Chlorine Dioxide Environmental Hazard and Risk Assessment Case 4023 Genevieve Angle Office of Pesticide Programs Antimicrobials Division U. S. Environmental Protection Agency 1200 Pennsylvania Avenue, NW Washington, DC 20460 April 6, 2006 Page 2 of 33 Chlorine Dioxide and Sodium Chlorite: Environmental Hazard and Risk Assessment Introduction The toxicity endpoints ( e. g. LC50, NOEC) included in this section are based on the results of sodium chlorite and chlorine dioxide toxicity studies that were submitted to EPA for review. Chlorine dioxide and sodium chlorite are used as antimicrobial pesticides at numerous use sites. Sodium chlorite is used as a precursor in the generation of chlorine dioxide. The antimicrobial registered uses of chlorine dioxide/ sodium chlorite fall into several major categories including use in the treatment of human drinking water systems; in industrial process and water systems; as a materials preservative; and as a general disinfectant in medical, residential, agricultural, commercial and industrial settings. The once through cooling tower use of chlorine dioxide/ sodium chlorite has been selected for risk assessment because out of all the uses of these chemicals, it is the one expected to have the most potential for environmental exposure. The environmental risk assessment will be conducted using sodium chlorite endpoints because under environmental conditions, chlorine dioxide converts mostly into chlorite ions. Currently, a quantitative evaluation of the likelihood of the ecological exposures resulting from the industrial uses of chlorine dioxide and sodium chlorite overlapping spatially and temporally with the exposures resulting from the agricultural uses of chlorine dioxide and sodium chlorite is not possible. Therefore, the ecological risks are not aggregated in this assessment.

Data Gaps Several data requirements, necessary to support the once through cooling tower use of chlorine dioxide/ sodium chlorite, are not fulfilled: 72 4/ 850.1300 Fish early life stage testing freshwater TGAI1 72 4b/ 850.1400 Invertebrate life cycle testing  freshwater TGAI 123 1/ 850.4225 Seedling emergence dose response in rice TEP2 123 1/ 850.4250 Vegetative vigor dose response in rice TEP 123 2/ 850.4400 Aquatic vascular plant dose response toxicity Lemna sp. TGAI or TEP 123 2/ 850.5400 Acute algal dose response toxicity  4 species TGAI or TEP 1TGAI = technical grade active ingredient 2TEP = typical end use product Page 3 of 33 Ecological Hazard Assessment:

I. Toxicity to Terrestrial Animals A. Birds, Acute and Subacute An acute oral toxicity study using the technical grade of the active ingredient ( TGAI) is required to establish the toxicity of chlorine dioxide/ sodium chlorite to birds. The preferred test species is either mallard duck ( a waterfowl) or bobwhite quail ( an upland game bird). The results of several toxicity studies are provided in the following table.

Table 1. Acute Oral Toxicity of Chlorine Dioxide and Sodium Chlorite to Birds Substance/% Active Ingredient ( AI) Organism Endpoints/ Results ( 95% conf. interval) mg/ kg Reference Study Classification Sodium Chlorite/ 80% Northern bobwhite ( Colinus virginianus) LD50 = 382 ( 300 520) NOAEL = 175 Robaidek, 1985 ACC # 259373 acceptable Sodium Chlorite/ 80% Northern bobwhite ( Colinus virginianus) LD50 = 390 ( 310 490) NOAEL = N. R. Robaidek and Johnson, 1985 ACC # 257341 acceptable Sodium Chlorite/ 80% Northern bobwhite ( Colinus virginianus) LD50 = 395 ( 272 573) NOAEL = N. R. Fletcher, 1984 ACC # 253378 acceptable Sodium Chlorite/ 83% Northern bobwhite ( Colinus virginianus) LD50 = 660 ( 540 810) Fletcher, 1973 MRID # 31610 acceptable Sodium Chlorite/ 80% Northern bobwhite ( Colinus virginianus) LD50 = 467 ( 372 585) Beavers, 1984 ACC # 254177 acceptable Sodium Chlorite/ 80% Mallard Duck ( Anas platyrhynchos) LD50 > 31.25 Beavers, 1984 ACC # 254176 supplemental Sodium Chlorite/ 25% Northern bobwhite ( Colinus virginianus) LD50 = 797( 420 2594) NOAEL= 125 MBA Laboratories, 1984 ACC# 252854 acceptable Note: LD50= Median Lethal Dose; NOAEL= No Observed Adverse Effect Level; N. R.= Not Reported These results indicate that chlorine dioxide/ sodium chlorite range from slightly to highly toxic to birds on an acute oral basis. The guideline requirement ( 71 1/ OPPTS 850.2100) is fulfilled.

Two subacute dietary studies using the technical grade of the active ingredient are required to establish the toxicity of a pesticide to birds. The preferred test species are mallard duck ( a waterfowl) and bobwhite quail ( an upland gamebird). Results of avian subacute dietary tests are tabulated below. Page 4 of 33 Table 2. Avian Subacute Dietary Toxicity of Chlorine Dioxide and Sodium Chlorite Substance/% AI Organism LC50 ( ppm) ( 95 % c. i.) NOAEC ( ppm) Reference Study Classification Sodium Chlorite/ 80% Mallard Duck ( Anas platyrhynchos) > 5000 5000 Johnson, 1984 MRID # 94068008 acceptable Sodium Chlorite/ 80% Northern bobwhite ( Colinus virginianus) > 5000 N. R. Fletcher, 1984 ACC # 253378 acceptable Sodium Chlorite/ 80% Mallard Duck ( Anas platyrhynchos) > 5000 N. R. Fletcher, 1984 ACC # 253378 acceptable Sodium Chlorite/ 80% Northern bobwhite ( Colinus virginianus) > 5000 N. R. Johnson, 1984 MRID # 94068005 acceptable Sodium Chlorite/ 80% Mallard Duck ( Anas platyrhynchos) > 5620 N. R. Beavers, 1984 ACC # 254178 acceptable Sodium Chlorite/ 80% Northern bobwhite ( Colinus virginianus) > 5620 N. R. Beavers, 1984 ACC # 254179 acceptable Sodium Chlorite/ 80% Northern bobwhite ( Colinus virginianus) > 10,000 N. R. Fink, 1977 MRID # 130649 acceptable Sodium Chlorite/ 80% Mallard Duck ( Anas platyrhynchos) > 10,000 N. R. Fink, 1977 MRID # 130650 acceptable Sodium Chlorite/ 25% Mallard Duck ( Anas platyrhynchos) 18686 ( 8186 109184) N. R. MBA Laboratories, 1983 ACC # 252854 acceptable Sodium Chlorite/ 25% Northern bobwhite ( Colinus virginianus) 2031( 1226 3903) 417 MBA Laboratories, 1984 ACC # 252854 acceptable Note: LC50= Median Lethal Concentration; NOAEC= No Observed Adverse Effect Concentration; N. R.= Not Reported These results indicate that chlorine dioxide/ sodium chlorite range from slighly toxic to practically non toxic to birds on a subacute dietary basis. The guideline requirement ( 71 2/ OPPTS 850.2200) is fulfilled.

B. Birds, Chronic Avian reproduction studies using the technical grade of the active ingredient are required for a pesticide when any of the following conditions are met: ( 1) birds may be subject to repeated or continuous exposure to the pesticide, especially preceding or during the breeding season, ( 2) the pesticide is stable in the environment to the extent that potentially toxic amounts may persist in animal feed, ( 3) the pesticide is stored or accumulated in plant or animal tissues, and/ or ( 4) information derived from mammalian reproduction studies indicates reproduction in terrestrial Page 5 of 33 vertebrates may be adversely affected by the anticipated use of the product. The currently registered uses of chlorine dioxide/ sodium chlorite do not require avian reproduction testing. II. Toxicity to Freshwater Aquatic Animals A. Freshwater Fish, Acute Two fish toxicity studies using the TGAI are required to establish the toxicity of a pesticide to freshwater fish. The preferred test species are rainbow trout ( a cold water fish) and bluegill sunfish ( a warm water fish). The results of studies submitted for sodium chlorite are provided in the following table.

Table 3. Acute Toxicity of Chlorine Dioxide and Sodium Chlorite to Freshwater Fish Substance/% Active Ingredient ( AI) Organism Endpoints/ Results ( ppm) ( 95% conf. interval) Reference Study Classification Sodium Chlorite/ 80% Rainbow trout ( Oncorhynchus mykiss) LC50 = 360 ( 216 600) NOAEC = 216 Barrows, 1984 MRID # 94068007 acceptable Sodium Chlorite/ 80% Bluegill ( Lepomis macrochirus) LC50 = 244 ( 196 304) NOAEC = 108 Larkin, 1984 ACC # 254181 acceptable Sodium Chlorite/ 80% Rainbow trout ( Oncorhynchus mykiss) LC50 = 360 ( 216 600) NOAEC = 216 Larkin, 1984 ACC # 254180 acceptable Sodium Chlorite/ 80.25% Bluegill ( Lepomis macrochirus) LC50 = 265 ( 231 309) NOAEC = 130 EG& G Bionomics, 1978 ACC # 69809 supplemental Sodium Chlorite/ 79% Bluegill ( Lepomis macrochirus) LC50 = 208 ( 165 262) NOAEC = N. R. Sleight III, 1971 MRID # 131351 supplemental Sodium Chlorite/ 79% Rainbow trout ( Oncorhynchus mykiss) LC50 = 50.6 ( 38.8 65.8) NOAEC = N. R. Sleight III, 1971 MRID # 131351 supplemental Sodium Chlorite/ 80% Rainbow trout ( Oncorhynchus mykiss) LC50 > 100 NOAEC = N. R. McMillen, 1985 ACC # 253743 supplemental Sodium Chlorite/ 80% Bluegill ( Lepomis macrochirus) LC50 > 100 NOAEC = N. R. McMillen, 1985 ACC # 253743 supplemental Sodium Chlorite/ 25% Rainbow trout ( Oncorhynchus mykiss) LC50 = 203 ( 175 236) NOAEC = 100 MBA Laboratories, 1984 ACC # 252854 acceptable Page 6 of 33 Substance/% Active Ingredient ( AI) Organism Endpoints/ Results ( ppm) ( 95% conf. interval) Reference Study Classification Sodium Chlorite/ 25% Bluegill ( Lepomis macrochirus) LC50 = 222 ( 207 237) NOAEC = 186 MBA Laboratories, 1983 ACC # 252854 supplemental Sodium Chlorite/ 81.5% Bluegill ( Lepomis macrochirus) LC50 = 310 ( 270 350) NOAEC = 220 Sousa, 1981 ACC # 245697 acceptable Sodium Chlorite/ 80.25% Rainbow trout ( Oncorhynchus mykiss) LC50 = 290 ( 250 340) NOAEC = < 70 EG& G Bionomics, 1979 ACC # 69810 acceptable Sodium Chlorite/ 80% Rainbow trout ( Oncorhynchus mykiss) LC50 = 340 ( 220 600) NOAEC = 130 Sousa and Surprenant, 1984 ACC # 253379 acceptable Sodium Chlorite/ 80% Bluegill ( Lepomis macrochirus) LC50 = 420 ( 220 600) NOAEC = 220 Sousa and Surprenant, 1984 MRID # 94068006 acceptable Note: LC50= Median Lethal Concentration; NOAEC= No Observed Adverse Effect Concentration; N. R.= Not Reported These results indicate that chlorine dioxide/ sodium chlorite range from slightly toxic to practically non toxic to freshwater fish on an acute basis. The guideline requirement ( 72 1/ OPPTS 850.1075) is fulfilled.

B. Freshwater Fish, Chronic A freshwater fish early life stage test using the technical grade of the active ingredient is required for a pesticide when it may be applied directly to water or if the end use product is expected to be transported to water from the intended use site, and any of the following conditions are met: ( 1) the pesticide is intended for use such that its presence in water is likely to be continuous or recurrent regardless of toxicity, ( 2) any aquatic acute LC50 or EC503 is less than 1 mg/ l, ( 3) the EEC ( estimated environmental concentration) in water is equal to or greater than 0.01 of any acute LC50 or EC50 value, or ( 4) the actual or estimated environmental concentration in water resulting from use is less than 0.01 of any acute LC50 or EC50 value and any one of the following conditions exist: studies of other organisms indicate the reproductive physiology of fish may be affected, physicochemical properties indicate cumulative effects, or the pesticide is persistent in water ( e. g., half life greater than 4 days). The preferred test species is rainbow trout, but other species may be used. Freshwater fish early life stage testing is required for chlorine dioxide and sodium chlorite in order to support once through cooling tower uses. No data under this topic have been submitted; therefore Guideline 72 4/ OPPTS 850.1300 is not fulfilled.

3 EC50= Median Effective Concentration Page 7 of 33 C. Freshwater Invertebrates, Acute A freshwater aquatic invertebrate toxicity test using the TGAI is required to establish the toxicity of chlorine dioxide and sodium chlorite to freshwater aquatic invertebrates. The preferred test species is Daphnia magna. Results of this test are tabulated below.

Table 4. Acute Toxicity of Chlorine Dioxide and Sodium Chlorite to Freshwater Invertebrates Substance/% Active Ingredient ( AI) Organism Endpoints/ Results ( ppm) ( 95% conf. interval) Reference Study Classification Sodium Chlorite/ 80% Daphnia magna EC50 = 0.027 ( 0.021 0.031) NOAEC = 0.003 Barrows, 1984 MRID # 146162 acceptable Sodium Chlorite/ 80% Daphnia magna EC50 = 0.39 ( 0.32 0.54) NOAEC = N. R. Hoberg and Surprenant, 1984 MRID # 141149 acceptable Sodium Chlorite/ 79% Daphnia magna EC50 = 0.29 ( 0.25 0.33) NOAEC = 0.10 Vilkas, 1976 MRID # 131350 acceptable Sodium Chlorite/ 80% Daphnia magna EC50 = 0.08 ( 0.06 0.10) NOAEC = 0.06 Larkin, 1984 ACC # 254182 acceptable Sodium Chlorite/ 80% Daphnia magna EC50 = 0.146 ( 0.12  0.18) NOAEC = 0.06 Nackord, 1984 MRID # 94068009 acceptable Sodium Chlorite/ 25% Daphnia magna EC50 = 1.4 ( 1.0 1.9 ) NOAEC = 0.4 MBA Laboratories, 1984 ACC # 252854 supplemental Note: EC50= Median Effective Concentration; NOAEC= No Observed Adverse Effect Concentration; N. R.= Not Reported These studies indicate that chlorine dioxide and sodium chlorite range from very highly toxic for technical grade sodium chlorite a. i. to moderately toxic for the formulated product to aquatic invertebrates on an acute basis. The guideline requirement ( 72 2/ OPPTS 850.1010) is fulfilled.

D. Freshwater Invertebrates, Chronic A freshwater aquatic invertebrate life cycle test using the technical grade of the active ingredient is required for a pesticide if the end use product may be applied directly to water or expected to be transported to water from the intended use site, and any of the following conditions are met: ( 1) the pesticide is intended for use such that its presence in water is likely to be continuous or recurrent regardless of toxicity, ( 2) any aquatic acute LC50 or EC50 is less than 1 mg/ l, ( 3) the Page 8 of 33 EEC in water is equal to or greater than 0.01 of any acute EC50 or LC50 value, or ( 4) the actual or estimated environmental concentration in water resulting from use is less than 0.01 of any aquatic acute EC50 or LC50 value and any of the following conditions exist: studies of other organisms indicate the reproductive physiology of invertebrates may be affected, physicochemical properties indicate cumulative effects, or the pesticide is persistent in water ( e. g., half life greater than 4 days). The preferred test species is Daphnia magna. Freshwater fish early life stage testing is required for chlorine dioxide/ sodium chlorite in order to support once through cooling tower uses. No data under this topic have been submitted; therefore Guideline 72 4b/ OPPTS 850.1400 is not fulfilled.

E. Freshwater Field Studies Freshwater field testing is required for pesticides in cases where there are risks of concern from labeled use patterns. This testing was not required for chlorine dioxide and sodium chlorite and is reserved at the present time.

III. Toxicity to Estuarine and Marine Animals A. Estuarine and Marine Fish, Acute Acute toxicity testing with estuarine/ marine fish using the technical grade of the active ingredient is required for a chemical when the end use product is intended for direct application to the marine/ estuarine environment or the active ingredient is expected to reach this environment because of its use in coastal counties. The preferred test species is sheepshead minnow. Results of this test are tabulated below.

Table 5. Acute Toxicity of Chlorine Dioxide/ Sodium Chlorite to Estuarine/ Marine Fish Substance/% Active Ingredient ( AI) Organism 96 hr LC50 mg/ L ( ppm) ( 95% conf. interval) NOAEC mg/ L ( ppm) Reference Study Classification Sodium Chlorite/ 79% Sheepshead minnow ( Cyprinodon variegatus) 75 ( 62.6 89.8) 13.9 Yurk and Overman, 1994 MRID # 43259401 acceptable Note: LC50= Median Lethal Concentration; NOAEC= No Observed Adverse Effect Concentration The results indicate that chlorine dioxide/ sodium chlorite are slightly toxic to estuarine/ marine fish on an acute basis. The guideline requirement ( 72 3a/ OPPTS 850.1025) is fulfilled.

B. Estuarine and Marine Fish, Chronic Estuarine/ marine fish early life stage testing is not required for the currently registered uses of chlorine dioxide and sodium chlorite. Since freshwater and estuarine/ marine fish are comparably Page 9 of 33 sensitive to sodium chlorite on an acute basis, the freshwater early life stage endpoints will suffice for assessing risk to estuarine/ marine fish species. However, as noted above, the data requirement for freshwater fish early life stage testing ( 72 4a/ 850.1300) has not been fulfilled.

C. Estuarine and Marine Invertebrates, Acute Acute toxicity testing with estuarine/ marine invertebrates using the technical grade of the active ingredient is required for a pesticide when the end use product is intended for direct application to the marine/ estuarine environment or the active ingredient is expected to reach this environment because of its use in coastal counties. The preferred test species are the mysid shrimp and eastern oyster. Results of these tests are tabulated below.

Table 6: Acute Toxicity of Chlorine Dioxide and Sodium Chlorite to Estuarine/ Marine Invertebrates Substance/ % Active Ingredient ( AI) Organism 96 hour EC50 mg/ L ( ppm) ( 95% conf. interval) Reference Study Classification Sodium Chlorite/ 79% Eastern oyster ( Crassostrea virginica) 21.4 ( 14.3 27.1) NOAEC = 14.3 Yurk and Overman, 1994 MRID # 43259403 acceptable Sodium Chlorite/ 79% Mysid ( Mysidopsis bahia) 0.576 ( 0.44 0.75) NOAEC= N. R. Yurk and Overman, 1994 MRID # 43259402 acceptable Note: EC50= Median Effective Concentration; NOAEC= No Observed Adverse Effect Concentration The results indicate that chlorine dioxide/ sodium chlorite range from highly toxic to slightly toxic to estuarine/ marine invertebrates on an acute basis. The guideline requirements ( 72 3b and 72 3c/ OPPTS 850.1035 and 850.1045) are fulfilled.

D. Estuarine and Marine Invertebrate, Chronic An estuarine/ marine invertebrate life cycle toxicity test is required for a pesticide if the end use product may be applied directly to estuarine or marine waters, or is expected to be transported to these waters from the intended use site, and any of the following conditions are met: ( 1) the pesticide is intended for use such that its presence in water is likely to be continuous or recurrent regardless of toxicity, ( 2) any aquatic acute LC50 or EC50 is less than 1 mg/ l, ( 3) the EEC in water is equal to or greater than 0.01 of any acute EC50 or LC50 value, or ( 4) the actual or estimated environmental concentration in water resulting from use is less than 0.01 of any aquatic acute EC50 or LC50 value and any of the following conditions exist: studies of other organisms indicate the reproductive physiology of invertebrates may be affected, physicochemical properties indicate cumulative effects, or the pesticide is persistent in water ( e. g., half life greater than 4 days). Due to the high acute toxicity of sodium chlorite to estuarine/ marine invertebrates, lifecycle testing is necessary; however, freshwater invertebrates tend to be more sensitive than estuarine/ marine invertebrates to sodium chlorite on an acute basis, and, therefore, freshwater life Page 10 of 33 cycle endpoints will suffice for assessing risk to estuarine/ marine invertebrate species. As noted above, freshwater invertebrate life cycle testing ( 72 4b/ 850.1400) has not been submitted. E. Estuarine and Marine Field Studies No estuarine or marine field study testing is currently required for chlorine dioxide and sodium chlorite.

IV. Toxicity to Plants A. Terrestrial/ Semi aquatic Currently, terrestrial plant testing is not required for pesticides other than herbicides except on a case by case basis ( e. g., labeling bears phytotoxicity warnings, incidents of plant damage have been reported, or literature indicating phytotoxicity is available). The once through cooling tower use of chlorine dioxide/ sodium chlorite requires such testing, due to the algaecidal nature of the chemical and the likelihood of exposure to semi aquatic plants along surface waters receiving industrial facility outfall from the cooling system. Results of these tests are tabulated below.

Table 7. Toxicity of Chlorine Dioxide/ Sodium Chlorite to Terrestrial/ Semi aquatic Plants Substance/% Active Ingredient ( AI) Organism EC25 ( ppm) Reference Study Classification Sodium Chlorite/ 80% Monocots & Dicots ( 10 Species) > 3.5 Backus et al., 1990 MRID # 41843101 acceptable Sodium Chlorite/ 80% Monocots & Dicots ( 9 Species) > 3.5 Backus et al., 1990 MRID # 41843102 acceptable Sodium Chlorite/ 80% Buckwheat ( Polygonum convolvulus) < 3.5 Backus et al., 1990 MRID # 41843102 acceptable Note: EC25= Effective Concentration ( 25th Percentile)

The results indicate that chlorine dioxide/ sodium chlorite are moderately toxic to terrestrial plants. The guideline requirement ( 122 1/ OPPTS 850.4100 and 850.4150) is fulfilled. However, since the maximum label rate for many of the chlorine dioxide/ sodium chlorite once through cooling labels was not used in these tests, it is necessary to conduct Tier II testing with rice. Guideline 123 1/ OPPTS 850.4225 and 850.4250, Seedling Emergence and Vegetative Vigor testing with Rice ( Oryza sativa) is not fulfilled.

B. Aquatic The once through cooling tower use of chlorine dioxide/ sodium chlorite requires that 5 aquatic plant tests be conducted due to the algaecidal nature of the chemical and the likelihood of exposure to aquatic plants in surface waters receiving industrial facility outfall from the cooling system. Guideline 123 2/ OPPTS 850.4400 and 850.5400, Vascular Aquatic Plant and Algal Page 11 of 33 dose response toxicity testing ( 5 species), is not fulfilled because only one study ( 1 species) under this topic has been submitted and 5 are required. The results of this test are tabulated below. The following aquatic plant studies are still required: blue green cyanobacteria ( Anabaena flos aquae), freshwater diatom ( Navicula pelliculosa), marine diatom ( Skeletonema costatum) and floating macrophyte ( Lemna gibba).

Table 8. Toxicity of Chlorine Dioxide/ Sodium Chlorite to Aquatic Plants Substance/% Active Ingredient ( AI) Organism 96 hr EC50 ( ppm) ( 95% conf. interval) Reference Study Classification Sodium Chlorite/ 80% Green algae ( Selenastrum capricornutum) 1.32 ( 1.18 1.47) NOAEC = < 0.62 Ward and Boeri, 1991 MRID # 41880403 supplemental Note: EC50= Median Effective Concentration; NOAEC= No Observed Adverse Effect Concentration The results indicate that chlorine dioxide/ sodium chlorite are moderately toxic to aquatic plants. Risk Assessment and Characterization:

Risk assessment integrates the results of the exposure and ecotoxicity data to evaluate the likelihood of adverse ecological effects. One method of integrating the results of exposure and ecotoxicity data is called the quotient method. For this method, risk quotients ( RQs) are calculated by dividing exposure estimates by ecotoxicity values, both acute and chronic:

RQ = EXPOSURE/ TOXICITY RQs are then compared to levels of concern ( LOCs). These LOCs are criteria used by OPP to indicate potential risk to nontarget organisms and the need to consider regulatory action. The criteria indicate that a pesticide used as directed has the potential to cause adverse effects on nontarget organisms. LOCs currently address the following risk presumption categories: ( 1) acute high  the potential for acute risk is high, regulatory action may be warranted in addition to restricted use classification; ( 2) acute restricted use  the potential for acute risk is high, but this may be mitigated through restricted use classification; ( 3) acute endangered species  the potential for acute risk to endangered species is high, and regulatory action may be warranted, and ( 4) chronic risk  the potential for chronic risk is high, and regulatory action may be warranted. Currently, AD does not perform assessments for chronic risk to plants, acute or chronic risks to nontarget insects, or chronic risk from granular/ bait formulations to mammalian or avian species.

The ecotoxicity test values ( i. e., measurement endpoints) used in the acute and chronic risk quotients are derived from the results of required studies. Examples of ecotoxicity values derived from the results of short term laboratory studies that assess acute effects are: ( 1) LC50 ( fish and birds) ( 2) LD50 ( birds and mammals) ( 3) EC50 ( aquatic plants and aquatic invertebrates) and ( 4) EC25 ( terrestrial plants). The NOAEC value is used as the ecotoxicity test value in assessing Page 12 of 33 chronic effects.

Risk presumptions, along with the corresponding RQs and LOCs are tabulated below.

Risk Presumptions for Terrestrial Animals Risk Presumption RQ LOC Birds and Wild Mammals Acute High Risk EEC1/ LC50 or LD50/ sqft2 or LD50/ day3 0.5 Acute Restricted Use EEC/ LC50 or LD50/ sqft or LD50/ day ( or LD50 < 50 mg/ kg) 0.2 Acute Endangered Species EEC/ LC50 or LD50/ sqft or LD50/ day 0.1 Chronic Risk EEC/ NOEC 1 1 abbreviation for Estimated Environmental Concentration ( ppm) on avian/ mammalian food items 2 mg/ ft2 3 mg of toxicant consumed/ day LD50 * wt. of bird LD50 * wt. of bird Risk Presumptions for Aquatic Animals Risk Presumption RQ LOC Acute High Risk EEC1/ LC50 or EC50 0.5 Acute Restricted Use EEC/ LC50 or EC50 0.1 Acute Endangered Species EEC/ LC50 or EC50 0.05 Chronic Risk EEC/ MATC2 or NOEC 1 1 EEC = ( ppm or ppb) in water 2 MATC = maximum allowable toxicant concentration Page 13 of 33 Risk Presumptions for Plants Risk Presumption RQ LOC Terrestrial and Semi Aquatic Plants Acute High Risk EEC/ EC25 1 Acute Endangered Species EEC/ EC05 or NOEC 1 Aquatic Plants Acute High Risk EEC1/ EC50 1 Acute Endangered Species EEC/ EC05 or NOEC 1 1 EEC = ( ppb/ ppm) in water 1. Environmental Fate Assessment Summary This section is a summary of the Environmental Fate Risk Assessment.

Chlorine dioxide and sodium chlorite are being assessed together, as these inorganics are a unique set of chemicals: chlorine dioxide is produced by a reaction of sodium chlorite ( and sometime sodium chlorate) and chloride/ acid. Moreover, chlorite is a breakdown product of chlorine dioxide.

Chlorine dioxide is a greenish yellow gas at room temperature. It is a free radical ( has an unpaired electron), and hence, it is an unstable molecule. In the presence of sunlight, its half life is about thirty minutes. A closed container with > 10% ( v/ v) chlorine dioxide is potentially explosive. Chlorine dioxide, when used as a disinfectant, is generated on site. It is highly water soluble (~ 3 g/ L). It has a short half life, and in the presence of sunlight, whether it is in water or as a gaseous molecule, its breakdown products are chloride and chlorate ions, between pH 4 and 7. Ultimately, oxygen is formed. At pH lower than 4, its breakdown products are chlorite and chlorate. Chlorite is the dominant breakdown product. The estimated log Kow of chlorine dioxide is  3.22 so it is not likely to bioaccumulate in aquatic organisms.

Sodium Chlorite is a solid, white powder. It is highly water soluble and immediately dissociates into sodium and chlorite ions. It dissolves in water, and its breakdown products are chloride and chlorate ions under similar conditions as chlorine dioxide. It is common to see chemical degradation if sodium chlorite in water and also in the presence of suspended soil particles containing ions, like Fe( II), Mn( II), I, S 2, through redox reactions. The end products are chloride and oxygen. The same end products are obtained when sodium chlorite is heated. The estimated log Kow for sodium chlorite is  7.17 and it is not likely to bioaccumulate in aquatic organisms. Page 14 of 33 Chlorate and chlorite ions show a tendency to undergo biodegradation under anaerobic conditions only. There are no reports indicating these ions undergo biodegradation under aerobic conditions. Biodegradation for chlorate and chlorite have been observed in anoxic ground water, sediments and some soils. The end products are again the same: chloride and oxygen. No adsorption/ desorption constants ( Kds) have been measured or reported in published literature for either chlorite or chlorate. Since these are ions, they are likely to be mobile and travel from surface to ground water easily.

2. Environmental Exposure Assessment The Probabilistic Distribution Model version 4 ( PDM4) was used to estimate exposure from once through cooling tower uses. The details of this model can be found in the Chlorine Dioxide and Sodium Chlorite Environmental Modeling Chapter. The model was used to provide the percentage of days per year various concentrations are exceeded for several different flow, application, and dosing scenarios.

Three different flow regimes were considered: high flow [ power plants with average stream flow rates of 1000" 50 million gallons per day ( MGD)]; medium flow ( power plants with average stream flow rates of 500" 50 MGD); and low flow ( power plants with average stream flow rates of 100" 10 MGD). These plants were taken from the NPDES database of plant codes; 12 plants were used in each the low and medium flow category, and 6 plants were used in the high flow category ( see Environmental Modeling Chapter, page 5, for a listing of these plants). The 7Q10 flow rate ( a flow rate that a stream is expected to be below for seven consecutive days once every ten years) for each of the selected plants was used to develop a mean 7Q10 flow rate for each category. This mean 7Q10 flow rate was used as the input parameter for flow in the PDM4 model.

Two pesticide application scenarios, continuous feed and intermittent feed, were used in the modeling, based on label instructions. For continuous feed use, the label rates ranged from 0.10 ppm to 2.0 ppm chlorine dioxide/ sodium chlorite in the water. For intermittent use, the label rates ranged from 0.10 ppm to 25 ppm chlorine dioxide/ sodium chlorite in the water. A single label contained the rate of 800 ppm chlorine dioxide/ sodium chlorite and did not specify whether this was for continuous or intermittent use. It is believed that the single label with the 800 ppm dose rate will be either cancelled or amended by the registrant to delete this dose. The concentrations ( the Aconcentrations of concern,@ or COC) used in the model were endpoints from aquatic organism toxicity studies with sodium chlorite.

Exceedance values for average and worst case situations were modeled. The average values were calculated by averaging all of the values for a given flow category. The worst case values were calculated by averaging the highest ( peak) values for a given flow category. Page 15 of 33 Additional details on the PDM4 model and the specific inputs, assumptions, and output can be found in the Environmental Modeling Chapter.

Risk to Aquatic Organisms from Once Through Cooling Use of Chlorine Dioxide/ Sodium Chlorite Since the modeling for chlorine dioxide/ sodium chlorite provides results as percent days per year a particular concentration is exceeded, Risk Quotients were not used in the usual way to provide numeric estimates of risk. Instead, the endpoints from various toxicity studies were adjusted to determine the numeric Level of Concern ( LOC) for each taxa for both acute and chronic effects. The adjustment factor is the same as the one used with the RQ method, e. g. 0.5 * LC50 or EC50 for acute effects, and 0.05 * LC50 or EC50 for acute endangered species risks. The chronic LOC needs no adjustment. The modeling results provided the percentage of days concentrations were exceeded for a range encompassing the numeric LOCs. When a specific LOC was not listed in the modeling output tables, the percent days exceeded for the LOC was interpolated from the closest numbers above and below the specific LOC. The percentage of days was then multiplied by 365 to provide the number of days per year the LOC is exceeded.

Values for LOC percent days exceeded were interpolated where necessary, using Tables 5 through 10 and 23 through 28 of the Environmental Modeling Chapter. If the number of days an LOC is exceeded is greater than the number of days used to determine the endpoint in toxicity testing, risk is assumed. This assumes that the number of days exceeded are consecutive, a conservative but not impossible assumption.

In the following tables, Arisk@ indicates that the LOC was exceeded for more than 2 days per year for freshwater invertebrates and for more than 4 days per year for all other organisms. Where there is risk, the number of days the LOC was exceeded is indicated in bold type. Page 16 of 33 Tables 9A L: Number of Days per Year Levels of Concern are Exceeded by the Once Through Cooling Use of Chlorine Dioxide/ Sodium Chlorite A. Continuous feed, 800 ppm, high flow scenario Levels of Concern ( LOC)

Taxa Endpoint value from study ( ppm) Acute Nontarget ( 0.5* LC50) [ average # of days exceeded] { worst case # of days exceeded} Acute Endangered Species ( 0.05* LC50) [ average # of days exceeded] { worst case # of days exceeded}

FW fish 96hLC50 = 50.6 25.3 ppm [ 262.44 days] { 363.54 days} 2.53 ppm [ 340.74 days] { 365 days}

FW invert. 48hEC50 = 0.027 0.0135 ppm [ 365 days] { 365 days} 0.001 ppm [ 365 days] { 365 days}

ME fish 96hLC50 = 75 37.5 ppm [ 246.74 days] { 359.16 days} 3.75 ppm [ 325.86 days] { 365 days}

ME mollusk 96hEC50 = 21.4 10.7 ppm [ 286.45 days] { 365 days} 1.07 ppm [ 358.54 days] { 365 days}

ME invert. 96hLC50 = 0.576 0.288 ppm [ 365 days] { 365 days} 0.029 ppm [ 365 days] { 365 days}

Aquatic plant 96hEC50 = 1.32 1.32 ppm ( LC50) [ 355.49 days] { 365 days} 0.62 ppm ( NOEC) [ 363.70 days] { 365 days}

The average scenario of a continuous feed of 800 ppm in a high flow facility results in acute risk to endangered and non endangered freshwater fish, endangered and non endangered freshwater invertebrates, endangered and non endangered marine/ estuarine fish, endangered and nonendangered marine/ estuarine invertebrates and endangered and non endangered aquatic plants. The worst case scenario of a continuous feed of 800 ppm in a high flow facility results in acute risk to endangered and non endangered freshwater fish, endangered and non endangered freshwater invertebrates, endangered and non endangered marine/ estuarine fish, endangered and non endangered marine/ estuarine invertebrates and endangered and non endangered aquatic Page 17 of 33 plants.

B. Continuous feed, 800 ppm, low flow scenario Levels of Concern ( LOC)

Taxa Endpoint value from study ( ppm) Acute Nontarget ( 0.5* LC50) [ average # of days exceeded] { worst case # of days exceeded} Acute Endangered Species ( 0.05* LC50) [ average # of days exceeded] { worst case # of days exceeded}

FW fish 96hLC50 = 50.6 25.3 ppm [ 170.82 days] { 363.54 days} 2.53 ppm [ 296.74 days] { 365 days}

FW invert. 48hEC50 = 0.027 0.0135 ppm [ 365 days] { 365 days} 0.001 ppm [ 365 days] { 365 days}

ME fish 96hLC50 = 75 37.5 ppm [ 147.46 days] { 359.16 days} 3.75 ppm [ 273.16 days] { 365 days}

ME mollusk 96hEC50 = 21.4 10.7 ppm [ 216.34 days] { 365 days} 1.07 ppm [ 324.96 days] { 365 days}

ME invert. 96hLC50 = 0.576 0.288 ppm [ 355.88 days] { 365 days} 0.029 ppm [ 365 days] { 365 days}

Aquatic plant 96hEC50 = 1.32 1.32 ppm ( LC50) [ 320.12 days] { 365 days} 0.62 ppm ( NOEC) [ 335.35 days] { 365 days}

The average scenario of a continuous feed of 800 ppm in a low flow facility results in acute risk to endangered and non endangered freshwater fish, endangered and non endangered freshwater invertebrates, endangered and non endangered marine/ estuarine fish, endangered and nonendangered marine/ estuarine invertebrates and endangered and non endangered aquatic plants. The worst case scenario of a continuous feed of 800 ppm in a low flow facility results in acute risk to endangered and non endangered freshwater fish, endangered and non endangered freshwater invertebrates, endangered and non endangered marine/ estuarine fish, endangered and non endangered marine/ estuarine invertebrates and endangered and non endangered aquatic plants. Page 18 of 33 C. Intermittent feed, 800 ppm, high flow scenario Levels of Concern ( LOC)

Taxa Endpoint value from study ( ppm) Acute Nontarget ( 0.5* LC50) [ average # of days exceeded] { worst case # of days exceeded} Acute Endangered Species ( 0.05* LC50) [ average # of days exceeded] { worst case # of days exceeded}

FW fish 96hLC50 = 50.6 25.3 ppm [ 1.11 days] { 3.46 days} 2.53 ppm [ 139.49 days] { 223 days}

FW invert. 48hEC50 = 0.027 0.0135 ppm [ 356.19 days] { 365 days} 0.001 ppm [ 365 days] { 365 days}

ME fish 96hLC50 = 75 37.5 ppm [ 0.35 days] { 1.25 days} 3.75 ppm [ 89.53 days] { 147.50 days}

ME mollusk 96hEC50 = 21.4 10.7 ppm [ 9.34 days] { 21.77 days} 1.07 ppm [ 199.29 days] { 313.35 days}

ME invert. 96hLC50 = 0.576 0.288 ppm [ 259.52 days] { 362.81 days} 0.029 ppm [ 338.65 days] { 365 days}

Aquatic plant 96hEC50 = 1.32 1.32 ppm ( LC50) [ 189.05 days] { 297.88 days} 0.62 ppm ( NOEC) [ 220.75 days] { 341.31 days}

The average scenario of an intermittent feed of 800 ppm in a high flow facility results in acute risk to endangered freshwater fish, endangered and non endangered freshwater invertebrates, endangered marine/ estuarine fish, endangered and non endangered marine/ estuarine invertebrates and endangered and non endangered aquatic plants. The worst case scenario of an intermittent feed of 800 ppm in a high flow facility results in acute risk to endangered freshwater fish, endangered and non endangered freshwater invertebrates, endangered marine/ estuarine fish, endangered and non endangered marine/ estuarine invertebrates and endangered and nonendangered aquatic plants. Page 19 of 33 D. Intermittent feed, 800 ppm, low flow scenario Levels of Concern ( LOC)

Taxa Endpoint value from study ( ppm) Acute Nontarget ( 0.5* LC50) [ average # of days exceeded] { worst case # of days exceeded} Acute Endangered Species ( 0.05* LC50) [ average # of days exceeded] { worst case # of days exceeded}

FW fish 96hLC50 = 50.6 25.3 ppm [ 1.73 days] { 18.54 days} 2.53 ppm [ 73.88 days] { 230.80 days}

FW invert. 48hEC50 = 0.027 0.0135 ppm [ 320.76 days] { 365 days} 0.001 ppm [ 364.64 days] { 365 days}

ME fish 96hLC50 = 75 37.5 ppm [ 0.89 days] { 10.11 days} 3.75 ppm [ 47.09 days] { 168.96 days}

ME mollusk 96hEC50 = 21.4 10.7 ppm [ 6.54 days] { 53.54 days} 1.07 ppm [ 105.97 days] { 304.80 days}

ME invert. 96hLC50 = 0.576 0.288 ppm [ 165.71 days] { 359.16 days} 0.029 ppm [ 293.61 days] { 365 days}

Aquatic plant 96hEC50 = 1.32 1.32 ppm ( LC50) [ 100.48 days] { 292.13 days} 0.62 ppm ( NOEC) [ 120.43 days] { 329.19 days}

The average scenario of an intermittent feed of 800 ppm in a low flow facility results in acute risk to endangered freshwater fish, endangered and non endangered freshwater invertebrates, endangered marine/ estuarine fish, endangered and non endangered marine/ estuarine invertebrates and endangered and non endangered aquatic plants. The worst case scenario of an intermittent feed of 800 ppm in a low flow facility results in acute risk to endangered and non endangered freshwater fish, endangered and non endangered freshwater invertebrates, endangered and nonendangered marine/ estuarine fish, endangered and non endangered marine/ estuarine invertebrates and endangered and non endangered aquatic plants. Page 20 of 33 E. Intermittent feed, 25 ppm, high flow scenario Levels of Concern ( LOC)

Taxa Endpoint value from study ( ppm) Acute Nontarget ( 0.5* LC50) [ average # of days exceeded] { worst case # of days exceeded} Acute Endangered Species ( 0.05* LC50) [ average # of days exceeded] { worst case # of days exceeded}

FW fish 96hLC50 = 50.6 25.3 ppm [ 9.78x10 7 days] { 5.40x10 6 days} 2.53 ppm [ 1.03 days] { 3.05 days}

FW invert. 48hEC50 = 0.027 0.0135 ppm [ 249.07 days] { 343.39 days} 0.001 ppm [ 329.96 days] { 365 days}

ME fish 96hLC50 = 75 37.5 ppm [ 1.24x10 7 days] { 7.01x10 7 days} 3.75 ppm [ 0.53 days] { 1.58 days}

ME mollusk 96hEC50 = 21.4 10.7 ppm [ 7.49x10 5 days] { 3.88x10 4 days} 1.07 ppm [ 1.63 days] { 4.80 days}

ME invert. 96hLC50 = 0.576 0.288 ppm [ 12.15 days] { 27.23 days} 0.029 ppm [ 204.15 days] { 293.61 days}

Aquatic plant 96hEC50 = 1.32 1.32 ppm ( LC50) [ 1.52 days] { 4.50 days} 0.62 ppm ( NOEC) [ 2.91 days] { 7.65 days}

The average scenario of an intermittent feed of 25 ppm in a high flow facility results in acute risk to endangered and non endangered freshwater invertebrates and endangered and non endangered marine/ estuarine invertebrates. The worst case scenario of an intermittent feed of 25 ppm in a high flow facility results in acute risk to endangered and non endangered freshwater invertebrates, endangered and non endangered marine/ estuarine invertebrates and endangered and nonendangered aquatic plants. Page 21 of 33 F. Intermittent feed, 25 ppm, low flow scenario Levels of Concern ( LOC)

Taxa Endpoint value from study ( ppm) Acute Nontarget ( 0.5* LC50) [ average # of days exceeded] { worst case # of days exceeded} Acute Endangered Species ( 0.05* LC50) [ average # of days exceeded] { worst case # of days exceeded}

FW fish 96hLC50 = 50.6 25.3 ppm [ 4.42x10 5 days] { 5.29x10 4 days} 2.53 ppm [ 1.34 days] { 13.82 days}

FW invert. 48hEC50 = 0.027 0.0135 ppm [ 163.81 days] { 341.49 days} 0.001 ppm [ 267.55 days] { 365 days}

ME fish 96hLC50 = 75 37.5 ppm [ 5.11x10 6 days] { 6.13x10 5 days} 3.75 ppm [ 0.71 days] { 7.33 days}

ME mollusk 96hEC50 = 21.4 10.7 ppm [ 2.55x10 3 days] { 0.03 days} 1.07 ppm [ 2.09 days] { 21.58 days}

ME invert. 96hLC50 = 0.576 0.288 ppm [ 8.03 days] { 61.32 days} 0.029 ppm [ 125.34 days] { 292.38 days}

Aquatic plant 96hEC50 = 1.32 1.32 ppm ( LC50) [ 1.96 days] { 20.25 days} 0.62 ppm ( NOEC) [ 2.92 days] { 27.80 days}

The average scenario of an intermittent feed of 25 ppm in a low flow facility results in acute risk to endangered and non endangered freshwater invertebrates and endangered and non endangered marine/ estuarine invertebrates. The worst case scenario of an intermittent feed of 25 ppm in a low flow facility results in acute risk to endangered freshwater fish, endangered and nonendangered freshwater invertebrates, endangered marine/ estuarine fish, endangered and nonendangered marine/ estuarine invertebrates and endangered and non endangered aquatic plants. Page 22 of 33 G. Continuous feed, 2.0 ppm, high flow scenario Levels of Concern ( LOC)

Taxa Endpoint value from study ( ppm) Acute Nontarget ( 0.5* LC50) [ average # of days exceeded] { worst case # of days exceeded} Acute Endangered Species ( 0.05* LC50) [ average # of days exceeded] { worst case # of days exceeded}

FW fish 96hLC50 = 50.6 25.3 ppm [ 9.89x10 3 days] { 0.04 days} 2.53 ppm [ 47.99 days] { 77.19 days}

FW invert. 48hEC50 = 0.027 0.0135 ppm [ 324.83 days] { 364.86 days} 0.001 ppm [ 364.64 days] { 365 days}

ME fish 96hLC50 = 75 37.5 ppm [ 2.03x10 3 days] { 9.75x10 3 days} 3.75 ppm [ 25.71 days] { 42.54 days}

ME mollusk 96hEC50 = 21.4 10.7 ppm [ 0.23 days] { 0.83 days} 1.07 ppm [ 74.64 days] { 118.66 days}

ME invert. 96hLC50 = 0.576 0.288 ppm [ 165.35 days] { 275.21 days} 0.029 ppm [ 303.90 days] { 364.52 days}

Aquatic plant 96hEC50 = 1.32 1.32 ppm ( LC50) [ 70.08 days] { 111.56 days} 0.62 ppm ( NOEC) [ 91.07 days] { 145.89 days}

The average scenario of a continuous feed of 2.0 ppm in a high flow facility results in acute risk to endangered freshwater fish, endangered and non endangered freshwater invertebrates, endangered marine/ estuarine fish, endangered and non endangered marine/ estuarine invertebrates and endangered and non endangered aquatic plants. The worst case scenario of a continuous feed of 2.0 ppm in a high flow facility results in acute risk to endangered freshwater fish, endangered and non endangered freshwater invertebrates, endangered marine/ estuarine fish, endangered and nonendangered marine/ estuarine invertebrates and endangered and non endangered aquatic plants. Page 23 of 33 H. Continuous feed, 2.0 ppm, low flow scenario Levels of Concern ( LOC)

Taxa Endpoint value from study ( ppm) Acute Nontarget ( 0.5* LC50) [ average # of days exceeded] { worst case # of days exceeded} Acute Endangered Species ( 0.05* LC50) [ average # of days exceeded] { worst case # of days exceeded}

FW fish 96hLC50 = 50.6 25.3 ppm [ 0.10 days] { 1.19 days} 2.53 ppm [ 22.60 days] { 98.70 days}

FW invert. 48hEC50 = 0.027 0.0135 ppm [ 259.22 days] { 364.57 days} 0.001 ppm [ 348.58 days] { 365 days}

ME fish 96hLC50 = 75 37.5 ppm [ 0.03 days] { 0.41 days} 3.75 ppm [ 12.82 days] { 62.60 days}

ME mollusk 96hEC50 = 21.4 10.7 ppm [ 0.68 days] { 7.74 days} 1.07 ppm [ 34.31 days] { 141.90 days}

ME invert. 96hLC50 = 0.576 0.288 ppm [ 78.84 days] { 264.26 days} 0.029 ppm [ 229.80 days] { 363.55 days}

Aquatic plant 96hEC50 = 1.32 1.32 ppm ( LC50) [ 32.30 days] { 134.50 days} 0.62 ppm ( NOEC) [ 42.03 days] { 165.88 days}

The average scenario of a continuous feed of 2.0 ppm in a low flow facility results in acute risk to endangered freshwater fish, endangered and non endangered freshwater invertebrates, endangered marine/ estuarine fish, endangered and non endangered marine/ estuarine invertebrates and endangered and non endangered aquatic plants. The worst case scenario of a continuous feed of 2.0 ppm in a low flow facility results in acute risk to endangered freshwater fish, endangered and non endangered freshwater invertebrates, endangered marine/ estuarine fish, endangered and nonendangered marine/ estuarine invertebrates and endangered and non endangered aquatic plants. Page 24 of 33 I. Continuous feed, 0.10 ppm, high flow scenario Levels of Concern ( LOC)

Taxa Endpoint value from study ( ppm) Acute Nontarget ( 0.5* LC50) [ average # of days exceeded] { worst case # of days exceeded} Acute Endangered Species ( 0.05* LC50) [ average # of days exceeded] { worst case # of days exceeded}

FW fish 96hLC50 = 50.6 25.3 ppm [ negligible] { negligible} 2.53 ppm [ 0.06 days] { 0.24 days}

FW invert. 48hEC50 = 0.027 0.0135 ppm [ 200.47 days] { 310.07 days} 0.001 ppm [ 294.19 days] { 365 days}

ME fish 96hLC50 = 75 37.5 ppm [ negligible] { negligible} 3.75 ppm [ 0.03 days] { 0.12 days}

ME mollusk 96hEC50 = 21.4 10.7 ppm [ 6.55x10 7 days] { 3.96x10 6 days} 1.07 ppm [ 0.09 days] { 0.37 days}

ME invert. 96hLC50 = 0.576 0.288 ppm [ 1.28 days] { 3.94 days} 0.029 ppm [ 143.21 days] { 225.21 days}

Aquatic plant 96hEC50 = 1.32 1.32 ppm ( LC50) [ 0.09 days] { 0.35 days} 0.62 ppm ( NOEC) [ 0.23 days] { 0.79 days}

The average scenario of a continuous feed of 0.10 ppm in a high flow facility results in acute risk to endangered and non endangered freshwater invertebrates and endangered marine/ estuarine invertebrates. The worst case scenario of a continuous feed of 0.10 ppm in a high flow facility results in acute risk to endangered and non endangered freshwater invertebrates and endangered marine/ estuarine invertebrates. Page 25 of 33 J. Continuous feed, 0.10 ppm, low flow scenario Levels of Concern ( LOC)

Taxa Endpoint value from study ( ppm) Acute Nontarget ( 0.5* LC50) [ average # of days exceeded] { worst case # of days exceeded} Acute Endangered Species ( 0.05* LC50) [ average # of days exceeded] { worst case # of days exceeded}

FW fish 96hLC50 = 50.6 25.3 ppm [ 1.53x10 7 days] { 1.84x10 6 days} 2.53 ppm [ 0.25 days] [ 2.92 days]

FW invert. 48hEC50 = 0.027 0.0135 ppm [ 109.28 days] { 304.56 days} 0.001 ppm [ 228.86 days] { 365 days}

ME fish 96hLC50 = 75 37.5 ppm [ 1.10x10 8 days] { 1.20x10 7 days} 3.75 ppm [ 0.13 days] { 1.52 days}

ME mollusk 96hEC50 = 21.4 10.7 ppm [ 3.20x10 5 days] { 3.85x10 4 days} 1.07 ppm [ 0.39 days] { 4.60 days}

ME invert. 96hLC50 = 0.576 0.288 ppm [ 1.88 days] { 19.97 days} 0.029 ppm [ 77.42 days] { 234.40 days}

Aquatic plant 96hEC50 = 1.32 1.32 ppm ( LC50) [ 0.37 days] { 4.31 days} 0.62 ppm ( NOEC) [ 0.59 days] { 6.67 days}

The average scenario of a continuous feed of 0.10 ppm in a low flow facility results in acute risk to endangered and non endangered freshwater invertebrates and endangered marine/ estuarine invertebrates. The worst case scenario of a continuous feed of 0.10 ppm in a low flow facility results in acute risk to endangered and non endangered freshwater invertebrates, endangered and non endangered marine/ estuarine invertebrates and endangered and non endangered aquatic plants. Page 26 of 33 K. Intermittent feed, 0.10 ppm, high flow scenario Levels of Concern ( LOC)

Taxa Endpoint value from study ( ppm) Acute Nontarget ( 0.5* LC50) [ average # of days exceeded] { worst case # of days exceeded} Acute Endangered Species ( 0.05* LC50) [ average # of days exceeded] { worst case # of days exceeded}

FW fish 96hLC50 = 50.6 25.3 ppm [ negligible] { negligible} 2.53 ppm [ negligible] { negligible}

FW invert. 48hEC50 = 0.027 0.0135 ppm [ 0.09 days] { 0.34 days} 0.001 ppm [ 16.06 days] { 34.31 days}

ME fish 96hLC50 = 75 37.5 ppm [ negligible] { negligible} 3.75 ppm [ negligible] { negligible}

ME mollusk 96hEC50 = 21.4 10.7 ppm [ negligible] { negligible} 1.07 ppm [ negligible] { negligible}

ME invert. 96hLC50 = 0.576 0.288 ppm [ negligible] { 1.83x10 8 days} 0.029 ppm [ 0.05 days] { 0.22 days}

Aquatic plant 96hEC50 = 1.32 1.32 ppm ( LC50) [ negligible] { negligible} 0.62 ppm ( NOEC) [ negligible] { negligible}

The average scenario of an intermittent feed of 0.10 ppm in a high flow facility results in acute risk to endangered freshwater invertebrates. The worst case scenario of an intermittent feed of 0.10 ppm in a high flow facility results in acute risk to endangered freshwater invertebrates. Page 27 of 33 L. Intermittent feed, 0.10 ppm, low flow scenario Levels of Concern ( LOC)

Taxa Endpoint value from study ( ppm) Acute Nontarget ( 0.5* LC50) [ average # of days exceeded] { worst case # of days exceeded} Acute Endangered Species ( 0.05* LC50) [ average # of days exceeded] { worst case # of days exceeded}

FW fish 96hLC50 = 50.6 25.3 ppm [ 0 days] { 0 days} 2.53 ppm [ negligible] { negligible}

FW invert. 48hEC50 = 0.027 0.0135 ppm [ 0.37 days] { 4.26 days} 0.001 ppm [ 9.82 days] { 70.08 days}

ME fish 96hLC50 = 75 37.5 ppm [ 0 days] { 0 days} 3.75 ppm [ negligible] { negligible}

ME mollusk 96hEC50 = 21.4 10.7 ppm [ 0 days] { 0 days} 1.07 ppm [ negligible] { negligible}

ME invert. 96hLC50 = 0.576 0.288 ppm [ 8.40x10 8 days] { 1.01x10 6 days} 0.029 ppm [ 0.24 days] { 2.74 days}

Aquatic plant 96hEC50 = 1.32 1.32 ppm ( LC50) [ negligible] { negligible} 0.62 ppm ( NOEC) [ negligible] { negligible}

The average scenario of an intermittent feed of 0.10 ppm in a low flow facility results in acute risk to endangered freshwater invertebrates. The worst case scenario of an intermittent feed of 0.10 ppm in a low flow facility results in acute risk to endangered and non endangered freshwater invertebrates.

3. Environmental Risk Assessment a. Terrestrial Organisms No model is available to estimate exposure and risk to birds and mammals from discharge of once through cooling system effluents into surface waters. The rapid degradation of the chemicals, coupled with the generally low toxicity of chlorine dioxide and sodium chlorite to birds and mammals, make risk to these organisms unlikely. The very limited data available to assess the phytotoxicity of chlorine dioxide/ sodium chlorite make it difficult to determine the risk to Page 28 of 33 terrestrial/ semi aquatic plants. b. Aquatic Organisms Acute risk to aquatic organisms is anticipated from the use of chlorine dioxide/ sodium chlorite in once through cooling towers based on the modeling conducted. At the highest doses there is risk to freshwater and marine/ estuarine fish and invertebrates and aquatic plants, and at the lowest doses there is risk only to freshwater invertebrates. See Table 9 A L for details. Chronic risk to aquatic organisms cannot be assessed at this time due to the lack of chronic toxicity endpoints for fish and aquatic invertebrates. When the required aquatic chronic toxicity testing described above is submitted, chronic risk to these organisms will be assessed.

4. Listed Species Section 7 of the Endangered Species Act, 16 U. S. C. Section 1536( a)( 2), requires all federal agencies to consult with the National Marine Fisheries Service ( NMFS) for marine and anadromous listed species, or the United States Fish and Wildlife Services ( FWS) for listed wildlife and freshwater organisms, if they are proposing an Aaction@ that may affect listed species or their designated habitat. Each federal agency is required under the Act to insure that any action they authorize, fund, or carry out is not likely to jeopardize the continued existence of a listed species or result in the destruction or adverse modification of designated critical habitat. To jeopardize the continued existence of a listed species means Ato engage in an action that reasonably would be expected, directly or indirectly, to reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or distribution of the species.@ 50 C. F. R. ' 402.02.

To facilitate compliance with the requirements of the Endangered Species Act subsection ( a)( 2) the Environmental Protection Agency, Office of Pesticide Programs has established procedures to evaluate whether a proposed registration action may directly or indirectly reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or distribution of any listed species ( U. S. EPA, 2004). After the Agency= s screening level risk assessment is performed, if any of the Agency= s Listed Species LOC Criteria are exceeded for either direct or indirect effects, a determination is made to identify if any listed or candidate species may co occur in the area of the proposed pesticide use. If determined that listed or candidate species may be present in the proposed use areas, further biological assessment is undertaken. The extent to which listed species may be at risk then determines the need for the development of a more comprehensive consultation package as required by the Endangered Species Act.

Acute risk to listed birds and mammals is not anticipated from the use of chlorine dioxide and sodium chlorite products due to low exposure and low toxicity. Further discussion is needed before it can be determined if there are risks to listed aquatic organisms from the once through cooling tower use of chlorine dioxide/ sodium chlorite. Page 29 of 33 Chronic risks to listed aquatic organisms cannot be assessed at this time; this risk will be assessed when required chronic toxicity data are submitted to and evaluated by the Agency. Page 30 of 33 REFERENCES ACC 245697. Sousa, J. V. 1981. Acute Toxicity of Sodium Chlorite to Bluegill ( Lepomis macrochirus). Unpublished Data. Conducted by EG& G, Bionomics for Olin Chemicals.

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ACC 252854. 1983. 96 Hour LC50 in Bluegill Perch. Unpublished Data. Conducted by Microbiological and Biochemical Assay Laboratories for Magna Corporation.

ACC 252854. 1984. 48 Hour LC50 in Daphnia magna. Unpublished Data. Conducted by Microbiological and Biochemical Assay Laboratories for Magna Corporation.

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MRID 43259403. Yurk, J. J. and M. A. Overman. 1994. Effect of Sodium Chlorite on New Shell Page 33 of 33 Growth in Eastern Oyster ( Crassostrea virginica). Conducted by Environmental Science & Engineering, Inc. for the Chemical Manufacturers Association.

MRID 94068005. Johnson, G. 1984. Avian Dietary LC50 Bobwhite Quail ( Colinus virginianus). Unpublished Data. Conducted by Hazleton Laboratories America, Inc. for Degussa Corporation.

MRID 94068006. Sousa and Surprenant, 1984. Acute Toxicity of A 66 ( Technical Sodium Chlorite) to Bluegill ( Lepomis macrochirus). Unpublished Data. Conducted by Springborn Binomics, Inc for Calgon Corporation.

MRID 94068007. Barrows, B. 1984. The Acute Toxicity of Sodium Chlorite Technical to the Rainbow Trout, Salmo gairdneri, in a Static Test System. Unpublished Data. Conducted by Biospherics Incorporated for Degussa Corporation.

MRID 94068008. Johnson, G. 1984. Avian Dietary LC50 Mallard Duck ( Anas platyrhynchos). Unpublished Data. Conducted by Hazleton Laboratories America, Inc. for Degussa Corporation.

MRID 94068009. Nachrord, S. 1984. Daphnia LC50 Bioassay. Unpublished Data. Conducted by Anater Tesconi Circle for Rio Linda Chemical Company, Inc.

USEPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs U. S. Environmental Protection Agency  Endangered and Threatened Species Effects Determinations, 1/ 23/ 04.


[Federal Register Volume 74, Number 99 (Tuesday, May 26, 2009)]
[Notices]
[Page 24849]
[FR Doc No: E9-12087]

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

[Docket No. ER09-1133-000]

Palmco Power PA, LLC; Supplemental Notice That Initial Market-
Based Rate Filing Includes Request for Blanket Section 204
Authorization

May 18, 2009.
    This is a supplemental notice in the above-referenced proceeding,
of Palmco Power PA, LLC's application for market-based rate authority,
with an accompanying rate schedule, noting that such application
includes a request for blanket authorization, under 18 CFR part 34, of
future issuances of securities and assumptions of liability.
    Any person desiring to intervene or to protest should file with the
Federal Energy Regulatory Commission, 888 First Street, NE.,
Washington, DC 20426, in accordance with Rules 211 and 214 of the
Commission's Rules of Practice and Procedure (18 CFR 385.211 and
385.214). Anyone filing a motion to intervene or protest must serve a
copy of that document on the Applicant.
    Notice is hereby given that the deadline for filing protests with
regard to the applicant's request for blanket authorization, under 18
CFR part 34, of future issuances of securities and assumptions of
liability is June 8, 2009.
    The Commission encourages electronic submission of protests and
interventions in lieu of paper, using the FERC Online links at http://www.ferc.gov. To facilitate electronic service, persons with Internet
access who will eFile a document and/or be listed as a contact for an
intervenor must create and validate an eRegistration account using the
eRegistration link. Select the eFiling link to log on and submit the
intervention or protests.
    Persons unable to file electronically should submit an original and
14 copies of the intervention or protest to the Federal Energy
Regulatory Commission, 888 First St., NE., Washington, DC 20426.
    The filings in the above-referenced proceeding(s) are accessible in
the Commission's eLibrary system by clicking on the appropriate link in
the above list. They are also available for review in the Commission's
Public Reference Room in Washington, DC. There is an eSubscription link
on the Web site that enables subscribers to receive e-mail notification
when a document is added to a subscribed docket(s). For assistance with
any FERC Online service, please e-mail<EMAIL_ADDRESS>or
call<PHONE_NUMBER> (toll free). For TTY, call<PHONE_NUMBER>.

Kimberly D. Bose,
Secretary.
[FR Doc. E9-12087 Filed 5-22-09; 8:45 am]
BILLING CODE 6717-01-P


[Federal Register Volume 85, Number 11 (Thursday, January 16, 2020)]
[Rules and Regulations]
[Pages 2642-2643]
[FR Doc No: 2020-00329]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 97

[Docket No. 31289; Amdt. No. 3885]

Standard Instrument Approach Procedures, and Takeoff Minimums and
Obstacle Departure Procedures; Miscellaneous Amendments

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: This rule establishes, amends, suspends, or removes Standard
Instrument Approach Procedures (SIAPs) and associated Takeoff Minimums
and Obstacle Departure Procedures (ODPs) for operations at certain
airports. These regulatory actions are needed because of the adoption
of new or revised criteria, or because of changes occurring in the
National Airspace System, such as the commissioning of new navigational
facilities, adding new obstacles, or changing air traffic requirements.
These changes are designed to provide safe and efficient use of the
navigable airspace and to promote safe flight operations under
instrument flight rules at the affected airports.

DATES: This rule is effective January 16, 2020. The compliance date for
each SIAP, associated Takeoff Minimums, and ODP is specified in the
amendatory provisions.
    The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of January 16, 2020.

ADDRESSES: Availability of matters incorporated by reference in the
amendment is as follows:

For Examination

    1. U.S. Department of Transportation, Docket Ops-M30, 1200 New
Jersey Avenue SE, West Bldg., Ground Floor, Washington, DC 20590-0001.
    2. The FAA Air Traffic Organization Service Area in which the
affected airport is located;
    3. The office of Aeronautical Navigation Products, 6500 South
MacArthur Blvd., Oklahoma City, OK 73169 or,
    4. The National Archives and Records Administration (NARA). For
information on the availability of this material at NARA, email
<EMAIL_ADDRESS>or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

Availability

    All SIAPs and Takeoff Minimums and ODPs are available online free
of charge. Visit the National Flight Data Center at nfdc.faa.gov to
register. Additionally, individual SIAP and Takeoff Minimums and ODP
copies may be obtained from the FAA Air Traffic Organization Service
Area in which the affected airport is located.

FOR FURTHER INFORMATION CONTACT: Thomas J. Nichols, Flight Procedures
and Airspace Group, Flight Technologies and Procedures Division, Flight
Standards Service, Federal Aviation Administration. Mailing Address:
FAA Mike Monroney Aeronautical Center, Flight Procedures and Airspace
Group, 6500 South MacArthur Blvd., Registry Bldg. 29, Room 104,
Oklahoma City, OK 73169. Telephone:<PHONE_NUMBER>.

SUPPLEMENTARY INFORMATION: This rule amends Title 14 of the Code of
Federal Regulations, Part 97 (14 CFR part 97), by establishing,
amending, suspending, or removes SIAPS, Takeoff Minimums and/or ODPS.
The complete regulatory description of each SIAP and its associated
Takeoff Minimums or ODP for an identified airport is listed on FAA form
documents which are incorporated by reference in this amendment under 5
U.S.C. 552(a), 1 CFR part 51, and 14 CFR part 97.20. The applicable FAA
forms are FAA Forms 8260-3, 8260-4, 8260-5, 8260-15A, and 8260-15B when
required by an entry on 8260-15A.
    The large number of SIAPs, Takeoff Minimums and ODPs, their complex
nature, and the need for a special format make publication in the
Federal Register expensive and impractical. Further, airmen do not use
the regulatory text of the SIAPs, Takeoff Minimums or ODPs, but instead
refer to their graphic depiction on charts printed by publishers of
aeronautical materials. Thus, the advantages of incorporation by
reference are realized and publication of the complete description of
each SIAP, Takeoff Minimums and ODP listed on FAA form documents is
unnecessary. This amendment provides the affected CFR sections and
specifies the types of SIAPs, Takeoff Minimums and ODPs with their
applicable effective dates. This amendment also identifies the airport
and its location, the procedure, and the amendment number.

Availability and Summary of Material Incorporated by Reference

    The material incorporated by reference is publicly available as
listed in the ADDRESSES section.
    The material incorporated by reference describes SIAPS, Takeoff
Minimums and/or ODPS as identified in the amendatory language for part
97 of this final rule.

The Rule

    This amendment to 14 CFR part 97 is effective upon publication of
each separate SIAP, Takeoff Minimums and ODP as Amended in the
transmittal. Some SIAP and Takeoff Minimums and textual ODP amendments
may have been issued previously by the FAA in a Flight Data Center
(FDC) Notice to Airmen (NOTAM) as an emergency action of immediate
flight safety relating directly to published aeronautical charts.
    The circumstances that created the need for some SIAP and Takeoff
Minimums and ODP amendments may require making them effective in less
than 30 days. For the remaining SIAPs and Takeoff Minimums and ODPs, an
effective date at least 30 days after publication is provided.
    Further, the SIAPs and Takeoff Minimums and ODPs contained in this
amendment are based on the criteria contained in the U.S. Standard for
Terminal Instrument Procedures (TERPS). In developing these SIAPs and
Takeoff Minimums and ODPs, the TERPS criteria were applied to the
conditions existing or anticipated at the affected airports. Because of
the close and immediate relationship between these SIAPs, Takeoff
Minimums and ODPs, and safety in air commerce, I find that notice and
public procedure under 5 U.S.C. 553(b) are impracticable and contrary
to the public interest and, where applicable, under 5 U.S.C 553(d),
good cause exists for making some SIAPs effective in less than 30 days.
    The FAA has determined that this regulation only involves an
established body of technical regulations for which frequent and
routine amendments are necessary to keep them operationally current.
It, therefore--(1) is not a ``significant regulatory action'' under
Executive Order 12866;(2) is not a ``significant rule'' under DOT
Regulatory Policies and Procedures (44 FR 11034; February 26,1979) ;
and (3) does not warrant preparation of a regulatory evaluation as the
anticipated impact is so minimal. For the same reason, the FAA
certifies that this amendment will not have a significant economic
impact on a substantial

number of small entities under the criteria of the Regulatory
Flexibility Act.

List of Subjects in 14 CFR Part 97

    Air Traffic Control, Airports, Incorporation by reference,
Navigation (Air).

    Issued in Washington, DC, on December 27, 2019.
Rick Domingo,
Executive Director, Flight Standards Service.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me, Title 14,
Code of Federal Regulations, Part 97 (14 CFR part 97) is amended by
establishing, amending, suspending, or removing Standard Instrument
Approach Procedures and/or Takeoff Minimums and Obstacle Departure
Procedures effective at 0901 UTC on the dates specified, as follows:

PART 97--STANDARD INSTRUMENT APPROACH PROCEDURES

0
1. The authority citation for part 97 continues to read as follows:

    Authority:  49 U.S.C. 106(f), 106(g), 40103, 40106, 40113,
40114, 40120, 44502, 44514, 44701, 44719, 44721-44722.

0
2. Part 97 is amended to read as follows:

Effective 30 January 2020

Chevak, AK, Chevak, RNAV (GPS) RWY 2, Amdt 1
Chevak, AK, Chevak, RNAV (GPS) RWY 20, Amdt 1
Chevak, AK, Chevak, Takeoff Minimums and Obstacle DP, Amdt 2
Coolidge, AZ, Coolidge Muni, VOR RWY 5, Amdt 1
Tucson, AZ, Tucson Intl, ILS OR LOC RWY 11L, Amdt 14B
Tucson, AZ, Tucson Intl, RNAV (GPS) RWY 11R, Orig-C
Tucson, AZ, Tucson Intl, RNAV (GPS) RWY 21, Orig-C
Tucson, AZ, Tucson Intl, RNAV (GPS) Z RWY 29R, Amdt 2E
Tucson, AZ, Tucson Intl, VOR OR TACAN RWY 29R, Amdt 2F
Monterey, CA, Monterey Rgnl, LOC RWY 28L, Amdt 5
Gainesville, FL, Gainesville Rgnl, VOR RWY 25, Orig-D, CANCELLED
Gainesville, FL, Gainesville Rgnl, VOR RWY 29, Orig-E, CANCELLED
Gainesville, FL, Gainesville Rgnl, VOR/DME RWY 7, Orig-D, CANCELLED
Gainesville, FL, Gainesville Rgnl, VOR/DME RWY 11, Orig-D, CANCELLED
Honolulu, HI, Daniel K Inouye Intl, ILS RWY 8L, Amdt 24
Honolulu, HI, Daniel K Inouye Intl, LDA RWY 26L, Amdt 6
Honolulu, HI, Daniel K Inouye Intl, RNAV (GPS) Y RWY 4R, Amdt 3
Honolulu, HI, Daniel K Inouye Intl, RNAV (GPS) Y RWY 8L, Amdt 3
Honolulu, HI, Daniel K Inouye Intl, RNAV (RNP) Z RWY 4R, Amdt 2
Honolulu, HI, Daniel K Inouye Intl, RNAV (RNP) Z RWY 8L, Amdt 3
Chicago, IL, Chicago Midway Intl, RNAV (GPS) Z RWY 22L, Amdt 1
Chicago, IL, Chicago Midway Intl, RNAV (RNP) Y RWY 22L, Amdt 3
Louisville, KY, Louisville Muhammad Ali Intl, LOC RWY 29, Amdt 1
Salisbury, MD, Salisbury-Ocean City Wicomico Rgnl, RNAV (GPS) RWY
14, Amdt 1B
Salisbury, MD, Salisbury-Ocean City Wicomico Rgnl, VOR RWY 5, Amdt
10A
Detroit, MI, Detroit Metropolitan Wayne County, ILS PRM Y RWY 4L
(CLOSE PARALLEL), Amdt 1C
Detroit, MI, Detroit Metropolitan Wayne County, ILS PRM Y RWY 22R
(CLOSE PARALLEL), Amdt 1B
Detroit, MI, Detroit Metropolitan Wayne County, ILS PRM Z RWY 4L
(CLOSE PARALLEL), ILS PRM Z RWY 4L (CLOSE PARALLEL) (CAT II), ILS
PRM Z RWY 4L (CLOSE PARALLEL) (CAT III), Orig-B
Detroit, MI, Detroit Metropolitan Wayne County, ILS PRM Z RWY 22R
(CLOSE PARALLEL), ILS PRM Z RWY 22R (CLOSE PARALLEL) (SA CAT I), ILS
PRM Z RWY 22R (CLOSE PARALLEL) (SA CAT II), Orig-B
Detroit, MI, Detroit Metropolitan Wayne County, ILS Y RWY 4L, Amdt
1C
Detroit, MI, Detroit Metropolitan Wayne County, ILS Y RWY 22R, Amdt
1B
Detroit, MI, Detroit Metropolitan Wayne County, ILS Z OR LOC RWY 4L,
ILS Z RWY 4L (CAT II), ILS Z RWY 4L (CAT III), Amdt 4C
Detroit, MI, Detroit Metropolitan Wayne County, ILS Z OR LOC RWY
22R, ILS Z RWY 22R (SA CAT I), ILS Z RWY 22R (SA CAT II), Amdt 4B
Lansing, MI, Capital Region Intl, ILS OR LOC RWY 28L, Amdt 28
Cuba, MO, Cuba Muni, RNAV (GPS) RWY 36, Orig-D
Harlowton, MT, Wheatland County at Harlowton, RNAV (GPS) RWY 9, Orig
Harlowton, MT, Wheatland County at Harlowton, Takeoff Minimums and
Obstacle DP, Orig
Lake Placid, NY, Lake Placid, RNAV (GPS)-A, Amdt 2A
Toledo, OH, Toledo Express, ILS OR LOC RWY 7, Amdt 29
Shawnee, OK, Shawnee Rgnl, ILS OR LOC RWY 17, Amdt 3
Dubois, PA, Dubois Rgnl, RNAV (GPS) RWY 7, Amdt 2
Dubois, PA, Dubois Rgnl, RNAV (GPS) RWY 25, Amdt 1A
Brownsville, TX, Brownsville/South Padre Island Intl, RNAV (GPS) RWY
31, Orig
El Paso, TX, El Paso Intl, RNAV (RNP) X RWY 8R, Orig
El Paso, TX, El Paso Intl, RNAV (RNP) Y RWY 8R, Orig
Waco, TX, Mc Gregor Executive, VOR RWY 17, Amdt 11
Baraboo, WI, Baraboo-Wisconsin Dells Rgnl, LOC RWY 1, Amdt 3
Baraboo, WI, Baraboo-Wisconsin Dells Rgnl, RNAV (GPS) RWY 19, Amdt 3
Baraboo, WI, Baraboo-Wisconsin Dells Rgnl, VOR-A, Amdt 13

Rescinded

    On November 29, 2019 (84 FR 65673), the FAA published an
Amendment in Docket No. 31283, Amdt No. 3879, to Part 97 of the
Federal Aviation Regulations under sections 97.27, 97.29, 97.33,
97.37. The following entries for Cloquet, MN, Pierre, SD, and
Mineral Wells, TX, effective January 30, 2020, are hereby rescinded
in its entirety:

Cloquet, MN, Cloquet Carlton County, NDB RWY 18, Amdt 4B
Cloquet, MN, Cloquet Carlton County, NDB RWY 36, Amdt 5B
Cloquet, MN, Cloquet Carlton County, Takeoff Minimums and Obstacle
DP, Amdt 3
Pierre, SD, Pierre Rgnl, RNAV (GPS) RWY 31, Amdt 1
Mineral Wells, TX, Mineral Wells Rgnl, ILS OR LOC RWY 31, Amdt 1A

Rescinded

    On December 12, 2019 (84 FR 67862), the FAA published an
Amendment in Docket No. 31285, Amdt No. 3881, to Part 97 of the
Federal Aviation Regulations under sections 97.23. The following
entry for Syracuse, NY, effective January 30, 2020, is hereby
rescinded in its entirety:

Syracuse, NY, Syracuse Hancock Intl, VOR RWY 15, Amdt 23B, CANCELLED

[FR Doc. 2020-00329 Filed 1-15-20; 8:45 am]
 BILLING CODE 4910-13-P