delineates the zone of ef fe, ctive photosynthetic oxygen production. To maintain satisfactory biological conditions, this depth cannot be substantially reduced. 0 Industrial requirements as related to water color have been standardized ( NAS, 1974). Table 2 lists the maximum value used as a source of water for various industries and industrial uses.

Through treatment, such waters can be made to meet almost any industrial requirement.

( QUALITY CRITERIA FOR WATER, JULY 1976) PB 263943 SEE APPENDIX C FOR METHODOLOGY 0 AQUATIC LIFE SUMMARY: * COPPER Acute toxicity data freshwater animals. At are available for species in 41 genera of a hardness of 50 mg/ L the genera range in sensitivity from 16.74 ug/ L for Ptychocheilus  to 10,240 ug/ L for Acroneuria. Data for eight species indicate that acute toxicity decreases as hardness increases. Additional data for several species indicate that toxicity also decreases with increases in alkalinity and total organic carbon.

Chronic values are available  or 15 freshwater species and range from 3.873 ug/ L  or brook trout to 60.36 ug/+ for northern pike. Fish and invertebrate species seem to be about equally sensitive to the chronic toxicity of copper.

Toxicity tests have been conducted on copper with a wide range of freshwater plants and the sensitivities are similar to those of animals. Complexing effects of the test media and a lack of good analytical data make interpretation and application of these results difficult. Protection of animal species,

however, appears to offer adequate protection of plants. Copper does not appear to bioconcentrate very much in the edible portion of freshwater aquatic species.

The acute sensitivities of saltwater animals to copper range from 5.8 ug/ L for the blue mussel to 600 ug/ L for the green crab.

A chronic life cycle test has been conducted with a mysid, and adverse effects were observed at 77 ug/ L but not at 38 ug/ L,

which resulted in an acute chronic ratio of 3.346. Several * Indicates susDended. canceled or restricted bv U. S. EPA Office of Pesticides ahd Toxic Substances  saltwater algal species have been tested, and effects were observed between 5 and 100 ug/ L. Oysters can bioaccumulate copper up to 28,200 times, and become bluish green, apparently without significant mortality. In long term exposures, the bay scallop was killed at 5 ug/ L.

NATIONAL CRITERIA:

The procedures described in the Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Uses indicate that, except possibly where a locally important species is very sensitive, freshwater aquatic organisms and their uses should not be affected unacceptably if the 4 day average concentration ( in ug/ L) of copper does not exceed the numerical value given, by .( 0.8545[ ln( hardness) 3  1.465)

more than once every 3 years on the average and if the 1 hour average concentration ( in ug/ L) does not exceed the numerical value given by ,( 0.9422 [ ln( hardness) 1 1.464) more than once every 3 years on the average. For example, at hardnesses of 50, 100,

and 200 mg/ L as CaC03 the 4 day average concentrations of copper are 6.5, 12, and 21 ug/ L, respectively, and the 1 hour average concentrations are 9.2, 18, and 34 ug/ L.

The procedures described in the Guidelines indicate that,

except possibly where a locally important species is very sensitive, saltwater aquatic organisms and their uses should not be affected unacceptably if the 1 hour average concentration of copper does not exceed 2.9 ug/ L more than once every 3 years on the average.

EPA believes that a measurement such as tsacid solublets would p r o v i d e a more s c i e n t i f i c a l l y c o r r e c t b a s i s upon which t o e s t a b l i s h c r i t e r i a f o r metals. The c r i t e r i a were developed on t h i s basis. However, a t t h i s t i m e , no EPA approved methods f o r such a measurement a r e a v a i l a b l e t o implement t h e c r i t e r i a through t h e r e g u l a t o r y programs of t h e Agency and t h e States.

The Agency is considering development and approval of methods f o r a measurement such a s acid s o l u b l e . U n t i l a v a i l a b l e ,

however, EPA recommends applying the c r i t e r i a using t h e t o t a l recoverable method. This has two impacts: ( 1) c e r t a i n species of some metals cannot be analyzed d i r e c t l y because t h e t o t a l r e c o v e r a b l e method does n o t d i s t i n g u i s h between i n d i v i d u a l oxidation s t a t e s , and ( 2) these c r i t e r i a may be overly protective when based on t h e t o t a l recoverable method.

The recommended exceedence frequency of 3 years is t h e Agency's best s c i e n t i f i c judgment of t h e average amount of t i m e it w i l l t a k e an unstressed system t o r e c o v e r from a p o l l u t i o n e v e n t i n which exposure t o copper exceeds t h e c r i t e r i o n . A stressed system, f o r example, one i n which several o u t f a l l s occur i n a l i m i t e d a r e a , would be expected t o r e q u i r e more t i m e f o r recovery. The r e s i l i e n c e of ecosystems and t h e i r a b i l i t y t o recover d i f f e r g r e a t l y , however, and s i t e s p e c i f i c c r i t e r i a may be established i f adequate j u s t i f i c a t i o n is provided.

The use of criteria i n developing waste treatment f a c i l i t i e s r e q u i r e s t h e s e l e c t i o n of an a p p r o p r i a t e wasteload a l l o c a t i o n model. Dynamic models a r e preferred f o r t h e application of these c r i t e r i a . L i m i t e d d a t a o r o t h e r f a c t o r s may make t h e i r use i m p r a c t i c a l , i n which case one should r e l y on a steady s t a t e model. The Agency recommends t h e interim use of 1Q5 o r l Q l O f o r 0 Criterion Maximum Concentration design flow and 745 or 7410 for the Criterion Continuous Concentration ( CCC) design flow in steady state models for unstressed and stressed systems respectively. These matters are discussed in more detail in the Technical Support Document for Water Quality Based Toxics Control ( U. S. EPA, 1985).

HUMAN HEALTH CRITERIA:

Sufficient data is not available for copper to derive a level which would protect against the potential toxicity of this compound. Using available organoleptic data, for controlling undesirable taste and odor quality of ambient water, the estimated level is 1 mg/ L. It should be recognized that organoleptic data as a basis for establishing a water quality criteria have 1 imitations and have no demonstrated relationship to potential adverse human health effects. I ( 45 F. R. 79318 Nov. 28,1980) ( 50 F. R. 30784, July 29, 1985) SEE APPENDIX A FOR METHODOLOGY CYANIDE AQUATIC  LIFE SUMMARY:

D a t a on t h e a c u t e t o x i c i t y of free cyanide ( t h e sum of cyanide p r e s e n t a s HCN and CN, expressed a s CN) are a v a i l a b l e f o r a w i d e v a r i e t y of freshwater s p e c i e s t h a t are i n v o l v e d i n d i v e r s e community functions. The acute s e n s i t i v i t i e s ranged from 44.73 ug/ L t o 2,490 ug/ L, b u t a l l of t h e s p e c i e s w i t h a c u t e s e n s i t i v i t i e s above 400 ug/ L were i n v e r t e b r a t e s . A long term s u r v i v a l , and a p a r t i a l and l i f e c y c l e t e s t with f i s h gave c h r o n i c v a l u e s o f 13.57, 7.849, and 16.39 ug/ L, r e s p e c t i v e l y .

Chronic v a l u e s f o r two f r e s h w a t e r i n v e r t e b r a t e s p e c i e s were 18.33 and 34.06 ug/ L. Freshwater p l a n t s were a f f e c t e d a t cyanide concentrations ranging from 30 ug/ L t o 26,000 ug/ L.

The acute t o x i c i t y of f r e e cyanide t o s a l t w a t e r species ranged from 4.893 ug/ L t o > 10,000 ug/ L and i n v e r t e b r a t e s w e r e both t h e most and l e a s t s e n s i t i v e species. Long term s u r v i v a l i n an e a r l y l i f e s t a g e test w i t h the sheepshead minnow gave a chronic v a l u e of 36.12 ug/ L. Long term s u r v i v a l i n a mysid l i f e c y c l e t e s t r e s u l t e d i n a c h r o n i c v a l u e of 69.71 ug/ L. T e s t s w i t h t h e red macroalga, Champia parvula  I showed cyanide t o x i c i t y a t 11 t o 25 ug/ L, b u t o t h e r s p e c i e s were a f f e c t e d a t c o n c e n t r a t i o n s up t o 3,000 ug/ L.

NATIONAL CRITERIA:

The procedures described i n t h e G u i d e l i n e s f o r Deriving Numerical National Water Q u a l i t y Criteria f o r t h e Protection of Aquatic Organisms and Their Uses indicate t h a t , except possibly where a l o c a l l y important s p e c i e s is very s e n s i t i v e , freshwater a q u a t i c o r g a n i s m s a n d t h e i r u s e s s h o u l d n o t be a f f e c t e d unacceptably if the 4 day average concentration of cyanide does not exceed 5.2 ug/ L more than once every 3 years on the average and if the 1 hour average concentration does not exceed 22 ug/ L more than once every 3 years on the average.

The procedures described in the Guidelines indicate that,

except possibly where a locally important species is very sensitive, saltwater aquatic organisms and their uses should not be affected unacceptably if the 1 hour average concentration of cyanide does not exceed 1.0 ug/ L more than once every 3 years on the average.

EPA believes that a measurement such as " acid soluble" would provide a more scientifically correct basis upon which to establish criteria for cyanide. The criteria were developed on this basis. However, at this time, no EPA approved methods for such a measurement are available to implement the criteria through the regulatory programs of the Agency and the States.

The Agency is considering development and approval of methods for a measurement such as acid soluble. Until available,

however, EPA recommends applying the criteria using the total recoverable method. These criteria may be overly protective when based on the total recoverable method.

The recommended exceedence frequency of 3 years is the Agency's best scientific judgment of the average amount of time it will take an unstressed system to recover from a pollution event in which exposure to cyanide exceeds the criterion. A stressed system, for example, one in which several outfalls occur in a limited area, would be expected to require more time for recovery. The resilience of ecosystems and their ability to recover differ greatly, however, and site specif ic criteria may be established if adequate justification is provided.

The use of criteria in designing waste treatment facilities requires the selection of an appropriate wasteload a1 location model. Dynamic models are preferred for the application of these criteria. Limited data or other factors may make their use impractical, in which case one should rely on a steady state model. The Agency recommends the interim use of 1Q5 or lQlO for Criterion Maximum Concentration design flow and 745 or 7410 f o r the Criterion Continuous Concentration design flow in steady

state models for unstressed and stressed systems respectively.

These matters are discussed in more detail in the Technical Support Document for Water Quality Based Toxics Control ( U. S.

EPA, 1985).

H" HEALTH CRITERIA The ambient water quality criterion for cyanide is recommended to be identical to the existing drinking water standard which is 200 ug/ L. Analysis of the toxic effects data resulted in a calculated level which is protective of human health against the ingestion of contaminated water and contaminated aquatic organisms. The calculated value is comparable to the present standard. For this reason a selective criterion based on exposure solely from consumption of 6.5 grams of aquatic organisms was not derived.

NOTE: The U. S. EPA is currently developing Acceptable Daily Intake ( ADI) or Verified Reference Dose ( RfD) values for Agency wide use for this chemical. The new value should be substituted when it becomes available. The January, 1986, draft Verified Reference Dose document cites an RfD of .02 mg/ kg/ day for free cyanide. , 0 CRITERIA:

DDT _.  DDT AND METABOLITES Aquatic Life For DDT and its metabolites the criterion to protect freshwater aquatic life as derived using the Guidelines is 0.0010 ug/ L as a 24 hour average and the concentration should not exceed 1.1 ug/ L at any time.

For DDT and its metabolites the criterion to protect'

saltwater aquatic life as derived using the Guidelines is 0.0010 ug/ L as a 24 hour average and the concentration should not exceed 0.13 ug/ L at any time.

TDE  The available data for TDE indicate that acute toxicity to freswater aquatic life occurs at concentrations as low as 0.6 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of TDE to sensitive freshwater aquatic life.

The available data for TDE indicate that acute toxicity to saltwater aquatic life occurs at concentrations as low as 3.6 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of TDE to sensitive saltwater aquatic life.

DDE  The available data for DDE indicate that acute toxicity './

to freshwater aquatic life occurs at concentrations as low as 1,050 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of DDE to sensitive freshwater aquatic life.

The available data for DDE indicate that acute toxicity to saltwater aquatic life occurs in concentrations as low as 14 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of DDE to sensitive saltwater aquatic life.

Human Health For the maximum protection of human health from the potential carcinogenic effects of exposure to DDT through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentration should be zero, based on the nonthreshold assumption for this chemical. However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk over the lifetime are estimated at and The corresponding recommended criteria are 0.24 nq/ L, 0.024 ng/ L, and 0.0024 ng/ L, respectively. If these estimates are made for consumption of aquatic organisms only, excluding consumption of water, the levels are 0.24 ng/ L, 0.024 ng/ L, and 0.0024 ng/ L, respectively.

( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY a CRITERION: DEMETON 0.1 ug/ L for freshwater and marine aquatic life RATIONALE:

Static LC50 bioassays yielded toxicity values for the organo

phosphorus pesticide demeton for carp, goldfish, fathead minnow,

channel catfish, guppy, rainbow, trout and bluegill, ranging from 70 ug/ L to 15,000 ug/ L ( Henderson and Pickering, 1958; Ludemann and Neumann, 1982; Macek and McAllister, 1970; McCann and Jasper,

1972; Pickering et al. 1962). Results of these tests demonstrate an apparent sharp division in species sensitivity, with bluegill ( Lepomis macrochirusr, rainbow trout ( Salmo gairdneri) and guppy, ( Poecilia   reticulatg,' being susceptible to lower concentrations while the remaining species were comparatively resistant. In the 96 hOUr exposures toxicity did not increase significantly with time, indicating that concentrations close to nominal may not have been maintained for more than a few hours,

Bluegills with a 24 hour LC50 of 70 ug/ L were the most sensitive fish ( Mccann and Jasper, 1972).

When fish were exposed to acutely toxic levels of demeton  or 12 hours by Weiss ( 1959, 1961) the maximum inhibition of brain acetiylcholinesterase ( AChE) was not reached. The lowest levels of AChE occurred after 24 to 48 hOUrS. It was demonstrated that maximum inhibition could last as long as two weeks after exposure, and subsequent recovery to levels approaching normal took many more weeks. Weiss ( 1958) reported a significant increase in mortality of fathead minnows exposed for a second time to the organophosphate, Sarin, before the fish had recovered normal brain AChE levels. The resistance of fully recovered fish was equal to that of previously unexposed controls. Weiss and Gakstatter ( 1964a) reported no significant inhibition of brain AChE in bluegills, goldfish and shiners ( Notemigonus __ crysoleucasl, __   following 15 day exposures to demeton at continuously replenished, nominal concentrations of 1 ug/ L.

Acute toxicity values reported for invertebrates range from 10 to 100,000 ug/ L ( Ludemann and Neumann, 1962; Sanders, 1972).

In general, molluscs and tubifex worms were very resistant while the smaller crustaceans and insect larvae were susceptible.

Ludemann and Neumann ( 1962) reported that Chironomus plumosus larvae were the most sensitive species they tested. A 24 hour exposure at 10 ug/ L produced undefined effects while 100 percent were killed at 1000 ug/ L. Calculated LC50 data for invertebrates apparently are limited to a single, nominal concentration static exposure of Gammarus ______ fasciatus ( Sanders, 1972). These 24 and 96 hourLC50 valuesarereportedas 500 and27 ug/ L, indicatinga time related effect not observed in the bioassays with fishes.

As only a fewofthe sensitive s p e c i e s h a v e b e e n t e s t e d a n d g r e a t variance in response can result with different test methods,

caution must be exercised in estimating the sub acute concentration for aquatic fauna in general. It appears that no study has been made of possible residual effects other than AChE inhibition, which might result from short exposures to subacute concentrations of organophosphates.

There are few data on the toxicity of demeton to marine organisms. Butler ( 1964) reported a 48 hour EC50 of 63 ug/ L for the pink shrimp, Peneaus duorarum, and a 24 hour LC50 of 550 ug/ L for the spot, Leiostomus xanthurus.

Chronic demeton toxicity data for freshwater organism are not currently available. Since no data are available at this time to indicate long term no effect levels for aquatic organisms, a criterion must be derived based partly on the fact that all organophosphates inhibit the production of the AChE enzyme.

Demeton is unique, however, in that the persistence of its AChE

inhibiting ability is greater than that of 10 other common organophosphates, even though its acute toxicity is apparently less. The effective " half life" of AChE inhibition for demeton is greater than one year ( Weiss and Gakstatter, 1964b). Because such inhibition may be additive with repeated exposures and may be compounded by any of the organophosphates, it is recommended that a criterion for demeton be based primarily on its enzyme

inhibiting potential. A criterion of 0.1 ug/ L demeton for freshwater and marine aquatic life is recommended since it will not be expected to significantly inhibit AChE over a prolonged period of time. In addition, the criteria recommendation is in close agreement with the criteria for the other organophosphates.

( QUALITY CRITERIA FOR WATER, JULY 1976) PB 263943 SEE APPENDIX C FOR METHODOLOGY DICHLOROBENZENES Aquatic  L i f e The available data for dichlorobenzenes indicate that acute and chronic toxicity to freshwater aquatic life occur at concentrations as low as 1,120 and 763 ug/ L, respectively, and would occur at lower concentrations among species that are more sensitive than those tested.

The available data for dichlorobenzenes indicate that acute toxicity to saltwater aquatic life occurs at concentrations as low as 1,970 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic' toxicity of dichlorobenzenes to sensitive saltwater aquatic life. 0 Human Health For the protection of human health from the toxic properties of dichlorobenzene ingested through water and contaminated aquatic organisms, the ambient water criterion is determined to be 4 0 0 ug/ L.

For the protection of human health from the toxic properties of dichlorobenzenes ingested through contaminated aquatic organisms alone, the ambient water criterion is determined to be 2.6 mg/ L.

( 4 5 F. R. 79318, November 28, 1980) SEE APPENDIX B. FOR METHODOLOGY 0 ., DICHLOROBENZIDINE CRITERIA:

Aquatic Life The data base available for dichlorobenzidines and freshwater organisms is limited to one test on bioconcentration of 3,3

dichlorobenzidine, and therefore, no statement can be made concerning acute or chronic toxicity.

No saltwater organisms have been tested with any dichlorobenzidine, and therefore, no statement can be made concerning acute or chronic toxicity.

Human Health For the maximum protection of human health from the potential carcinogenic effects of exposure to dichlorobenzidine through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentrations should be zero, based on the nonthreshold assumption for this chemical. However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk over the lifetime are estimated at and lo'.

The corresponding recommended criteria are 0.103 ug/ L, 0.010 ug/ L, and 0.001 ug/ L, respectively. If these estimates are made for consumption'of aquatic organisms only, excluding consumption of water, the levels are 0.204 ug/ L, 0.020 ug/ L, and 0.002 ug/ L, respectively. 0 ( 45 F. R. 79318, November 28, 1980)

_.* SEE APPENDIX B FOR METHODOLOGY DICHLOROETHYLENES Aquatic Life The available data for dichloroethylenes indicate that acute toxicity to freshwater aquatic life occurs at concentrations as low as 11,600 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No definitive data are available concerning the chronic toxicity of dichloroethylenes to sensitive freshwater aquatic life.

The available data for dichloroethylenes indicate that acute and chronic toxicity to saltwater aquatic life occurs at concentrations as low as 224,000 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of dichloroethylenes to sensitive saltwater aquatic life.

Human Health 1,1 Dichloroethylene For the maximum protection of human health from the potential carcinogenic effects of exposure to 1, l dichloroethylene through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentrations should be zero,

based on the non threshold assumption for this chemical.

However, zero level may not be attainable at the present time.

Therefore, the levels which may result in incremental increase of cancer risk over the lifetime are estimated at 10 5e 10

0 . 6, and The corresponding recommended criteria are 0.33 ug/ L, 0.033 ug/ L, and 0.003 ug/ L, respectively. If these estimates are made for consumption of aquatic organisms only, excluding consumption of water, the levels are 18.5 ug/ L, 1.85 ug/ L, and 0.185 ug/ L, respectively.

1,2 Dichloroethylene Using the present guidelines, a satisfactory criterion cannot be derived at this tine because of insufficient available data for 1,2 dichloroethylene.

( 4 5 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY 2,4 DICHLOROPHENOL CRITERIA:

Aquatic Life The available data for 2,4 dichlorophenol indicate that acute and chronic toxicity to freshwater aquatic life occurs at concentrations as low as 2,020 and 365 ug/ L, respectively, and would occur at lower concentrations among species that are more sensitive than those tested. Mortality to early life stages of one species of fish occurs at concentrations as low as 70 ug/ L.

Only one test has been conducted with saltwater organisms and 2,4 dichlorophenol and therefore, no statement can be made concerning acute or chronic toxicity.

Human Health For comparison purposes, two approaches were used to derive criterion levels for 2,4 dichlorophenol. Based on available toxicity data, to protect public health the derived level is 3.09 mg/ L. Using available organoleptic data, to control undesirable taste and odor qualities of ambient water the estimated level is 0.3 ug/ L. It should be recognized that organoleptic data have limitations as a basis for establishing a water quality criterion, and have no demonstrated relationship to potential adverse human health effects.

( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY DICHLOROPROPANES/ DICHLOROPROPROPENES CRITERIA:

Aquatic Life The available data for dichloropropanes indicate that acute and chronic toxicity to freshwater aquatic life occurs at concentrations as low as 23,000 and 5,700 ug/ L, respectively, and would occur at lower concentrations among species that are more sensitive than those tested.

The available data for dichloropropene indicate that acute and chronic toxicity to freshwater aquatic life occurs at concentrations as low as 6,060 and 2 4 4 ug/ L, respeptively, and would occur at lower concentrations among species that are more sensitive than those tested.

The available data for dichloropropane indicate that acute and chronic toxicity to saltwater aquatic life occur at concentrations as l o w as 10,300 and 3,040 ug/ L, respectively, and would occur at lower concentrations among species that are more sensitive than those tested.

The available data for dichloropropene indicate that acute toxicity to saltwater aquatic life occurs at concentrations as low as 790 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of dichloropropene to sensitive saltwater aquatic life. Human Health Using the present guidelines, a satisfactory criterion cannot be derived at this time because of insufficient available data for dichloropropanes.

( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY Aquatic Life The available data for 2,4 dimethylphenol indicate that acute toxicity to freshwater aquatic life occurs at concentrations as low as 2,120 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of dimethylphenol to sensitive freshwater aquatic life.

No saltwater organisms have been tested with 2,4

dimethyl phenol and therefore, no statement can be made concerning acute or chronic toxicity.

Human Health Sufficient data are not available for 2,4 dimethylphenol to derive a level which would protect against the potential toxicity of this compound. Using available organoleptic data, to control undesirable taste and odor quality of ambient water the estimated level is 400 ug/ L. It should be recognized that organoleptic data have limitations as a basis for establishing a water quality criterion, and have no demonstrated relationship to potential adverse human health effects.

( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY CRITERIA: DINITROTOLUENE Aquatic Life The available data for dinitrotoluenes indicate that acute and chronic toxicity to freshwater aquatic life occurs at concentrations as low as 330 and 230 ug/ L, respectively, and would occur at lower concentrations among species that are more sensitive than those tested.

The available data for dinitrotoluenes indicate that acute toxicity to saltwater aquatic life occurs at concentrations as low as 5 9 0 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of dinitrotoluenes to sensitive saltwater aquatic life but a decrease in algal cell numbers occurs at concentrations as low as 370 ug/ L.

Human Health For the maximum protection of human health from the potential carcinogenic effects of exposure to 2,4 dinitrotoluene through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentration should be zero, based on the nonthreshold assumption for this chemical. However,

zero level may not be attainable at the present time. Therefore,

the levels which may result in incremental increase of cancer risk over the lifetime are estimated at and The corresponding recommended criteria are 1.1 ug/ L, 0.11 ug/ L, and 0.011 ug/ L, respectively. If these estimates are made for consumption of aquatic organ isms only, excluding consumption of water, the levels are 91 ug/ L, 9.1 ug/ L, and 0.91 ug/ L,

respectively.

( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY DIPHENYLHYDRAZINE Aquatic Life The available data for 1,2 diphenylhydrazine indicate that acute toxicity to freshwater aquatic life occurs at concentrations as low as 270 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of 1,2 diphenylhydrazine to sensitive freshwater aquatic life.

NO saltwater organisms have been tested with 1,2

diphenylhydrazine and therefore, no statement . can be made concerning acute or chronic toxicity.

Human Health For the maximum protection of human health from the potential carcinogenic effects of exposure to diphenylhydrazine through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentrations shopld be zero, based on the nonthreshold assumption for this chemical. However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk over the lifetime are estimated at and The corresponding recommended criteria are 422 ng/ L, 42 ng/ L, and 4 ng/ L, respectively. If these estimates are made for consumption of aquatic organisms only, excluding consumption of water, the levels are 5.6 ug/ L, 0.56 ug/ L, and 0.056 ug/ L, 0 respectively.

0 ( 4 5 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY ENDOSULFAN Aquatic Life For endosulfan the criterion to protect freshwater aquatic life as derived using the Guidelines is 0.056 ug/ L as a 24 hour average and the concentration should not exceed 0.22 ug/ L at any time.

For endosulfan the criterion to protect saltwater aquatic life as derived using the Guidelines is 0.0087 ug/ L as a 24 hour average and the concentration should not exceed 0.034 ug/ L at any time.

Human Health For the protection of human ' health from the toxic properties of endosulfan ingested through water and contaminated aquatic organisms, the ambient water criterion is determined to be 74 ug/ L.

For the protection of human health from the toxic properties of endosulfan ingested through contaminated aquatic organisms alone, the ambient water criterion is determined to be 159 ug/ L.

( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY CRITERIA: * ENDRIN Aquatic Life For endrin the criterion to protect freshwater aquatic life as derived using the Guidelines is 0.0023 ug/ L as a 24 hour average, and the concentration should not exceed 0.18 ug/ L at any time.

For endrin the criterion to protect saltwater aquatic life as derived using the Guidelines is 0.0023 ug/ L as a 24 hour average,

and the concentration should not exceed 0.037 ug/ L at any time.

Human Health The ambient water quality criterion for endrin is recommended to be identical to the existing water standard which is 1.0 ug/ L.

Analysis of the toxic effects data resulted in a calculated level which is protective of human health against the ingestion of contaminated water and contaminated aquatic organisms. The calculated value is comparable to the present standard. For this reason a selective criterion based on exposure solely from assumption of 6.5 g of aquatic organisms was not derived.

* Indicates suspended, canceled or restricted by W. S. EPA Office of Pesticides and Toxic Substances ( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY 0 CRITERIA:

The avai 3 B da ETHYLBENZENE A q u a t i c Life 3 for ethylbenzene idicate t at acute toxicity to freshwater aquatic life occurs at concentrations as low as 32,000 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No definitive data are available concerning the chronic toxicity of ethylbenzene to sensitive freshwater aquatic life.

The available data for ethylbenzene indicate that acute toxicity to saltwater aquatic life occurs at concentrations as low as 430 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of ethylbenzene to sensitive saltwater aquatic life.

Human Health For the protection of human health from the toxic properties of ethylbenzene ingested through water and contaminated aquatic organisms, the ambient water criterion is determined to be 1.4 W/ L.

For the protection of human health from the toxic properties of ethylbenzene ingested through contaminated aquatic organisms alone, the ambient water criterion is determined to be 3.28 mg/ L.

( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY NOTE: The U. S. EPA is currently developing Acceptable Daily Intake ( ADI) or Verified Reference Dose ( RfD) values for Agency wide use for this chemical. The new value should be substituted when it becomes available. The January, 1986, draft Verified Reference Dose document cites an RfD of 0.1 mg/ kg/ day for ethylbenzene. FLUORANTHENE Aquatic Life The available data for fluoranthene indicate that acute toxicity to freshwater aquatic life occurs at concentrations as l o w as 3,980 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of f luoranthene to sensitive  freshwater aquatic life.

The available data  or fluoranthene indicate that acute and chronic toxicity to saltwater aquatic life occur at concentrations as low as 40 and 16 ug/ L, respectively, and would occur at lower concentrations' among species that are more sensitive than those tested. a Human Health For the protection of human health from the toxic properties of fluoranthene ingested through water and contaminated aquatic organisms, the ambient water criterion is determined to be 42 ug/ L.

For the protection of human health from the toxic properties of fluoranthene ingested through contaminated aquatic organisms alone, the ambient water criterion is determined to be 54 ug/ L.

( 45 F. R. 79318, Novembe r 28, 1980) SEE APPENDIX B FOR METHODOLOGY GASES, TOTAL DISSOLVED CRITERION:

To protect freshwater and marine aquatic life, the total dissolved gas concentrations in water should not exceed 110 percent of the saturation value for gases at the existing atmospheric and hydrostatic pressures.

RATIONALE:

Fish in water containing excessive dissolved gas pressure or tension are killed when dissolved gases in their circulatory system come out of solution to form bubbles ( emboli) which block the flow of blood through the capillary vessels. In aquatic organisms this is commonly referred to as " gas bubble diseasett.

External bubbles ( emphysema) also appear in the fins, on the opercula, in the skin and in other body tissues. Aquatic invertebrates are also affected by gas bubble disease, but usua1l. y at supersaturation levels higher than those lethal to fish. 0 The standard method of analyzing for gases in solutions has been the Van Slyke method ( Van Slyke et al. 1934); now, gas chromatography also is used f o r determination of individual and total gases. For determination of total gas pressure, Weiss has developed the saturometer, a device based upon a thin wall silicone rubber tube that is permeable to gases but impermeable to water. Gases pass from the water through the tube, thus 0 raising the internal gas pressure which is measured by a manometer or pressure gauge connected to the tube ( NAS, 1974).

This method alone does not separate the total gas pressure into the separate components, but Winkler oxygen determinations can be run simultaneously, and gas concentrations can be calculated.

Total dissolved gas concentrations must be determined because analysis of individual gases may not determine with certainty that gas supersaturation exists. For example, water could be highly supersaturated with oxygen, but if nitrogen were at less than saturation, the saturation as measured by total gas pressure might not exceed 100 percent. Also, if the water was highly supersaturated with dissolved oxygen, the oxygen alone might be sufficient to create gas pressures or tensions greater than the Criterion limits, but one would not know the total gas pressure or tension, or by how much the criterion was exceeded. The rare and inert gases such as argon, neon and helium are not usually involved in causing gas bubble disease as their contribution to total gas pressures is very low. Dissolved nitrogen ( NZ), which comprises roughly 80 percent of the earth's atmosphere, is nearly inert biologically and is the most significant cause of gas bubble disease in aquatic animals. Dissolved oxygen, which is extremely bioactive, is consumed by the metabolic processes of the organism and is less important in causing serious gas bubble disease though it may be involved in initiating emboli formation in the blood ( Nebeker et al. 1976a).

Percent saturation of water containing a given amount of gas varies with the absolute temperature and with the pressure.

Because of the pressure changes, percent saturation with a given amount of gas changes with depth of the water. Gas supersaturation decreases by 10 percent per meter of increase in water depth because of hydrostatic pressure; a gas that is at 130 percent saturation at the surface would be at 100 percent saturation at 3 meters' depth. Compensation  or altitude may be needed because a reduction in atmospheric pressure changes the water/ gas equilibria, resulting in changes in solubility of dissolved gases.

There are several ways that total dissolved gas supersaturation can occur:

1. Excessive biological activity dissolved oxygen concentrations often reach supersaturation because of excessive algal photosynthesis. Renfro ( 1963) reported gas bubble disease in fishes resulting, in part, from algal blooms. Algal blooms often accompany an increase in water temperature and this higher temperature further contributes to supersaturation. I 2. Lindroff ( 1957) reported that water spillage at hydropower dams caused supersaturation. When excess water is spilled over the face of a dam it entrains air as it plunges to the stilling or plunge pool atthebaseofthedam. Themomentum of the fall carries the water and entrained gases to great depths in the pool; and, under increased hydrostatic pressure, the entrained gases are driven into solution, causing supersaturation of dissolved gases.

3. Gas bubble disease may be induced by discharges from power generating and other thermal sources ( Marcello et al. ./ 1975). Cool, gas saturated water is heated as it passes through the condenser or heat exchanger. As the temperature of the water rises, percent saturation increases because of the reduced solubility of gases at higher temperatures. Thus, the discharged water becomes supersaturated with gases and fish or other organisms living in the heated water may exhibit gas bubble disease ( DeMont and Miller, 1972: Malouf et al. 1972; Keup,

1975). ! In recent years, gas bubble disease has been identified as a major problem affecting valuable stocks of salmon and trout in the Columbia River system ( Rulifson and Abel, 1971). The disease is caused by high concentrations of dissolved atmospheric gas which enter the river's water during heavy spillinq at hydroelectric dams. A report by Ebel et al. ( 1975) presents results from field and laboratory studies on the lethal,

sublethal and physiological effects of gas on fish, depth distribution of fish in the river ( fish can compensate for some high concentrations of gas by moving deeper into the water column), detection and avoidance of gas concentrations by fish,

intermittent exposure of fish to gas concentrations, and bioassays of many species of fish exposed to different concentrations of gas. Several conclusions resulting from these studies are:

1. When either juvenile or adult salmonids are confined to shallow water ( 1 m), substantial mortality occurs at and above 115 percent total dissolved gas saturation.

2. When either juvenile or adult salmonids are free to sound and obtain hydrostatic compensation either in the laboratory or in the field, substantial mortality still occurs when saturation , levels ( of total dissolved gases) exceed 120 percent saturation.

3. On the basis of survival estimates made in the Snake River from 1966 to 1975, it is concluded that juvenile fish losses ranging from 40to 95 p e r c e n t d o o c c u r a n d a m a j o r p o r t i o n of this mortality can be attributed to fish exposure to supersaturation by atmospheric gases during years of high flow.

4. Juvenile salmonids subjected to sublethal periods of exposure to supersaturation can recover when returned to normally saturated water, but adults do not recover and generally die from direct and indirect effects of the exposure.

5. Some species of salmon and trout can detect and avoid supersaturated water; others may not.

6. Higher survival was ' observed during periods of intermittent exposure than during continuous exposure.

7. In general, in acute bioassays, salmon and trout were less tolerant than the nonsalmonids.

Dawley and Ebel ( 1975) found that exposure of juvenile spring chinook salmon, Oncorhynchus tshawytscha,  and steelhead trout,

Salmo qairdneri, to 120 percent saturation for 1.5 days resulted in over 50 percent mortality; 100 percent mortality occurred in less than 3 days. They also determined that the threshold level where significant mortalities begin occurring is at 115 percent nitrogen saturation ( 111 percent total gas saturation in this test).

Rucker ( 1974), using juvenile coho salmon, Oncorhynchus kisutch, determined the effect of individual ratios of oxygen and nitrogen and established that a decrease in lethal effect .,

occurred when the nitrogen content fell below 109 percent saturation even though total gas saturation remained at 119 percent saturation, indicating the importance of determining the concentration of the individual components ( 02 and N 2 ) of the atmospheric supersaturation. Nebeker et al. ( 1976a), using juvenile sockeye salmon, Oncorhynchus nerka, also showed that there was a significant increase in fish mortality when the nitrogen concentration was increased while holding the total percent saturation constant. They also showed that there was no significant difference in fish mortality at different C02 concentrations.

Research collected by Bouck et al. ( 1975) showed that gas supersaturated water at and above 115 percent total gas saturation is acutely lethal to most species of salmonids, with 120 percent saturation and above rapidly lethal to all salmonids tested. Levels as low as 110 percent will produce emphysema in most species. Steelhead trout were most sensitive to gas

supersaturatea water followed by sockeye salmon, Oncorhyncnus nerka. Chinook salmon, ______ Oncorhynchus _____ __ tshawytscha  I were intermediate in sensitivity. Coho salmon, Oncorhyncnus kisutch,

were significantly the more tolerant of the salmonids though

still much more susceptible than non salmonids like bass or carp.

 DaFnia  rmqna __ exhibited a sensitivity to supersaturation similar to that of the salmonids ( Nebeker et al. 1975), with 115 percent saturation lethal within a few days. Stoneflies exhibited an intermediate sensitivity similar to bass with mortality at 130 percent saturation. Crayfish were very tolerant, with levels near 140 percent total gas saturation resulting in mortality. No d i f f e r e n c e s are proposed i n t h e c r i t e r i a   o r freshwater and marine aquatic l i f e a s t h e data a v a i l a b l e indicate t h a t there probably is l i t t l e d i f f e r e n c e i n o v e r a l l t o l e r a n c e s between marine and freshwater species.

The development of gas bubble disease i n menhaden, S o o r t i a sp., and t h e i r t o l e r a n c e t o g a s s a t u r a t i o n i n l a b o r a t o r y bioassays and i n t h e f i e l d ( P i l g r i m Nuclear Power S t a t i o n Discharge Canal) a r e discussed by Clay e t a l . ( 1975) and Marcello e t a l . ( 1 9 7 5 ) . A t 1 0 0 p e r c e n t and 1 0 5 p e r c e n t n i t r o g e n saturation, no gas bubbles developed e x t e r n a l l y o r i n any of t h e i n t e r n a l organs of menhaden. A t 105 percent nitrogen saturation,

however, c e r t a i n b e h a v i o r a l changes became apparent. Fish sloughed o f   mucus, s w a m e r r a t i c a l l y , were more e x c i t a b l e , and became darker i n color. Menhaden behavioral changes observed a t 110 p e r c e n t n i t r o g e n s a t u r a t i o n were s i m i l a r t o t h o s e noted a t 3.05 percent. I n a d d i t i o n , a t 110 p e r c e n t gas emboli were found i n t h e i n t e s t i n e s , t h e p y l o r i c caeca, and o c c a s i o n a l l y t h e operculum. The behavioral changes described w e r e a l s o observed a t 115 p e r c e n t , and c l e a r l y d e f i n e d subcutaneous emphysema was observed i n t h e f i n s and o c c a s i o n a l l y i n t h e eye. A t 1 2 0 p e r c e n t and 130 percent nitrogen saturation, menhaden developed within a f e w hours c l a s s i c symptoms of g a s bubble d i s e a s e . E x t e r n a l l y ,

emboli were e v i d e n t i n a l l f i n s , t h e operculum and w i t h i n the o r a l cavity.

Exophthalmia a l s o occurred and emboli developed i n i n t e r n a l The bulbous a r t e r i o s i s and s w i m b l a d d e r w e r e s e v e r e l y J distended, and emboli were found along t h e l e n g t h of t h e g i l l a r t e r i o l e s , r e s u l t i n g i n hemostasis. A t water temperatures of 30 organs.

0 OC, menhaden did not survive, regardless of gas saturation level.

At water temperatures of 15 , 22 , and 25 OC 100 percent of the menhaden died within 24 hours at 120 percent and 130 percent gas saturation. Fifty percent died after 96 hours at 115 percent ( 22 OC) Menhaden survival after 96 hours at 110 percent nitrogen saturation ranged from 92 percent at 22O and 25' to 83 percent at 15 OC. Observations on the relationship between the mortality rate of menhaden and gas saturation levels at Pilgrim Station during the April 1975, incident suggest that the fish may tolerate somewhat higher gas saturation levels in nature.

It has been shown by Bouck et al. ( 1975) and Dawley et al.

( 1975) that survival of salmon and steelhead smolts in seawater is not affected by prior exposure to gas supersaturation while in fresh water. No significant mortality of juvenile coho and sockeye salmon occurred when they were exposed to sublethal concentrations of supersaturated water and then transferred to seawater ( Nebeker et al. 197633).

( QUALITY CRITERIA FOR WATER, JULY 1976) PB 263943 SEE APPENDIX C FOR METHODOLLIGY GUTHION CRITERION:

.01 ug/ L for freshwater and marine aquatic life.

RATIONALE :

Ninety six hour LC50 values for fish exposed to the organophosphorus pesticide guthion range from 4 to 4270 ug/ L ( Katz, 1961: Pickering et al. 1962; Lahav and Sarig, 1969; Macek et al. 1969; Macek and McAllister, 1970). The only long term fish exposure data available are those obtained recently by Adelman and Smith ( unpublished data) Decreased spawning ( eggs produced per female) was observed in fathead minnows, PimephalE prrelas  I exposed during a complete life cycle. An estimated " safe" long term exposure concentration f o r fathead minnows lies between 0.3 and 0.5 ug/ L. survival of larvae was reduced at approximately 0.7 ug/ L. 0 An investigation of the persistence of guthion in fish revealed that 50 percent of the chemical was lost in less than one week ( Meyer, 1965). Analysis of plankton and pond water in the same study indicated a 50 percent loss of guthioninabout48 hours. Flint et al. ( 1970) determined the half life of guthion at 30C in pond water and in a phosphate buffer protected from light in the laboratory. The half life in pond water was 1.2 days whereas that in the laboratory solution was 10 days. The more rapid degradation in pond water was attributed to the effect of sunlight and microorganisms.

Organophosphate pesticides are toxic because they inhibit the enzyme acetylcholinesterase ( AChE) which is essential to nerve impulse conduction and transmission ( Holland et al. 1967). Weiss ( 1958, 1959, 1961) demonstrated that a 40 to 70 percent inhibition of fish brain AChE usually is lethal. Centrarchids generally are considered one of the more sensitive groups of fish to guthion ( Pickering et al. 1962; Weiss and Gakstatter, 1964;

Meyer, 1965). Weiss and Gakskatter ( 1964) found that over a 15

day period bluegills, _ Lepomis __ macrochirus 1 exhibited AChE inhibition at 1.0 ug/ L guthion but not at 0.1 ug/ L. Exposure at 0.05 ug/ L for 30 days also failed to produce inhibition below the range of normal variation, but the authors stated that it appeared there was a downward trend in brain enzyme activity and that if exposure was continued a definite reduction might develop. Weiss ( 1961) found that about 30 days were required for fathead minnow and bluegill brain AChE levels to recover after 8 to 24 hours exposure to 10 ug/ L guthion.

Benke and Murphy ( 1974) showed that repetitive injection of fish with guthion caused cumulative inhibition of brain AChE and mortality. After substantial inhibition by guthion exposure, it takes several weeks for brain AChE of fishes to return to normal even though exposure is discontinued ( Weiss, 1959, 1960; Carter,

1971). Inhibition of brain AChE of fishes by 46 percent or more has been associated with harmful effects in exposures to there organophosphate pesticides for a life cycle ( Eaton, 1970) and for shorter periods ( Carter, 1971; Coppage and Duke, 1971; Coppage,

1972; Coppage and Matthews, 1974: Post and Leasure, 1974; Coppage et al. in press). In static tests, similar inhibition of AChE and mortality were caused in the sheepshead minnow, Cyprinodon variegatus, in 2, 24, 48 and 72 hours at concentrations of 50, 7,

3.5 and 3 ug/ L, respectively ( Coppage, 1972). These data indicate that reduction of brain AChE activity of marine fishes by 70 to 80 percent or more in short term exposures to guthion may be associated with some deaths.

There is no evidence to indicate that guthion would cause adverse effects through the food chain. Tissue residue accumulation for whole fish calculated from the data of Meyer ( 1965) indicate no more than a twentyfold accumulation. LC50 toxicity values for birds are relatively high and range from 70 to 2,000 mg/ kg ( Tucker and Crabtree, 1970).

Ninety six hour LC50 values for aquatic invertebrates range from 0.10 to 22.0 ug/ L ( Nebeker and Gaufin, 1964; Gaufin et al.

1965: Jensen and Gaufin, 1966: Sanders and Cope, 1968: Sanders,

1969, 1972). Sanders ( 1972) exposed the grass shrimp,

Paleomonetes kadiakensis ___ r to guthion in a continuous flow bioassay for up to 20 days and found that the 5 and 20 day LC50 values were 1.2 and 0.16 ug/ L, respectively. He found that the amphipod,  Gammarus  I_ fasciatus 1 was the most sensitive aquatic organism tested, with a 96 hour LC50 of 0.10 ug/ L. Jensen and Gaufin ( 1966), also using a continuous flow system, exposed two species of stonefly naiads in 4 and 30 day studies. They observed 96 hour and 30 day LC50 values for Acroneuria pacifica of 2.0 and 0.24 ug/ L, respectively, whereas for Pteronarcys   californica the values were 4.6 and 1.3 ug/ L, respectively.

Results of other toxicity studies on marine organisms have 1 . 3 been reported. The 24 hour LC50 for the white mullet, _ M U G 1 _ 0 curema, was found to be 5.5 ug/ L guthion ( Butler, 1963). The 96

hour LC50 for the striped mullet, Mugil cephalus, was determined by Lahav and Sarig ( 1969) to be 8 ug/ L guthion. Portman ( 1972)

reported the 48 hour LC50 for the fish,  Pleuronectes  limanda, to be 10 to 30 ug/ L. The 48 hour LC50 for the European shrimp,

Cranqon crangon, was found to be 0.33 ug/ L guthion ( Portman,

1972). Butler ( 1963) found that the 24 hour EC50  or blue crab,

 Callinectes  sapidus, was 550 ug/ L and the 48 hour EC50  or pink shrimp, Penaeus duorarum, was 4.4 ug/ L guthion. The 48 hour TLm was estimated to be 6 2 0 ug/ L   o r fertilized oyster eggs,

Crassostrea  vixinica  I and 860 ug/ L for fertilized clam eggs,

Mercenaria  mercenaria ( Davis and Hidu, 1969).

A criterion level of .01 ug/ L for guthion is based upon use of an 0.1 application factor applied to the 96 hour LC50 of 0.1 ug/ L for  Gammarus and a similar value of 0.3 ug/ L for the European shrimp.

( QUALITY CRITERIA FOR WATER, JULY 1976) PB 263943 SEE APPENDIX C FOR METHODOLOGY HALOETHERS CRITERIA:

Aquatic Life The available data for haloethers indicate that acute and chronic toxicity to freshwater aquatic life occurs at concentrations as low as 360 and 122 ug/ L, respectively, and would occur at lower concentrations among species that are more sensitive than those tested.

No saltwater organisms have been tested with any haloether and therefore, no statement can be made concerning acute or chronic toxicity.

Human Health Using the present guidelines, a satisfactory criterion cannot be derived at this time because of insufficient available data for ha 1 oethers. 0 ( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY HALOMETHANES CRITERIA:

Aquatic Life The available data for halomethanes indicate that acute toxicity to freshwater aquatic life occurs at concentrations as low a 11,000 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chroni c toxicity of halomethanes to sensitive freshwater aquatic life.

The available data for halomethanes indicate that acute and chronic toxicity to saltwater aquatic life occurs at concentrations as low as 12,000 and 6,400 ug/ L, respectively, and would occur at lower concentrations among species that are more sensitive than those tested. A decrease in algal cell numbers occurs at concentrations as low as 11,500 ug/ L. 0 Human Health For the maximum protection of human health from the potential carcinogenic effects of exposure to chloromethane,

bromomethane, dichloromethane, bromodichloromethane,

tribromomethane, dichlorodifluoromethane, trichlorofluoromethane,

or combinations of these chemicals through ingestion of contaminated water and aquatic organisms, the ambient water concentration should be zero, based on the non threshold assumption for this chemical, However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk over the lifetime 0  are estimated at loe6 and The corresponding recommended criteria are 1.9 ug/ L, 0.19 ug/ L, and 0.019 uq/ L,

respectively. If these estimates are made for consumption of aquatic organisms only, excluding consumption of water, the levels are 157 ug/ L, 15.7 ug/ L, and 1.57 ug/ L, respectively.

( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY HARDNESS I" RODUC" ION:

Water hardness is caused by the polyvalent metallic ions disolved in water. In fresh water these are primarily calcium and magnesium although other metals such as iron, strontium and manganese contribute to the extent that appreciable concentrations are present. Hardness commonly is reported as an equivalent concentration of calcium carborate ( CaC03).

The concept of hardness comes from water supply practice. It is measured by soap requirements for adequate lather formation and as an indicator of the rate of scale formation in hot water heaters and low pressure boilers. A commonly used classification is given in the following table ( Sawyer, 1960).

TABLE 3.

Classification of Water by Hardness Content Conc. mg/ L CaC03 Description 0  75 75  150 150  300 300 and up soft moderately hard hard very hard Natural sources of hardness principally are limestones which are dissolved by percolating rainwater made acid by dissolved carbon dioxide. Industrial and industrially related sources include the inorganic chemical industry and discharges from operating and abandoned mines.

Hardness in fresh water frequently is distinguished in carbonate and non carbonate fractions. The carbonate fraction is chemically equivalent to the bicarbonates present in water. I Since bicarbonates generally are measured as alkalinity, the carbonate hardness usually is considered equal to the alkalinity.

RATIONALE:

The determination of hardness in raw waters subsequently treated and used for domestic water supplies is useful as a parameter to characterize the total dissolved solids present and for calculating dosages where lime soda softening is practiced.

Because hardness concentrations in water have not been proven health related, the final level achieved principally is a function of economics. Since hardness in water can be removed with treatment by such processes as lime soda softening and zeolite or ion exchange systems, a criterion for raw waters used for public water supply is not practical.

The effects of hardness on freshwater fish and other aquatic life appear to be related to the ions causing the hardness rather than hardness. Both the NTAC ( 1968) and NAS ( 1974) panels have recommended against the use of the term hardness but suggest the inclusion of the concentrations of the specific ions. This procedure should avoid confusion in future studies but is not helpful in evaluating previous studies. For most existing data,

it is difficult to determine whether toxicity o f various metal ions is reduced because of the formation of metallic hydroxides and carbonates caused by the associated increases in alkalinity,

or because of an antagonistic effect of one of the principal cations contributing to hardness, e. g., calcium, or a combination of both effects. Stiff ( 1971) presented a theory ( without proof) t h a t i f cupric ions were t h e t o x i c form of copper whereas copper carbonate complexes were r e l a t i v e l y non toxic, then t h e observed difference i n t o x i c i t y of copper between hard and s o f t waters can be e x p l a i n e d by t h e d i f f e r e n c e i n a l k a l i n i t y r a t h e r t h a n hardness. Doudoroff and K a t z ( 1953), i n t h e i r review of t h e l i t e r a t u r e on t o x i c i t y , presented d a t a showing t h a t i n c r e a s i n g calcium i n p a r t i c u l a r reduced t h e t o x i c i t y of other heavy metals.

Under u s u a l conditions i n fresh water and assuming t h a t o t h e r b i v a l e n t metals behave s i m i l a r l y t o copper, it is reasonable t o assume t h a t both effects occur simultaneously and e x p l a i n t h e observed reduction of t o x i c i t y of m e t a l s i n waters containing carbonate hardness. T h e amount of reduced t o x i c i t y related t o hardness, as measured by a 40 hour LC50 f o r rainbow t r o u t , has been estimated t o be about f o u r t i m e s f o r copper and z i n c when t h e hardness was increased from 1 0 t o 1 0 0 mg/ L a s CaC03 ( NAS,

1974)

L i m i t s on hardness f o r i n d u s t r i a l u s e s a r e q u i t e v a r i a b l e .

Table 4 lists maximum values t h a t have been accepted by various i n d u s t r i e s a s a source of raw w a t e r ( NAS, 1 9 7 4 ) . Subsequent treatment g e n e r a l l y can reduce hardness t o t o l e r a b l e l i m i t s although c o s t s of such t r e a t m e n t a r e a n important f a c t o r i n determining its d e s i r a b i l i t y  or a p a r t i c u l a r water source.

Hardness is not a determination of concern f o r i r r i g a t i o n use o f water. The c o n c e n t r a t i o n s o f t h e c a t i o n s c a l c i u m and magnesium, which comprise hardness, are important i n determining t h e exchangeable sodium i n a g i v e n water. T h i s p a r t i c u l a r calculation w i l l be discussed under t o t a l dissolved s o l i d s rather TABLE 4.

Maximum Hardness Levels Accepted By Industry as a Raw Water Source*

Industry Electric utilities Maximum Concentration m& L as CaC03  5,000 Textile 120 Pulp and paper 475 Chemical 1,000 Petroleum 900 Primary metals 1,000 * Requirements for final use within a process may be essential11 zero, which requires treatment f o r concentration reductions. than hardness.

a ( QUALITY CRITERIA FOR WATER, JULY 1976) PB 263943 SEE APPENDIX C FOR METHODOLOGY HEFTACHLOR CRITERIA:

Aquatic Life For heptachlor the criterion to protect freshwater aquatic life as derived using the Guidelines is 0.0038 ug/ L as a 24 hour average, and the concentration should not exceed 0.52 ug/ L at any time.

For heptachlor the criterion to protect saltwater aquatic life as derived using the Guidelines is 0.0036 ug/ L as a 24 hour average, and the concentration should not exceed 0.053 ug/ L at any time.

Human Health For the maximum protection of human health from the potential carcinogenic effects of exposure to heptachlor through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentration should be zero, based on the non threshold assumption for this chemical. However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk over the lifetime are estimated at and The corresponding recommended criteria are 2.00 ng/ L, 0.20 ng/ L, and 0.020 ng/ L, respectively. If these estimates are made for consumption of aquatic organisms only, excluding consumption of water, the levels are 2.04 ng/ L, 0.20 ng/ L, and 0.020. ng/ L, 0 respectively.

0 ( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY HEXACHLOROBUTADIENE CRITERIA:

Aquatic Life The available data for hexachlorobutadiene indicate that acute and chronic toxicity to freshwater aquatic life occur at concentrations as low as 90 and 9.3 ug/ L, respectively,

and would occur at lower concentrations among species that are more sensitive than those tested.

The available data for hexachlorobutadiene indicate that acute toxicity to saltwater aquatic life occurs at concentrations as low as ? 2 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are I available concerning the chronic toxicity of hexachlorobutadiene to sensitive saltwater aquatic life. 0 Human Health For the maximum protection of human health from the potential carcinogenic effects of exposure to hexachlorobutadiene through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentrations should be zero, based on the nonthreshold assumption for this chemical. However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk over the lifetime ' are estimated at and The corresponding recommended criteria are 4.47 ug/ L, 0.45 ug/ L, and 0.045 ug/ L, respectively. If these estimates are 0 i .

made for consumption of aquatic organisms only, excluding consumption of water, t h e l e v e l s are 500 ug/ L, 50 ug/ L, and 5.0 ug/ L, respectively.

( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY HEXACHUIROCYCLOHEXANE CRITERIA:

Aquatic Life Lindane For lindane the criterion to protect freshwater aquatic life as derived using the Guidelines is 0.080 ug/ L as a 24 hour average and the concentration should not exceed 2.0 ug/ L at any time.

For saltwater aquatic life the concentration of lindane should not exceed 0.16 ug/ L at any time. No data are available concerning the chronic toxicity of lindane to sensitive saltwater aquatic life.

BHC  The available data for a mixture of isomers of BHC indicate that acute toxicity to freshwater aquatic life occurs at concentrations as low as 100 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of a mixture of isomers of BHC to sensitive freshwater aquatic life.

The available data for a mixture of isomers of BHC indicate that acute toxicity to saltwater aquatic life occurs at concentrations as low as 0.34 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of a mixture of isomers of BHC to sensitive saltwater aquatic life.

0 i. Human Health For the maximum protection of human health from the potential carcinogenic effects of exposure to hexachlorocyclohexane through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentrations should be zero, based on the nonthreshold assumption for this chemical. However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk , and 10 over the lifetime are estimated at loq5,

The corresponding recommended criteria are 2 2 ng/ L, 2.2 7 ng/ L, and . 2 2 ng/ L, respectively. If these estimates are made for consumption of aquatic organisms only, excluding consumption of water, the levels are 74 ng/ L, 7.4 ng/ L, and .74 ng/ L,

respectively. 10 6 For the maximum protection of human health from the potential carcinogenic effects of exposure to hexachlorocyclohexane through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentrations should be zero, based on the nonthreshold assumption for this chemical. However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk over the lifetime are estimated at and The corresponding recommended criteria are 134 ng/ L, 13.4 ng/ L,

and 1.34 ng/ L, respectively. If these estimates are made for consumption of aquatic organisms only, excluding consumption of water, the levels are 450 ng/ L, 45.0 ng/ L, and 4.50 ng/ L,

respectively. For the maximum protection of human health from the potential carcinogenic effects due to exposure of r

hexachlorocyclohexane through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentrations should be zero, based on the nonthreshold assumption for this chemical. However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk over the lifetime are estimated at and The corresponding recommended criteria are 186 ng/ L, 18.6 ng/ L, and 1.86 ng/ L,

respectively. If these estimates are made for consumption of aquatic organisms only, excluding consumption of water, the levels are 625 ng/ L, 62.5 ng/ L, and 6.25 ng/ L, respectively.

For the maximum protection of human health from the potential carcinogenic effects of exposure to technical

hexachlorocyclohexane through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentrations should be zero, based on the nonthreshold assumption for this chemical. However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk over the lifetime are estimated at 10 5, loe6, and The corresponding recommended criteria are 52 ng/ L, 5.2 ng/ L, and  52 ng/ L, respectively. If these estimates are made for consumption of aquatic organisms only, excluding consumption of water, the levels are 174 ng/ L, 17.4 ng/ L, and 1.74 ng/ L, respectively.

, / .* , Using the present guidelines, s a t i s f a c t o r y c r i t e r i a cannot be derived a t t h i s t i m e f o r d and e hexachlorocyclohexane because of i n s u f f i c i e n t a v a i l a b l e data.

( 4 5 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY HEXACHLOROCYCLOPENTADIENE CRITERIA:

Aquatic Life The available data for hexachlorocyclopentadiene indicate that acute and chronic toxicity to freshwater aquatic life occurs at concentrations as low as 7.0 and 5.2 ug/ L, respectively, and would occur at lower concentrations among species that are more sensitive than those tested.

The available data for hexachlorocyclopentadiene indicate that acute toxicity to saltwater aquatic life occurs at concentrations as low as 7.0 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. NO data are available concerning the chronic toxicity of hexachlorocyclopentadiene to sensitive saltwater aquatic life. 0 Human Health For comparison purposes, two approaches were used to derive criterion levels for hexachlorocyclopentadiene. Based on available toxicity data, to protect public health the derived level is 2 0 6 ug/ L. Using available organoleptic data, to control undersirable taste and odor quality of ambient water the estimated level is 1 ug/ L. It should be recognized that organoleptic data have limitations as a basis for establishing water quality criteria, and have no demonstrated relationship to potential adverse human health effects.

. , ( 4 5 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY 0.3 mg/ L f o r domestic water supplies ( welfare).

1.0 mg/ L f o r freshwater aquatic l i f e .

INTRODUCTION:

Iron is t h e fourth most abundant, by weight, of t h e elements t h a t make up t h e e a r t h ' s c r u s t . Common i n many r o c k s , it is an important component of many s o i l s , e s p e c i a l l y t h e c l a y s o i l s where u s u a l l y it i s a major c o n s t i t u e n t . I r o n i n water may be present i n varying q u a n t i t i e s dependent upon t h e geology of t h e area and o t h e r chemical components of the waterway.

I r o n is an essential trace element r e q u i r e d by b o t h p l a n t s and animals. I n some waters it may be a l i m i t i n g f a c t o r f o r the growth of a l g a e and o t h e r plants; t h i s is t r u e e s p e c i a l l y i n some marl l a k e s where it is p r e c i p i t a t e d by t h e h i g h l y a l k a l i n e c o n d i t i o n s . It is a v i t a l oxygen t r a n s p o r t mechanism i n t h e blood of all vertebrate and some i n v e r t e b r a t e animals.

The ferrous, o r b i v a l e n t ( Fe++), and t h e ferric, o r t r i v a l e n t ( Fe+++) i r o n s , are t h e primary forms o f concern i n t h e a q u a t i c environment, although other forms may be i n organic and inorganic wastewater streams. The f e r r o u s ( Fe++) form c a n p e r s i s t i n waters v o i d of d i s s o l v e d oxygen and o r i g i n a t e s u s u a l l y from groundwaters o r mines when these a r e pumped o r d r a i n e d . For p r a c t i c a l purposes t h e f e r r i c ( Fe +++) form i s i n s o l u b l e . I r o n can e x i s t i n n a t u r a l o r g a n o m e t a l l i c o r humic compounds and c o l l o i d a l forms. B l a c k o r brown swamp w a t e r s may c o n t a i n i r o n c o n c e n t r a t i o n s o f s e v e r a l mg/ L i n t h e p r e s e n c e o r absence o f .. . .,_. ,~ .,.,.

...,,

~~

dissolved oxygen, but t h i s i r o n form has l i t t l e effect on aquatic l i f e .

( QUALITY CRITERIA FOR WATER, JULY 1976) PB 263943 SEE APPENDIX C FOR METHODOLOGY a ..

.

i . :/ ISOPHORONE Aquatic Life The available data for isophorone indicate that acute toxicity to freshwater aquatic life occurs at concentrations as low as 117,000 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of isophorone to sensitive freshwater aquatic life.

The available data for isophorone indicate that acute toxicity to saltwater aquatic life occurs at concentrations as low as 12,900 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of isophorone to sensitive saltwater aquatic life. I Human Health For the protection of human health from the toxic properties of isophorone ingested through water and contaminated aquatic organisms, the ambient water criterion is determined to be 5.2 W/ L.

For the protection of human health from the toxic properties of isophorone ingested through contaminated aquatic organisms alone, the ambient water criterion is determined to be 5 2 0 mg/ L.

( 45 F. R. 79318, November 28, 1980)

0 ;;. : SEE APPENDIX B FOR METHODOLOGY . . ...*. LEAD AQUATIC LIFE SUMMARY:

The acute toxicity of lead to several species of freshwater animals has been shown to decrease as the hardness of water increases. At a hardness of 50 mg/ L the acute sensitivities of 10 species range from 142.5 ug/ L for an amphipod to 235,900 ug/ L for a midge. Data on the chronic effects of lead on freshwater animals are available for two fish and two invertebrate species.

The chronic toxicity of lead also decreases as hardness increases and the lowest and highest available chronic values ( 12.26 and 128.1 ug/ L) are both for a cladoceran, but in soft and hard water, respectively. Acute chronic ratios are available for three species and range from 18 to 62. Freshwater algae are affected by concentrations of lead above 500 ug/ L, based on data for four species. Bioconcentration factors are available for four invertebrate and two fish species and range from 42 to 1,700. 0 Acute values are available for 13 saltwater animal species and range from 315 ug/ L for the mummichog to 27,000 ug/ L for the soft shell clam. A chronic toxicity test was conducted with a mysid; unacceptable effects were observed at 37 ug/ L but not at 17 ug/ L and the acute chronic ratio for this species is 124.8. A species of macroalgae was affected at 20 ug/ L.

Available bioconcentration factors range from 17.5 to 2,570.

NATIONAL CRITERIA:

The procedures described in the Guidelines for Deriving 0  2 Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses indicate that, except possibly where a locally important species is very sensitive, freshwater aquatic organisms and their uses should not be affected unacceptably if the 4 day average concentration ( in ug/ L) of lead does not exceed the numerical value given by ( 1.273 [ ln( hardness) 3  4.705) more than once every 3 years on the e average and if the 1 hour average concentration ( in ug/ L) does not exceed the numerical value given. by .( 1.273 [ ln( hardness) 3

1.460) more than once every 3 years on the average. For example,

at hardnesses of 50, 100, and 200 mg/ L as CaC03 the 4 day average concentrations of lead are 1.3, 3.2, and 7.7 ug/ L, respectively,

and the 1 hour average concentrations are 34, 82, and 200 ug/ L.

The procedures described in, the Guidelines indicate that,

except possibly where a locally important species is very sensitive, saltwater aquatic organisms and their uses should not be affected unacceptably if the 4 day average concentration of lead does not exceed 5.6 ug/ L more than once every 3 years on the average and if the 1 hour average concentration does not exceed 140 ug/ L more than once every three years on the average.

EPA believes that a measurement such as tfacid solubletl would provide a more scientifically correct basis upon which to establish criteria for metals. The criteria were developed on this basis. However, at this time, no EPA approved methods for such a measurement are available to implement the criteria through the regulatory programs of the Agency and the States.

a The Agency is considering development and approval of methods for a measurement such as acid soluble. Until available, however,

EPA recommends applying the criteria using the total recoverable method. T h i s has two impacts: ( 1) Certain species of some metals cannot be analyzed d i r e c t l y because t h e t o t a l recoverable method does not distinguish between individual oxidation s t a t e s , and ( 2)

these c r i t e r i a may be overly protective when based on the t o t a l recoverable method.

The recommended exceedence frequency of 3 y e a r s is t h e Agency's b e s t s c i e n t i f i c judgment of t h e average amount of time it w i l l t a k e an unstressed system t o recover from a p o l l u t i o n e v e n t i n which exposure t o lead exceeds t h e c r i t e r i o n . A stressed system, f o r example, one i n which several o u t f a l l s occur i n a l i m i t e d a r e a , would be expected t o r e q u i r e more t i m e f o r recovery. The r e s i l i e n c e of ecosystems and t h e i r a b i l i t y t o recover d i f f e r g r e a t l y , however, ' and s i t e s p e c i f i c c r i t e r i a may be established i f adequate j u s t i f i c a t i o n is provided.

The use of c r i t e r i a i n designing waste treatment f a c i l i t i e s r e q u i r e s t h e s e l e c t i o n of an a p p r o p r i a t e wasteload a l l o c a t i o n model. Dynamic models a r e preferred f o r the application of these c r i t e r i a . L i m i t e d d a t a o r o t h e r f a c t o r s may make t h e i r use i m p r a c t i c a l , i n which c a s e one should r e l y on a steady s t a t e model. The Agency recommends t h e interim use of lQ5 or lQl0 f o r Criterion Maximum Concentration design flow and 745 o r 7Q1Q f o r t h e C r i t e r i o n Continuous Concentration d e s i g n flow i n steady

s t a t e models f o r unstressed and stressed systems, respectively.

These m a t t e r s a r e discussed i n more d e t a i l i n t h e Technical Support Document f o r Water Quality Based Toxics Control ( U. S. 0 HUMAN HEALTH CRITERIA:

The ambient water quality criterion for lead is recommended to be identical to the existing drinking water standard which is 50 ug/ L. Analysis of the toxic effects data resulted in a calculated level whic is protective to human health against the ingestion of contaminated water and contaminated aquatic organisms. The calculated value is comparable to the present standard. For this reason a selective criterion based on expoeure Soley from consumption of 6.5 grams of aquatic organisms was not derived.

( 45 F. R. 79318 Nov. 28,1980) ( 50 F. R. 30784, July 29, 1985) SEE APPENDIX A FOR METHODOLOGY e CRITERION: MALATHION 0.1 ug/ L for freshwater and marine aquatic life.

RATIONALE:

The freshwater fish most sensitive to malathion, an organophosphorus pesticide, appear to be the salmonids and centrarchids. Post and Schroeder ( 1971) report a 96 hour LC50 between 120 and 265 ug/ L for 4 species of salmonids. Macek and McAllister ( 1970) found a 96 hour LC50 range between 101 and 285 ug/ L for 3 species of centrarchids and 3 species of salmonids.

Other 96 hour LCSO's are: rainbow trout,  Salmo gairdrleri, 68 ug/ L ( Cope, 1965) i largemouth bass, MicroEerus  I salmoides 50 ug/ L ( Pickering et al. 1962); and chinook salmon, Oncorhynchus I

tshawytscha  I 23 ug/ L ( Katz, 1961). All of the above tests were in static systems. Eaton ( 1970) determined a 96 hour LC50 for bluegill,  LeEmis         I macrochirus in a flow through system at110 ug/ L. Macek and McAllister ( 1970) reported a similar 96 hOUr LC50 for the bluegill in a static exposure. Static 96 hour LC50s of 120 and 160 ug/ L were reported by Post and Schroeder ( 1971)

for brook trout, Salvelinus fontha&. Bender ( 1969) indicated that the acute toxicity to fathead minnows, Pimephales  promelas,

is slightly greater ( about 2.0 times) in a static system than in a f low through system. The f low through acute toxicity to fathead minnows reported by Mount and Stephan ( 1967) approximated the static acute toxicity reported by Henderson and Pickering 0 ( 1958) and Bender ( 1969).

0 x i Many aquatic invertebrates appear t o be more s e n s i t i v e than f i s h to malathion. The 96 hour LC50 f o r Gammarus l a c u s t r i s w a s 1.0 ug/ L ( Sanders, 1 9 6 9 ) ; f o r P t e r o n a r c e l l a badia 1 1.1 ug/ L ( Sanders and Cope, 1 9 6 8 ) ; and f o r  Gammarus  f a s c i a t u s 1 0.76 ug/ L ( Sanders, 1 9 7 2 ) . T h e 4 8  h O U r LC50 f o r Simocephalus  s e r r u l a t u s w a s 3.5 ug/ L and f o r  Daphnia  pulex, 1.8 ug/ L ( Sanders and Cope,

1 9 6 6 ) .  Daphnia  were immobilized i n 5 0 h o u r s i n 0.9 ug/ L ( Anderson, 1960). The 24 hour LC50s f o r two s p e c i e s of midge larvae were 2.1 ug/ L ( Mulla and Xhasawinah, 1969) and 2.0 ug/ L ( Karnak and Collins, 1974).

S a f e l i f e c y c l e e x p o s u r e c o n c e n t r a t i o n s f o r t h e more s e n s i t i v e i n v e r t e b r a t e s are n o t known. T h e most s e n s i t i v e a q u a t i c organisms probably have n o t y e t been tested; safe c o n c e n t r a t i o n s f o r t h e m o s t s ' e n s i t i v e i n v e r t e b r a t e s exposed through a complete l i f e c y c l e have n o t been determined; and effects of low c o n c e n t r a t i o n s on i n v e r t e b r a t e behavior a r e unknown.

The s t a b i l i t y of malathion i n water is dependent on t h e chemical and b i o l o g i c a l c o n d i t i o n s of t h e water ( P a r i s e t a l .

1975). Weiss and Gakstatter ( 1964) have shown t h a t t h e h a l f l i f e of malathion w a s reduced from about 5 months a t pH 6 to 1 t o 2 weeks a t pH 8. Eichelberger and Lichtenberg ( 1971) found t h a t o n l y 1 0 p e r c e n t remained i n t h e L i t t l e M i a m i R i v e r ( pH 7.3 8.0)

a f t e r 2 weeks. Bender ( 1969) s t a t e s t h a t one of t h e malathion breakdown products may be more t o x i c than t h e parent compound.

It h a s been shown t h a t a measured c o n c e n t r a t i o n of 575 ug/ L malathion i n flowing seawater k i l l s 4 0 to 60 p e r c e n t of t h e marine fish, Lagodon rhomboides, i n 3.5 hours and causes about 75 percent brain a c e t y l c h o l i n e s t e r a s e ( AChE) i n h i b i t i o n ( Coppage e t a l . 1975). S i m i l a r i n h i b i t i o n of AChE and m o r t a l i t y were caused i n p i n f i s h i n 24, 48, and 72 h o u r s ' a t measured concentrations of 1 4 2 , 9 2 and 58 ug/ L, r e s p e c t i v e l y . A c o n c e n t r a t i o n o f 3 1 ug/ L caused 34 percent AChE i n h i b i t i o n i n p i n f i s h but no deaths i n 72 hours. Coppage and Matthews ( 1974) demonstrated t h a t death may be a s s o c i a t e d w i t h r e d u c t i o n s of b r a i n AChE a c t i v i t y of f o u r marine f i s h e s by 70 t o 80 percent or more i n short term exposures t o malathion. Coppage and Duke ( 1971) found t h a t moribund m u l l e t , Mugil cephalus, i n an estuary sprayed w i t h malathion ( 3 oz./ acre) d u r i n g a large scale mosquito c o n t r o l o p e r a t i o n had about 98 percent i n h i b i t i o n of b r a i n AChE. T h i s is i n agreement w i t h 70 t o 80 percent o r more i n h i b i t i o n of b r a i n AChE l e v e l s a t and below which some d e a t h s are l i k e l y t o occur i n short term exposure. S p o t , Leiostomus xanthurus, and A t l a n t i c c r o a k e r ,

Micropogon  u n d u l e , a l s o had s u b s t a n t i a l i n h i b i t i o n of brain during t h e spray operation ( 70 percent o r more i n h i b i t i o n ) . 0 T o x i c i t y s t u d i e s h a v e been made on a number of marine animals. E i s l e r ( 1970) s t u d i e d t h e 96 hour LC50 f o r s e v e r a l marine fishes a t 20 OC i n static, aerated seawater. The 96 hour LC50 v a l u e s ( i n ug/ L) were: Menidia menidia, 125:  Mugil cephalus,

550; F u n d u l u s rnnialis _ 1 250; F u n d u l u s h e t e r o c l i t u s , 2 4 0 ;

 s p h a e r o i d e s ___ _ I m a c u l a t u s 3250: A n q u i l l a __ ____ _____ I r o s t r a t a 8 2 : a n d Thalassoma bifasciatum, 27. Katz ( 1961) reported t h e s t a t i c 24

hour LC50 f o r Gasterosteus a c u l e a t u s i n 2 5 o/ oo saltwater as 76.9 ug/ L a c t i v e i n g r e d i e n t . T h e 96 hour LC50 f o r s t r i p e d b a s s , Morone __ . I s a x a t i l i s i n i n t e r m i t t e n t flowing seawater has been r e p o r t e d a s 1 4 ug/ L ( U. S. BSFW, 1 9 7 0 ) .

Reporting on s t u d i e s of t h e t o x i c i t y of malathion on marine i n v e r t e b r a t e s , E i s l e r ( 1969) found t h e 96 hour LC50 ( s t a t i c , 2 4 o/ oo s a l i n i t y a e r a t e d ) t o be 33 ug/ L f o r sand shrimp, Crangon septemspinosa; 8 2 ug/ L f o r grass shrimp, S a e m o n e t e s v u l g a r i s ;

and 83 ug/ L f o r hermit crab, Pagurus longicarpus. Growth of oyster, Crassostrea virginica, was reduced 32 percent by 96 hour e x p o s u r e t o 1 mg/ L ( B u t l e r , 1 9 6 3 ) . T h e 48 hour L C 5 0 f o r f e r t i l i z e d eggs of oysters was estimated by Davis and Hidu ( 1969)

t o be 9.07 mg/ L and the 14 day LC50 f o r larvae, 2.66 mg/ L.

Malathion e n t e r s t h e a q u a t i c environment p r i m a r i l y as a r e s u l t of its application as an insecticide. Because it degrades quite rapidly i n most waters, depending on pH, its occurrence is sporadic rather than continuous. Because t h e t o x i c i t y is exerted through i n h i b i t i o n of AChE and because such i n h i b i t i o n may be additive w i t h repeated exposures and may be caused by any of t h e organophosphorus insecticides, inhibition of AChE by more than 35 percent may be expected t o r e s u l t i n damage t o aquatic organisms.

An a p p l i c a t i o n f a c t o r of 0.1 i s a p p l i e d t o t h e 9 6  h O U r LC50 data f o r Gammarus l a c u s t r i s ,  G. f a s c i a t i s and Daphnia, which a r e a l l approximately 1.0 ug/ L, yielding a c r i t e r i o n of 0.1 ug/ L.

( QUALITY CRITERIA FOR WATER, JULY 1976) PB 263943 SEE APPENDIX C FOR METHODOLOGY MANGANESE 50 ug/ L for domestic water supplies ( welfare):

100 ug/ L for protection of consumers of marine molluscs.

INTRODUCTION:

Manganese does not occur naturally as a metal but is found in various salts and minerals, frequently in association with iron compounds. The principal manganese containing substances are manganese dioxide ( MnOZ) , pyrolusite, manganese carbonate ( rhodocrosite) and manganese silicate ( rhodonite) ~

The oxides are the only important minerals mined. Manganese is not mined in the United States except when manganese is contained in iron ores that are deliberately used to f o h ferro manganese alloys.

The primary uses of manganese are in metal alloys, dry cell batteries, micro nutrient fertilizer additives, organic compounds used in paint driers and as chemical reagents. Permanganates are very strong oxidizing agents of organic materials.

Manganese is a vital micro nutrient for both plants and animals. When manganese is not present in sufficient quantities,

plants exhibit chlorosis ( a yellowing of the leaves) or failure of the leaves to develop properly. Inadequate quantities of manganese in domestic animal food results in reduced reproductive capabilities and deformed or poorly maturing young. Livestock feeds usually high corn diet have sufficient manganese, but beef cattle on a may require a supplement. RATIONALE:

Although inhaled manganese dusts have been reported to be toxic to humans, manganese normally is ingested as a trace nutrient in food. The average human intake is approximately 10 mg/ day ( Sollman, 1957). Very large doses of ingested manganese can cause some disease and liver damage but these are not known to occur in the United States. Only a few manganese toxicity problems have been found throughout the world and these have occurred under unique circumstances, i. e., a well in Japan near a deposit of buried batteries ( McKee and Wolf, 1963).

It is possible to partially sequester manganese with special treatment but manganese is not removed in the conventional treatment of domestic waters ( Riddick et al. 1958: Illig, 1960).

Consumer complaints arise when manganese exceeds a concentration of 150 ug/ L in water supplies ( Griffin, 1960). These complaints are concerned primarily with the brownish staining of laundry and objectionable tastes in beverages. It is possible that the presence of low concentrations of iron may intensify the adverse effects of manganese. Manganese at concentrations of about 10 to 2 0 ug/ L is acceptable to most consumers. A criterion for domestic water supplies of 50 ug/ L should minimize the objectionable qua1 ities.

McKee and Wolf ( 1963) summarized data on toxicity of manganese to freshwater aquatic life. Ions of manganese are found rarely at concentrations above 1 mg/ L. The tolerance values reported range from 1.5 mg/ L to over 1000 mg/ L. Thus,

manganese is not considered to be a problem in fresh waters.

Permanganates havebeen reportedtokill fish in 8to 18 hours at concentrations of 2.2 to 4.1 mg/ L, but permanganates are not persistent because they rapidly oxidize organic materials and are thereby reduced and rendered nontoxic.

Few data are available on the toxicity of manganese to marine organisms. The ambient concentration of manganese is about 2 ug/ L ( Fairbridge, 1966). The material is rapidly assimilated and bioconcentrated into nodules that are deposited on the sea floor.

The major problem with manganese may be concentration in the edible portions of molluscs, as bioaccumulation factors as high as 12,000 have been reported ( NAS, 1974). In order to protect against a possible health hazard to humans by manganese accumulation in shellfish, a criterion of 100 ug/ L is recommended for marine water.

Manganese is not known to be a problem i q water consumed by livestock. At concentrations of slightly less than 1 mg/ L to a few milligrams per liter, manganese nay be toxic to plants from irrigation water applied to soils with pH values lower than 6.0.

The problem may be rectified by liming soils to increase the pH.

Problems may develop with long term ( 20 year) continuous irrigation on other soils with water containing about 10 mg/ L of manganese ( NAS, 1974). But, as stated above, manganese is rarely found in surface waters at concentrations greater than 1 mg/ L.

Thus, no specific criterion for manganese in agricultural waters is proposed. In select areas, and where acidophilic crops ate cultivated and irrigated, a criterion of 200 ug/ L is suggested 0 for consideration. i \+./ Most industrial users of water can operate successfully where the criterion proposed for public water supplies is observed.

Examples of industrial tolerance of manganese in water are summarized for industries such as dyeing, milk processing, paper,

textiles, photography and plastics ( McKee and Wolf, 1 9 6 3 ) . A more restrictive criterion may be needed to protect or ensure product quality.

( QUALITY CRITERIA FOR WATER, JULY 1976) PB 2 6 3 9 4 3 SEE APPENDIX C FOR METHODOLOGY * MERCURY AQUATIC LIFE Data are SUMMARY :

a v a i l a b l e on t h e acute t o x i c i t y of mercury( I1) , to 28 genera of freshwater animals. Acute v a l u e s f o r i n v e r t e b r a t e species range from 2.2 ug/ L f o r Daphnia pulex t o 2,000 ug/ L f o r t h r e e i n s e c t s . Acute v a l u e s f o r f i s h e s range from 3 0 ug/ L f o r the guppy t o 1,000 ug/ L f o r t h e  Mozambique tilapia. Few data a r e a v a i l a b l e f o r v a r i o u s organomercury compounds and mercurous n i t r a t e , and they a l l appear t o be 4 t o 3 1 t i m e s more a c u t e l y t o x i c than mercury( I1).

A v a i l a b l e chronic d a t a i n d i c a t e t h a t methylmercury is t h e most chronically toxic of t h e tested mercury compounds. T e s t s on methylmercury w i t h Daphnia magna and brook t r o u t produced chronic v a l u e s less than 0.07 ug/ L. For mercury( I1) t h e chronic v a l u e obtained with  D a a n i a __ m s n a  was about 1.1 ug/ L and t h e acute

chronic r a t i o was 4.5. I n both a l i f e c y c l e t e s t and a n e a r l y l i f e stage test on mercuric chloride w i t h t h e fathead minnow, t h e chronic value was less than 0.26 ug/ L and t h e acute chronic r a t i o was over 600. 0 Freshwater p l a n t s show a w i d e range of s e n s i t i v i t i e s t o mercury, b u t t h e most s e n s i t i v e p l a n t s a p p e a r t o be l e s s s e n s i t i v e than t h e most s e n s i t i v e freshwater animals t o both mercury( I1) and methylmercury. A bioconcentration f a c t o r of 4 , 9 9 4 is a v a i l a b l e f o r m e r c u r y ( I I ) , b u t t h e bioconcentration factors f o r methylmercury range f r o m 4,000 t o 85,000.

0 \.., * I n d i c a t e s suspended, canceled o r r e s t r i c t e d by U. S. EPA Office of Pesticides and Toxic Substances Data on the acute toxicity of mercuric chloride are available for 2 9 genera of saltwater animals, including annelids, molluscs,

crustaceans, echinoderms, and fishes. Acute values range from 3.5 ug/ L for a mysid to 1,678 ug/ L for winter flounder. Fishes tend to be more resistant and molluscs and crustaceans tend to be more sensitive to the acute toxic effects of mercury( I1).

Results of a life cycle test with the mysid show that mercury( I1)

at a concentration of 1.6 ug/ L significantly affected time of first spawn and productivity; the resulting acute chronic ratio was 3.1.

Concentrations of mercury that affected growth and photosynthetic activity of one saltwater diatom and six species of brown algae range from 10 to 160 ug/ L. Bioconcentration factors of 10,000 and 40,000 have been obtained for mercuric chloride and methylmercury with an oyster.

NATIONAL CRITERIA:

Derivation of a water quality criterion for mercury is more complex than for most metals because of methylation of mercury in sediment, in fish, and in the food chain of fish. Apparently almost all mercury currently being discharged is mercury( I1).

Thus mercury( I1) should be the only important possible cause of acute toxicity and the Criterion Maximum Concentrations can be based on the acute values for mercury( I1).

The best available data concerning long term exposure of fish to mercury( I1) indicates that concentrations above 0.23 ug/ L caused statistically significant effects on the fathead minnow and caused the concentration of total mercury in the whole body t o exceed 1.0 mg/ kg. Although it is n o t known what p e r c e n t of t h e mercury i n t h e f i s h w a s methylmercury, it is a l s o n o t known whether uptake from food would increase the concentration i n t h e f i s h i n n a t u r a l s i t u a t i o n s . Species such as rainbow t r o u t , coho salmon, and e s p e c i a l l y t h e b l u e g i l l , might s u f f e r chronic effects and accumulate h i g h residues of mercury about t h e same a s t h e fathead minnow.

W i t h regard t o long term exposure t o methylmercury, M c K i m e t a l . ( 1976) found t h a t brook t r o u t can exceed the FDA action l e v e l without s u f f e r i n g s t a t i s t i c a l l y s i g n i f i c a n t adverse effects on s u r v i v a l , growth, o r reproduction. Thus f o r methylmercury t h e Final Residue Value would be s u b s t a n t i a l l y lower than the Final Chronic Value.

Basing a freshwater c r i t e r i o n on t h e F i n a l Residue Value of 0.012 ug/ L derived from the bioconcentration f a c t o r of 81,700 f o r methylmercury w i t h t h e fathead minnow ( Olson e t a l . 1975)

e s s e n t i a l l y assumes t h a t a l l discharged mercury is methylmercury.

On t h e o t h e r hand, there is t h e p o s s i b i l i t y t h a t i n f i e l d s i t u a t i o n s uptake from food might add t o t h e u p t a k e from water.

S i m i l a r considerations apply t o t h e d e r i v a t i o n of t h e saltwater c r i t e r i o n of 0.025 ug/ L u s i n g t h e BCF of 4 0 , 0 0 0 o b t a i n e d f o r methylmercury w i t h t h e Eastern oyster ( Kopfler, 1974). Because t h e F i n a l Residue Values f o r methylmercury a r e s u b s t a n t i a l l y below t h e F i n a l Chronic Values f o r m e r c u r y ( I I ) , it is probably not too important t h a t many fishes, including t h e rainbow t r o u t ,

coho salmon, b l u e g i l l , and haddock might n o t be a d e q u a t e l y protected by the freshwater and saltwater F i n a l Chronic Values f o r mercury( I1). In contrast to all the complexities of deriving numerical criteria for mercury, monitoring for unacceptable environmental effects should be relatively straightforward. The most sensitive adverse effect will probably be exceedence of the FDA action level. Therefore, existing discharges should be acceptable if the concentration of methylmercury in the edible portion of exposed consumed species does not exceed the FDA action level.

The procedures described in the Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses indicate that, except possibly where a locally important species is very sensitive, freshwater aquatic organisms and their uses should not be affected unacceptably if the 4 day average concentration of mercury does I not exceed 0.012 ug/ L more than once every 3 years on the average and if the 1 hour average concentration does not exceed 2.4 ug/ L more than once every 3 years on the average. If the 4 day average concentration exceeds 0.012 ug/ L more than once in a 3

year period, the edible portion of consumed species should be analyzed to determine whether the concentration of methylmercury exceeds the FDA action level.

The procedures described in the Guidelines indicate that,

except possibly where a localy important species is very sensitive, saltwater aquatic organisms and their uses should not be affected unacceptably if the 4 day average concentration of mercury does not exceed 0.025 ug/ L more than once every 3 years on the average and if the 1 hour average concentration does not exceed 2.1 ug/ L more than once every 3 years on the average. If the 4 day average concentration exceeds 0.025 ug/ L more than once i n a 3 year period, t h e e d i b l e protion of consumed species should be a n a l y z e d t o d e t e r m i n e w h e t h e r t h e c o n c e n t r a t i o n of mathylmercury exceeds t h e FDA action l e v e l . 0 EPA b e l i e v e s t h a t a measurement such as " acid soluble" would p r o v i d e a more s c i e n t i f i c a l l y c o r r e c t b a s i s upon w h i c h t o e s t a b l i s h c r i t e r i a f o r metals. The c r i t e r i a w e r e developed on t h i s basis. However, a t t h i s t i m e , no EPA approved methods f o r such a measurement are a v a i l a b l e t o implement t h e c r i t e r i a through t h e r e g u l a t o r y programs of t h e Agency and t h e S t a t e s .

The Agency is considering development and approval of methods f o r a measurement such as acid soluble. U n t i l a v a i l a b l e , however,

EPA recommends applying t h e criteria using t h e t o t a l recoverable method. T h i s has two impacts: ( 1) c e r t a i n species of some metals cannot be analyzed d i r e c t l y because t h e t o t a l recoverable method does not d i s t i n g u i s h between i n d i v i d u a l oxidation states, and ( 2 )

these criteria may be o v e r l y p r o t e c t i v e when based on t h e t o t a l recoverable method. 0 T h e recommended exceedence frequency o f 3 y e a r s is t h e Agency's best s c i e n t i f i c judgment of t h e a v e r a g e amount of t i m e it w i l l t a k e an u n s t r e s s e d system t o r e c o v e r from a p o l l u t i o n e v e n t i n which exposure t o mercury exceeds t h e c r i t e r i o n . A stressed system, f o r example, one i n which s e v e r a l o u t f a l l s occur i n a l i m i t e d area, would be expected t o r e q u i r e more t i m e f o r recovery. T h e r e s i l i e n c e of ecosystems and t h e i r a b i l i t y t o recover d i f f e r g r e a t l y , however, and s i t e specif ic criteria may be e s t a b l i s h e d i f adequate j u s t i f i c a t i o n is provided. 0 .., ,' The use of criteria in designing waste treatment facilities requires the selection of an appropriate wasteload a1 location model. Dynamic models are preferred for the application of these criteria. Limited data or other factors may make their use impractical, in which case one should rely on a steady state model. The Agency recommends the interim use of 1Q5 or lQl0 for Criterion Maximum Concentration design flow and 745 or 7410 for the Criterion Continuous Concentration design flow in steady

state models for unstressed and stressed systems respectively.

These matters are discussed in more detail in the Technical Support Document for Water Quality Based Toxics Control ( U . S EPA, 1985).

HUMAN HEALTH CRITERIA I For the protection of human health from the toxic properties of mercury ingested through water and contaminated aquatic organisms, the ambient water criterion is determined to be 144 nWL.

For the protection of human health from the toxic properties of mercury ingested through contaminated aquatic organisms alone,

the ambient water criterion is determined to be 146 ng/ L.

NOTE: These values include the consumption of freshwater, estuarine, and marine species.

( 45 F. R. 79318 Nov. 28,1980) ( 50 F. R. 30784, July 29, 1985) SEE APPENDIX A FOR METHODOLOGY 0 CRITERIA: METHOXYCHMR 100 ug/ L f o r domestic water supply ( health);

0.03 ug/ L f o r freshwater and marine aquatic l i f e .

RATIONALE :

The highest l e v e l of methoxychlor found t o have minimal o r no long term e f f e c t s i n man is 2.0 mg/ kg of body weight/ day ( Lehman,

1965). Where adequate human data a r e a v a i l a b l e f o r corroboration of t h e animal r e s u l t s , t h e t o t a l tfsafe't drinking water i n t a k e level is assumed t o be l/ lOO of t h e no effect o r minimal effect l e v e l r e p o r t e d f o r t h e most s e n s i t i v e animal tested, i n t h i s case, man.

Applying t h e a v a i l a b l e d a t a and based upon t h e assumptions t h a t 20 p e r c e n t of t h e t o t a l i n t a k e of methoxychlor is from d r i n k i n g water, and t h a t t h e average person weighs 7 0 kg and consumes 2 l i t e r s of water per day, the formula f o r calculating a c r i t e r i o n is 2.0 mg/ kg x 0.2 x 70 kg x 1/ 100 x 1/ 2 = 0.14 mg/ L.

A c r i t e r i o n l e v e l f o r domestic water supply of 1 0 0 ug/ L is recommended.

Few data: are a v a i l a b l e on a c u t e and chronic e f f e c t s of methoxychlor on freshwater f i s h . Merna and E i s e l e ( 1973)

observed reduced h a t c h a b i l i t y of f a t h e a d minnow p i m z h a l e s

prcelas)  embryos a t 0.125 ug/ L and l a c k of spawning a t 2.0 ug/ L. Yellow perch, Perca  flavescens, exposed t o 0.6 ug/ L f o r 8 months exhibited reduced growth. The 36 hour LC50 concentration was 7.5 and 22 ug/ L f o r t h e f a t h e a d minnow and yellow perch,

. r e s p e c t i v e l y . Korn and Earnest ( 1374) obtained a 96 hour LC50 of 3.3 ug/ L with juvenile stripped bass, Morone _ I saxatilis exposed to methoxychlor in a flowing water bioassay.

Sanders ( 1972) determined a 96 hour LC50 value of 0.5 ug/ L for the crayfish, Orconectes nais. Merna and Eisele ( 1973)

obtained a 96 hour LC50 value of 0.61 ug/ L for the scud, Gammarus pseudolimnaeus and 96 hour LC5O's ranging from 1.59 to 7.05 ug/ L for the crayfish, Orconectes  I nais and three aquatic insect larvae. In 28 day exposuresI reduction in emergence of mayflies,

 Stenonema sp. and in pupation of caddisf lies, Cheumatospsyche _

sp., were observed at 0.5 and 0.25 ug/ L concentrations,

respectively. They also found methoxychlor to be degraded in a few weeks or less in natural waters.

Eisele ( 1974) conducted a study in which a section of a natural stream was dosed at 0.2 ug/ L methoxychlor for 1 year.

The near extinction of one species of scud, wllella  azteca, and reductions in populations of other sensitive species, as well as biomass, were observed. Residue accumulation of up to 1,000 times the level in the stream was observed in first year crayfish, Orconectes __ nais. Metcalf et al. ( 1971) traced the rapid conversion of methoxychlor to water soluble compounds and elimination from the tissues of snails, mosquito larvae and mosquitofish. Thus, methoxychlor appears to be considerably less bioaccumlative in aquatic organisms than some of the other chlorinated pesticides.

Methoxyhlor has a very low accumulation rate in birds and mammals ( Stickel, 1973), and relatively low avian ( Heath et al.

1972) and mammalian ( Hodge et al. 1950) toxicities. No administrative guidelines for acceptable levels in edible fish tissues have been established by the U. S. Food and Drug Administration.

The above data indicate that 0.1 ug/ L methoxychlor would be just below chronic effect level for the fathead minnow and one

fifth the acute toxicity level in a crayfish species. Therefore,

a criterion level of 0.03 ug/ L is recommended. This criterion should protect fish as sensitive as striped bass and is 10 times lower than the level causing effects on some invertebrate populations in a 1 year dosing of a natural stream.

Bahner and Nimmo ( 1974) found the 96 hour LC50 of methoxychlor for the pink shrimp, Penaeus  I duorarum to be 3.5 ug/ L and the 30 day LC50 to be 1.3 ug/ L. Using an application factor of 0.01 with the pink shrimp's acute toxicity of 3.5 ug/ L, the recommended criterion for the marine environment is 0.03 ug/ L.

Butler ( 1971) found accumulation factors of 470 and 1,500 for the molluscs, Mercenaria _______ _________ mercenaria and gyg arenaria,

respectively, when exposed to 1 ug/ L methoxychlor for 5 days.

Using the 1,500 accumulation factor as a basis, a water concentration of 0.2 ug/ L would be required to meet the U. S. Food and Drug Administration's guideline for methoxychlor in meat products. Thus, the recommended marine criterion of 0.03 ug/ L is an order of magnitude lower than this concentration.

( QUALITY CRITERIA FOR WATER, JULY 1976) PB 263943 SEE APPENDIX C FOR METHODOLOGY  ., MIREX CRITERION:

0.001 ug/ L f o r freshwater and marine aquatic l i f e .

RATIONAL??.:

Mirex is used t o c o n t r o l t h e imported f i r e a n t S o l e n z s i s

saevissima richteri i n t h e southeastern United States. Its use is e s s e n t i a l l y limited t o the control of t h i s insect and it is always presented i n b a i t . I n t h e most common formulation,

technical grade mirex i s dissolved i n soybean o i l and sprayed on corncob g r i t s . The b a i t produced i n t h i s manner consists of 0.3 p e r c e n t mirex, 14.1 percent soybean o i l and 85 percent corncob g r i t s . b a i t o f t e n is a p p l i e d a t a rate of 1.4 kg/ ha, The mirex I equivalent t o 4.2 grams of toxicant per hectare.

R e l a t i v e l y few studies have been made of t h e e f f e c t s of mirex on freshwater i n v e r t e b r a t e s og yhrdr, o n l y Dudke e t a l . ( 1971)

r e p o r t chemical analyses of mirex i n t h e water. Their study r e p o r t e d effects on two c r a y f i s h s p e c i e s exposed t o mirex by three techniques. F i r s t , f ield col l e c t e d crayfish were exposed t o s e v e r a l s u b l e t h a l c o n c e n t r a t i o n s of t e c h n i c a l grade mirex s o l u t i o n s   o r v a r i o u s p e r i o d s o f t i m e ; second, c r a y f i s h w e r e exposed t o m i r e x l e a c h e d from b a i t ( 0.3 p e r c e n t a c t i v e ingredient) ; and t h i r d , the crayfish w e r e fed mirex bait.

Procambarus u a n d i n g i j u v e n i l e s were exposed t o 1 o r 5 ug/ L f o r 6 t o 144 hours, t r a n s f e r r e d t o c l e a n water and observed f o r 10 days. A f t e r 5 days i n clean w a t e r , 95 percent of t h e animals exposed t o 1 ug/ L f o r 14 hours w e r e dead. Exposure t o 5 ug/ L f o r 6, 24, and 58 hours r e s u l t e d i n 26, 50, and 98 percent m o r t a l i t y 10 days a f t e r t r a n s f e r t o c l e a n water. Crayfish, Procambarus 0 '..

 hayi, were exposed to 0.1 and 0.5 ug/ L for 48 hours. Four days after transfer to clean water, 65 percent of the animals exposed to 0.1 ug/ L were dead. At the 0.5 ug/ L concentration, 71 percent of the animals were dead after 4 days in clean water.

Tissue residue accumulations ( wet weight basis) ranged from 940

to 27,210 fold above water concentrations. In leached bait experiments, 10 bait particles were placed in 2 liters of water but isolated from 20 juvenile crayfish. Thirty percent of the crayfish were dead in 4 days and 95 percent were dead in 7 days.

Water analysis indicated mirex concentrations of 0.86 ug/~. In feeding Qxperiments, 108 crayfish each were fed one bait particle. Mortality was noticed on the first day after feeding,

j8 and by the sixth day 77 percent were dead. In another experiment,

all crayfish were dead 4 days after having been fed 2 bait particles each. From this report it is obvious that mirex is extremely toxic to these species of crayfish. Mortality and accumulation increases with time of exposure to the insecticide.

Concentrations as low as 0.1 ug/ L or the ingestion of one particle resulted in death. $

Research to determine effects of mirex on fish has been concentrated on species which have economic and sport fishery importance. Hyde et al. ( 1974) applied mirex bait ( 0.3 percent mirex) at the standard rate ( 1.4 kg/ ha) in four ponds containing channel catfish, Ictalurus punctatus. Three applications were made over an 8~ 011th period with the first application 8 days after fingerling ( average weight 18.4 g ) catfish were placed in the ponds. Fish were collected at each subsequent application ( approximately 4 month i n t e r v a l s ) . Two and one h a l f months after t h e f i n a l a p p l i c a t i o n , t h e ponds were drained, a l l f i s h were measured and weighed, and t h e p e r c e n t s u r v i v a l was c a l c u l a t e d .

Mirex r e s i d u e s i n t h e f i s h a t termination of t h e experiment ranged from 0.015 ug/ g ( ppm) i n t h e f i l l e t t o 0.255 uq/ g i n t h e f a t . 0 I n another study, Van Valin e t a l . ( 1988) exposed b l u e g i l l s ,

 Lepomis macrochirus, and t h e g o l d f i s h , Carassius a u r a t u s , t o mirex by feeding a mirex treated d i e t ( 1, 3, and 5 mg mirex p e r kg body weight) o r by t r e a t i n g h o l d i n g ponds w i t h mirex b a i t ( 1.3, 1 0 0 , and 1000 ug/ L computed water concentration). They reported no m o r t a l i t y or t i s s u e pathology f o r t h e b l u e g i l l s ;

however, a f t e r 58 days of exposure, g i l l breakdown i n g o l d f i s h was found i n t h e 100 and 1 0 0 0 ug/ L c o n t a c t exposure ponds, and kidney breakdown was occurring i n the 1000 ug/ L ponds. Mortality i n t h e feeding experiments was n o t r e l a t e d t o t h e l e v e l of exposure, although growth of t h e b l u e g i l l s fed 5 ug/ L mirex w a s reduced.

I n laboratory and f i e l d test systems, reported concentrations of mirex u s u a l l y are between 0 . 5 and 1.0 ug/ L ( Van Valin e t a l .

1968: Ludke e t a l . 1971). Although mirex seldom is found above 1 ug/ L i n t h e aquatic environment, several f i e l d studies have shown t h a t t h e i n s e c t i c i d e is accumulated through t h e food chain.

Borthwick e t a l . ( 1973) r e p o r t e d t h e accumulation of mirex i n South Carolina e s t u a r i e s . T h e i r d a t a r e v e a l e d t h a t mirex was transported from treated land and marsh t o t h e estuary animals and t h a t accumulation, e s p e c i a l l y i n predators, occurred. I n t h e test area, water supplies consistently w e r e less than 0.01 ug/ L. Residues i n f i s h v a r i e d from non detectable percent of t h e samples containing and the percent of samples containing mirex residues. t o 0.8 ug/ g w i t h 15 The amount of mirex increased a t higher t r o p h i c l e v e l s . F i f t y f o u r p e r c e n t of t h e raccoons sampled contained mirex r e s i d u e s up t o 4.4 ug/ g and 78 p e r c e n t of t h e b i r d s contained r e s i d u e s up t o 1 7 ug/ g. Navgi and de l a Cruz ( 1973) r e p o r t e d average r e s i d u e s f o r molluscs ( 0.15 ug/ g), f i s h ( 0.26 ug/ g), i n s e c t s ( 0.29 ug/ g), c r u s t a c e a n s ( 0 . 4 4 ug/ g) and annelids ( 0.63 ug/ g. They a l s o reported t h a t mirex was found i n areas n o t t r e a t e d w i t h mirex which s u g g e s t s movement of t h e p e s t i c i d e i n t h e environment. Wol fe and Norment ( 1973) sampled an a r e a f o r one y e a r f o l l o w i n g an a e r i a l a p p l i c a t i o n of mirex b a i t ( 2.1 g mirex/ ha). Crayfish r e s i d u e s ranged from 0.04 t o 0.16 ug/ g. F i s h r e s i d u e s w e r e about 2 t o 2 0 t i m e s g r e a t e r t h a n t h e c o n t r o l s and averaged from 0.01 t o 0.78 ug/ g. Kaiser ( 1974),

r e p o r t e d t h e presence of rnirex i n f i s h from t h e Bay of Q u i n t e ,

Lake Ontario, Canada. Concentrations range from 0.02 ug/ g i n the gonads of t h e northern long nose gar, Lepistosteus osseus, t o 0.05 ug/ g i n t h e a r e a l f i n of t h e n o r t h e r n p i k e , ___ Esox l u c i u s .

Mirex has never been registered f o r u s e i n Canada.

Mirex does n o t appear t o be g r e a t l y t o x i c t o b i r d s , w i t h LCSO's f o r t h e young of four species ranging from 547 t o g r e a t e r than 1667 ug/ g ( Heath e t a l . 1 9 7 2 ) . Long term d i e t a r y dosages caused no adverse effect a t 3 u g / g w i t h m a l l a r d s a n d 1 3 ug/ gwith pheasants ( Heath and Spann, 1973). However, it has been reported ( Stoke e t a l . 1978) t h a t the persistence of mirex i n b i r d t i s s u e exceeds t h a t of a l l organochlorine compounds tested except f o r DDE. Delayed mortality occurred among birds subjected to doses above expected environmental concentration.

A summary examination of the data available at this time shows a mosaic of effects. Crayfish and channel catfish survival is affected by mirex in the water or by ingestion of the bait particles. Bioaccumulation is well established for a wide variety of organisms but the effect of this bioaccumulation on the aquatic ecosystem is unknown. There is evidence that mirex is very persistent in bird tissue. Considering the extreme toxicity and potential for bioaccumulation, every effort should be made to keep mirex bait particles out of water containing aquatic organisms and water concentrations should not exceed 0.001 ug/ L mirex. This value is based upon an application factor of 0.01 applied to the lowest levels at which effects on crayfish have been observed.

Data upon which to base a marine criterion involve several estuarine and marine crustaceans. A concentration of 0.1 ug/ L technical grade mirex in flowing seawater was lethal to juvenile pink shrimp, Penaeus durorarum, in a 3 week exposure ( Lowe et al.

1971). In static tests with larval stages ( megalopal) of the mud crab, Rhithropanopeus harrisii, reduced survival was observed in 0.1 ug/ L mirex ( Bookhout et al. 1972). In three of four 28 day seasonal f low through experiments, Tagatz et al. ( 1975) found reduced survival of __ Callinectes sapidus, Penaeus durorarum, and grass shrimp, ____ Palaemonetes ~ us&, at levels of 0.12 ug/ L in summer, 0.06 ug/ L in fall and 0.09 ug/ L in winter.

Since two reports, Lowe et al. ( 1971) and Bookhout et al.

( 1972), stated that effects of mirex on estuarine and marine c r u s t a c e a n s w e r e observed o n l y a f t e r c o n s i d e r a b l e t i m e had e l a p s e d , it seems reasonable t h a t l e n g t h of exposure is an important consideration  or t h i s chemical. This may not be t h e case i n f r e s h water s i n c e t h e c r a y f i s h were a f f e c t e d w i t h i n 4 8 hours. Therefore, a 3 t o 4 week exposure might be considered 88acute81 and by applying an a p p l i c a t i o n f a c t o r of 0.01 t o a reasonable average of toxic effect l e v e l s as summarized above, a recommended marine c r i t e r i o n of 0.001 ug/ L r e s u l t s .

( QUALITY CRITERIA FOR WATER, JULY 1976) PB 263943 SEE APPENDIX C FOR METHODOLOGY N? QrnLENE Aquatic Life The available data for naphthalene indicate that acute and chronic toxicity to freshwater aquatic life occurs at concentrations as low as 2,300 and 620 ug/ L, respectively, and would occur at lower concentrations among species that are more sensitive than those tested.

The available data for naphthalene indicate that acute toxicity to saltwater aquatic 1 ife occurs at concentrations as low as 2,350 ug/ L and would occur at lower concentrations among species that are more sensitive than those tested. No data are available concerning the chronic toxicity of naphthalene to sensitive saltwater aquatic life. I Human Health Using the present guidelines, a satisfactory criterion cannot be derived at this time because of insufficient available data for naphthalene.

( 45 F. R. 79318, November 28, 1980) SEE APPENDIX B FOR METHODOLOGY NICKEL Aquatic Life FOI total recoverable nickel the criterion ( in ug/ L) to protect freshwater aquatic life as derived using the Guidelines is the numerical value given by e( 0.76[ 1n( hardness)]+ l. 06) as a 24 hour average, and the concentration ( in ug/ L) should not exceed the numerical value given by .( 0.76[ ln ( hardness)]+ 4.02)

at any time. For example, at hardnesses of 5 0 , 100, and 200 mg/ L as CaC03 the criteria are 56, 96, and 160 ug/ L, respectively, as 24 hour averages, and the concentrations should not, exceed 1,100,

1,800, and 3,100 ug/ L, respectively, at any time.

For total recoverable nickel the criterion to protect saltwater aquatic life as derived using the Guidelines is 7.1 ug/ L as a 24 hour average, and the concentration should not exceed 140 ug/ L at any time. 0 Human Health For the protection of human health from the toxic properties of nickel ingested through water and contaminated aquatic organisms, the ambient water criterion is determined to be 632 wl/ L.

For the protection of human health from the toxic properties of nickel ingested through contaminated aquatic organisms alone, the ambient water criterion is determined to be 4.77 W/ L.

( 45 F. R. 79318, November 28, 1980) 0 SEE APPENDIX B FOR METHODOLOGY 0 CRITERION: NITF? ATES/ NITRITES 10 mg/ L n i t r a t e nitrogen ( N) f o r domestic water supply ( h e a l t h ) .

INTRODUCTION:

Two gases ( m o l e c u l a r n i t r o g e n and n i t r o u s oxide) and f i v e forms o f nongaseous, combined n i t r o g e n ( amino and amide groups,

ammonium, n i t r i t e , and n i t r a t e ) are important i n t h e n i t r o g e n cycle. The amino and amide groups are found i n s o i l o r g a n i c matter and as c o n s t i t u e n t s of p l a n t and animal p r o t e i n . The ammonium ion either is released from proteinaceous organic matter and urea, o r is s y n t h e s i z e d i n i n d u s t r i a l p r o c e s s e s i n v o l v i n g atmospheric n i t r o g e n f i x a t i o n . The n i t r i t e i o n i s formed from t h e n i t r a t e or t h e ammonium ions by c e r t a i n microorganisms found i n s o i l , water, sewage, and t h e d i g e s t i v e tract. The n i t r a t e ion is formed by t h e complete o x i d a t i o n of ammonium i o n s by s o i l o r water microorganisms; n i t r i t e is an intermediate product of t h i s n i t r i f i c a t i o n process. I n oxygenated n a t u r a l water systems n i t r i t e is r a p i d l y o x i d i z e d t o n i t r a t e . Growing p l a n t s assimilate n i t r a t e o r ammonium ions and convert them t o protein.

A process known as d e n i t r i f i c a t i o n takes p l a c e when n i t r a t e

containing s o i l s become anaerobic and t h e conversion t o n i t r i t e ,

molecular nitrogen, or n i t r o u s oxide occurs. Ammonium ions may a l s o be produced i n some circumstances. 0 Among t h e major p o i n t s o u r c e s of n i t r o g e n e n t r y i n t o water bodies are municipal and i n d u s t r i a l wastewaters, s e p t i c t a n k s ,

and feed l o t discharges. D i f f u s e s o u r c e s o f n i t r o g e n i n c l u d e farm site f e r t i l i z e r and animal wastes, lawn f e r t i l i z e r , leachate a from waste disposal in dumps or sanitary landfills, atmospheric fallout, nitric oxide and nitrite discharges from automobile exhausts and other combustion processes, and losses from natural sources such as mineralization of soil organic matter ( NAS,

1972). Water reuse systems in some fish hatcheries employ a nitrification process for ammonia reduction; this may result in exposure of the hatchery fish to elevated levels of nitrite ( Russo et al. 1974).

RATIONALE :

In quantities normally found in food or feed, nitrates become toxic only under conditions in which they are, or may be, reduced to nitrites. Otherwise, at " reasonable" concentration nitrates are rapidly excreted in the urine. High intake of nitrates constitutes a hazard primarily to warmblooded animals under conditions that are favorable to reduction to nitrite. Under certain circumstances, nitrate can be reduced to nitrite in the gastrointestinal tract which then reaches the bloodstream and reacts directly with hemoglobin to produce methemoglobin,

consequently impairing transport. I The reaction of nitrite with hemoglobin can be hazardous in infants under 3 months of age. Serious and occasionally fatal poisonings in infants have occurred following ingestion of untreated well waters shown to contain nitrate at concentrations greater than 10 mg/ L nitrate nitrogen ( N) ( NAS, 1974). High nitrate concentrations frequently are found in shallow farm and rural community wells, often as the result o f inadequate protection from barnyard drainage or from septic tanks ( USPHS, 1961; Stewart et al. 1967). Increased concentrations of nitrates also have been found in streams from farm tile drainage in areas of intense fertilization and farm crop production ( Harmeson et al. 1971). Approximately 2,000 cases of infant methemoglobinemia have been reported in Europe and North America since 1945; 7 to 8 percent of the affected infants died ( Walton, 1951;

Sattelmacher, 1962). Many infants have drunk water in which the nitrate nitrogen content was greater than 10 mg/ L without developing methemoglobinemia. Many pub1 ic water supplies in the United States contain levels that routinely exceed this amount,

but only one U. S. case of infant methemoglobinemia associated with a public water supply has ever been reported ( Virgil et al.

1965). The differences in susceptibility to methemoglobinemia are not yet understood but appear to be related to a combination of factors including nitrate concentration, enteric bacteria, and the lower acidity characteristic of the digestive systems of baby mammals. Methemoglobinemia systems and other toxic effects were observed when high nitrate well waters containing pathogenic bacteria were fed to laboratory mammals ( Wolff et al. 1972).

Conventional water treatment has no significant effect on nitrate removal from water ( NAS, 1974).

Because of the potential risk of methemoglobinemia to bottle

fed infants, and in view of the absence of substantiated physiological effects at nitrate concentrations below 10 mg/ L nitrate nitrogen, this level is the criterion for domestic water supplies. Waters with nitrite nitrogen concentrations over 1 0 ~ mg/ L should not be used for infant feeding. Waters with a significant nitrite concentration usually would be heavily polluted and probably bacteriologically unacceptable.

Westin ( 1974) determined that the respective 96 hOUr and 7

day LC50 values for chinook salmon, Oncorhynchus tshawytscha,

were 1,310 and 1,080 mg/ L nitrate nitrogen in fresh water and 990 and 900 mg/ L nitrate nitrogen in 15 o/ oo saline water. For fingerling rainbow trout, Salmo qairdneri, the respective 96 hour and 7 day LC50 values were 1,360 and 1,060 mg/ L nitrate nitrogen in fresh water, and 1,050 and 900 mg/ L nitrate nitrogen in 15 o/ oo saline water. Trama ( 1954) reported that the 96 hOUr LC50 for bluegills, Asomis  macrochirus  I at 20 ° C was 2 , 0 0 0 mg/ L nitrate nitrogen ( sodium nitrate) and 420 mg/ L nitrate nitrogen ( potassium nitrate). Knepp and Arkin ( 1973) observed that largemouth bass, Micropterus salmoides, and channel catfish,

Ictalurus punctatus, could be maintained at concentrations up to 400 mg/ L nitrate ( 90 mg/ L nitrate nitrogen) without significant effect upon their growth and feeding activities.

The 96 hour and 7 day LC50 values for chinook salmon,

___ Qncorhynchus tshawytscha, were found to be 0.9 and 0.7 mg/ L nitrite nitrogen in fresh water ( Westin, 1974). Smith and Williams ( 1974) tested the effects of nitrite nitrogen and observed that yearling rainbow trout, Salmo gairdneri, suffered a 55 percent mortality after 24 hours at 0.55 mg/ L; fingerling rainbow trout suffered a 50 percent mortality after 24 hours of exposure at 1.6 mg/ L; and chinook salmon, Oncorhynchus tshawytscha, suffered a 40 percent mortality within 24 hours at 0.5 mg/ L. There w e r e no m o r t a l i t i e s among rainbow t r o u t exposed t o 0.15 mg/ L n i t r i t e nitrogen f o r 48 hours. These data indicate t h a t salmonids are more s e n s i t i v e t o n i t r i t e t o x i c i t y than a r e other f i s h s p e c i e s , e. g., minnows, _ Phoxinus l a e v i s t h a t suffered a 50 percent mortality within 1.5 hours of exposure t o 2,030 mg/ L n i t r i t e n i t r o g e n , b u t required 1 4 days of exposure  or m o r t a l i t y t o occur a t 1 0 mg/ L ( K l i n g l e r , 1 9 5 7 ) , and carp,

Cyprinus  c a r e , when r a i s e d i n a water reuse system, t o l e r a t e d up t o 1.8 mg/ L n i t r i t e nitrogen ( Saeki, 1965).

G i l b e t t e , e t a l . ( 1952) observed t h a t t h e critical range f o r creek chub, Semotilus  atromaculatus, was 80 t o 400 mg/ L n i t r i t e nitrogen. Wallen e t a l . ( 1957) reported a 24 hour LC50 of 1.6 mg/ L n i t r i t e n i t r o g e n , and 48 and 96 hour LC50 v a l u e s of 1.5 mg/ L n i t r i t e nitrogen f o r mosquitofish, Gambusia a f f i n i s . McCoy ( 1972) tested t h e n i t r i t e s u s c e p t i b i l i t y of 13 f i s h species and found t h a t logperch, Percina  caprodes  _ I were t h e most s e n s i t i v e s p e c i e s tested ( m o r t a l i t y a t 5 mg/ L n i t r i t e n i t r o g e n i n less than 3 hours of exposure) whereas carp, 9 p r i n u s c a r p i o , and b l a c k bullheads,  I c t a l u r u s  melas 8 s u r v i v e d 40 mg/ L n i t r i t e nitrogen  or a 48 hour exposure period; t h e common white sucker,

Catostomus .. I commersoni and t h e q u i l lback, Carpiodes cyprinus,

survived 100 mg/ L f o r 48 and 36 hours, respectively. e Russo e t a l . ( 1974) performed f low through n i t r i t e bioassays i n hard water ( hardness = 1 9 9 mg/ L CaC03; a l k a l i n i t y = 176 mg/ L CaCQ3; pH = 7.9) on rainbow t r o u t , Salmo g a i r d n e r i , of f o u r d i f f e r e n t s i z e s , and obtained 9 6  h O U r LC50 values ranging from 0.19 t o 0.39 mg/ L n i t r i t e nitrogen. Duplicate bioassays on 1 2