UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D. C. 20460 OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES April 13, 2006 MEMORANDUM SUBJECT: Environmental Fate Assessment of Alkyl* dimethyl benzyl ammonium chloride *( 50% C14, 40% C12, 10% C16) ( ADBAC) for the Reregistration Eligibility Decision ( RED) Document Case No.: 0350 26186 DP Barcode: 322870 FROM: Srinivas Gowda, Microbiologist/ Chemist Risk Assessment and Science Support Branch ( RASSB) Antimicrobials Division ( 7510C)

TO: Mark Hartman, Branch Chief Benjamin Chambliss, Team Leader Najm Shamim, Risk Assessor Regulatory Management Branch II Antimicrobials Division ( 7510C)

Jacqueline McFarland, Chemical Review Manager Regulatory Management Branch I Antimicrobials Division ( 7510C)

THRU: Siroos Mostaghimi, Acting Team Leader, Team one Risk Assessment and Science Support Branch ( RASSB) Antimicrobials Division ( 7510C)

Norman Cook, Branch Chief Risk Assessment and Science Support Branch ( RASSB) Antimicrobials Division ( 7510C)

Chemical Name PC Code CAS# Common Name Alkyl* dimethyl benzyl ammonium chloride 069105 68424 85 1 ADBAC *( 50% C14, 40% C12, 10% C16)

Environmental Fate Science Chapter and Fate Assessment on ADBAC is submitted for Reregistration Eligibility Decision ( RED). Page 2 of 14 ALKYL DIMETHYL BENZYL AMMONIUM CHLORIDE ( ADBAC) ENVIRONMENTAL FATE SCIENCE CHAPTER EXECUTIVE SUMMARY ADBAC is used primarily as a disinfectant, a sanitizer, or as a microbicide/ microbiostat. It also serves as an algaecide, bactericide/ bacteriostat, fungicide/ fungistat, insecticide, miticide, virucide, defoliant, feeding depressant, repellent and tuberculocide. Use sites for ADBAC include agricultural premises and equipment, food handling, commercial, industrial and institutional settings, residential areas or areas of public access, pets and kennels, medical facilities, swimming pools, aquatic areas, and industrial water systems. ADBAC is also used as a wood preservative. As an agricultural pesticide, ADBAC is used for ornamental plants, shrubs, and vines. Some of the required guideline studies for an environmental fate assessment have been submitted. The Agency is using the available environmental fate studies for fate assessment of ADBAC to fulfill the reregistration requirements. Because of its use as a wood preservative, an aqueous availability study evaluating the leachability of ADBAC from treated wood is required. However, no data have been submitted to the Agency.

ADBAC is hydrolytically stable under abiotic and buffered conditions over the pH 5 9 range. ADBAC is also stable to photodegradation in pH 7 buffered aqueous solutions. However, in the presence of a photosensitizer ( e. g., acetone), ADBAC has been shown to degrade with an estimated half life of 7.1 days.

Aquatic metabolism studies under aerobic and anaerobic conditions indicate that ADBAC is stable to microbial degradation. ADBAC did not degrade in flooded sand loam soil that was incubated at 24 27 E C in the dark for up to 30 days in an aerobic aquatic metabolism study. Under anaerobic conditions, ADBAC was found to be very resistant to degradation with a calculated half life of 1,815 days. However, a report on the biodegradability of ADBAC prepared by the Registrant concluded that the degree of ADBAC biodegradability is variable and is influenced by the chemical concentration, alkyl chain length, the presence of anionic moieties and the quantity and characteristics of the microbial population. According to this report, ADBAC is biodegradable and environmentally acceptable. This report was based on information from the open literature, unpublished sources, and meeting proceedings and has not been reviewed by the Agency.

ADBAC is immobile in soil. The available soil mobility study shows that ADBAC has a strong tendency to bind to sediment/ soil with Freundlich Kads values were 6,172 for the sand soil, 10,797 for the silt loam, 5,123 for the sandy loam soil, and 32,429 for the clay loam and the corresponding Koc values were 6,171,657 for the sand soil, 2,159,346 for the silt loam, 640,389 for the sandy loam soil, and 1,663,039 for the clay loam. Because of its strong adsorption to soils, ADBAC is not expected to contaminate surface and ground waters.

Bioaccumulation of ADBAC in freshwater fish is not likely to occur. Maximum bioconcentration factors ( BCF) were 33X for edible tissues ( muscle, skin), 160X for nonedible Page 3 of 14 tissues ( viscera, head, carcass), and 79X for whole fish tissues. ADBAC is not expected to pose a concern for bioconcentration in aquatic organisms.

I. Environmental Fate Assessment A. Abiotic In a hydrolysis study conducted under abiotic and buffered conditions, alkyl dimethyl benzyl ammonium chloride ( ADBAC), did not hydrolyze at pH 9 ( estimated half life = 379 days) and appeared hydrolytically stable at pH 5 and 7 ( estimated half lives = 150 183 days). The study was conducted at 25 ± 1 E C for up to 30 days. The hydrolysis data requirements ( OPP 161 1) for ADBAC have been fulfilled by this study ( MRID 408356 02).

The photodegradation potential of ADBAC was investigated in sensitized and nonsensitized buffer solutions adjusted to pH 7 [ 0.2 M tris( hydroxyl methyl) amino methane]. ADBAC did not degrade in the pH 7 sterile buffered aqueous solution that was continuously irradiated over a 30 day period at 25 E C. In contrast, ADBAC degraded with an estimated halflife of 7.1 days in a similar buffer solution that had been sensitized with 1% acetone. ADBAC did not degrade in the dark controls of the sensitized and non sensitized solutions. An unidentified degradate, isolated from the sensitized irradiated solution 30 days post treatment, accounted for 74.5% of the applied radioactivity. Because of missing information, the photodegradation in water guideline requirements ( OPP 161 2) have not been fulfilled by this study ( MRID No. 408356 03).

B. Biotic In a study on an aerobic aquatic system, ADBAC did not degrade in flooded sand loam soil that was incubated at 24 27 E C in the dark for up to 30 days. During the study, most of the applied radioactivity, of which > 90% was extractable, was observed in the soil fraction. The aerobic aquatic metabolism guideline requirements ( OPP 162 4) have been fulfilled by this study ( MRID 408356 04).

Under anaerobic conditions, ADBAC was found to be very resistant to degradation in flooded sandy loam soil that had been incubated for a year at 25 E C. The registrant calculated half life was 1,815 days. No degradation products were found. This study satisfies the anaerobic aquatic metabolism guideline requirements ( OPP 162 3) ( MRID Nos. 411055 01 & 424151 01).

A review of information from the open literature, unpublished sources and meeting proceedings prepared by the Registrant indicates that ADBAC is readily and ultimately degradable. The report author noted that the aerobic and anaerobic aquatic metabolism studies for ADBAC were designed to assess environmental fate of ADBAC based on outdoor applications of agricultural chemicals, but not the direct biodegradability potential of this chemical as a result of its use as an antimicrobial. Other limitations of the tests were noted, such as loss of microbial activity during air drying of soil material and limited gas exchange in the Page 4 of 14 aerobic test. According to this report, the degree of ADBAC's biodegradability is variable and is influenced by the chemical concentration, alkyl chain length, the presence of anionic moieties and the quantity and characteristics of the microbial population. A mechanism of biodegradation for ADBAC, in which several bacterial species are needed for ultimate biodegradation of this compound, is also described.

The adsorption/ desorption characteristics of ADBAC were studied on four representative agricultural soils: sand, sandy loam, silt loam, and clay loam. The study determined ADBAC to be immobile in all soils tested. Freundlich Kads values were 6,172 for the sand soil, 10,797 for the silt loam, 5,123 for the sandy loam soil, and 32,429 for the clay loam and the corresponding Koc values were 6,171,657 for the sand soil, 2,159,346 for the silt loam, 640,389 for the sandy loam soil, and 1,663,039 for the clay loam. Following the first desorption step, Freundlich Kdes values were 7,137 for the sand soil, 14,083 for the silt loam soil, 96,540 for the sandy loam soil, and 165,556 for the clay loam soil; corresponding Koc values were 7,137,310 for the sand soil, 2,816,590 for the silt loam soil, 12,067,457 for the sandy loam soil, and 8,490,062 for the clay loam soil. Since the study only provides information on the mobility of unaged ADBAC, the adsorption/ desorption guideline requirements ( OPP 163 1) have been partially fulfilled ( MRID Nos. 408356 05 & 424148 01).

A study consisting of a 35 day bioconcentration and a 21 day depuration period was conducted to evaluate the bioconcentration of ADBAC in bluegill sunfish under flow through aquarium conditions. Analysis of edible tissues ( muscle, skin), whole fish, and nonedible tissues ( viscera, carcass) were performed throughout the exposure period. Maximum bioconcentration factors ( BCFs), based on total radioactivity, were 33X for edible tissues, 79X for whole fish tissues and160X for nonedible tissues. The maximum concentrations of residues occurred at day 35 and were 3.4, 6.6, and 13 ppm for edible tissues, whole fish, and nonedible tissues, respectively. After 21 days of depuration, 14[ C] residues were 2.4 ppm in edible tissues, 3.7 ppm in whole fish tissues, and 5.3 ppm in nonedible tissues. 14[ C] residues in edible tissues did not decline significantly from the concentrations detected during the exposure period. The study is scientifically valid, but it does not satisfy the guidelines ( OPP 165 4) for bioaccumulation in fish ( MRID 410268 01) since residues present at 0.05 ppm or greater in the treated water and fish were not identified. Page 5 of 14 APPENDIX Environmental Fate Data for ADBAC A. Environmental Fate Guideline Studies 1. Hydrolysis ( OPP Guideline Number 161 1, MRID No. 408356 02)

This study was reviewed by the Agency and found to be scientifically valid. The hydrolysis data requirements for ADBAC have been fulfilled.

Uniformly ring labeled [ 14C] ADBAC ( alkyl dimethyl benzyl ammonium chloride; radiochemical purity 98%; specific activity 2.03 x 104 dpm/ µ g), diluted with nonradiolabeled ADBAC and deionized water, was added at 1,298 µ g/ flask to sterile pH 5 ( acetic acid), pH 7 [ N 2 hydroxyethyl piperazine N' 2 ethanesulfonic acid ( HEPES)], pH 7 [ tris( hydroxymethyl) aminomethane ( TRIS)] and pH 9 ( boric acid) aqueous buffer solutions. Acetonitrile was added to the buffer solutions as a cosolvent at < 1%. The final nominal concentration of [ 14C] ADBAC in the treated solutions was 9.7 µ g/ ml. Aliquots of the treated buffer solutions were added to amber colored silanized vials. The vials were capped and incubated in the dark at 25 ± 1 E C for 30 days. Duplicate samples were collected at 0, 1, 3, 7, 14, 22 and 30 days post treatment.

At each sampling interval, duplicate aliquots of the buffer solutions were analyzed for total radioactivity by liquid scintillation counting ( LSC). Sample solutions were also analyzed for specific [ 14C] compounds by one dimensional TLC on silica gel plates developed in a chloroform: methanol: formic acid ( 60: 40: 2, v: v) solvent system. A radioscanner was used to locate radioactive areas on the plates. Autoradiographs were prepared from the 0 and 30 day TLC plates. After scrapping radioactive areas from the plates, the radioactivity was desorbed and quantified by LSC. The pH of each solution was also measured at each sampling interval.

Uniformly ring labeled [ 14C] ADBAC, at a nominal concentration of 9.7 µ g / ml, was relatively stable to hydrolysis in pH 5 and 7 buffer solutions ( half lives were 150 183 days), decreasing by   2.3% of the recovered radioactivity during 30 days of incubation. [ 14C] ADBAC did not hydrolyze in pH 9 buffer solution; the half life was calculated to be 379 days.

In the buffer solutions, the parent was present at 89.5   92.8% of the applied radioactivity at 30 days post treatment. The original containers for all individual samples with less than 90% recovery were further extracted with methanol. The 30 day mass balance increased to 92.2 97.4% of the applied radioactivity when the methanol rinse of the vials was analyzed. The pH of all buffer solutions remained stable throughout the study period.

2. Photodegradation in Water ( OPP Guideline No. 161 2, MRID No. 408356 03)

This photodegradation study was reviewed by the Agency and found scientifically valid. However, in its original review the Agency concluded that the study did not meet guideline Page 6 of 14 requirements since information on characterization of the light source was not reported and one [ 14C] compound isolated 30 days post treatment from the sensitized irradiated solution at 74.5% ( 6.97 ppm) of the applied radioactivity was not identified. Supplemental information ( MRID 424152 01) submitted by the Registrant provided information on the light source; however, the identity of the degradate was not reported. The Agency noted that there are many organic photosensitizers in the environment, so it is important to identify the major photoproduct that was detected in the photosensitized system ( EFGB, 1993). The photodegradation in water guideline requirements for ADBAC have not been fulfilled. This study is classified as upgradable.

In this study, ring labeled [ 14C] ADBAC ( alkyl dimethyl benzyl ammonium chloride; radiochemical purity 98%; specific activity 2.03 x 104 dpm/ µ g), diluted with nonradiolabeled ADBAC and deionized water, was added to two flasks containing sterile pH 7 buffer solution ( tris( hydroxy methyl) amino methane) prepared with < 1% acetonitrile as cosolvent. The solution in one flask was photosensitized with 1% acetone ( v: v). Final concentrations of [ 14C] ADBAC were 9.11 ppm and 9.35 ppm in the nonsensitized solution and sensitized solution, respectively.

Aliquots of the treated solutions were transferred to capped culture tubes. Half of the vials containing each solution were covered with aluminum foil and stored inside a closed box ( dark control solutions). The box was placed along with the unwrapped vials in a photolysis apparatus. A xenon lamp, characterized as having approximately one half the intensity of sunlight, was used to irradiate the samples. The temperature in the photolysis chamber was maintained at 25 ± 1 E C. Duplicate samples of irradiated and dark control solutions were removed for analysis at approximately 0, 1, 3, 7, 10, 14, 21, and 30 days post treatment.

At each sampling interval, duplicate samples of irradiated and dark control solutions were analyzed without extraction for total radioactivity by liquid scintillation counting ( LSC). The aliquots were also analyzed for specific [ 14C] compounds using one dimensional TLC on silica gel plates developed in a chloroform: methanol: formic acid ( 60: 40: 2, v: v) solvent system. A radioscanner was used to locate radioactive areas on the plates. In addition, autoradiographs were prepared from the 0 and 30 day TLC plates. After scrapping radioactive areas from the plates, the radioactivity was desorbed and quantified by LSC. The pH of each solution was measured at each sampling interval. The volatilization of [ 14C] residues from the irradiated and dark control samples was also measured by analyzing the trapping solutions at 0, 1, 3, 7, 10, 14, 21, and 30 days post treatment for total radioactivity using LSC.

Ring labeled [ 14C] ADBAC ( alkyl dimethyl benzyl ammonium chloride; radiochemical purity 98%; specific activity 2.03 x 104 dpm/ µ g), at approximately 9 ppm, did not degrade in a sterile buffer solution that was irradiated continuously for 30 days with a xenon light source and maintained at 25 ± 1 E C or in a sterile buffer solution used as dark control. [ 14C] ADBAC accounted for > 99% of the applied radioactivity at 30 days post treatment in the sterile buffer solutions. During the study, the material balance of the sterile buffer solutions ranged from 96.3 to 105% of the applied radioactivity. In contrast, [ 14C] ADBAC degraded with a calculated halflife of 7.1 days in the irradiated solution that had been sensitized with 1% acetone. The parent Page 7 of 14 compound declined from 76.9% of the applied radioactivity at 3 days post treatment to approximately 37% at 7 and 10 days, and 16.3% at 30 days post treatment. An unidentified degradate accounted for 74.5% of the applied radioactivity. [ 14C] ADBAC did not degrade in the sensitized dark control. The material balance of the sensitized solutions ranged from 90.3 to 101% of the applied radioactivity during the study. Volatilization of [ 14C] residues from the sensitized and nonsensitized buffered solutions accounted for 3.4 5.4% of the applied radioactivity during 30 days of incubation.

3. Anaerobic Aquatic Metabolism ( OPP Guideline No. 162 3, MRID Nos. 411055 01 & 424151 01)

This anaerobic aquatic metabolism study was reviewed by the Agency and found to be acceptable after supplemental information was submitted by the Registrant ( MRID No. 424151 02) ( EFGB, 1993). The anaerobic aquatic metabolism data requirement for ADBAC has been satisfied. Information was extracted directly from the study report with minor editing changes.

In this study, samples of well water and sandy loam soil, preincubated under anaerobic conditions for 34 days, were fortified with [ 14C] ADBAC at a nominal test concentration of 10 µ g/ g. The fortified samples were placed in metabolism vessels in an environmental chamber maintained at an average temperature of 25.2 ± 0.5 E C under dark conditions. The treatment samples were incubated anaerobically for one year following dosing. In addition to the day 0 soil and water analysis, samples of soil, water and trapping solutions were collected for analysis at 1, 3, 7, 14 days post treatment and 1, 2, 3, 4, 6, 9 and 12 months post treatment. Trapping solutions were also sampled at 5, 7, 8, 10, and 11 months.

On each sample day, sample tubes were vortexed and centrifuged to separate the water layer from the soil. The aqueous phase was pippetted into a separate silanized tube and adjusted to volume with deionized water. The remaining soil in each tube was extracted three times with dimehtylformamide: acetic acid. Triplicate aliquots of the both the aqueous phase and soil extracts were analyzed by liquid scintillation counting ( LSC) to determine total radioactivity. Bound residues were determined by combustion of triplicate aliquots of the post extracted soil followed by LSC analysis. The trapping solutions were also analyzed in triplicate by LSC. Thinlayer chromatography ( TLC) was used to characterize [ 14C] residues in the samples.

Throughout the year long study, [ 14C] residues levels in the water remained low ranging from 0.7 to 2.4% of the total residues ( mean value of 1.2 ± 0.4%). The non extractable residues of [ 14C] ADBAC accounted for 10.9% of the total residues at the end of the study. Volatilization of [ 14C] residues was minimal with only 0.3% of the applied dose present in the volatile trap samples after 366 days of anaerobic incubation.

The parent compound was the only compound detected in the TLC analysis of the soil extracts. The recovery of [ 14C] activity from the thin layer plates ranged from 89.1 to 106.1% of the applied radioactivity ( mean of 96.1 ± 4.2%). Most of the radioactivity recovered was in the zone corresponding to the co chromatographed parent compound. The mean recovery as parent compound was 94.8 ± 4.3%. Based on the levels of ADBAC present in the extractable residues, Page 8 of 14 the half life was determined to be 1,815 days. The mass balance ranged from 100 to 112 % of the measured day 0 levels ( mean of 106 ± 4%).

4. Aerobic Aquatic Metabolism ( OPP Guideline No. 162 4, MRID No. 408356 04)

This aerobic aquatic metabolism study was reviewed by the Agency and found scientifically valid. In its original review the Agency noted that the study did not meet guideline requirements since several [ 14C] residues present at   0.01 ppm were not identified, including one degradate present at 0.12 µ g/ g and the composite of all the scraped TLC material known as " remainder" that accounted for up to 0.97 µ g / g. Supplemental information ( MRID 424149 01) submitted by the Registrant indicated that the degradate represents only a minor impurity, not a metabolic degradate, and was not detected after day 2. In addition, the " remainder" fraction contained only nondistinct components that were less than 1% of the initial dose. After review of the supplemental information, the Agency concluded that the study is acceptable and satisfies the aerobic aquatic metabolism data requirement for ADBAC ( EFGB, 1993).

In this study, samples ( 10 g) of sieved ( 2 mm) sandy loam soil ( 64% sand, 20% silt, 16% clay, 1.6% organic matter, pH 6.2, CEC 9.5 meq/ 100 g) were weighed into silanized culture tubes and then flooded with 20 ml of well water that had been treated with approximately 10 µ g/ ml of ring labeled [ 14C] ADBAC ( alkyl dimethyl benzyl ammonium chloride; radiochemical purity 98%; specific activity 2.03 x 104 dpm/ µ g). The treated soil: water samples were homogenized and divided between two 3 L glass metabolism vessels. Humidified air was pumped continuously into the vessels holding the tubes of soil; effluent air was then passed through an ethylene glycol trap, a 1 N sulfuric acid trap and two 1 N potassium hydroxide traps. The test tubes were maintained at 24 27 E C under dark conditions. One sample was collected from each metabolism vessel at 0, 1, 2, 7, 14, 21, and 30 days post treatment. Volatile traps were sampled at the same intervals.

At each sampling interval, soil: water samples were vortexed and centrifuged and the aqueous phase decanted. Aliquots of the aqueous phase were analyzed for total radioactivity by liquid scintillation counting ( LSC) and for specific compounds using normal phase thin layer chromatography ( TLC) on silica gel plates developed in chloroform: methanol: formic acid ( 60: 40: 20). The soil fraction was extracted three times with dimethylformamide: acetic acid ( 80: 20); the extracts were separated from the soil by centrifugation and combined. Aliquots of the extracts were analyzed for total radioactivity by LSC and for specific compounds using normal phase TLC as described for the aqueous phase aliquots. Unextractable [ 14C] residues in the soil were quantified by LSC following combustion. Residues were corrected for combustion recovery efficiencies in controls. Radioactivity in the volatile trapping solutions was quantified by LSC.

Ring labeled [ 14C] ADBAC, at approximately 10 µ g/ g, did not degrade in aerobic flooded sandy loam soil that was incubated in the dark at 24 27 E C for 30 days. During the study, the soil fraction contained 9.19 10.34 µ g of radioactivity/ g while the aqueous fraction contained 0.095 0.204 µ g of radioactivity/ g, with no definitive pattern. More than 90% of the radioactivity in the Page 9 of 14 soil fraction was extractable. In the soil fraction, there was a steady decrease from day 0 to day 30 in the concentration of extractable radioactivity associated with the origin ( from 0.78 to 0.0% of the recovered radioactivity from the TLC plate), with an unidentified [ 14C] compound at Rf 0.15 ( from 0.92 to 0%), and with the remainder radioactivity ( from 11.3 to 1.63%). The remainder radioactivity was defined as all radioactivity on the TLC plate that was not associated with the origin, ADBAC, or the unknown at Rf 0.15. The concentration of extractable [ 14C] ADBAC ( Rf 0.4) increased from 87.0% at day 0 to 98.4% of the recovered radioactivity at day 30. Unextractable [ 14C] residues in the soil fraction increased in concentration from 0.272 µ g/ g at day 0 to 0.520 µ g/ g at day 30. In the water fraction, [ 14C] ADBAC accounted for 68.1 86.3% of the radioactivity recovered from the TLC plate while the origin material and " remainder" comprised 0.92 4.19% and 10.9 27.7%, respectively. Volatiles accounted for a small fraction of the radioactivity ( 1.36 µ g) at day 30. Recoveries from the TLC plates ranged from 86.4 104% of the applied radioactivity during the 30 day study. The material balance during the study ranged from 96.1 to 103.4% of the nominal application rate.

5. Adsorption/ Desorption ( OPP Guideline No. 163 1, MRID Nos. 408356 05 & 424148 01)

This adsorption/ desorption study was reviewed by the Agency and found scientifically valid. However, the study only provides information on the mobility of unaged ADBAC. The adsorption/ desorption data requirements for ADBAC has been partially fulfilled.

Based on the results of a preliminary study of the adsorption of ring labeled [ 14C] ADBAC to sand, sandy loam, silt loam, and clay loam soils, a soil: solution ratio of 1: 200 and an equilibration period of 20 hours were chosen for the definitive adsorption and desorption study.

In the definitive study, sand, silt loam, sandy loam, and clay loam soils were sieved ( 10 mesh screen) and sterilized by autoclaving at 250 ° F ( 121 ° C) and 15 psi for 1 hour. Uniformly ring labeled [ 14C] ADBAC was purified to 98.4%, as determined by TLC/ radiochemical analysis, and mixed with non radiolabeled ADBAC ( specific activity 2.03 x 104 dpm/ µ g).

For the adsorption phase of the study, subsamples of each soil were weighed into nalgene bottles and mixed with 0.01 M CaCl2 solution. The soil: solution slurries ( 1: 200) were individually treated at nominal concentrations of 0.1, 0.5, 1.0, and 2.0 µ g/ ml with [ 14C] ADBAC. After shaking the bottles for 20 hours in the dark at 25 ± 1 E C ( adsorption equilibration period), the soil: solution slurries were centrifuged and aliquots of the supernatant were analyzed for total radioactivity by liquid scintillation counting ( LSC).

For the desorption phase of the study, 196 ml of 0.01M CaCl2 were added to each sample. The soil: solution slurries were shaken for 14 hours and 45 minutes and centrifuged. Aliquots of the supernatant were analyzed for total radioactivity by LSC. The soil was air dried and analyzed for total radioactivity by LSC following combustion.

Uniformly phenyl ring labeled [ 14C] ADBAC, at approximately 0.1, 0.5, 1.0, and 2.0 Page 10 of 14 µ g/ ml, was determined to be immobile in sterilized sand, silt loam, sandy loam, and clay loam soil: solution slurries ( 1: 200) that were equilibrated in the dark for 20 hours at 25 ± 1 E C. Freundlich Kads values were 6,172 for the sand soil, 10,797 for the silt loam, 5,123 for the sandy loam soil, and 32,429 for the clay loam and the corresponding Koc values were 6,171,657 for the sand soil, 2,159,346 for the silt loam, 640,389 for the sandy loam soil, and 1,663,039 for the clay loam. Following the first desorption step, Freundlich Kdes values were 7,137 for the sand soil, 14,083 for the silt loam soil, 96,540 for the sandy loam soil, and 165,556 for the clay loam soil; corresponding Koc values were 7,137,310 for the sand soil, 2,816,590 for the silt loam soil, 12,067,457 for the sandy loam soil, and 8,490,062 for the clay loam soil. Material balances ranged from 71.66 to 123.43%.

It should be noted that the soils tested in this study were sterilized by autoclaving prior to the experiment. Autoclaving affects the physical and chemical properties of the soils. However, the Registrant noted that at the time the protocol was developed, the use of autoclaved soils was a generally accepted practice. It was also noted that autoclaving is expected to enhance the apparent mobility of the chemical; however, the results of the study showed that ADBAC is immobile. The Agency concluded that the results are acceptable ( EFGB, 1993).

6. Aquatic Field Dissipation ( OPP Guideline No. 164 2)

The Agency has waived data requirements for an aquatic field dissipation study for ADBAC.

7. Bioaccumulation in Fish ( OPP Guideline No. 165 4, MRID No. 410268 01)

This bioaccumulation study was reviewed by the Agency and found scientifically valid. However, the study does not meet guidelines for the fulfillment of data requirements for ADBAC on the bioaccumulation in fish since [ 14C] residues present at 0.05 ppm or greater in the treated water and fish tissues were not characterized. This study was classified by the Agency as supplemental ( EFGB, 1993).

Bluegill sunfish ( Lepomis macrochirus; average length 65 mm, average weight 3.6 g) were maintained in a cultured tank under a light/ dark cycle of 16 hours/ 8 hours for at least 14 days prior to the initiation of the study. Flow through aquatic exposure systems were prepared using two 75 L aquaria ( one exposure and one control). Each aquarium was continuously supplied with well water ( pH 6.9 7.1, dissolved oxygen 78 88% of saturation, hardness 24 28 mg/ L as CaCO3, alkalinity 19 22 mg/ L as CaCO3, temperature 18 ° C) at a flow rate of 10 turnovers per day. Bluegill sunfish ( 190) were placed in each aquarium. The exposure aquarium was continuously treated with ring labeled [ 14C] ADBAC ( alkyl dimethyl benzyl ammonium chloride; radiochemical purity 98.9%, specific activity 227013 dmp/ µ g) combined with unlabeled ADBAC ( 30.64% active), at a concentration of 0.05 ppm.

Water samples were collected from the exposure and control aquaria prior to introducing the fish and at days 1, 3, 7, 8, 9, 10, 14, 21, 23, 28 and 35. During the exposure period, five fish were collected from the exposure aquarium at days 1, 3, 7, 10, 14, 21, 28 and 35. Fish were Page 11 of 14 collected from the control aquarium at days 0, 9, and 35.

Following a 35 day exposure period, 35 of the fish remaining in the exposure aquarium were transferred to an aquarium containing untreated water for a 21 day depuration period. Water samples and [ 14C] ADBAC treated fish ( 5) were collected during the depuration period on days 1, 3, 7, 10, 14, 16 and 21. Control fish were collected on day 21.

At each sampling interval, water samples were analyzed for total radioactivity by liquid scintillation counting ( LSC). The detection limit was 0.014 ppm.

Fish from the exposure and depuration periods were dissected and separated into edible tissues ( muscle and skin) and nonedible tissues ( viscera, head and carcass). The edible and nonedible fractions were analyzed for total radioactivity by LSC following combustion; the limit of detection was 0.1 ppm. The edible tissue fractions from additional fish ( three sets of ten fish) collected after 35 days of exposure were homogenized with dry ice and extracted with hexane followed by methanol. The extracts were analyzed by LSC while the unextractable radioactivity remaining in the tissues were quantified by LSC following combustion. In addition, the skins from ten additional fish also collected after 35 days of exposure were analyzed for radioactivity by combustion to determine if external surface binding of the test substance had occurred.

Radiolabeled residues accumulated in bluegill sunfish that were exposed for 35 days to uniformly phenyl ring labeled [ 14C] ADBAC, at a concentration of 0.05 ppm, under flow through aquarium conditions. Maximum bioconcentration factors ( BCF) were 33X for edible tissues ( muscle, skin), 160X for nonedible tissues ( viscera, head, carcass), and 79X for whole fish tissues. The maximum concentrations of [ 14C] residues ( day 35) were 3.4, 13 and 6.6 ppm in edible tissues, nonedible tissues and whole fish, respectively.

Of the total radioactivity found in the edible tissues, 1.2 4.2% was extractable into hexane and 6.7 18.5% was extractable into methanol. Unextractable radioactivity accounted for 72 89.3% of the total radioactivity in edible tissues. [ 14C] ADBAC at concentrations of 2.7 6.4 ppm was determined in the skin of fish after 35 days of exposure.

After 21 days of depuration, 14[ C] residues were 2.4 ppm in edible tissues, 5.3 ppm in nonedible tissues, and 3.7 ppm in whole fish tissues. 14[ C] residues in edible tissues did not decline significantly from the concentrations detected during the exposure period.

8. Aqueous Availability ( Leachability) ( American Wood Preservers' Association Standard Method E11 97 " Standard Method for Determining the Leachability of Wood Preservatives, None)

Because of its use as a wood preservative, an aqueous availability study evaluating the leachability of ADBAC from treated wood is required. However, no data have been submitted to the Agency. Page 12 of 14 9. Assessment of the Biodegradability of ADBAC and DDAC ( No MRID Number)

This report is an assessment of the biodegradability of ADBAC and DDAC based on the review of information from the open literature, unpublished sources and meeting proceedings. It also provides a summary of the current information available on the environmental fate of ADBAC and DDAC. The report was submitted by the registrant to EPA, but has not been reviewed by the Agency.

Based on the review of the studies in the report, Lee ( 1992) concluded that:

" Results of studies published in the open literature, literature reviews, conference proceedings and information obtained from unpublished sources indicate that ADBAC and DDAC are biodegradable with the rate and extent of degradation influenced by quat concentration, alkyl chain length, the presence of anionic moieties, and the type of microbes. These factors and the design of the test system are important in interpreting the reliability of biodegradability test results.

After release of ADBAC and DDAC to domestic waste streams or in the open environment, a combination of physical and chemical properties, in addition to biodegradability, influence their fate through the environmental compartments of air, water, soil/ sediment and biota. Important properties for evaluating the environmental fate of these materials include solubility, vapor pressure, surface activity and adsorptive properties."

In a study by Dobbs et al., 1995, biodegradation was studied under aerobic conditions using the CO2 production test. The OECD guideline used states that if > 60% of the theoretical CO2 is produced in 28 days, then the chemical is considered readily biodegradable. The results show that 65.9% of the possible theoretical CO2 was released in 29 days in the 10 mg/ L ADBAC treatment, but only 6.8% was released in the 20 mg/ L ADBAC treatment. The authors suggest that the treatment at the lower concentration indicates that ADBAC is readily biodegradable, but that at the higher concentration is bactericidal. Use of ADBAC as a molluscicide is suggested at concentrations of 2.5 mg/ L. Therefore, the authors concluded that results of this test suggest that ADBAC would be biodegradable under the conditions specified for its use. Page 13 of 14 BIBLIOGRAPHY MRID Citation 408356 02 Carpenter, M. and M. Fennessey. 1988. Hydrolysis of ADBAC as a function of pH at 25 ° . ABC Amended Final Report # 35712. Unpublished study performed by Analytical Bio Chemistry Laboratories, Inc., Columbia, MO, and submitted by Chemical Specialties Manufacturers Association, Washington, DC.

408356 03 Carpenter, M. and M. Fennessey. 1988. Determination of the photolysis rate of ADBAC in pH 7 buffered solution at 25 ° C. ABC Final Report # 35713. Unpublished study performed by Analytical Bio Chemistry Laboratories, Inc., Columbia, MO, and submitted by Chemical Specialties Manufacturers Association, Washington, DC.

408356 04 Daly, D. and W. Cranor. 1988. Aerobic aquatic metabolism of alkyl dimethyl benzyl ammonium chloride. ABC Final Report # 35715. Unpublished study performed by Analytical Bio Chemistry Laboratories, Inc., Columbia, MO, and submitted by Chemical Specialties Manufacturers Association, Washington, DC.

408356 05 Daly, D. and W. Cranor. 1992. Soil/ Sediment Adsorption Desorption of Alkyl Dimethyl Ammonium Chloride. Performed by ABC Laboratories, Inc., Columbia, Missouri. Submitted by ADBAC Joint Venture/ Chemical Specialties Manufacturers Association, Washington, DC.

410268 01 Flacker, P. 1989. Bioconcentration and elimination of 14C residues by bluegill ( Lepomis macrochirus) exposed to alkyl dimethyl benzyl ammonium chloride ( ADBAC). Study No. 11572 0287 6103 140B, Report No. 89 1 2921. Unpublished study performed by Springborn Life Sciences, Inc., Wareham, MA, and submitted by ADBAC Quat Joint Venture/ Chemical Specialties Manufacturers Assoc., Washington, DC.

411055 01 Daly, D. and W. Cranor. 1989. Anaerobic aquatic metabolism of alkyl dimethyl benzyl ammonium chloride. ABC Amended Final Report # 35714. Unpublished study performed by Analytical Bio Chemistry Laboratories, Inc., Columbia, MO, and submitted by ADBAC Joint Venture/ Chemical Specialties Manufacturers Association, Washington, DC.

424148 01 Daly, D. and W. Cranor. 1992. Soil/ Sediment Adsorption Desorption of Alkyl Dimethyl Ammonium Chloride. Supplement in support of MRID# 408356 05. Performed by ABC Laboratories, Inc., Columbia, Missouri. Submitted by ADBAC Joint Venture/ Chemical Specialties Manufacturers Association, Washington, DC. Page 14 of 14 424149 01 Daly, D. and W. Cranor. 1992. Aerobic metabolism of alkyl dimethyl benzyl ammonium chloride. Supplement in support of MRID# 408356 04. Performed by ABC Laboratories, Inc., Columbia, Missouri. Submitted by ADBAC Joint Venture/ Chemical Specialties Manufacturers Association, Washington, DC.

424151 01 Daly, D. and W. Cranor. 1989. Anaerobic aquatic metabolism of alkyl dimethyl benzyl ammonium chloride. ABC Amended Final Report # 35714. Supplement in support of MRID# 411055 01. Unpublished study performed by Analytical Bio Chemistry Laboratories, Inc., Columbia, MO, and submitted by ADBAC Joint Venture/ Chemical Specialties Manufacturers Association, Washington, DC.

424151 02 Daly, D. and W. Cranor. 1992. Anaerobic metabolism of alkyl dimethyl benzyl ammonium chloride. Supplement in support of MRID# 411055 01. Performed by ABC Laboratories, Inc., Columbia, Missouri. Submitted by ADBAC Joint Venture/ Chemical Specialties Manufacturers Association, Washington, DC.

424152 01 Carpenter, M. and M. Fennessey. 1992. Determination of the photolysis rate of ADBAC in pH 7 buffered solution at 25 ° C. Supplement in support of MRID# 408356 03. Performed by ABC Laboratories, Inc., Columbia, Missouri. Submitted by ADBAC Joint Venture/ Chemical Specialties Manufacturers Association, Washington, DC.

Dobbs, M. G., Cherry, D. S., Scott, J. C., Petrille, J. C. 1995. Environmental Assessment of an Alkyl Dimethyl Benzyl Ammonium Chloride ( ADBAC) Based Molluscicide Using Laboratory Tests. Virginia Tech University Center for Environmental and Hazardous Materials Studies Blacksburg, VA Environmental Fate and Groundwater Branch ( EFGB). 1993. EFGB review of alkyl dimethyl benzyl ammonium chloride. Memo from E. Regelman, EFGB, to J. Lee, Antimicrobial Program Branch.

Lee, C. 1992. Assessment of the Biodegradability of ADBAC and DDAC. Unpublished report prepared by Roy F. Weston, Inc. Contractor's Fate Summary Review. Document Image No. 2011644.


[Federal Register: March 16, 2006 (Volume 71, Number 51)]
[Notices]
[Page 13592-13596]
[DOCID:fr16mr06-43]

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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OAR-2006-0094; FRL-8045-6]

Proposed Approval of Central Characterization Project's
Transuranic Waste Characterization Program at the Savannah River Site

AGENCY: Environmental Protection Agency.

ACTION: Notice of availability; opening of public comment period.

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SUMMARY: The Environmental Protection Agency (``EPA'' or ``we'') is
announcing the availability of, and soliciting public comments for 45
days on, the proposed approval of the waste characterization program
implemented by the Central Characterization Project (``CCP'') to
characterize transuranic (``TRU'') radioactive waste at the Savannah
River Site (SRS) proposed for disposal at the Waste Isolation Pilot
Plant (``WIPP''). In accordance with the WIPP Compliance Criteria, EPA
evaluated the CCP's characterization of TRU debris waste and soils/
gravel from SRS during an inspection conducted October 31-November 3,
2005. Using the systems and processes developed as part of the
Department of Energy's (``DOE's'') Carlsbad Field Office (``CBFO'')
CCP, EPA verified whether DOE could adequately characterize TRU waste
consistent with the Compliance Criteria. The results of EPA's
evaluation of the SRS CCP program and the proposed approval are
described in EPA's inspection report, which is available for review in
the public dockets listed in ADDRESSES. We will consider public
comments received on or before the due date mentioned in DATES.
    This notice summarizes the waste characterization processes EPA
evaluated, the ``tier'' EPA assigned to each waste characterization
process component, and the TRU waste categories proposed for approval.
As required by the 40 CFR 194.8 changes promulgated in July 2004, at
the end of a 45-day comment period EPA will evaluate public comments
received, finalize the report responding to the relevant public
comments, and issue the final report and an approval letter to DOE's
Carlsbad Field Office. Waste that is characterized by the SRS CCP is
not eligible for disposal at WIPP until EPA formally grants its
approval.

DATES: Comments must be received on or before May 1, 2006.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2006-0094, by one of the following methods:
     http://www.regulations.gov: Follow the on-line

instructions for submitting comments.
     E-mail: to<EMAIL_ADDRESS>     Fax:<PHONE_NUMBER>.
     Mail: Air and Radiation Docket and Information Center,
Environmental Protection Agency, Mailcode: 6102T, 1200 Pennsylvania
Ave., NW., Washington, DC 20460.
    Instructions: Direct your comments to Attn: Docket ID No. EPA-HQ-
OAR-2006-0094. The Agency's policy is that all comments received will
be included in the public docket without change and may be made
available online at http://www.regulations.gov, including any personal

information provided, unless the comment includes information claimed
to be Confidential Business Information (CBI) or other information
whose disclosure is restricted by statute. Do not submit information
that you consider to be CBI or otherwise protected through http://www.regulations.gov or e-mail. The http://www.regulations.gov Web site

is an ``anonymous access'' system, which means EPA will not know your
identity or contact information unless you provide it in the body of
your comment. If you send an e-mail comment directly to EPA without
going through http://www.regulations.gov your e-mail address will be

automatically captured and included as part of the comment that is
placed in the public docket and made available on the Internet. If you
submit an electronic comment, EPA recommends that you include your name
and other contact information in the body of your comment and with any
disk or CD-ROM you submit. If EPA cannot read your comment due to
technical difficulties and cannot contact you for clarification, EPA
may not be able to consider your comment. Electronic files should avoid
the use of special characters, any form of encryption, and be free of
any defects or viruses. For additional information

about EPA's public docket visit the EPA Docket Center homepage at
http://www.epa.gov/epahome/dockets.htm    Docket: All documents in the docket are listed in the http://.

http://www.regulations.gov index. Although listed in the index, some

information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available either electronically
at http://www.regulations.gov or in hard copy at the Air and Radiation

Docket in the EPA Docket Center, (EPA/DC) EPA West, Room B102, 1301
Constitution Ave., NW., Washington, DC. The EPA Docket Center Public
Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through
Friday, excluding legal holidays. The telephone number for the Public
Reading Room is<PHONE_NUMBER>, and the telephone number for the Air and
Radiation Docket is<PHONE_NUMBER>. These documents are also available
for review in hard-copy form at the following three EPA WIPP
informational docket locations in New Mexico: in Carlsbad at the
Municipal Library, Hours: Monday-Thursday, 10 a.m.-9 p.m., Friday-
Saturday, 10 a.m.-6 p.m., and Sunday, 1 p.m.-5 p.m., phone number: 505-
885-0731; in Albuquerque at the Government Publications Department,
Zimmerman Library, University of New Mexico, Hours: Vary by semester,
phone number:<PHONE_NUMBER>; and in Santa Fe at the New Mexico State
Library, Hours: Monday-Friday, 9 a.m.-5 p.m., phone number: 505-476-
9700. As provided in EPA's regulations at 40 CFR part 2, and in
accordance with normal EPA docket procedures, if copies of any docket
materials are requested, a reasonable fee may be charged for
photocopying.

FOR FURTHER INFORMATION CONTACT: Rajani Joglekar, Radiation Protection
Division, Center for Federal Regulations, Mail Code 6608J, U.S.
Environmental Protection Agency, 1200 Pennsylvania Avenue, Washington,
DC 20460; telephone number:<PHONE_NUMBER>; fax number:<PHONE_NUMBER>; e-
mail address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

I. General Information

A. What Should I Consider as I Prepare My Comments for EPA?

    1. Submitting CBI. Do not submit this information to EPA through
http://www.regulations.gov or e-mail. Clearly mark the part or all of

the information that you claim to be CBI. For CBI information in a disk
or CD ROM that you mail to EPA, mark the outside of the disk or CD ROM
as CBI and then identify electronically within the disk or CD ROM the
specific information that is claimed as CBI. In addition to one
complete version of the comment that includes information claimed as
CBI, a copy of the comment that does not contain the information
claimed as CBI must be submitted for inclusion in the public docket.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2.
    2. Tips for Preparing Your Comments. When submitting comments,
remember to:
     Identify the rulemaking by docket number and other
identifying information (subject heading, Federal Register date and
page number).
     Follow directions--The agency may ask you to respond to
specific questions or organize comments by referencing a Code of
Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree; suggest alternatives
and substitute language for your requested changes.
     Describe any assumptions and provide any technical
information and/or data that you used.
     If you estimate potential costs or burdens, explain how
you arrived at your estimate in sufficient detail to allow for it to be
reproduced.
     Provide specific examples to illustrate your concerns, and
suggest alternatives.
     Explain your views as clearly as possible, avoiding the
use of profanity or personal threats.
     Make sure to submit your comments by the comment period
deadline identified.

II. Background

    DOE is developing the WIPP near Carlsbad in southeastern New Mexico
as a deep geologic repository for disposal of TRU radioactive waste. As
defined by the WIPP Land Withdrawal Act (LWA) of 1992 (Pub. L. 102-
579), as amended (Pub. L. 104-201), TRU waste consists of materials
containing processes having atomic numbers greater than 92 (with half-
lives greater than twenty years), in concentrations greater than 100
nanocuries of alpha-emitting TRU isotopes per gram of waste. Much of
the existing TRU waste consists of items contaminated during the
production of nuclear weapons, such as rags, equipment, tools, and
sludges.
    On May 13, 1998, EPA announced its final compliance certification
decision to the Secretary of Energy (published May 18, 1998, 63 FR
27354). This decision stated that the WIPP will comply with EPA's
radioactive waste disposal regulations at 40 CFR part 191, subparts B
and C.
    The final WIPP certification decision includes conditions that (1)
prohibit shipment of TRU waste for disposal at WIPP from any site other
than the Los Alamos National Laboratories (LANL) until the EPA
determines that the site has established and executed a quality
assurance program, in accordance with Sec. Sec.  194.22(a)(2)(i),
194.24(c)(3), and 194.24(c)(5) for waste characterization activities
and assumptions (Condition 2 of Appendix A to 40 CFR part 194); and (2)
(with the exception of specific, limited waste streams and equipment at
LANL) prohibit shipment of TRU waste for disposal at WIPP (from LANL or
any other site) until EPA has approved the procedures developed to
comply with the waste characterization requirements of Sec.
194.22(c)(4) (Condition 3 of Appendix A to 40 CFR part 194). The EPA's
approval process for waste generator sites is described in Sec.  194.8.
    In July 2004, EPA promulgated changes to the ``Criteria for the
Certification and Recertification of the Waste Isolation Pilot Plant's
Compliance with Disposal Regulations'' (69 FR 42571-42583, July 16,
2004). These changes went into effect October 14, 2004, which modified
the EPA approval of waste characterization (``WC'') programs at DOE's
TRU waste sites. These revisions provide equivalent or improved
oversight and better prioritization of technical issues in EPA
inspections to evaluate WC activities at DOE WIPP waste generator
sites, and also offer more direct public input into the Agency's
decisions about what waste can be disposed of at WIPP. They do not
modify the technical approach that EPA has employed since the 1998 WIPP
Certification Decision.
    Condition 3 of the WIPP Certification Decision requires that EPA
conduct independent inspections at DOE's waste generator/storage sites
of their TRU waste characterization capabilities before approving their
program and the waste for disposal at the WIPP. The revised inspection
and approval process gives EPA greater (a) discretion in establishing
technical priorities, (b) ability to accommodate variation in the
site's waste characterization capabilities, and (c) flexibility in
scheduling site WC inspections. The Sec.  194.8 changes require that
EPA conduct a baseline inspection at every previously approved TRU site
(such as SRS CCP). EPA expects that within two years after the
effective date of October 2004 most of the previously approved TRU
sites (such as Hanford, Los Alamos

CCP, and Savannah River Site CCP) will undergo EPA baseline
inspections. Following these inspections, the Agency will issue a new
baseline compliance decision for these sites.
    As part of the baseline inspection, EPA must evaluate each WC
process component (equipment, procedures, and personnel training/
experience) for its adequacy and appropriateness in characterizing TRU
waste destined for the disposal at WIPP. During the inspection, the
site demonstrates its capabilities to characterize TRU waste(s) and its
ability to comply with the regulatory limits and tracking requirements
under Sec.  194.24. The baseline inspection can result in approval with
limitations/conditions or may require follow-up inspection(s) before
approval. The approval must specify what subsequent WC program changes
or expansion should be reported to EPA. The Agency is required to
assign Tier 1 (``TI'') and Tier 2 (``T2'') to the reportable changes
depending on their potential impact on data quality. A T1 designation
requires that the site must notify EPA of proposed changes to the
approved components of an individual WC process (such as radioassay
equipment or personnel), and EPA must also approve the change before it
can be implemented. A WC element with a T2 designation allows the site
to implement changes to the approved components of individual WC
processes (such as visual examination procedures) but requires EPA
notification. The Agency may choose to inspect the site to evaluate
technical adequacy before approval. EPA inspections conducted to
evaluate T1 or T2 changes are follow-up inspections under the authority
of Sec.  194.24(h). In addition to the follow-up inspections, if
warranted, EPA may opt to conduct continued compliance inspections at
TRU waste sites with a baseline approval under the authority of Sec.
194.24(h).
    The revisions to the site inspection and approval process outlined
in Sec.  194.8 require EPA to issue a Federal Register notice proposing
the baseline compliance decision, docket the inspection report for
public review, and seek public comment on the proposed decision for a
period of 45 days. The report must describe the WC processes EPA
inspected at the site, as well as their compliance with Sec.  194.24
requirements.

III. Proposed Baseline Compliance Decision

    From October 31-November 3, 2005, EPA performed a baseline
inspection of TRU waste characterization activities of the DOE's CCP
staff at SRS (EPA Inspection No. EPA-SRS-CCP-10.05-8). This inspection
is the second baseline inspection that EPA has performed under the
Sec.  194.8 regulatory changes promulgated in July 2004.
    The CCP is a mobile characterization program that assists TRU waste
generator sites with complex waste characterization activities. At some
sites (such as Los Alamos National Laboratory and Savannah River Site)
and small TRU waste generator sites (such as Argonne National
Laboratory and Lawrence Livermore National Laboratory) the CCP has the
sole responsibility to characterize contact-handled (``CH''),
retrievably-stored TRU waste destined for the disposal at the WIPP.
    The purpose of EPA's inspection was to verify that CCP is
characterizing CH TRU retrievably-stored debris waste (S5000) and
soils/gravel (S4000) from SRS properly and in compliance with the
regulatory requirements at 40 CFR 194.24. EPA did not evaluate the
characterization of solid waste (S3000) at this time and will inspect
this at a later date. During the inspection, EPA also evaluated CCP's
use of the WIPP Waste Information System (``WWIS'') for tracking the
contents of CH TRU waste containers destined for disposal at WIPP. This
tracking ensures that the volume emplaced in the WIPP repository and
characteristics of the emplaced wastes conform to the requirements of
the WIPP LWA and the specific conditions of the WIPP Certification
Decision.
    During the inspection, EPA evaluated the adequacy, implementation,
and effectiveness of SRS-CCP's waste characterization activities. The
Agency's evaluation focused on the individual components--equipment,
procedures, and personnel training/experience of the following waste
characterization processes: Acceptable knowledge (``AK''),
nondestructive assay (``NDA''), visual examination techniques
(``VET''), visual examination/real-time radiography (``VE/RTR''), load
management, and the WWIS. The overall program adequacy and
effectiveness of SRS-CCP was based on the following DOE-provided upper-
tier documents: (1) CCP-PO-001--Revision 11, 3/10/05--CCP Transuranic
Waste Characterization Quality Assurance Project Plan and (2) CCP-PO-
002--Revision 12, 3/10/05--CCP Transuranic Waste Certification Plan.
    EPA evaluated the CCP-implemented waste characterization processes
at SRS for specific CH TRU waste categories, as follows:
     Acceptable knowledge (AK) and load management for contact-
handled (``CH'') retrievably-stored and newly-generated TRU debris
waste (S5000) and soil/gravel waste (S4000).
     Visual examination techniques (``VET'') for CH newly-
generated debris waste (S5000) and soil/gravel waste (S4000).
     Visual examination (``VE'') as a quality control check of
real-time radiography (``RTR'') for CH retrievably-stored TRU debris
waste (S5000) and soil/gravel waste (S4000).
     RTR for CH retrievably-stored TRU debris waste (S5000) and
soil/gravel waste (S4000).
     Nondestructive assay (``NDA'') and the WIPP Waste
Information System (``WWIS'') for CH retrievably-stored and newly-
generated TRU debris waste (S5000) and soil/gravel waste (S4000).
    Two NDA systems (Imaging Passive-Active Neutron/Gamma Energy
Analysis [``IPAN/GEA''] system and the MCS IQ3 gamma system) were
evaluated for characterizing debris (S5000) and soil/gravel (S4000)
wastes.
    In addition to reviewing individual components (namely, procedures,
and equipment) of each of the WC processes (AK, NDA, VET, VE/RTR, load
management, and the WWIS), the Agency interviewed and reviewed training
records of personnel responsible for compiling data, analyzing waste
contents, operating equipment, and preparing data for WWIS tracking.
EPA also required radioassay replicate analysis on selected containers
from the population of previously analyzed waste containers on the same
system or instrument for the two different waste categories. The
purpose of this replicate testing is to provide EPA with an independent
means to verify that the radioassay equipment being assessed for
approval can provide consistent, reproducible results for the
determination of the quantity of 10 WIPP-tracked radionuclides (241Am,
137Cs, 238Pu, 239Pu, 240Pu, 242Pu, 90Sr, 233U, 234U, and 238U) as well
as TRU alpha concentration. The results of the replicate analysis help
EPA to determine whether:
     The instrument produces results consistent with the
reported total measurement uncertainty (``TMU'') by comparing the
sample standard deviation for a number of replicate measurements taken
over several hours or days to the reported TMU.
     The instrument provides reproducible results over longer
periods of time, such as weeks or months, by comparing the results of
the replicate

measurement(s) to the original reported values.
    EPA's inspection team identified one finding and five concerns. The
one finding and two of the concerns required a response from DOE. All
concerns and findings are documented on EPA Inspection Issue Tracking
Forms (see Attachments C.1 through C.6 of the baseline Inspection
Report available in the EPA Docket). The Agency received responses to
the one finding and two concerns which required responses and, upon
further evaluation, concluded that the responses were adequate. As a
result, there are no open issues resulting from this inspection.
    EPA's inspection team determined that SRS-CCP's WC program
activities were technically adequate. EPA is proposing to approve the
SRS-CCP WC program in the configuration observed during this inspection
and described in this report and in the checklists in Attachment A.
This proposed approval includes the following waste characterization
activities:
    (1) The AK and load management process for CH retrievably-stored
TRU debris and soil/gravel,
    (2) The IPAN and IQ3 NDA systems for assaying soil/gravel and
debris waste,
    (3) VE as a QC check of the RTR process for retrievably-stored
soil/gravel and debris waste,
    (4) The VET process for newly-generated debris and soil/gravel
wastes,
    (5) The nondestructive examination process of RTR for retrievably-
stored soil/gravel and debris wastes, and
    (6) The WWIS process for tracking of waste contents of debris and
soil/gravel wastes. As required by the new (194.8 revisions, EPA has
assigned specific ``tiers'' to the different waste characterization
processes. As seen from the table below, both T1 and T2 changes are
reportable changes. A T1 change requires EPA approval prior to
implementation of the change and may require EPA inspection to
determine technical adequacy. A T2 change may be implemented prior to
EPA approval; however, this type of change must be reported to EPA
quarterly. Any changes to WC activities from the date of the baseline
inspection must be reported to and, if applicable, approved by EPA,
according to the following table:

                           Proposed Tiering of TRU WC Processes Implemented by SRS-CCP
                           [Based on October 31-November 3, 2005, Baseline Inspection]
----------------------------------------------------------------------------------------------------------------
                                        SRS-CCP WC process        SRS-CCP WC process        SRS-CCP general T2
        WC process elements             specific T1 changes      specific T2 changes*            changes*
----------------------------------------------------------------------------------------------------------------
AK including Load Management.......  Any new waste category..  WSPFs, including updates  Changes to site
                                     Changes to WWIS            or additions to waste     procedures requiring
                                      algorithms specific to    stream(s) within an       CBFO approvals and
                                      load management.          approved waste category   other changes as
                                                                (see Section 8.1).        discussed in Section
                                                               Changes in load            8.1 of this report.
                                                                management status of
                                                                approved waste
                                                                stream(s).
NDA................................  New equipment or          Changes to software for   Changes to site
                                      physical modifications    approved equipment (see   procedures requiring
                                      to approved               Section 8.2).             CBFO approvals and
                                      equipment.**.            Changes to operating       other changes as
                                     Changes to approved        range(s) upon CBFO        discussed in Section
                                      calibration range for     approval.                 8.2 of this report.
                                      approved equipment (see
                                      Section 8.2).
RTR................................  N/A.....................  New equipment or changes  Changes to site
                                                                to approved equipment.    procedures requiring
                                                                                CBFO approvals and
                                                                                other changes as
                                                                                discussed in Section
                                                                                8.3 of this report.
VE and VET.........................  Changes in vendor         N/A.....................  Changes to site
                                      performing VE and/or                                procedures requiring
                                      VET.                                                CBFO approvals and
                                                                                other changes as
                                                                                discussed in Section
                                                                                8.4 of this report.
WWIS...............................  N/A.....................  N/A.....................  Changes to site
                                                                                procedures requiring
                                                                                CBFO approvals and
                                                                                other changes as
                                                                                discussed in Section
                                                                                8.5 of this report.
----------------------------------------------------------------------------------------------------------------
* Upon receiving EPA approval, SRS-CCP will report all T2 changes to EPA every three months.
** Modifications to approved equipment include all changes with the potential to affect NDA data relative to
  waste isolation and exclude minor changes, such as the addition of safety-related equipment.

    EPA will notify the public of the results of its evaluations of
proposed T1 and T2 changes through the WIPP Website and by sending
messages via the WIPP-NEWS e-mail listserv. All T1 changes must be
submitted for approval before their implementation and will be
evaluated by EPA. Upon approval, EPA will post the results of the
evaluations via the WIPP Website and the WIPP-NEWS listserv, as
described above. The Agency will post T2 changes approximately every
three months beginning with the date of EPA's approval of the TRU WC
program implemented at SRS-CCP. EPA expects the first report of SRS-
CCP's T2 changes approximately three months from the date of EPA's
approval of the TRU WC program implemented at SRS-CCP.
    The scope of the proposed site baseline compliance decision is
based on EPA's inspection completed on November 3, 2005. The Agency
will not approve any changes to the SRS-CCP program until this proposed
baseline approval is finalized. Based on prior approvals, SRS-CCP is
currently approved to dispose of debris waste (S5000) at the WIPP. SRS-
CCP is permitted to continue WC and disposal of debris waste while EPA
evaluates public comment to this proposed approval and establishes a
final approval.

IV. Availability of the Baseline Inspection Report for Public Comment

    EPA has placed the report discussing the results of EPA's
inspection of the CCP at SRS in the public docket as described in
ADDRESSES. In accordance with 40 CFR 194.8, EPA is providing the public
45 days to comment on these documents. The Agency requests comments on
the tiering designations

and the proposed approval decision. EPA will accept public comment on
this notice and supplemental information as described in Section 1.B.
above. The EPA will not make a determination of compliance before the
45-day comment period ends. At the end of the public comment period,
EPA will evaluate all relevant public comment and revise the inspection
report as necessary. The Agency will then issue an approval letter and
the final inspection report, both of which will be posted on the WIPP
Web site. The letter of approval will allow CCP to use the approved TRU
waste characterization processes to characterize TRU waste at SRS.
    Information on the certification decision is filed in the official
EPA Air Docket, Docket No. A-93-02 and is available for review in
Washington, DC, and at the three EPA WIPP informational docket
locations in New Mexico (as listed in ADDRESSES). The dockets in New
Mexico contain only major items from the official Air Docket in
Washington, DC, plus those documents added to the official Air Docket
since the October 1992 enactment of the WIPP LWA.

    Dated: March 9, 2006.
William L. Wehrum,
Acting Assistant Administrator for Air and Radiation.
 [FR Doc. E6-3813 Filed 3-15-06; 8:45 am]

BILLING CODE 6560-50-P


[Federal Register Volume 80, Number 204 (Thursday, October 22, 2015)]
[Notices]
[Page 64051]
[FR Doc No: 2015-26864]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

Seventh Meeting: RTCA Special Committee (231) Terrain Awareness
Warning Systems (TAWS)

AGENCY: Federal Aviation Administration (FAA), U.S. Department of
Transportation (DOT).

ACTION: Notice of Seventh RTCA Special Committee 231 Meeting.

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SUMMARY: The FAA is issuing this notice to advise the public of the
seventh RTCA Special Committee 231 meeting.

DATES: The meeting will be held December 8th-10th from 9:00 a.m.-5:00
p.m.

ADDRESSES: The meeting will be held at RTCA, Inc., 1150 18th Street
NW., Suite 450, Washington, DC, 20036, Tel:<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: The RTCA Secretariat, 1150 18th Street
NW., Suite 910, Washington, DC 20036, or by telephone at (202) 833-
9339, fax at<PHONE_NUMBER>, or Web site at http://www.rtca.org or Hal
Moses, Program Director, RTCA, Inc<EMAIL_ADDRESS>(202) 330-0654.

SUPPLEMENTARY INFORMATION: Pursuant to section 10(a)(2) of the Federal
Advisory Committee Act (Pub. L. 92-463, 5 U.S.C., App.), notice is
hereby given for a meeting of RTCA Special Committee 231. The agenda
will include the following:

Tuesday, December 8, 2015

1. Welcome/Introduction
2. Administrative Remarks
3. Agenda Review
4. Summary of Working Group activities
5. Other Business
6. Date and Place of Next Meeting

Wednesday, December 9, 2015

1. Continuation of Plenary or Working Group Session

Thursday, December 10, 2015

1. Continuation of Plenary or Working Group Session

    Attendance is open to the interested public but limited to space
availability. With the approval of the chairman, members of the public
may present oral statements at the meeting. Plenary information will be
provided upon request. Persons wishing to present statements or obtain
information should contact the person listed in the FOR FURTHER
INFORMATION CONTACT section. Members of the public may present a
written statement to the committee at any time.

    Issued in Washington, DC, on October 16, 2015.
Latasha Robinson,
Management & Program Analyst, Next Generation, Enterprise Support
Services Division, Federal Aviation Administration.
[FR Doc. 2015-26864 Filed 10-21-15; 8:45 am]
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