil and gas activity that can be separated into three subclasses; salt water disposal, enhanced oil recovery, and hydrocarbon storage Conductor Casing The first and largest diameter casing string that helps near-surface hole stability and must be cemented to the surface Conversion well Existing oil/gas well that is proposed to be or has been converted to a salt water injection well Deepest underground source of drinking water (USDW) The lowermost aquifer that could potentially provide drinking water or has a total dissolved solids (TDS) value of less than 10,000 parts per million DOGRM, a division within ODNR Hydraulic fracturing Completion process where water, sand, and chemicals are pumped into the wellbore to fracture rock and allow hydrocarbons to flow into the wellbore Mechanical Integrity A well has mechanical integrity if there is no leak in the casing, tubing, or packer. This is tested by pressuring the annular space and measuring any change or variation in the pressure. Mechanical Integrity Test (MIT) A pressure test of the tubing and packer that must be passed before an injection well can enter active injection operations. ODNR Packer Piece of down-hole equipment used to block flow of fluids through the annular space Production Casing This third string of casing is run to the injection zone and must be cemented at least 300 feet back above the injection zone. RBDMS (Risk Based Data Management System) Fully functional oil and gas well database maintained by DOGRM RCRA Resource Conservation and Recovery Act Storage Tank Liquid tight tank used for storing fluids before injection Surface Casing A smaller diameter casing that is run second to the conductor casing. This casing s primary function is to protect groundwater resources. It must be run 50 feet below the deepest USDW and be cemented to the surface. Surface Facility The collective protective measures that prevent surface contamination from injection well locations. Facility includes unloading pad with drain and sump, containment dike, and impervious liner. Tubing This is the final string of steel pipe that is run inside the production casing. The injection fluid is pumped through this and into the formation. Tubing is set on a packer to isolate the injection zone from the annular space. USEPA United States Environmental Protection Agency Wellhead The equipment installed at the top of the wellbore (valves, gauges, etc.)

7 GENERAL FAQs ON EARTHQUAKES & SEISMICITY How are earthquakes recorded? How are earthquakes measured? How is the magnitude of an earthquake determined? Earthquakes are recorded by a seismographic network. Each seismic station in the network measures the movement of the ground at the site. The slip of one block of rock over another in an earthquake releases energy that makes the ground vibrate. That vibration pushes the adjoining piece of ground and causes it to vibrate, and thus the energy travels out from the earthquake in a wave. There are many different ways to measure different aspects of an earthquake. Magnitude is the most common measure of an earthquake s size. It is a measure of the size of the earthquake source and is the same number no matter where you are or what the shaking feels like. The Richter scale is an outdated method that is no longer used that measured the largest wiggle on the recording, but other magnitude scales measure different parts of the earthquake. Intensity is a measure of the shaking and damage caused by the earthquake, and this value changes from location to location. What is intensity? What is the Modified Mercalli Intensity Scale? Intensity is a qualitative measure of the strength of ground shaking at a particular site. The Mercalli Scale is used to determine the intensity. The Mercalli Scale is based on observable earthquake damage. From a scientific standpoint, the magnitude scale is based on seismic records while the Mercalli is based on observable data which can be subjective. Thus, the magnitude scale is considered scientifically more objective and therefore more accurate.for example a level I-V on the Mercalli scale would represent a small amount of observable damage. At this level doors would rattle, dishes break and weak or poor plaster would crack. As the level rises toward the larger numbers, the amount of damage increases considerably. The top number, 12, represents total damage. What is the difference between intensity scales and magnitude scales? Intensity scales, like the Modified Mercalli Scale and the Rossi-Forel scale, measure the amount of shaking at a particular location. So the intensity of an earthquake will vary depending on where you are. Sometimes earthquakes are referred to by the maximum intensity they produce. Magnitude scales, like the Richter magnitude and moment magnitude, measure the size of the earthquake at its source. So they do not depend on where the measurement is made. Often, several slightly different magnitudes are reported for an earthquake. This happens because the relation between the seismic measurements and the magnitude is complex and different procedures will often give slightly different magnitudes for the same earthquake. Magnitude / Intensity Comparison Magnitude and Intensity measure different characteristics of earthquakes. Magnitude measures the energy released at the source of the earthquake. Magnitude is determined from measurements on seismographs. Intensity measures the strength of shaking produced by the earthquake at a certain location. Intensity is determined from effects on people, human structures, and the natural environment. The following table gives intensities that are typically observed at locations near the epicenter of earthquakes of different magnitudes. Magnitude Typical Maximum Modified Mercalli Intensity I II - III IV - V VI - VII VII - IX 7.0 and higher VIII or higher

8 GENERAL FAQs ON EARTHQUAKES & SEISMICITY (page 2) Abbreviated Modified Mercalli Intensity Scale I. Not felt except by a very few under especially favorable conditions. II. Felt only by a few persons at rest, especially on upper floors of buildings. III. Felt quite noticeably by persons indoors, especially on upper floors of buildings. Many people do not recognize it as an earthquake. Standing motor cars may rock slightly. Vibrations similar to the passing of a truck. Duration estimated. IV. Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably. V. Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned. Pendulum clocks may stop. VI. Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight. VII. Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken. VIII. Damage slight in specially designed structures; considerable damage in ordinary substantial buildings with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned. IX. Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations. X. Some well-built wooden structures destroyed; most masonry and frame structures destroyed with foundations. Rails bent. XI. Few, if any (masonry) structures remain standing. Bridges destroyed. Rails bent greatly. XII. Damage total. Lines of sight and level are distorted. Objects thrown into the air. From The Severity of an Earthquake. At what magnitude does damage begin to occur in an earthquake? It isn t that simple. There is not one magnitude above which damage will occur. It also depends on other variables, such as the the distance from the earthquake, what type of soil you are on, etc. That being said, damage does not usually occur until the earthquake magnitude reaches somewhere above 4 or 5. What was the duration of the earthquake? Why don t you report the duration of each earthquake? How does the duration affect the magnitude? The duration of an earthquake is related to its magnitude but not in a perfectly strict sense. There are two ways to think about the duration of an earthquake. The first is the length of time it takes for the fault to rupture and the second is the length of time shaking is felt at any given point (e.g. when someone says I felt it shake for 10 seconds they are making a statement about the duration of shaking). The duration of fault rupture is related to both how long it takes for a spot on the fault to slip (which seems to be quite fast) and the time it takes rupture to proceed along a fault. You have to think of an earthquake as an area on a fault rather than just a point. It starts at a point and then the rupture propagates along the fault at around 2 kilometers or so per second. So the larger the area of the fault that ruptures, the longer the duration of the earthquake. And larger magnitude earthquakes have larger fault areas. So there is a general relationship between duration and magnitude. The reason we don t list this sort of duration on the Recent Earthquake web sites is that figuring out how long an earthquake took to rupture is still a research project that takes some time rather than an automated process. The duration of shaking at a point on the ground depends on how long the earthquake took to occur and how the waves move through the ground to that point. If there are a lot of reflections and resonances near the point (for instance in a sedimentary valley) the shaking will last longer. In an area without resonances (for instance on a hard block of rock) it will last a shorter time. You also have to specify a duration of shaking over a given level. We can actually detect the shaking from the very largest earthquakes for weeks after they occur but no one would say that they felt it for that long. So the duration of shaking is a very complex topic. We actually do use the duration of shaking to estimate the magnitude for some small earthquakes. If you see a Md or duration magnitude on the Latest Earthquake webpages, this is what has been done. (continued on page 3)

9 GENERAL FAQs ON EARTHQUAKES & SEISMICITY (page 3) For an explanation see Magnitude. This is sort of like having someone yell, counting the echos, and then estimating how loud they yelled from how many echos you could hear. Finally, the damage to a given structure will depend both on the amplitude of the shaking and its duration. How to best combine these quantities into an estimate of the amount of damage is ongoing research. (contributed by Andy Michael) (The magnitude is a number that characterizes the relative size of an earthquake. Magnitude is based on measurement of the maximum motion recorded by a seismograph. Several scales have been defined, but the most commonly used are (1) local magnitude (ML), commonly referred to as Richter magnitude, (2) surface-wave magnitude (Ms), (3) bodywave magnitude (Mb), and (4) moment magnitude (Mw). Scales 1-3 have limited range and applicability and do not satisfactorily measure the size of the largest earthquakes. The moment magnitude (Mw) scale, based on the concept of seismic moment, is uniformly applicable to all sizes of earthquakes but is more difficult to compute than the other types. All magnitude scales should yield approximately the same value for any given earthquake.) How can an earthquake have a negative magnitude? Magnitude calculations are based on a logarithmic scale, so a ten-fold drop in amplitude decreases the magnitude by 1. If an amplitude of 20 millimetres as measured on a seismic signal corresponds to a magnitude 2 earthquake, then: 10 times less (2 millimetres) corresponds to a magnitude of 1; 100 times less (0.2 millimetres) corresponds to magnitude 0; 1000 times less (0.02 millimetres) corresponds to magnitude -1. An earthquake of negative magnitude is a very small earthquake that is not felt by humans. What does it mean that the earthquake occurred at a depth of 0 km? An earthquake cannot occur at depth of 0 km. In order for an earthquake to occur, two blocks of crust must slip past one another, and it is physically impossible for this to happen at the surface of the earth. So why do we report that the earthquake occured at a depth of 0 km sometimes? Sometimes it is simply a very shallow event with poor depth resolution, but more often it is not actually an earthquake, but a quarry blast. These explosions are recorded by the seismic network and located by the software. When they are reviewed by a seismic analyst, they are labeled as a quarry blast in the earthquake catalog. What are isoseismal maps? Isoseismal maps are maps that show the distribution of intensities from the shaking of an earthquake with contours of equal intensity.

10 FAQs ON INDUCED SEISMICITY Do all wastewater disposal wells induce earthquakes? No. Of more than 150,000 Class II injection wells in the United States, roughly 40,000 are waste fluid disposal wells for oil and gas operations. Only a small fraction of these disposal wells have induced earthquakes that are large enough to be of concern to the public. How does the injection of wastewater at depth cause earthquakes? Earth s crust is pervasively fractured at depth by faults. These faults can sustain high stresses without slipping because natural tectonic stress and the weight of the overlying rock pushes the opposing fault blocks together, increasing the frictional resistance to fault slip. The injected wastewater counteracts the frictional forces on faults and, in effect, pries them apart, thereby facilitating earthquake slip. Is the recent sequence of earthquakes near Youngstown, Ohio, related to the wastewater disposal activities there? There is a credible connection between the wastewater injection activities near Youngstown and the recent earthquakes, including the magnitude 4 earthquake that occurred on New Year s Eve, This connection is based on the close proximity of the earthquakes to the injection well and depth of injection, and the observation that these events began soon after the start of the injection activities. How large are the earthquakes induced by fluid injection? Of the case histories for which there is a scientific consensus that an injection operation induced earthquakes, the largest are magnitude*5. At the Rocky Mountain Arsenal well, near Denver, Colorado, a large volume of wastewater was injected between 1962 and A substantial earthquake sequence was induced by these injection activities. Injection was terminated in 1966 due to the induced earthquakes. More than a year after injection ceased, three earthquakes with magnitudes near 5 occurred, after which the earthquake sequence finally decayed. Over the years, even larger magnitude earthquakes have been tentatively associated with fluid injection activities, but more research is needed to establish if there is a connection for any of these recent cases. Are earthquakes induced by fluid-injection activities always located close to the point of injection? No. Given enough time, the injected fluids can migrate substantial horizontal and vertical distances from the injection location. Induced earthquakes commonly occur several kilometers below the injection point. In some cases, the induced earthquakes have been located as far as 10 km (6 mi.) from the injection well. Is there any possibility that a wastewater injection activity could interact with a nearby fault to trigger a major earthquake that causes extensive damage over a broad region? So far, there is no conclusive example linking injection operations to triggering of major earthquakes, however we cannot eliminate this possibility. More research is needed to either confirm or refute this possibility. Is it possible to anticipate whether a planned wastewater disposal activity will trigger earthquakes that are large enough to be of concern? Currently, there are no methods available to do this. Evidence from some case histories suggests that the magnitude of the largest earthquake tends to increase as the total volume of injected wastewater increases. Injection pressure may also be a factor. More research is needed to determine the answer to this important question. Can you prevent large earthquakes by making lots of small ones, or by lubricating the fault with water or another material? Seismologists have observed that for every magnitude 6 earthquake there are 10 of magnitude 5, 100 of magnitude 4, 1,000 of magnitude 3, and so forth as the events get smaller and smaller. This sounds like a lot of small earthquakes, but there are never enough small ones to eliminate the occasional large event. It would take 32 magnitude 5 s, 1000 magnitude 4 s, 32,000 magnitude 3 s to equal the energy of one magnitude 6 event. So, even though we always record many more small events than large ones, there are never enough to eliminate the need for the occasional large earthquake.as for lubricating faults with water or some other substance, injecting high pressure fluids deep into the ground is known to be able to trigger earthquakes to occur sooner than would have been the case without the injection. However this would be a dangerous pursuit in any populated area, as one might trigger a damaging earthquake.

11 FAQs ON INDUCED SEISMICITY (page 2) Can we use a lot of explosives to cause small earthquakes in order to prevent having large ones? No. Even huge amounts of explosive almost never cause even small earthquakes (see previous FAQ), and it would take hundreds and thousands of small earthquakes to equal a large one, even if it could be done. In addition, we wouldn t have any control over the size of the earthquake being created if it worked, since small and large earthquakes all start out in exactly the same way. It s just not physically possible. How does the injection of wastewater at depth cause earthquakes? Earth s crust is pervasively fractured at depth by faults. These faults can sustain high stresses without slipping because natural tectonic stress and the weight of the overlying rock pushes the opposing fault blocks together, increasing the frictional resistance to fault slip. The injected wastewater counteracts the frictional forces on faults and, in effect, pries them apart, thereby facilitating earthquake slip. Does the production of natural gas from shales cause earthquakes? If so, how are the earthquakes related to these operations? To produce natural gas from shale formations, it is necessary to increase the interconnectedness of the pore space (permeability) of the shale so that the gas can flow through the rock mass and be extracted through production wells. This is usually done by hydraulic fracturing ( fracking ). Fracking causes small earthquakes, but they are almost always too small to be a safety concern. In addition to natural gas, fracking fluids and formation waters are returned to the surface. These wastewaters are frequently disposed of by injection into deep wells. The injection of wastewater into the subsurface can cause earthquakes that are large enough to be felt and may cause damage. Can we cause earthquakes? Is there any way to prevent earthquakes? Earthquakes induced by human activity have been documented in a few locations in the United States, Japan, and Canada. The cause was injection of fluids into deep wells for waste disposal and secondary recovery of oil, and the use of reservoirs for water supplies. Most of these earthquakes were minor. The largest and most widely known resulted from fluid injection at the Rocky Mountain Arsenal near Denver, Colorado. In 1967, an earthquake of magnitude 5.5 followed a series of smaller earthquakes. Injection had been discontinued at the site in the previous year once the link between the fluid injection and the earlier series of earthquakes was established. Other human activities, even nuclear detonations, have not been linked to earthquake activity. Energy from nuclear blasts dissipates quickly along the Earth s surface. Earthquakes are part of a global tectonic process that generally occurs well beyond the influence or control of humans. The focus (point of origin) of earthquakes is typically tens to hundreds of miles underground. The scale and force necessary to produce earthquakes are well beyond our daily lives. We cannot prevent earthquakes; however, we can significantly mitigate their effects by identifying hazards, building safer structures, and providing education on earthquake safety. Source: Nicholson, Craig and Wesson, R.L., 1990, Earthquake Hazard Associated with Deep Well Injection--A Report to the U.S. Environmental Protection Agency: U.S. Geological Survey Bulletin 1951, 74 p. What work is the ODNR-DOGRM doing to better understand the occurrence of injection-induced earthquakes? ODNR-DPGRM has deployed seismometers at sites of known or possible injection-induced earthquakes in Mahoning and Washington counties, and has additional deployment planned to other counties with newly permitted deep injection wells. These seismic networks will enable ODNR-DOGRM to monitor and identify if the earthquakes near and adjacent the injection wells are generated by injection well(s), which would allow for dynamic regulation and immediate decision to maintain public and operational safety. The ODNR-DOGRM is also working together with the Environmental Protection Agency and USC-ISC (University of South California-Induced Seismicity Consortium) through the IOGCC (Interstate OIL AND GAS Compact Commission) and its subcommittee (ERRT-Energy Resources, Research, and Technology Committee) on how to assess the earthquake hazard associated with wastewater injection activities at Class II disposal wells.

12 I S O L Fact Sheet A N D W A T E R Fact Sheet R E S O U R C E S Water Withdrawal Regulations for Oil and Gas Drilling Introduction Fresh water is a critical component for the drilling and development of Ohio s oil and gas resources. Water is used for support purposes, such as dust control on access roads and equipment cleaning; drilling operations for making drilling fluids and the cement used for securing casing in the bore hole; and for well stimulation processes such as hydraulic fracturing. In most cases, between two and six million gallons of water are needed to complete hydraulic fracturing on a Marcellus or Utica shale well. Drilling and hydraulic fracturing of deep shale wells is in its early stages in Ohio, but all indications are that oil and gas development from shale will expand in the next few years. With the expansion of deep shale drilling, the need for reliable water supplies will expand at an equal pace. To assist oil and gas drilling companies with understanding the regulations governing withdrawal and use of water in Ohio, the following provides general information regarding water rights, water withdrawal regulations, diversions of water across the Lake Erie - Ohio River watershed divide, and consumptive use of water. Water Rights in Ohio In Ohio, land owners have the right to make reasonable use of ground water underlying their land or of the water in a lake or watercourse located on or flowing through or along their riparian land. This right to a reasonable use is a property right protected by Article 1 Section 19b of the Ohio Constitution. Withdrawals that unreasonably interfere with the withdrawals of other land owners using the same stream or aquifer may be subject to liability via civil litigation. Water Withdrawal Registration Section of the Ohio Revised code requires any owner of a facility, or combination of facilities, with the capacity to withdraw water at a quantity greater than 100,000 gallons per day (about 70 gallons per minute) to register such facilities with the Ohio Department of Division of Soil and Water Resources. It is important to note that the law requires registration if a facility has the capacity to withdraw 100,000 gallons per day even if a lower volume is actually withdrawn. Registration under this program is not a permit to withdraw water, nor does registration impose any restrictions on withdrawals. Withdrawal registration requirements pertain to all of Ohio. Diversion of Water from the Ohio River Drainage Basin into the Lake Erie Drainage Basin Ohio Law (ORC ) requires a permit, issued by the Director of the Department of Natural Resources, to divert more than an average of 100,000 gallons per day, over any 30-day period, out of the Ohio River drainage basin into the Lake Erie drainage basin. Diversion as applied in this section means the transfer of water from the Ohio River drainage basin to the Lake Erie drainage basin. Consumptive Use of Water No facility may have a new or increased consumptive use of more than 2 million gallons of water per day, averaged over any 30-day period (60 million gallons per month), without first obtaining a permit from the Director of the Department of Natural Resources (ORC ). Consumptive use as used in this law, means a use of water resources, other than a diversion, that results in a loss of that water to the basin from which it is withdrawn and includes, but is not limited to, evaporation, evapotranspiration, and incorporation of water into a product. For oil and gas operations, this could include the incorporation of water into drilling fluids and hydraulic fracturing fluids. Lake Erie Basin Requirements The permitting requirements listed below apply only to the Lake Erie Basin. Diversion of Water from the Lake Erie Drainage Basin into the Ohio River Drainage Basin The Great Lakes St. Lawrence River Basin Water Resources Compact (Compact), a binding agreement among the eight states that border the Great Lakes, Continued on back!

13 which has been enacted into Ohio law and carries the force of Federal law, specifically prohibits (with very limited exceptions) any new or increased diversion of any amount of water out of the Lake Erie drainage basin. Therefore, no permits for the transfer of water out of the Lake Erie basin for oil and gas operations, or other types of operations, are allowed. Prior Notice and Consultation Requirement of the Compact In December 2013 and thereafter, the Compact requires all Lake Erie basin proposals for new or increased consumptive uses of 5 million gallons per day or more, averaged in any 90-day period (450 million gallons or more in a three month period), to be submitted to the eight Great Lakes States and the Canadian provinces of Ontario and Quebec for review and comment. General Permitting Requirements A permit is required for a new or increased withdrawal or consumptive use directly from Lake Erie of at least 2.5 million gallons per day averaged over any 90 day period. A permit is also required for a new or increased withdrawal or consumptive use of at least one million gallons per day, averaged over any 90 day period, from any river or stream or from ground water in the Lake Erie watershed. Permits for Withdrawals from High Quality Waters* A permit is required for a new or increased withdrawal or consumptive use of one hundred thousand gallons per day from any river, stream, or segment, and the entire watershed upstream; if the river, stream, or segment is a high quality water. If the drainage area above the intake is greater than 100 square miles, there is a 90 day averaging period that applies to the permit requirement. If the drainage area above the intake is less than 100 but more than 50 square miles, a 45 day averaging period applies. If the drainage area is 50 square miles or less, no averaging period applies. *High quality water means a river or stream segment that has been designated by the EPA under Chapter of the Administrative Code as an exceptional warm water habitat, cold water habitat, outstanding state water, or superior high-quality water. For more information please contact: Division of Soil and Water Resources Water Inventory and Planning Program 2045 Morse Road Columbus, Ohio Voice: (614) Fax: (614) dswc@dnr.state.oh.us Website: Media contact: Office of Communications (614) R 9/17/2012