# Class I Mechanical Integrity Failure Analysis (1993-1998)

preparedfor: 

## u.s. Environmental Protection Agency Office of Ground Water and Drinking Water Underground Injection Control Program PrincipalInvestigator: Larry Browning ProjectManager: Steve Wyngarden Contract No. 68-C6-0029 WorkAssignment No. 11

September 30, 19981 Class I

### MlFqilureAnalysis 0993-1998) 

### Executive Summary 

### We studiedworkoverandmechanicalintegritytest (MIT) records of541 Class I wells in 13 states, for the period February 1993 to July 1998. These 13 states were selectedto track with the states examinedin asimilarstudyperformedfor theperiod 1988-1993. This sample includes 100percent of the Class I Hazardous waste injection wells and 

### 85percent ofthe Class I Non-hazardous waste injection wells activein the U.

### S. since 1993. We found 129certain internalMIfailures, and 19probable MIfailures. The internal MIfailures were detectedimmediatelybythe continuous annulusmonitoring system requiredofClassI wells, andthe wells were usuallyshut-in untiloperators couldmake repairs. In allstates except Texas, the incidence ofMIfailures in Class I wells was found to decrease byabouthalf, when comparedto theprevious 5-yearstudyperiod (the ratio ofwellfailures to active wells was 18percentbetween 1993-1998 versus 33percent between 1988-1993). In Texas, MI failures from 1993-1998 were found to triple comparedto thepreviousstudy (96MI failures/wellfailure to active wellratio of89 percent, versus45 failures/wellfailure to active wellratio of31 percentfrom 1988­

1993). Furthermore, the severityofMI failures in Texas (as denotedbyincidence of long-stringcasingfailure) was foundto also triple (38 cases/66percentofcertain MI failures, versus 8 cases/18percentoffailures forthepreviousstudy). Overthe 5-year studyperiod, ClassINon-hazardous waste wellsin allstates except Texas were found to failthree-timesless often than Class IHazardous waste wells failed (13percentfor NHWversus40percentforHW, 1993-1998). In Texas, however, Class IHazardous andNon-hazardous waste wells experiencedMIfailures ata similar (andmuch higher) rate (90percentversus 87percent). Allofthesepercentagesreferto the ratio ofwell failures to the numberofactive wells, not the fraction ofwells that failedbecause many wells failedseveraltimes. We worked closely with staffin the Texas Underground Injection Control (UIC) Program to assemble andreview the data on Class I wellfailures in Texas. We also sentthe Texas UICstaffa draft version ofthe compileddata andresults for thatstate in an effort to ensure completeness and accuracy. However, recognizing the substantialdifferences between the results for Texas andthe restofthe nation, we recommendthatthisreportbereviewedbystaffin TexasandEPA Region 6 to confirm these results and, ifnecessary, provide additionaldata andanalysis.2 CklssIMlFailureAnalysis U993-19981 

### We found 11 

### externalMIfailures. We also investigated27

### cases ofsignificant waste migration outofthe injectionzone. Fourcases ofwastemigration are known to have affectedan Underground Source ofDrinking Wateror USDW

### (3 in Florida and 

### 1in Texas'), eight cases are suspected to affecta USDW (Florida), 15 

### cases involved migration from the injection zone intopermitted(3) 

### orunpermitted (12) 

### salinezones (7 Florida, 

### 1 Ohio, and 

### 7 Texas), and five cases ofsuspected migration remain unknown as to extent (Texas). Eleven externalMIfailures and

### 26migration cases were detected by routine periodic external MITs (every five years) orbyperiodic sampling ofstate-mandated deep monitoring wells. Five of the waste migration

.incidents, however, were attributable to externalorinternalMI failures ofmonitoring

wells atthe site.

ITbeTexas case (WDW-117, Jetco Chemicals) didnotinvolve migration. Rather, in 1974 and 1990 the TexasVIC primacy agencypermitteda ClassIwell to

### injectdirectlyinto a VSDW

### (about5,000mgtl total dissolved solids). The well permitwas canceled in

### May 1994 whenthe errorwas discovered after 20 years' injection (and about 1.6 billion gallons). The injection zone 

### is a drinking water source 

### in adjacentcounties.Class 1M!FailureAnalysis a993-19981 3 

### 1.0 Background The purpose ofthis report is to assess the number of, reasons for, and responses to Class I injection well MI failures that occurred from February 1993through July 1998. Class Iinjection wells are regulated according to the nature ofthe injectate, whether Hazardouswaste (Haz or HW) or Non-hazardouswaste (Non-haz or NHW). We include in this study 100percent ofthe Class I HW wells and 85 percent of the Class I NHW wells active in the US since 1993.2 

### We directly examined and interpreted Class Iwell records for Texas and Louisiana (48 percent of all Class I wells and 70 percent of Class I Hazardous wells), and primacy agencies and EPA Regions 4 and 5 supplied us with well records and data concerning the other states (FL, KY, TN, MS, IN, IL, MI, OH, AR, OK, and KS) (Table 1). This study is a follow-on to a similar study performed for the period January 1988 through January 1993, and utilizes the same methods and assumptions. 2.0 Class I construction elements and failures All Class I HW wells are newlydrilled for dedicated disposal service, rather than being converted from oil and gas wells or wells in other service. A few Class I NHW wells are conversions ofexisting wells, and the conversion must meetthesame construction standards as newlydrilled wells. Mechanical integrity (M!) of a Class I well consists of two types: internal MI is the absence of leaks in the tubular goods of the well, whereas external MI is the absence offlow along the outside of the casing (i.e., the integrity of the cement seal). Class I wells are required to maintain mechanical integrity (M!) at all times. We define an "MI failure" of a Class I well as any loss of mechanical integrity, whether discovered in an MI test (MIT) or during operational service. The program of construction and testing of a Class I well is specified by the UIC Director as a permit condition. The process of drilling and construction is sometimes witnessed by a representative ofthe UIC agency. The key construction elements of a Class I well (Figure 1) are:

2Inventorytotals arefor "Active" wells in

### Injection WellInventoryFY1997,

### V.S. EPAVIC Program, Office of Ground Water and Drinking Water (August 1997), or were specified (as noted) by primacy agencies.4 ClassIMlFailureAnalvsis (]993-19981 

## Figure 1: Components ofaTypical Class IWell

Cement**~** Baseof 10,000mgllTOS USOW**~IE--** SurfaceCasing

,.-- LongString Casing Annulus**-~~** InjectionTubing**~:: :~.:::~** **~** ir

# J~

X ...IF..f--lnjection Packer ConfiningZone

...**------------~~** 

# . _S ../'-...

# ~**--"'r=~** 

# ------.'"" r-'" InjectionZone 

## .?**:'.~** ":.**::~.**

# ~_l_'_____ 

# J5 ClassIMIFailureAnalysis 0993-19981 

### A. Surface casing This "string" of pipe is the outermost ofthe three concentric layers of protection of a Class Iwell (surface and long-string casing, and tubing). Typically sized from 7 Y2 to 103/4 inches diameter, this carbon steel casing extends from the surface to belowthe lowermost USDW having at least 10,000mg/I total dissolved solids (TDS) content, and is cemented fullytothe surface. The purpose of cement is to completely seal the casing to the borehole wall, in order to prevent external fluid movement (outside the casing) and corrosion. Because surface casing is installed as one ofthefirst steps in the construction process, it also protects USDWs from the effects of drilling. The quality of the casing and the effectiveness of the cement seal is carefully tested and approved by the Director before drilling can continue. However, the integrity ofsurface casing cannot be tested during operation, and failure analysis of surface casing is not possible. B. Long-string casing Long-string casing extends from the surface to or through the injection zone. Typically from 4 Y2 to 8 5/8 inches in diameter, long-string casing is either perforated or terminates in a screen assembly to facilitate the passage of waste from the wellbore into the formation. Most long-string casing is carbon steel, although a variety of corrosion-resistant materials may be used for casing (e.g., stainless and High-Nickel alloys, orfiberglass-reinforced plastic). Long-string caSing is usually cemented along its entire length, to prevent external fluid movement and corrosion. The condition of casing and the effectiveness ofthe cement seal are tested by the operator3 

### before authorization to inject is given. The absence of leaks in this casing is continuously monitored in Class I wells (see annulus, below), and the condition of the casing and cement seal are tested downhole every five years. 

## c. Injectiontubing Tubing is the innermost element of the well (2 Y2 to 7 inches diameter), and conducts the waste from the surface to the injection zone. Because it is in 3Manyofthesetests arewitnessed

### by stateorRegionalVICstaff.6 Class T 

### Ml FailureAnalvsis 0993-/9981 

### continuous contact with the waste, tubing frequently utilizes corrosion-resistant design and materials (coatings or linings, or construction offiberglass-reinforced plastic), However corrosion-proofthe material may be, tubing must have threaded joints to allow itto be installed in the well, Because a well may contain as many as 600tubing unions, these threads may develop minor leaks from time to time. The MI of the tubing is assured before injection begins, and is monitored continuously during operation. Tubing is usually pulled from the well at least every five years and tested and inspected atthe surface. 

### D. Packer annulus This mechanical device seals the outside diameter of the tubing to the inside diameterofthe long-string casing. This device may consist of a simple, mechanically set rubber element, ora complex, concentric-seal assembly tens of feet long and constructed of corrosion-resistant materials. The purpose of the device is to isolate the casing from injected waste and create a fluid-tight seal of the tubingcasing annularspace (sealed atthe surface bythe wellhead), allowing a constant pressure to be maintained on the annulus. Continuous monitoring ofthis pressure allows a direct indication of the internal MI of the well at all times. Periodically (once per year for HW wells, once per five years for NHWwells), the operator is required to conduct adistinct pressure test ofthe well annulus, and to inspect the continuous monitoring system. Annulus tests and continuous monitoring data are reported to the UIC agency on a quarterly basis. Each of the components of a Class I well can fail due to corrosion, manufacturing defects, improper installation, or mechanical damage during construction or operation. The operator of every Class I HW well is required to conduct continuous monitoring ofthe annulus pressure, and all HW (and many NHW) well monitoring systems are also connected to an auto-shutdown system, so that in the event of a loss of MI the operator is immediately alerted and injection automatically ceases. The operator is required to notifythe State UIC Directorwithin 24hours of a loss of MI or shutdown, and shut in the well until repairs are completed and approved. Because MI is monitored continuously in Class I wells, there are very few formal MIT failures for Class Iwells, compared to losses of MI in service discovered immediately bythe monitoring system. Forthis study, we analyzed not only MIT records but also records of well workovers. For example, from 1988 to 1993 in Louisiana, the Department of Natural Resources recorded only two formal MIT failures of Class IC/gss l MlFailureAnalvsis U993-19981 7 

### wells, whereas Class I operators performed 38 workovers to repair losses of MI in service. We grouped component failures as to tubing, packer, casing, wellhead, or, when detailed information was not available, non-specific annulus leaks. In response to a failure, the entire tubing string may be replaced, or only a few individual "joints" (which implies a minor defect). Similarly, packers may be replaced, or only re-set. Casing may be repaired by installation of a Iiner,4 

### squeeze-cementing,5 plugback,6 or sidetracking7 

### (which imply progressively more serious casing problems). 

### 3.0 Internal MI Failure 

### We found 

### 129 certain internal MI failures of 

### 541 Class I wells that were active at sometimefrom February 1993toJuly 1998 (Table 1). There were also 19additional, probable MI failures in Texas, forwhich we lack complete data (these 19 probable MI failures are considered in calculations onlywhere noted).8 

### A statistical projection of the probability of MI failure ofan individual well is notvalid, because manywells failed

4Alineris another stringofcasing (eitherfull-length orpartial)installedwithintheexistinglong-string casing, eitherhungwithaseal assemblyorcemented inplace.
5A squeeze is aremedialprocedure where the casing is perforated and cementis forced outside the casing. This technique is capable ofrepairing both internal casing leaks and external fluid-movement problems.
6Aplugbackis arepairprocedurefor acasingfailure withinthepermittedinjection interval. Thewell is repairedby cementing insidethe casingfromthebottom ofthe wellto abovethelocationofthecasing leak. The casingisthenre-perforated, andinjectioncontinuedinto ahigherzoneinthepermittedinterval. 7Thistechniqueinvolvespluggingbackthewellto someintervalabovethecasingproblem, andcutting a window in casingto allow directionally drilling a divergent, duplicate lower section ofthe well at an angletotheoriginal,completedinthe sameoranotherzoneofthepermittedinterval. 8Probablecasesinvolvedreferences

### incorrespondencetoMI-typeworkoveroperations (e.g., squeezecementing or replacing a tubing string), but which contained no specific reference to loss ofMI and/or detailsoftheprocedure. Somereferenceswerefairly definitebutnotpositive, whereasmostindicatedonly thatreplacementofMI-relatedcomponentstookplace. Wealsousedprobablefailures forthe 1993 study, butbecausetheywerefewer wecountedthem

### inall calculations.8 Class l MIFailureAnalvsis (J993-19981



### Table 1 Class I Inventory and MI Failure Incidence (1993-1998) Wells MI Failures Haz Non-haz Haz Non-haz Florida 

### 1 129 0 3' Mississippi 

### 2 5 3 0 Indiana 4 

### 7 2 1 Illinois 

### 6 0 1 0 Michigan 

### 9 13 2 9 12 Ohio 

### 10 3 1 Arkansas 

### 6 10 1 

### 5 Louisiana 

### 17 25 12 10 Oklahoma 

### 0 11 0 0 443 

### 273 

### Texas 

### 70 38 Kansas 

### ...5. 

## .6.1 ..2 ...5. Total 

### 130 302 68 61
Does not include 4 external MI failures and 17 incidents of migration. Does not include 1 external MI failure and 1 incident of migration. 3 Does not include 19 probable MI failures, six external MI failures, and eight incidents of migration. Source: Appendix A9 ClassIMIFailureAnalysis (]993-J998/ 

### several

### times during the study period, and others notat all (AppendixA).9 In addition, Class Iwells were plugged and Temporarily Abandoned during the study period at a higher rate than newwells were drilled, and states varied 

### in the rates that Class Iwells were added or subtracted from their inventory. In order to present comparative 

### estimates (for information only), we base our rate estimates (percent) on the number of Class Iwells active 

### in each state in 1998. Nationally, we found that432 active 

### Class Iwells experienced 129 certain internal MI failures between February 1993 and July 1998 (a ratio of well failures to active 

### wells of 30 percent). We found that Class Iwells in Texas experienced MI failure at a much higher rate (a well failure to active 

### well ratio of 66 percent or 83 percent including probable failures) (Table 1). Due to the contradictory nature of our findings, we present separate discussions for results observed 

### in 12 states (Florida, Kentucky, Tennessee, Mississippi, Indiana, Illinois, Michigan, Ohio, Arkansas, Louisiana, Oklahoma, and Kansas), and for results observed 

### in Texas. 3.1 All States exceptTexas We found that 324 active 

### Class Iwells'oexperienced 58 internal MI failures between 1993 and 1998 (18 percent). Probably due tothe corrosive 

### nature of many hazardous wastes, 60 active 

### Class I HW wells experienced 24 internal MI failures (40 percent), a rate three times greaterthan that of NHW wells (13 percent; 264 NHW wells with 34failures) (Table 1). In these states, 78 percent of Class I internal MI failures involved 

### tubing, packer, or wellhead. Twenty percent of internal MI failures involved 

### long-string casing (Table 2). Because it represents the outermost layer of protection capable of MI, long-string casing failures werejudged more serious. In contrast, a 1993study of Class II (oilrelated) MI failures showed that about 50 percent of Class II MI failures involved 

### longstring casing." The long-string casing in Class II wells is not usually fully cemented,

9

### About329 Class I wells didnotexperienceMI failure duringthe studyperiod. Atotal of103 wells failed 154 times: 34 wells failed more than once during the study period (Feb 1993 through July 1998), onelostMI 6times, two lostMI 4times, nine lostMI 3times, and 22 failed twice. Similarresults were foundfortheperiod 1988-1993.
10

### About396 ClassIwellswereactive atsometimeduringthestudyperiod. 11

### Analysis oftherateofand

### reasonsfor{ClassII]injectionwellMechanicalIntegritytest failures, L. 

### BrowningandJ.D. Smith, SocietyofPetroIe urnEngineersPaperNo. 25967 (August 1993).Class

### TMlFailureAnalysis 0993-/998) 10 

### and is subject to corrosion from saline formation fluids. Most Class I wells in these states feature fully cemented casing, and this requirement may explain the lower incidence of casing failure observed in these Class Iwells. 3.2 Texas We found in Texas that 108 active Class I wells experienced 71 certain and 19 probable internal MI failures between 1993 and 1998 (well failure to active well ratio of 66 percent for certain failures, 83 percent including probable). Unlike all other states, NHWwellswere found to experience a similar rate of internal MI failure as HW wells (71 percent NHW versus 63 percent HW for certain MI failures,'or 82 percent NHW

### 184 percent HW including probable)12 

### (Table 1). In Texas, 66 percent of internal MI failures with known reasons involved long-string casing, compared to 20 percent in all other states (Table 2). This incidence of casing failure is more characteristic of Class II 

### wells, which do not usually feature fully cemented casing. 13 

### An EPA Region 6 studyof Class Iwells in Texas found that many Texas Class I HWwells do notfeature complete cement as per UIC regulation. Forthe Class I wells that had cementing data, Region 6 found that: 1. 90 percent ofTexas Class Iwells did nothave long-string cementto surface; 2. 30 percent ofTexas Class Iwells did not have cement that extended even to the bottom of surface casing; and 3. 44percent had majorcement problems over hundreds or thousands offeet of long-string casing, and that up to 22 percent featured absent to poor cement bond overall. 14

12PorcertainMI failures, 38 NHWwells experienced27MIfailures between2/93-7/98 (71 percent) versus 70 HW wells experienced 44 MI failures (63 percent). Porprobable failures, 38 NHW wells/31 failures (82 percent) versus 70 HWwells/59 failures (84 percent). Thesevalues do not include six (4/2) externalMIfailures. 13Analysisoftherateof andreasonsfor[ClassII]injectionwellMechanicalIntegrity test failures, 

### L. BrowningandJ.D. Smith, SocietyofPetroleumEngineersPaperNo. 25967 (August 1993). 14ExternalMechanical Integrity Log Interpretationsfor Class I Wells in Texas, prepared for EPA Region6byTheCadmusGroup (September30, 1993).11 ClgssTMlFailureAnalysis a993-19281 

### Table 2 Types and Incidence of Class I Internal MI Failures (1993-1998) 

### All States (exceptTexas) Tubing Packer Wellhead Casing Unspecified Total (non-TX) 

## J:iaz 14 3 0 5 2 24 

## 3/2. 64% 14% 22% 40% NHW 14 11

2 6 1 34**~** 

### 42% 33%

6% 18%. 13% Total 28 14 2 11

3 58 % 51 % 25% 4% 20% 18% Texas Tubing Packer Wellhead Casing Unspecified Total (Texas)1**~** 

### 9 4 0 20 11 

### 44 

## 3/2. 27% 12% 61% 63% NHW 5 2 0 18 2 27**~** 

### 20%

8% 72% 71 % 

### IQl.al 14

6 0 38 13 71 

## 3/2. 24% 10% 66% 66% Does not include 19 probable and 6 external MI failures.



### EPA Region 6 suggested thatthe problems with cement coverage ofTexas Class I wells mightstemfrom the unconsolidated nature ofGulfCoastsediments, which could present speCial problems for operators in the process of well cementing. Class I operators in Louisiana, however, encounter the same cementing problems as do12 ClassTMTFailureAnalysis a993-19981 

### operators in coastal 15 

### Texas. We performed the identical search of Class I files in Louisiana as Texas, and found that casing failures in Louisiana account for only 18 percent of MI failures (for both HW and NHW wells), the same percentage found for all other states (Appendix A). For these reasons, we believe that external cement coverage, ratherthan waste corrosivity, is the more likely reason for long-string casing failure in Texas Class Iwells.

• Because high or low pH makes for characteristic hazardous waste, HW injectate is often far more corrosive than NHW industrial waste. Class I HW wells in Texas, however, experienced a lower incidence of casing failure than NHW wells (61 percent of MI failures with known reasons versus 72 percent for NHW wells). In our examination ofTexas Class Ifiles, we found that some Class I NHW wells are conversions of oil wells and tests, and that many NHW wells feature less cement coverage of long-string casing than HW wells. • In our examination of Louisiana Class I files, we found that although similar corrosive wastes are injected, Louisiana HWwells generally feature more extensive cement coverage than do Texas Class I wells. Louisiana's HW experience also suggests that cement coverage, rather than waste corrosivity, may be the reason for 72 percent fewer casing failures found there (and in all other states) than in Texas. 4.0 External MI and Migration External MI failure usually involves either improper installation of cement outside the long-string casing, or failure of cement due to corrosive dissolution or fracturing. Migration of wastes from the injection zone can occur either along casing (due to external MI failure), or can occuratsome distance from the wellbore. The possibility for USDW contamination due to uniform upward seepage of wastes is extremely remote in most areas, due to alternating layers of permeable and impermeable formations that are presentto contain thewaste. 16 

### Ofgreater concern is the presence of natural or man-made conduits that may allow a direct pathway for injected waste ordisplaced saline formation fluids to contaminate USDWs. Conduits include natural
15Actually, about 1/3 ofTexasClassIwells are

### innon-coastal "hard-rockcountry" suchas westTexas. Casingfailures, however, werefound tooccuraboutequally 

### inbothareas. 16Ground water modeling studies performed 

### in support ofthe Class I Regulatory Negotiation Committee,U.S. EPA(March 1987).13 ClassIMIFailureAnalysis U993-19981 

### fractures or transmissive faults, man-made hydraulic fractures due to excessive injection pressures, and unplugged or improperly sealed abandoned oil and gas wells. The primary objective of the No-Migration Petition process for Class I wells involves an analysis ofthe potential presence of both natural and man-made conduits. Where geologic conditions might permit the existence of natural fractures in the confining zone, or where alternating permeable/impermeable layers do not provide secondary containment in the event of migration, monitoring wells can be required. We found 11 external MI failures in Florida, Ohio, and Texas (Appendix A). We also investigated 27 cases of significant waste migration out ofthe injection zone. Four cases of waste migration are known to have affected a USDW (3 in Florida and 1 in Texas17), 

### eight cases are suspected to affect a USDW (Florida), 15 cases involved migration from the injection zone into permitted (3) or unpermitted (12) saline zones (7 Florida, 1 Ohio, and 7 Texas), and five cases of suspected migration remain unknown as to extent (Texas). The 11 external MI failures were detected by routine (5-year) external MIT. Migration incidents were detected by external MITor by periodic sampling of state-mandated deep monitoring wells. Five of the waste migration incidents, however, were attributable to external or internal MI failures of monitoring wells (Florida). One ofthe migration incidents (into an unpermitted saline zone) was caused by an internal MI failure (Florida). Two-thirds of migration incidents occurred in Florida, and involved migration of Nonhazardous waste from the injection zone in areas of natural fracturing that may also lackalternating permeable and impermeable layers (AppendixA). These Class Iwells inject Non-hazardous municipal sewage effluent, pre-treated to secondary standards and suitable for surface discharge. In each case, the UIC Director required deep monitoring wells as a permit condition.18 

### The same geologievariability, however, that allowed minor waste migration from the injection zone allows communication of surface water with valuable shallow drinking water aquifers. On that basis, the UIC
17TheTexascase (WDW-117, Jetco Chemicals)didnotinvolvemigration. Rather, in 1974and 1990 the Texas VIC primacy agencypermittedaClassIwellto injectdirectlyinto aUSDW (about5,000mgtl TDS). Thewellpermitwas canceledinMay 1994

### whentheerrorwasdiscoveredafter20years' injection (and

### about 1.6

### billiongallons). Theinjectionzoneisadrinking

### watersourceinadjacentcounties. 18Four ofthemigrationincidents were causedby internal

### andexternalMI failures ofsite monitoring wells.Class1MlFailureAnalysis U993-1998) 14 

### Director made a resource-based decision that injection was preferred over surface discharge as a method of disposal. Most remaining incidents involved migration of wastes along casing, either into unpermitted saline zones or permitted "containmentzones" provided in No-migration petitions and permits. These incidents were discovered by routine external MI testing. One incident involved Class I injection directly into a USDW in Texas. A Class Iwell atJetco Chemical (Corsicana, Texas) was permitted by Texas UIC agencies in 1973 and drilled in 1974. It operated continuously, as permitted, from June 1974 until it was plugged and abandoned in May 1994. The Texas UIC agency amendedthe permit in August 1985, and re-permitted it in August 1990. In December 1993, a staff member of the Texas Natural Resource Conservation Commission (TNRCC, the UIC primacy agency since September 1993), determined thatthe Woodbine injection zone (as originally permitted and constructed, from -2790 to -2960 feet) was actually a USDW, and contained water of about 5,000 mg/I TDS. Since 1974, WDW-117 was permitted to inject 150 gpm at 750 psig and up to 79 million gallons per year of hazardous and (after 1992) non-hazardous waste. In adjacent counties, the Woodbine injectionzone serves as adrinking watersource. Afterdetermining thatthe WDW-117 injection zone was a USDW and notifying the permittee, TNRCC allowed Jetco to continue injecting for four months while Jetco developed surface treatment options. 

### 5.0 Comparison with 1988-1993 data 

### The Class Iwell inventory has remained stable since the previous study (428 wells in 1992versus432 in 1998), although the number and percentage of Hazardous to Nonhazardous waste wells has decreased (240/188 or 56 percent in 1992versus 60/264 or 23 percent). 5.1 All states except Texas The incidence and severity of internal MI failures in these Class I wells was found to decrease by half, compared to the previous 5-year study period (the ratio of well failures to active wells was 18 percent between 1993-1998 versus 33 percent between 1988-1993). Class I Non-hazardous waste wells in these states were found to fail at one-third the rate of Hazardous waste wells (13 percent for NHW wells versus 40 percentfor HW wells), similartothevalues observed during 1988-1993 (15 percent NHWversus 64 percent HW). Twenty percent of MI failures between 1993­ 1998 involved casing, versus 19 percentfrom 1988-1993 (Table 3).15 Class TMTFailureAnalysis U993-1998)


### Table 3 Comparison of 1993-1988 Data With 1988-1993 Data All States (exceptTexas) 1993-1998 1988-1993 

### Number of Wells Hazardous 60 wells 96 wells Non-hazardous 264wells 188 wells MI Failures Hazardous (%) 

### 24failures (40%) 62 failures (64%) Non-hazardous (%) 

### 34failures (13%) 28 failures (15%) Total (%) 

### 58 failures (18%) 90failures (33%) Casing MI failures (%)' 

### 11 esg fails (20%) 15 esg fails (19%) 

### Texas Number of Wells Hazardous 70 wells 144wells Non-hazardous 38 wells 2 

### MI Failu.res3 

### Hazardous (%) 

### 63 failures (90%) 2 

### Non-hazardous (%) 

### 33 failures (87%) 2 

### Total (%) 

### 96 failures (89%) 45 failures (31 %) 

### Casing MI failures (%)' 

### 38 esg fails (66%) 8 esg fails (18%) Percent of certain MI failures with known reasons Although wells in Texas injected both HW and NHW waste streams, Texas did not distinguish between HW and NHW during the 1988-1993timeframe. Includes 19 probable MI failures (15 H/4 N) and 6 external MI failures (4 H/2 N). 

### NQ1e.: All 

### % values refer to the ratio of well failures to active wells, notto the 

### fraction ofwells thatfailed (many wells failed several times as noted in footnote 9 on p. 9). 316 ClassIMIFailureAnalysis U993-19981 

### 5.2 Texas In Texas, internal MI failures from 1993-1998 were found to almost triple compared to the previous study (90 internal MI failures/well failure to active well ratio of 83 percent, versus 45 failures/well failure to active well ratio of 31 percent from 1988­ 1993).19 Furthermore, the severity of MI failures in Texas (as denoted by incidence of long-string casing failure) also was found to almost quadruple (38 cases/66 percent of certain MI failures with known reasons, versus 8 cases/18 percent for the previous study). In Texas, Hazardous and Non-hazardous Class Iwells experienced MI failures ata similar rate (84 percent HWversus 82 percent).19 For the 1993study, however, Texas made no distinction between Hazardous and Non-hazardous waste wells, and no HW/NHW comparison is possible. We were concerned thatthe increase in Texas MI failures was due to undercounting failures forthe 1993study. We performed similar screening ofthe Texas Class Ifiles in both 1993 and 1998. The 1993 screening was performed with microfiche, whereas the 1998 screening was done with unsorted paper files. It may have been easier to locate references to MI failures in the paper files of 1998, compared to the microfiche files of 1993. On the other hand, we found in the 1993 study that the incidence and severity of Texas MI failures were almost identical to those of all other states: 31.7 percent for Class Iwells in 14otherstatesversus Texas at 31.2 percent, and 19 percent casing failures versus 18 percentforTexas. Based on these data, we do not believe that MI failures were undercounted for the 1993study, butthat MI failures have increased since then. There is no lessening ofthe effect in either case, however, because:

• ifwe undercounted in 1993,Texas MI failures have occurred much morefrequently than the national average since 1988; or • ifwe did not undercount, Texas MI failures have occurred much more frequently than the national average only since 1993.

19IncludesprobableMIfailuresforboth 1993-1998and 1988-1993.Class TMIFailure Analysis U993-J998) 17 

### 5.3External MI and Migration For the 1993 study, we reported only 5 cases of waste migration (3 Florida, 1 Michigan, 1 Ohio), all involving Non-hazardous waste. We reported only one case of actual external MI failure. Forthe current study (1993-1998), we reported 11 cases of external MI loss, and 27 cases of waste migration from the injection zone. We are unsure if incidents of external MI failure and migration have actually increased since 1993. Twofactors may help to explain the perceived increase: 1. Migration of groundwater is relatively slow, and migration may have been occurring for some time before being discovered only recently. 2. Improvements in MITdetection technology and standardization of MIT methods may be partly responsible for the perceived increase during the 1993-1998 timeframe. It may be that more incidents are being detected, rather than more occurring.

# APPENDIX A
Class I MI Failure Analysis (1993-1998) September 30, 1998 Contract No. 68-C6-0029 Work Assignment No. 11 Key to Abbreviations tbg = 

### tubing pkr 

# = packer csg 

# = casing migr 

# = migration unsp 

# = non-specific annulus leak extMI = 

### external Mechanical Integrity monit. = 

### monitoring P 

### & A = 

### plug and abandon RAT 

### = radioactive tracer test

### FLORIDA The Class I primacy program is administered by the Florida Department of Environmental Regulation. In FY 1997, EPA reports that 130 Class I wells were active, one injecting Hazardous and 129 Non-hazardous wastes (1993: 1H, 123 NH).· The FL DER cited three internal MI failures and 17 external MI failures of Class I Non-hazardous wells. The dates shown for some external MI failures represent the earliest date migration was suspected, although subsequent testing since 1992 has served to confirm the extent and amount. Those incidents with dates preceding February 1992were not included in the previous report because migration had not been confirmed at that time. All of these cases of external MI failure involved Class I Non-hazardous wells injecting secondary-treated municipal sewage (listed as "Muni" in attached summary). Upward migration took place into unpermitted zones above the injection zone. However, with the exception of three facilities, this fluid movement has not involved a USDW. Where fluid movement into a USDW has occurred, the qualityofthe USDW has been gene'rally poor (TDS greater than 3,000 - 7,000 mg/l). All occurrences offluid movement into unpermitted zones were detected by State-mandated monitoring well programs, required as preventive measures in excess of the Federal minimum standards. These monitoring wells were located in each case within 150feet ofthe injection well, completed in azone between the top ofthe injection zone and the base of the lowermost USDW. Fluid migration is suspected to occur due to small-scale natural fracturing in limestone/dolomite confining zones, although in 3 of 17 cases migration occurred due to deficiencies in the construction ofthe monitoring wells. Source ofdata: Florida Department of Environmental Regulation (R. Deuerling) Type of MI failure 1993-1998 1988-1993 Tubing failure 1 Packer failure 

### 2 (casing) Waste migration 17 

### ***~(none** USDW) 20 (none haz) 5 (none haz) Note: * Three cases feature proven migration into USDWs, 8 cases feature suspected migration into USDWs, and 6 cases feature proven migration into unpermitted saline zones.
"wellinventorytotalsarefor"Active" wells,eitherspecifiedbyStateprogramsortakenfromInjection WellInventory, FY1997and1992, U.S. EPAUIeProgram, Office ofGroundWaterandDrinkingWater.Summary ofClass I MI failures in Florida (2/93 - 7/98' Source: Florida Dept. of Environmental Regulation Waste Outside Operator Well No. Haz? Date Type of Failure Response Weliborellnj.Zone? Martin County Utilities North facility Plant IW1 N Aug 96 Packer failure Downgraded' No Jensen Beach
Charlotte County Utilities Zemel Rd. Landfill Plant IW1 N Jun 97 Packer failure Replace packer No Punta Gorda City of Plantation Utilities Central RO plant Plant IW1 N Jan 95 Tubing failure Replace tubing Yes, to unpermitted saline zone Regional WWTP 2 wells N (muni) Jan 97 Waste migration due Re-permit injection Yes, to unpermitted to poor confinement zone to include saline zone
Miami-Dade Water & Sewer S. District 17 wells N (muni) Jul 94 Waste migration Orders on Consenf Yes, to unused USOW Regional WWTP due to monitor well (> 7,000 mg/l TDS) internal MI failure
Seacoast Utilities Plant IW1 N (muni) Aug 93 Waste migration due USDW exemption Yes, to USDW Palm Beach Gardens to poor confinement requested
Broward County 4 wells N (muni) Dec 91 Waste migration due re-permit injection Yes, to unpermitted North Regional WWTP to poor confinement zone to include saline zone City of Ft Lauderdale G.T. Lohmeyer 5 wells N (muni) Feb 91 Waste migration repair monit. well Yes, to unpermitted WWTP due to monitor well saline zone external MI failure

'Downgraded by Director from Industrial Waste category to Municipal treated waste injection only; municipal waste wells do not require tubing and packer. 2Plugged back injection-zone monitoring well; also conducting studies concerning geologic confinement as contributing to migration. Migration discovered by State-ordered monitoring network, more stringent 40 CFR 146 UIC regs. Continuing operation at present under Corrective action order. 

### 2Summary of Class I MI failures in Florida (2/93 - 7198) (cont'd) Source: Florida Dept. of Environmental Regulation Waste Outside Operator Well No. Type of Failure Response Welibore/lnj.Zone? Palm Beach County Utilities South Regional 2 wells N (muni) Jul 94 Waste migration due in progress3 Yes, into USDW? WWTP to poor confinement City of St. Petersburg Utilities Whitted WWTP 2 wells N (muni) Mar 91 Waste migration due none reported Yes, to USDW to poor confinement 4 Northeast WWTP 3 wells N (muni) Mar 91 Waste migration due in progress Yes, into USDW? to poor confinement Northwest WWTP 2 wells N (muni) Mar 91 Waste migration due in progress Yes, into USDW? to poor confinement Southwest WWTP 3 wells N (muni) Mar 91 Waste migration due in progress Yes, into USDW? to poor confinement
Pinellas County Utilities South Cross Bayou 3 wells N (muni) Mar 91 Waste migration due in progress Yes, into USDW? WWTP to poor confinement St. Petersburg McKay Creek WW 2 wells N (muni) Mar 91 Waste migration due in progress Yes, into USDW? Largo to poor confinement
Brevard County Utilities Sykes Creek WTP 2 wells N (muni) Dec 86 Waste migration due in progress Yes, into USDW? Merrit Island to poor confinement? S. Beaches WWTP 1 well N (muni) Dec 86 Waste migration due Re-permit inj. Yes, to unpermitted Melbourne to poor confinement zone to include saline zone**~ity** of Melbourne Utilities D.B. Lee WWTP 1 well N (muni) Mar 89 Waste migration due P & A Yes, to unpermitted to poor confinement saline zone (and external MI?)

3Drilling additional monitoring wells to determine if fluid has moved into base of lowest USDW; if so, will petition for aquifer exemption. 41nvestigation in progress to determine if waste entered base of lowermost USDW. 

### 3Summary of Class I MI failures in Florida (2/93 - 7/98) (cont'd) Source: Aorida Dept. of Environmental Regulation
Waste Outside Operator Well No. Tvpe of Failure Response Weliborellnj.Zone? City of Melbourne Utilities (cont'd) Grant St. WWTP 1 well N (muni) Sep 89 Waste migration due Consent Order Yes, to unpermitted to poor confinement saline zone (and external MI of monitoring well?) City of Sunrise 3 wells N (muni) Nov 91 Waste migration due re-permit inj. Yes. into unpermitted to poor confinement zone to include saline zone



### 4

## KENTUCKY and TENNESSEE The Class I program in these States is directly administered by EPA Region IV. Although 16 wells were active in for the 1993 study in Kentucky and Tennessee, these wells have been plugged by 1998. Region IV reports no MI failures of Class I wells from 1993 to 1998. (1988-1993 data: no MI failures) Source of data: EPA Region IV (N. Marsh, Class I coordinator)



## MISSISSIPPI The Class I primacy program is administered by the Mississippi Department of Environmental Ouality. EPA reports thatseven Class I wells were active in 

### FY 1997, two Hazardous and five Non-hazardous 

### (1992: 5H and 

### 1 NH). The Mississippi DEO (J. Crawford) reports that between 

### 2/93 and 

### 8/98, three Class I hazardous wells experienced MI failures (1988-1993: six). Type of MI failure 1993-1998 1988-1993

Hazardous well 

### 3 (2 tubing, 1 casing) 

### 5 (5 tubing) Non-Hazardous well 

### --.0.... ...J...(1 packer) 

### 3 6



### 5·Summary of Class I MI failures in Mississippi (2/93 - 7198) Source: Mississippi Department of Environmental Quality (J. Crawford) Operator Well No. Type of Failure Response Waste Outside WellborellnLZone? E.I Dupont De Lisle Plant #1 y Feb 94 Tubing failure Replace tubing No Plant #2 y Sep 95 Casing leak Sidetrack No Plant #3 y Dec 95 Tubing failure Squeeze and sidetrack No



### 6

### INDIANA
The Class I program is administered by EPA Region 5. In 1998, Region 5 reports that eleven wells were active, four injecting Hazardous and seven Non-hazardous wastes (1993: 13 wells, 7H and 6 NH). Three MI failures were observed (two in Hazardous wells), versus four between 1988-1993. Source of Data: EPA Region 5 (N. Wiser)
Type of MI failure 1993-1998 1988-1993

Hazardous well 

### 2 (1 tubing, 1 casing) 

### 4 (1 tubing, 3 casing) Non-Hazardous well _1 (1 casing) 

### ....Q.. 

### 3 4



### 7Summary of Class I MIfailures in Indiana (2/93 ­ 7198) Source: EPA Region 5
Operator Well No. Haz? Date Type of Failure Response Waste Outside WellborellnLZone? Bethlehem Steel Chesterton 127·1·1 Y Nov 93 Apr 98 Casing Leak Tubing leak Install liner Replace tubing No No
Hoskins Mfg. New Paris 39-11-1 N Jul 96 Casing leak Squeeze-cement No



## 8

### ILLINOIS
The Class I primacy program is administered bythe Illinois Environmental Protection Agency. Region 5 reports that in 1998,sixwells were active, all Hazardous (1993: 5H and 3 NH). One MI failure was recorded (Haz well), versus four between 1988-1993. Source of Data: EPA Region 5 (N. Wiser)

Type of MI failure 1993-1998 1988-1993

Hazardous well 1 (1 tubing) 

### 4 (1 tubing, 3 packer) Non-Hazardous well 

### -..0... 4



### 9Summary ofClass I MI failures in Illinois (2/93 - 7198) Source: EPA Region 5

Waste Outside Operator Well No. Type of Failure Response Weliborellnj.Zone? LTV Steel 4-Wl-JL y Mar 94 Tubing leak Replace tubing No Hennepin



### 10

### MICHIGAN
The Class I UIC program in Michigan is administered by EPA Region V. In 1998, Region 5 reports that 22 wells were active, 9 Hazardous and 13 Non-hazardous (1993: 25, 13 Hand 12 NH). Eleven Class I MI failures were observed from February 1993 to July 1998 (2 injecting Hazardous waste versus 9 Non-hazardous), compared to 18 failures observed between 1988-1993. Source of Data: EPA Region V (N. Wiser)

Type of MI failure 1993-1998 1988-1993

Hazardous well 2 (2 tubing) 10 (1 tbg, 6 pkr, 1 unsp, 1 whd, 1 csg) Non-Hazardous 

### ...9. (3 tbg, 3 pkr, 1 whd, 1 unsp, 1 csg) --.8...(4 tbg, 1 whd, 2 csg, 1 migr) 11 18



### 11Operator Heinz USA Holland

Hoskins Mfg. Milo

Kalium Chemicals Hersey
Upjohn Kalamazoo Well No. 139-11-1

139-11-2 139-11-3

135-11-1

133-11-1 133-11-2
77-1W-1 Summary of Class I MI failures in Michigan (2/93 - 7198) Source: EPA Region 5

Haz? Date Type of Failure Response N Nov 95 Packer leak Reset packer Oct 97 Tubing leak Replace tubing N Mar 97 Tubing leak Replace tubing N Feb 94 Casing leak Install liner Sep 94 Wellhead leak Repair wellhead
N Mar 97 Annulus leak Unknown Jun 97 Tubing leak Replace tubing
N Feb 96 Packer leak Reset packer N Sep 96 Packer leak Reset packer
y Jun 95 Tubing leak Replace joints Apr 96 Tubing leak Replace tubing Waste Outside Wellbore/lnLZone? No No No No No
No No
No No
No No



### 12

### OHIO

The Class I primacy program is administered by the Ohio Environmental Protection Agency. Region 5 reports thirteen wells active in 1998, ten injecting Hazardous waste and three Nonhazardous (1993: 16, 9 Hand 7 NH). Three Class 1 MI failures were observed between February 1993 and July 1998 (2 injecting Hazardous waste), compared to 13 from 1988­ 1993. One current incident is an external MI failure, in which data from well tests and samples from a deep monitoring well indicated that waste has migrated from the injection zone into the permitted saline "Containment Interval" underlying the Confining zone. Source of Data: Ohio E.P.A. (Amy Klei)

Type of MI failure 1993-1998 1988-1993

Hazardous well 

### 2 (1 casing, 1 migration) 11 (6 tbg, 2 pkr, 3 unsp) Non-Hazardous well 

### .J. (1 casing) .2.,.(1 pkr, 1 migration) 

### 3 13



### 13Summaryof Class I MI failures in Ohio (2/93 - 7198) Source: Ohio Envr. Prot. Agency

Waste Outside Operator Well No. Haz? Type of Failure Response Weliborellnj.Zone? BP Chemicals Lima 03-02-003 Y Nov 93 Casing leak Replace joints

Tomen

Perry Agro 02-43-006 N Apr 91 Casing leak Install liner No

Waste Mgmt Vickery of OH 4 wells Y Unknown Waste migration due to poor confinement Increase monitoring Yes6

BAn improper wellhead connection caused fresh water to corrode the uppermost casing, from the outside-in. Approximately 25 gallons of annulus-protection fluid (propylene glycol) was spilled onto the concrete wellhead pad, but was recovered before contact with the soil. Release of waste was not involved. 8Mechanical Integrity tests and data from a deep monitoring well indicate that waste has moved from the Injection Interval (top @ -2800 feet) into the Containment Interval (@ -2500 feet). contrary to predictions made for the HSWA Exemption Petition. Note that the Containment Interval underlies the Confining Zone, into which waste is prohibited from entry. No waste migration into or degradation of the lowermost USDW (@ -500 feet) has been observed in a dedicated USDW monitoring well. The well is continuing operation under increased monitoring. 

### 14

### ARKANSAS
The Class I primacy program is administered by the Department of Pollution Control and Ecology. EPA reports that 16 wells were active in FY 1997, six Hazardous and ten Nonhazardous (1993: 12 wells, 5 Hand 7 NH). Six MI failures have been observed since 1993, one of which involved hazardous waste. Source ofdata: AR Dept. of Pollution Control and Ecology (G. Delavan, UIC Coordinator).

Type of MI failure 1993-1998 1988-1993

Hazardous well . 1 (1 packer) 4 (1 tubing, 3 packer) Non-Hazardous well 

### -.li (1 tubing, 3 packer, 1 whd) 2.,(1 tubing, 1 packer) 

### 6 

### 6



### 15Summary of Class I MI failures in Arkansas (1194· - 

### 7/98' Source: Arkansas Department of Pollution Control and Ecology *Note: AR DOPC&E was unable to access MI records for year 1993.

Operator Well No. Haz? Date Type of Failure Response Albermarle Corp. WDW 1 Y Apr 95 Packer leak Reset packer Magnolia Great Lakes Chemical Corp. Marysville WDW 14M N Jun 94 Packer leak Replace packer EI Dorado WDW 7 N May 94 Tubing leak Replace joints WDW 3x N May 94 Packer leak Reset packer Feb 95 Wellhead leak Adjust fitting Newell WDW 7N N Oct 97 Packer leak Replace packer Waste Outside Weliborellnj.Zone? No

No No No No No

a 

### 16

### LOUISIANA The Class I primacy program is administered by the Louisiana Department of Natural Resources. In FY 1997, EPA reports that 42 wells were active, 17 Hazardous and 25 Nonhazardous (1993: 53 wells, 39 Hand 14 NH). Twenty two MI failures were observed from February 1993to July 1998, versus 32 failures between 1988-1993. Source ofdata: ICF analysis of Louisiana DNR well workoverfiles (and other information furnished byJoe Ball)

Type of MI failure 1993-1998 1988-1993

Hazardous well 12 (8 tbg, 2 pkr, 2 csg) 23 (6 tbg, 6 pkr, 1 unsp, 3 whd, 7 csg) Non-Hazardous well 

### 1.Q (6 tbg, 2 pkr, 2 csg)**~(7** tbg, 1 pkr, 1 csg) 22 32



### 17Summary of Class I MI failures in Louisiana (2/93 - 7198) Source: ICF analysis of Louisiana DNR records Operator Well No. Type of Failure Response Waste Outside WellborellnLZone? Borden Chemical Geismar #3 N May 98 Packer leak Replace packer No
Calumet Lubricants Princeton #2 N Jan 94 Packer leak Replace pkr No
Chevron Chemical Belle Chasse #2 N Aug 93 Mar 94 Tubing Tubing leak leak Replace Replace tubing tubing No No #3 N Aug 93 Tubing leak Replace tubing No Mar 94 Tubing leak Replace tubing No
CYTEC Industries Westwego7 #1 Y Jan 93 Dec 95 Tubing Tubing failure failure Replace Replace tubing tubing No No Dec 96 Tubing failure Replace tubing No #2 y Nov 95 Tubing failure Replace tubing No
E.I. DuPont LaPlace #7 Y Jan 94 May 94 Tubing Tubing leak leak Replace joint Re-torque joint No No Laidlaw Environmental Bayou Sorrels #1 Y (C) Apr 98 Casing leak Squeeze and patch No
Monsanto Luling Ag Products #2 #4 N N Aug 95 Jan 98 Casing Casing leak leak Install liner (500') Squeeze No No Rubicon Chemical Geismar #1 Y Jun 93 Apr 95 Packer Casing leak split Replace packer Sidetrack No No #2 y Jun 95 Packer leak Reset packer No

7formerly American- Cyanamid, Inc. Sformerly Rollins Environmental Services 

### 18Summary of Class I MI failures in Louisiana (2/93 - 7198) (cont'd) Source: ICF analysis of Louisiana DNR records Waste Outside Operator Well No. Type of Failure Response Weliborellni.Zone? Rubicon (cont'd) #4 y Dec 94 Tubing leak Replace tubing No Geismar Aug 96 Tubing leak Replace tubing No
Witco Chemical #3 N Mar 95 Tubing failure Replace tubing No Taft #4 N Aug 95 Tubing leak Replace tubing No



### 19

### OKLAHOMA
The Class I primacy program is administered by the Oklahoma State Department of Health. EPA reports that 11 Class I wells were active in FY 1997, all Non-hazardous (1993: 12 wells, 5H and 7 NH). The Oklahoma State Department of Health observed no MI failures in Class I wells between 1988 and 1993. In fact, they have reported only two minor MI losses for all Class I wells since 1988. Source of Data: OK State Dept. of Health (D. Barrett, Chief Environmental Engineer)

Type of MI failure 1993-1998 1988-1993

Hazardous well 

## o 1 (1 tubing) Non-Hazardous well ...Q _1_(1 packer) 

## o 2



### 20

### TEXAS

The Class I program in Texas is administered by the Texas Natural Resource Conservation Commission. TNRCC reports that in 1998, 108 Class I wells were active (70 injecting Hazardous waste and 38 Non-hazardous). Ninety-six MI failures were observed from February 1993 to July 1998, 77 definite and 19 probable" (based on incomplete records). For the previous study, Texas was found to have 144Class I wells, 73 Hand 71 NH, and experienced 45 MI failures between 1988 and 1993. Class I wells in Texas experienced a higher percentage of MI failures from 1993-1998 than was observed in the previous study (89 percent versus 31 percent over 5 years), and the MI failures incorporated a much larger proportion of casing failures, a more serious type of MI failure (38 cases and 66 percent of all definite failures, versus 8 cases and 18 percent). In addition, from 1993-1998 Class I wells in Texas experienced eight cases of waste migration (six cases into unpermitted zones), and a well injecting since 1974was found to be permitted to inject directly into a USDW (Jetco Chemicals, WDW-117).

Source of data: ICF analysis ofTNRCC files, and other data supplied by TNRCC (courtesy 

### B. Knape, C. Green, and K. Cronan).
Type of MI failure 1993-1998 1988-1993

Hazardous well 50 (9 tbg, 4 pkr, 11 unsp, 45 (22 tbg, 4 pkr, 11 unsp, 8 csg) 20 csg, 6 extMI) Non-Hazardous 

# n (5 tbg, 2 pkr, 2 unsp, 18csg) --.U..(no haz/non-haz distinction until 1993) 77 (not including 19 probable) 45

"These probable cases involved references in correspondence to MI-type workover operations (e.g., squeezecementing orreplacing atubing string), but no specific references to loss of Mechanical Integrity and/or details ofthe procedure. Some references were fairly definite but not positive (e.g., Casing leak?), others strongly suggested MIrelated activities (reported as LostMI?), whereas the majority of references to probable cases indicated only that a majorworkover of MI-type componentstook place (e.g., Major workover). 

### 21Summary ofClass I MIfailures in Texas (2/93 - 7198) Source: ICF analysis of Texas files and other data supplied by TNRCC
Operator Well No. Haz? Date Type of Failure Response Waste Outside Weliborellnj.Zone7 American Winona9 Ecology WOW·186 Y Oct 92 Dec 92 Casing leak Failed MIT ? No
WOW-229 Y Feb 93 May 93 Nov 94 Failed MIT Failed MIT Casing leak ? ? Straddle-packers ? ?
ARCO Channelview WOW-148 y Oct 96 Casing leak Sidetrack Yes, to permitted saline zone
ASARCO Amarillo WOW-129 WOW-324 y N Sep 93 Aug 97 Major workover Casing leak ? Squeeze-cement ?

BASF Freeport WOW-51 WOW-99 y y Jan Feb 95 93 Casing leak? Failed MIT Sidetrack ? ?

BP Chemicals Port Lavaca WOW-165 y Mar 95 Major workover ? ?
Cogema

Bruni Mining WOW-150 N Feb 96 Casing leak and poor ext. MI Squeeze-cement ?
WOW-1S1 N Mar 96 Annulus leak Replace tbg & pkr No WOW-19S N Jul 94 Casing plus annulus leak Squeeze plus replace tbg & pkr ? Holiday-Mesquite WOW-197 N May 93 Major workover ? ?

9formerly Gibraltar Wastewater, Inc. 

## 22Summary of Class I MI Failures in Texas (cont'd)
Operator Well No. Type of Failure Response Waste Outside Wellbore/lni-Zone? Chern Waste Port Arthur Management WOW-160 V Jun 94 Jan 95 May 95 Jun 95 Aug 97 Feb 98 Casing leak Casing leak Tubing leak Annulus leak Packer leak Casing leak (new) Squeeze and install liner Straddle packer Replace joint(s) Reset packer Squeeze and sidetrack ?
No ? No
Corpus Christi'O WDW-70 Y May 93 Packer leak Reset packer No
Diamond McKee Shamrock WOW-192 V Jul 97 Casing leak Reset packer higher No

E.!. DuPont de Nemours Beaumont WOW-100 V Jun Mar 94 97 Lost Lost MI? MI? Replace Replace tbg & pkr packer No No WDW-101 V Feb 93 Lost MI? Squeeze and sidetrack No Ingleside WDW-109 N Sep 93 Casing leak. no ext. MI P&A Yes, to unpermitted saline zone WDW-121 N Mar 94 Casing leak no ext. MI P & A Yes, to unpermitted saline zone LaPorte WDW-82 N Jan 95 Casing leak Straddle-packers Sabine Works WOW-57 Y Mar 97 Ext. MI loss Squeeze P & A and Yes, to permitted saline zone WDW-191 y Dec 95 Aug 96 Nov 97 Apr 98 Casing/tbg failure Major workover Casing leak Casing leak (same?) Sidetrack ? Squeeze No
? WDW-207 Y Aug 95 Major workover

'o,-he Corpus Christi site is now owned and operated by the GNI Group as Disposal Systems Inc., Corpus Christi. 

### 23Summary of Class I MI Failures in Texas (cont'd)
Waste Outside Operator Well No_ Type of Failure Response Wellborellni-Zone? E.!. Dupont (cont'd) Victoria WDW-30 Y Mar 96 Tubing leak Re-thread No WDW-142 Y Jan 93 Casing leak Squeeze-cement WDW-144 Y Jul 98 Casing leak Squeeze-cement WDW-145 Y Jul 94 Failed MIT Jan 96 Packer leak Replace packer No
Elf Atochem WDW-122 N Jul 95 Packer leak Repair packer No Crosby Empak, Inc. WDW-157 Y Mar 94 Major workover Deer Park
GNI" WDW-169 Y Jul 93 Tubing failure Replace tbg & pkr No Deer Park Sep 93 Tubing failure (new) Replace tubing No Jun 96 Tubing leak Replace tubing No Jan 98 Lost MI? Recomplete higher Hampshire WDW-222 N Mar 95 Tubing leak Replace tubing No Deer Park Hoecst-Celanese Bay City WDW-14 Y Feb 94 Casing leak P & A Yes, to unpermitted saline zone WDW-32 Y Jun 96 Annulus leak P & A WDW-49 Y Oct 93 Tubing leak Replace tbg & pkr No Mar 94 Casing leak ? WDW-ll0 Y Jan 95 Major workover Bishop WDW-212 Y May 93 No ext. MI Squeeze-cement Yes, to unpermitted saline zone Clear Lake WDW-45 Y Jun 98 Annulus leak

"formerly Disposal Systems Inc. 

## 24Summary of Class I MI Failures in Texas (cont'd)
Operator ISP Technologies Texas City

Jetco Chemicals Corsicana
Malone Services Texas City
Monsanto Chocolate Bayou

Oxy Petrochemicals Corpus Christi
ilexene Odessa Well No. WOW-34 Y

WOW·114 Y WOW-299 Y
WOW-117 N

WDW-73 Y

WOW-2 Y WDW-224 Y

WDW-152 Y

WOWs 16, Y 88, 126, 154 Date Dec 94 Jan 96 Jan 97 Feb 93 Feb 93?
Oct 93 Dec 93
Jul 95

Feb 93 Apr 93

Nov 96 Apr 97 May 93 Type of Failure Tubing leak Tubing leak Casing leak No ext. MI No ext. MI Casing leak Injection to USOW
Annulus leak

lost MI? Casing leak?

Failed MIT Major workover (same)
No ext. MI due to fractures Waste Outside Response Wellborellnj.Zone? Replace tbg & pkr Replace tubing Straddle-packers Temp. abandoned Temp. abandoned No No

?
Install liner P & A (5/94) ? Yes, to USOW 12

Replace tubing Squeeze-cement and sidetrack No ?

shut-in Replace tbg & pkr No No Quarterly RAT, Corrective Action13

12This well was permitted by TNRCC in 1973 and drilled in 1974. Itoperated continuously, as permitted, from June 1974 until it was plugged and abandoned in May 1994 by order of the TNRCC. TNRCC amended the permit in August 1985, and re-permitted WOW-117 in August 1990. In December 1993, a TNRCC UIC staffer determined that the Woodbine injection zone (as originally permitted and constructed, from 2790-2960) was actually a USOW, containing water of about 5,000 mgll TOS. Since 1974, WOW-117 injected 150 gpm (max) at 750 psig WHIP (max), up to 79 million gallons per year of hazardous and non-hazardous (after 1992) waste. Up-dip from the Jetco facility, the Woodbine serves as adrinking water source. After determining that the WOW117 injection zone was a USOW, TNRCC allowed the operator to continue injecting for four months while Jetco developed surface treatment options. (Source: TNRCC WOW-117 file) 131njection testing in May 1993 created fractures in the injection zone. Since 1997, the operator is required to operate at restricted injection rates, perform quarterly radioactive EMIT, and perform Corrective Action (such as plugging offset wells) in the Area of Review. Migration of waste from the injection zone is unknown. 

### 25Summary of Class I MI Failures in Texas (cont'd)
Waste Outside Operator Well No. Date Type of Failure Response Weilbore/lnLZone? Sandoz'4 WDW-125 N Nov 93 Tubing leak Re-torque, reset No Beaumont Nov 97 Casing leak Squeeze-cement ? Mar 98 Major workover ? WDW-155 Y Apr 97 Packer leak Replace packer No WDW-301 N Oct 94 Casing leak ? No Mar 95 Casing failure (new) Install liner Aug 95 Major workover (new) ? ? Sterling Chemical WDW-196 Y May 96 Tubing failure, Replace tbg & pkr, ? Texas City casing leak reset higher WDW-314 Y Aug 97 Lost MI? Recomplete higher ? Mar 98 Casing failure Install liner and then sidetrack
Thomas Disposal WDW-311 N Sept 93 Casing leak Squeeze-cement

Perryton Mar 95 Major workover ? ? Feb 96 Casing leak Squeeze-cement ?
USX Uranium WDW-123 N Mar 95 Casing leak Install liner, George West tubing, and packer WOW-140 N Aug 94 Packer leak and straddle packers casing leak May 96 Casing failure Uner, then ? sidetrack WDW-141 N Jan 95 Tubing leak Replace joints No Mar 95 Tubing leak Replace tubing No WDW-174 N Feb 93 Casing leak Squeeze-cement
Witco Chemical Houston WDW-111 N Sep 95 Failed MIT ? ? Apr 96 Casing failure Recomplete higher ? WOW-139 N Aug 96 Casing failure Recomplete higher Dec 96 Lost MI? Replace tbg & pkr No
14formerly BASF Corporation 

### 26Summary of Class I MI Failures in Texas (cont'd)
Operator WeI! No. Tvpe of Failure Response Waste Outside WellborellnLZone? Witco Chemical Marshall (cont'd) WDW-180 Y Ssp 93 Oct 94 Nov 95 Packer and casing leak Major workover(same?) Casing leak and no ext. MI Squeeze and sidetrack WDW-243 Y Dec Nov 93 97 No ext. MI Tubing leak Replace tubing Yes, to unpermitted saline zone?16 No
Uranium Rosita Resources WDW-250 N Aug 95 Oct 95 Tubing and packer leak Packer leak Re-torque tbg and reset packer Replace packer No No

16RAT test in 1993 showed upward migration along casing for over 300 feet, and probably out of injection zone. Subsequent tests show similar movement, including December 1997 (latest) test. Files are unclear if any regulatory. attention or restrictions visited on operator. 

## 27

### KANSAS
The Class I primacy program is administered by the Kansas Department of Health and Environment. EPA reports that 66 Class I wells were active in Kansas in FY 1997, five Hazardous and 61 Non-hazardous (1993: 5H and 41 NH). Seven MI failures were observed in Class I wells between 1/93 and 7/98, two of which involved hazardous waste wells. Source of data: Kansas Dept·. of Health and Envr. (M. Cochran, Chief Geology Unit).

Type of MI failure 1993-1998 1988-1993

Hazardous well 

### 2 (2 unspecified) 

## o Non-Hazardous well ..Q (3 tbg, 1 pkr, 1 csg) 

### --.U..* 7 

## o

Note: 

### *Kansas did notfurnish data for Class I Non-Hazardous wells for the previous study.



### 28Summary of Class I MI failures in Kansas (2/93 - 7/98) Source: Kansas Department of Health and Environment
Waste Outside Operator Well No. Haz? ...QM!L Type of Failure Response WeliborellnLZone? KN Processing Plant #2 N NA Tubing failure Replace tubing No Bushton Plant #4 N NA Tubing leak Replace joints No Plant #5 N NA Tubing leak NA No
.<och Storage Plant #2 N NA Packer leak Reset packer No Conway
Morton Salt Plant #1 N NA Casing leak Install liner No Hutchinson
lulcan Chemicals Plant #3 y Sep 94 Annulus leak Replace tbg & pkr No Wichita Plant #8 y Aug 97 Annulus leak Replace tbg & pkr No



## 29