UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, DC. 20460 

OCT I5 1993 

OFFICE OF 

WATER 

Dear Environmental Advocate: 

On October 1, 1993, I signed a memorandum regarding the Office of Water’s Policy 

and Technical Guidance on Interpretation and Implementation of Aquatic Life Metals 

Criteria. This memorandum covers a number of areas including the expression of aquatic 

life criteria, total maximum daily loads, National Pollution Discharge Elimination System 

permits and enforcement, effluent monitoring, and ambient monitoring. The policy and 

guidance in this document considers comments received from the US. Environmental 

Protection Agency (EPA) Regional Offices, recommendations made to EPA by the 

participants in a meeting held in January 1993 in Annapolis, Maryland, and public comments 

in the June 8, 1993, Federal Register notice requesting general public comments on the 

Annapolis meeting recommendations. As stated in the enclosed memorandum, we will 

continue to issue guidance as more information becomes available. 

Sincerely yours, 

Martha G. Prothro 

Acting Assistant Administrator 

Enclosure 
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OCT 1 1995 

OFFICE OF 

MEMORANDUM 

WATER 

SUBJECT: Office of Water Policy and Technical Guidance on Interpretation and 

Implementation of Aquatic Life Metals Criteria 

FROM: Martha G. Prothro 

Acting Assistant Administrator for Water 

TO: Water Management Division Directors 

Environmental Services Division Directors 

Regions I-X 

Introduction 

The implementation of metals criteria is complex due to the site-specific nature of 

metals toxicity. We have undertaken a number of activities to develop guidance in this area, 

notably the Interim Metals Guidance, published May 1992, and a public meeting of experts 

held in Annapolis, MD, in January 1993. This memorandum transmits Office of Water 

(OW) policy and guidance on the interpretation and implementation of aquatic life criteria for 

the management of metals and supplements my April 1, 1993, memorandum on the same 

subject. The issue covers a number of areas including the expression of aquatic life criteria; 

total maximum daily loads (TMDLs), permits, effluent monitoring, and compliance; and 

ambient monitoring. The memorandum covers each in turn. Attached to this policy 

memorandum are three guidance documents with additional technical details. They are: 

Guidance Document on Expression of Aquatic Life Criteria as Dissolved Criteria 

(Attachment #2), Guidance Document on Dynamic Modeling and Translators (Attachment 

#3), and Guidance Document on Monitoring (Attachment #4). These will be supplemented 

as additional data become available. (See the schedule in Attachment #1.) 

Since metals toxicity is significantly affected by site-specific factors, it presents a 

number of programmatic challenges. Factors that must be considered in the management of 

metals in the aquatic environment include: toxicity specific to effluent chemistry; toxicity 

specific to ambient water chemistry; different patterns of toxicity for different metals; 

evolution of the state of the science of metals toxicity, fate, and transport; resource 

limitations for monitoring, analysis, implementation, and research functions; concerns 

regarding some of the analytical data currently on record due to possible sampling and 

analytical contamination; and lack of standardized protocols for clean and ultra&an metals 

analysis. The States have the key role in the risk management process of balancing these 

factors in the management of water programs. The site-specific nature of this issue could be 

perceived as requiring a permit-by-permit approach to implementation. However, we believe 
2 

that this guidance can be effectively implemented on a broader level, across any waters with 

roughly the same physical and chemical characteristics, and recommend that we work with 

the States with that perspective in mind. 

wssion of Aauatic Life Criteria 

0 Dissolved vs. Total Recoverable Metal 

A major issue is whether, and how, to use dissolved metal concentrations (“dissolved 

metal’) or total recoverable metal concentrations (“total recoverable metal”) in setting State 

water quality standards. In the past, States have used both approaches when applying the 

same Environmental Protection Agency (EPA) criteria numbers. Some older criteria 

documents may have facilitated these different approaches to interpretation of the criteria 

because the documents were somewhat equivocal with regards to analytical methods. The 

May 1992 interim guidance continued the policy that either approach was acceptable. 

It is now the policy of the Office of Water that the use of dissolved metal to set and 

measure compliance with water quality standards is the recommended approach, because 

dissolved metal more closely approximates the bioavailable fraction of metal in the water 

column than does total recoverable metal. This conclusion regarding metals bioavailability is 

supported by a majority of the scientific community within and outside the Agency. One 

reason is that a primary mechanism for water column toxicity is adsorption at the gill surface 

which requires metals to be in the dissolved form. 

The position that the dissolved metals approach is more accurate has been questioned 

because it neglects the possible toxicity of particulate metal. It is true that some studies have 

indicated that particulate metals appear to contribute to the toxicity of metals, perhaps 

because of factors such as desorption of metals at the gill surface, but these same studies 

indicate tie toxicity of particulate metal is substantially less than that of dissoivcd metal. 

Furthermore, any error incurred from excluding the contribution of particulate metal 

will generally be compauated by other factors which make criteria coamtive. For 

example, metals in toxicity tests are added as simple salts to relatively clean water. Due to 

the likely v of a significant concentration of metals binding agents in many discharges 

and ambient waters, metals in toxicity tests would generally be expected to be more 

bioavailabile than metals in discharges or in ambient waters. 

If total ncoverable metal is used for the purpose of water quality stand&s, 

compounding of factors due to the lower bioavailability of partioulate metal and lower 

bioavailability of metals as they are discharged may result in a ‘&nserWive water quality 

standard. The use of dissolved metal in water quality standards gives a more accura& result. 

However, the majority of the participants at the Annapolis meeting felt that total recoverable 

measurements in ambient water had some value, and that exceedences of criteria on a total 

recoverable basis were an indication that metal loadings could be a stress to the ecosystem, 

particularly in locations other than the water column. 
3 

The reasons for the potential consideration of total recoverable measurements include 

risk management considerations not covered by evaluation of water column toxicity. The 

ambient water quality criteria are neither designed nor intended to protect sediments, or to 

prevent effects due to food webs containing sediment dwelling organisms. A risk manager, 

however, may consider sediments and food chain effects and may decide to take a 

conservative approach for metals, considering that metals are very persistent chemicals. This 

conservative approach could include the use of total recoverable metal in water quality 

standards. However, since consideration of sediment impacts is not incorporated into the 

criteria methodology, the degree of conservatism inherent in the total recoverable apprach is 

unknown. The uncertainty of metal impacts in sediments stem from the lack of sediment 

criteria and an imprecise unde&anding of the fate and transport of metals. EPA will 

continue to pursue research and other activities to close these knowledge gaps. 

Until the scientific uncertainties are better resolved, a range of different risk 

management decisions can be justified. EPA recommends that State water quality standards 

be based on dissolved metal. (See the paragraph below and the attached guidance for 

technical details on developing dissolved criteria.) WA will also approve a State risk 

management decision to adopt standards based on total recoverable metal, if those standards 

are otherwise approvable as a matter of law. 

0 Dissolved Criteria 

In the toxicity tests used to develop EPA metals criteria for aquatic life, some fraction 

of the metal is dissolved while some fraction is bound to particulate ma=. The present 

criteria were developed using total recoverable metal measurements or measures expected to 

give equivalent results in toxicity tests, and are articulated as total recoverable. Therefore, 

in order to express the EPA criteria as dissolved, a total recoverable to dissolved correction 

factor must be used. Attachment #2 provides guidance for aMating EPA dissolved criteria 

from the published total recoverable criteria. The data expressed as percentage metal 

dissolved are presented as recommended values and ranges. However, the choice within 

ranges is a State risk management decision. We have ncently suppiernaM the data for 

copper and are proc&ing to further supplementhe data for copper and other metals. As 

testing is completed, we will make this information available and this is expected to rake 

the magnitude of the ranges for some of the conversion f&ctors provided. We also strongly 

encourage the application of dissolved criteria across a water&d or watehody, as 

tcchnicalIy sound and the best use of resources. 

0 Site-Specific Criteria Modifications 

While the above methods will correct some site-specific factors affecting metals 

toxicity, further refinements are possible. EPA has issued guidance (Water Quality 

Standards Handbook, 1983; Guidelines for Deriving Numerical Aquatic Site-Specific Water 

Quality Criteria by Modifying National Criteria, EPAd00;3-He099, October 1984) for three 

site-specific criteria development methodologies: recalculation procedure, indicator species 

procedure (also known as the water-effect ratio (WER)) and resident species procedure. 

Only the first two of these have been widely used. 
4 

In the National Toxics Rule (57 FR 60848, December 22, 1992), EPA identified the 

WER a~ an optional method for site-specific criteria development for certain metals. EPA 

committed in the NTR preamble to provide guidance on determining the WER. A draft of 

this guidance haJ been circulated to the States and Regions for review and comment. As 

justified by water characteristics and as recommended by the WER guidance, we strongly 

encourage the application of the WER across a watershed or waterbody as opposed to 

application on a discharger by discharger basis, as technically sound and an efficient use of 

ESOUrcts. 

In order to meet current needs, but allow for changes suggested by protocol users, 

EPA will issue the guidance as ‘interim.’ EPA will accept WERs developed using this 

guidance, as well as by using other scientifically defensible protocols. OW expects the 

interim WER guidance will be issued in the next two months. 

. . . . . . Total MaxlmumM~LoadsOandn System 

DES) Peru& 

0 Dynamic Water Quality Modeling 

Although not specifically part of the reassessment of water quality criteria for metals, 

dynamic or probabilistic models are another useful tool for implementing water quality 

criteria, espazially for those criteria protecting aquatic life. These models provide another 

way to incorporate site-specific data. The 1991 Technical Support Document for Water 

Quality-based Toxics Control (TSD) (EPA/505/2-90401) describes dynamic, as well as static 

(steady-state) models. Dynamic models make the best use of the specified magnitude, 

duration, and ikaquency of water quality criteria and, therefore, provide a more accurate 

representation of the probability that a water quality standard exccedence will occur. In 

contrast, steady-state models make a number of simplifying, worst case assumptions which 

makes them less complex and less accurate than dynamic models. 

Dynamic models have received incrcaxd attention over the last few years as a result 

of the widespread belief that steady-state modeling is over~servative due to 

environmentally consuvative dilution assumptions. ntir belief has led to the misconception 

that dynamic models will always lead to less stringent ngulatoiy controls (e.g., NPDES 

effluent limit@ than steady-state models, which is not true in evq applications of dynamic 

models. EPA considers dynamic models to be a m~fe accu approach to implementing 

water quality criteria and continues to recommend their use. Dynamic modeling does require 

commitment of resources to develop appropriate data. (See Attachment #3 and the TSD for 

details on the use of dynamic models.) 

0 Dissolved-Total Metal Translators 

Expressing water quality criteria as the dissolved form of a metal poses a need to be 

able to translate from dissolved metal to total recoverable metal for TMDLt and NPDES 

permits. TMDLs for metals must be able to calculate: (1) dissolved metal in order to 

ascertain attainment of water quality standards, and (2) total recoverable metal in order to 

achieve mass balance necessary for permitting purposes. 
5 

EPA’s NPDES regulations require that limits of metals in permits be stated as toa 

recoverable in most cases (see 40 CFR $122.45(c)) except when an effluent guideline 

specifies the limitation in another form of the metal, the approved analytical methods 

measure only dissolved metal, or the permit writer expresses a metals limit in another form 

(e.g., dissolved, valent, or total) when rqclired to carry out provisions of the Clean Water 

Act. This is because the chemical conditions in ambient waters frequently differ substantially 

from those in the effluent, and there is no assurance that effluent particulate metal would not 

dissolve after discharge. The NPDES rule does not require that State water quality standards 

be expressed as total recoverable; rather, the rule requires permit writers to translate between 

different metal forms in the calculation of the permit limit so that a tota! recoverable limit 

can be established. Both the TMDL and NPDES uses of water quality criteria require the 

ability to translate between dissolved metal and total recoverable metal. Attachment #3 

provides methods for this translation. 

. . Guidance on Monttonng 

0 Use of Clean Sampling and Analytical Techniques 

In assessing waterbodies to determine the potential for toxicity problems due to 

metals, the quality of the data used is an important issue. Metals data arc used to determine 

attainment status for water quality standards, discern trends in water quality, estimate 

background loads for TMDLs, calibrate fate and transport models, estimate effluent 

concentrations (including effluent variability), assess permit compliance, and conduct 

research. The quality of trace level metal data, especially below 1 ppb, may be 

compromised due to contamination of sampies during collection, preparation, storage, and 

analysis. Depending on the level of metal present, the use of ‘clean” and ‘ultraclean’ 

techniques for sampling and analysis may be critical to accurate data for implementation of 

aquatic life criteria for metals. 

The magnitude of the contamination problem increases as the ambient and effluent 

metal concentration decreases and, therefore, problems arc more likely in ambient 

measurements. “Clean” techniques refer to those requirements (or practices for sample 

collection and handling) nv to produce reliable analytical data in the part per billion 

(ppb) range. “Ultraclean’ techniques refer to those requinments or practices necessary to 

produce reliable analytical data in the part per trillion (ppt) range. Because typical 

concentrations of metals in surface waters and effluents vary from one metal to another, the 

effect of contamination on the quality of metals monitoring &a varies appreciably. 

We plan to develop protocols on the use of clean and ultra-clean techniques and are 

coordinating with the United States Geological Survey (USGS) on this project, because USGS 

has been doing work on these techniques for some time, e-s-y the sampling procedures. 

We anticipate that our draft protocols for clean techniques will be available in late calendar 

year 1993. The development of comparable protocols for ultra-clean techniques is underway 

and will be available in 1995. In developing these protocols, we will consider the COSTS of 

these techniques and will give guidance as to the situations where their use is necessary. 

Appendix B to the WER guidance document provides some general guidance on the use of 
6 

clean analytical techniques. (See Attachment #4.) We recommend that this guidance be used 

by Staus and Regions as an interim step, while the clean and ultra-clean protocols are being 

developed. 

0 Use of Historical Data 

The concerns about metals sampling and analysis discussed above raise corresponding 

concerns about the validity of historical data. Data on effluent and ambient metal 

concentrations are collected by a variety of organizations including Federal agencies (e.g., 

EPA, USGS), State pollution control agencies and health departments, local government 

agencies, municipalities, industrial dischargers, researchers, and others. The data are 

collected for a variety of purposes as discussed above. 

Concern about the reliability of the sample collection and analysis procedures is 

greatest where they have been used to monitor very low level metal concentrations. 

Specifically, studies have shown data sets with contamination problems during sample 

collection and laboratory analysis, that have resulted in inaccurate measurements. For 

example, in developing a TMDL for New York Harbor, some historical ambient data showed 

extensive metals problems in the harbor, while other historical ambient data showed only 

limited metals problems. Careful resampling and analysis in 199Zl993 showed the latter 

view was correct. The key to producing accurate data is appropriate quality assurance (QA) 

and quality control (QC) procedures. We believe that most historical data for metals, 

collected and analyzed with appropriate QA and QC at levels of 1 ppb or higher, are 

reliable. The data used in development of EPA criteria are also considered reliable, both 

because they meet the above test and because the toxicity test solutions are created by adding 

known amounts of metals. 

With respect to effluent monitoring reported by an NPDES permit&e, the permittee is 

responsible for collecting and reporting quality data on a Discharge Monitoring Report 

(DMR). Permitting authorities should continue to consider the information reported to be 

true, accurate, and complete as certified by the permittee. Where the permittee becomes 

aware of new information specific to the effluent discharge that questions the quality of 

previously submitted DMR data, the permittee must promptly submit that information to the 

permitting authority. The permitting authority will consider all information submitted by the 

permittee in detamSng appropriate enforcement responses to monitoring/reporting and 

effIuent violatia~. (See Attachment X4 for additional d&is.) 

The management of metals in the aquatic environment is complex. The science 

supporting our technical and regulatory programs is amtinuing to evolve, here as in ail 

areas. The policy and guidance outlined above represent the position of OW and should be 

incorporated into ongoing program operations. We do not expect that ongoing operations 

would be delayed or deferred because of this guidance. 
7 

If you have questions concerning this guidance, please contact Jim Hanlon, Acting 

Director, Office of Science and Technology, at 202-260-5400. If you have questions on 

specific details of the guidance, please contact the appropriate OW Branch Chief. The 

Branch Chiefs responsible for the various areas of the water quality program are: Bob April 

(202-260-6322, water quality criteria), Elizabeth Fellows (202-260-7046, monitoring and data 

issues), Russ Kinerson (202-260-1330, modeling and translators), Don Brady (202-260-7074, 

Total Maximum Daily Loads), Sheila Frace (202-260-9537, permits), Dave Sabock 

(202-260-1315, water quality standards), Bill Telliard (202-260-7134, analytical methods) 

and Dave Lyons (202-260-8310, enforcement). 

Attachments 
ATTACHMENT #1 

TECHNICAL GUIDANCE FOR METALS 

Schedule of Upcoming Guidance 

Water-effect Ratio Guidance - September 1993 

Draft “Clean” Analytical Methods - Spring 1994 

Dissolved Criteria - currently being done; as testing is completed, we will release the 

updated percent dissolved data 

Draft Sediment Criteria for Metals - 1994 

Final Sediment Criteria for Metals - 1995 
ATTACHMENT #2 

GUIDANCE DOCUMENT 

ON DISSOLVED CRITERIA 

Expression of Aquatic Life Criteria 

October 1993 
10-1-93 

Percent Dissolved in Aquatic Toxicity Tests on Metals 

The attached table contains all the data that were found 

concerning the percent of the total recoverable metal that wag 

dissolved in aquatic toxicity tests. This table is intended to 

contain the available data that are relevant to the conversion of 

EPA's aquatic life criteria for metals from a total recoverable 

basis to a dissolved basis. (A factor of 1.0 is used to convert 

aquatic life criteria for metals that are expressed on the basis 

of the acid-soluble measurement to criteria expressed on the 

basis of the total recoverable measurement.) Reports by Grunwald 

(1992) and Brungs et al. (1992) provided references to many of 

the documents in which pertinent data were found. Each document 

was obtained and examined to determine whether it contained 

useful data. 

"Dissolved" is defined as metal that passes through a 0.45 - μm 

membrane filter. If otherwise acceptable, data that were 

obtained using 0.30 - μm glass fiber filters and 0.1 - μm membrane 

filters were used, and are identified in the table; these data 

did not seem to be outliers. 

Data were used only if the metal was in a dissolved inorganic 

form when it was added to the dilution water. In addition, data 

were used only if they were generated in water that would have 

been acceptable for use as a dilution water in tests used in the 

derivation of water quality criteria for aquatic life; in 

particular, the pH had to be between 6.5 and 9.0, and the 

concentrations of total organic carbon (TOC) and total suspended 

solids (TSS) had to be below 5 mg/L. Thus most data generated 

using river water would not be used. 

Some data were not used for other reasons. Data presented by 

Carroll et al. (1979) for cadmium were not used because 9 of the 

36 values were above 150%. Data presented by Davies et al. 

(1976) for lead and Holcombe and Andrew (1978) for zinc were not 

used because "dissolved" was defined on the basis of 

polarography, rather than filtration. 

Beyond this, the data were not reviewed for quality. Horowitz et 

al. (1992) reported that a number of aspects of the filtration 

procedure might affect the results. In addition, there might be 

concern about use of "clean techniques" and adequate QA/QC. 

Each line in the table is intended to represent a separate piece 

of information. All of the data in the table were determined in 

fresh water, because no saltwater data were found. Data are 

becoming available for copper in salt water from the New York 

1 
Harbor study; based on the first set of tests, Hansen (1993) 

suggested that the average percent of the copper that is 

dissolved in sensitive saltwater tests is in the range of 76 to 

82 percent. 

A thorough investigation of the percent of total recoverable 

metal that is dissolved in toxicity tests might attempt to 

determine if the percentage is affected by test technique 

(static, renewal, flow-through), feeding (were the test animals 

fed and, if so, what food and how much), water quality 

characteristics (hardness, alkalinity, pH, salinity), test 

organisms (species, loading), etc. 

The attached table also gives the freshwater criteria 

concentrations (CMC and CCC) because percentage8 for total 

recoverable concentrations much (e.g., more than a factor of 3) 

above or below the CMC and CCC are likely to be less relevant. 

When a criterion is expressed as a hardness equation, the range 

given extends from a hardness of 50 mg/L to a hardness of 200 

v/LThe following is a summary of the available information for each 

metal: 

The data available indicate that the percent dissolved is about 

100, but all the available data are for concentrations that are 

much higher than the CMC and CCC. 

Cadmium 

Schuytema et al. (1984) reported that "there were no real 

differences" between measurements of total and dissolved cadmium 

at concentrations of 10 to 80 ug/L (pH - 6.7 to 7.8, hardness - 

25 mg/L, and alkalinity - 33 mg/L); total and dissolved 

concentrations wsre said to be "virtually equivalent". 

The CMC and CCC are close together and only range from 0.66 to 

8.6 ug/L. The only available data that are known to be in the 

range of the CMC and CCC were determined with a glass fiber 

filter. The percentages that are probably most relevant are 75, 

92, 89, 78, and 80. 

The percent dissolved decreased as the total recoverable 

concentration increased, even though the highest concentrations 

reduced the pH substantially. The percentages that are probably 

2 
most relevant to the CMC are 50-75, whereas the percentages that 

are probably most relevant to the CCC are 86 and 61. 

Chromium(VIl 

The data available indicate that the percent dissolved is about 

100, but all the available data are for concentrations that are 

much higher than the CMC and CCC. 

CODDeq 

Howarth and Sprague (1978) reported that the total and dissolved 

concentrations of copper were "little different" except when the 

total copper concentration was above 500 ug/L at hardness - 360 

mg/L and pH = 8 or 9. Chakoumakos et al. (1979) found that the 

percent dissolved depended more on alkalinity than on hardness, 

PH, or the total recoverable concentration of copper. 

Chapman (1993) and Lazorchak (1987) both found that the addition 

of daphnid food affected the percent dissolved very little, even 

though Chapman used yeast-trout chow-alfalfa whereas Lazorchak 

used algae in most tests, but yeast-trout chow-alfalfa in some 

tests. Chapman (1993) found a low percent dissolved with and 

without food, whereas Lazorchak (1987) found a high percent 

dissolved with and without food. All of Lazorchak's values were 

in high hardness water; Chapman's one value in high hardness 

water was much higher than his other values. 

Chapman (1993) and Lazorchak (1987) both compared the effect of 

food on the total recoverable LCSO with the effect of food on the 

dissolved LC50. Both authors found that food raised both the 

dissolved LCSO and the total recoverable LCSO in about the same 

proportion, indicating that food did not raise the total 

recoverable LCSO by sorbing metal onto food particles; possibly 

the food raised both LCSOs by (a) decreasing the toxicity of 

dissolved metal, (b) forming nontoxic dissolved complexes with 

the metal, or (c) reducing uptake. 

The CMC and CCC are close together and only range from 6.5 to 34 

w/L. The percentages that are probably most relevant are 74, 

95, 95, 73, 57, 53, 52, 64, and 91. 

The data presented jn Spehar et al. (1978) were from Holcombe et 

al. (1976). Both Chapman (1993) and Holcombe et al. (1976) found 

that the percent dissolved increased as tha total recoverable 

concentration increased. It would seem reasonable to expect more 

precipitate at higher total recoverable concentrations and 

3 
therefore a lower percent dissolved at higher concentrations. 

The increase in percent dissolved with increasing concentration 

might be due to a lowering of the pH as more metal is added if 

the stock solution was acidic. 

The percentages that are probably most relevant to the CMC are 9, 

18, 25, 10, 62, 68, 71, 75, 81, and 95, whereas the percentages 

that are probably most relevant to the CCC are 9 and 10. 

The only percentage that is available is 73, but it is for a 

concentration that is much higher than the CMC. 

Nickel 

The percentages that are probably most relevant to the CMC are 

88, 93, 92, and 100, whereas the only percentage that is probably 

relevant to the CCC is 76. 

Seleniun 

No data are available. 

Silver 

There is a CX, but not a CCC. The percentage dissolved seems to 

be greatly reduced by the food used to feed daphnids, but not by 

the food used to feed fathead minnows. The percentages that are 

probably most relevant to the CMC are 41, 79, 79, 73, 91, 90, and 

93. 

Zinc 

The CMC and CCC are close together and only range from 59 to 210 

v/L* The percentages that are probably most relevant are 31, 

77, 77, 99, 94, 100, 103, and 96. 

4 
Recommended'Values (%)A and Ranges of Measured Percent Dissolved 

Considered Most Relevant in Fresh Water 

Metal 

Arsenic(II1) 

Cadmium 

Chromium(II1) 

Chromium(V1) 

Copper 

Lead 

Mercury 

Nickel 

Selenium 

Silver 

Zinc 

QE ccc 

Recommended Recommended 

Value f%1 [Ranae $1 Value f%1 (Ranae %L 

95 1oo-104B 95 1oo-104B 

85 75-92 85 75-92 

85 50-75 85 61-86 

- 

95 100' 95 loo* 

85 52-95 85 52-95 

50 9-95 25 9-10 

85 73B NAE NAE 

85 88-100 85 76 

NAE NAC NAE NAc 

85 41-93 YYD YP 

85 31-103 85 31-103 

A The recommended values are based on current knowledge and are 

subject to change as more data becomes available. 

* All available data are for concentrations that are much higher 

than the CMC. 

= NA = No data aro available. 

D YY = A CCC is not available, and therefore cannot be adjusted. 

E NA = Bioaccumulative chemical and not appropriate to adjust to 

percent dissolved. 
Concn. A Percent 

lYaL.l I2ia.2 g t+eciesD $RFe FOOC$ Hard. AUL EH Ref. 

B (Freshwater: CCC = 190 Ug/L; CMC = 360 W/L) 

600-15000 104 5 ? ? ? 48 41 7.6 Lima et al. 1984 

12600 100 3 I94 F No 44 43 7.4 Spehar and Fiandt 1986 

QiDW 

0.16 

0.28 

0.4-4.0 

13 

15-21 

42 

10 

35 

51 

6-80 

3-232 

450-6400 

(Freshwater: CCC = 0.66 to 2.0 ug/L; CMC 

41 3 DM R Yes 53 

75 ? Dkl R Yes 103 

92O ? cs F No 21 

89 3 FM F No 44 

96 8 Fn S No 42 

84 4 Fn S No 45 

78 3 DIY S No 51 

77 ? DH S No 105 

59 3 Df4 S No 209 

80 ' 8 ? S No 47 

90" 5 ? F ? 46 

70 5 FM F No 202 

= 1.8 to 8.6 WL) p 

46 7.6 

83 7.9 

19 7.1 

43 7.4 

Chapman 1993 

Chapman 1993 

Finlayeon and Verrue 1982 

Spehar and Fiandt 1986 

31 

41 

7.5 

7.4 

38 7.5 

88 8.0 

167 8.4 

Spehar and Carbon 1984 

Spehar and Zarlson 1984 

Chapman 1993 

Chapman 1993 

Chapman 1993 

44 7.5 Call et al. 1982 

42 7.4 Spehar eti al. 1978 

157 7.7 Pickering and Cast 1972 
CHROHIUH(IXI) (Freshwater: ccc = 120 to 370 q/L; CMC = 980 to 3100 ug/L)F 

5-13 

19-495 

>llOO 

94 ? 

86 

50-75 

SG F ? 25 24 

SG F ? 25 24 

SG F No 25 24 

Stevens and Chapman 1984 

Stevens and Chapman 1984 

Stevens and Chapman 1984 

7.3 

7.2 

7.0 

8.2 

7.4 

6.3' 

6.7 

6.0' 

6.2' 

Chapman 1993 

Chapman 1993 

Chapman 1993 

Chapman 1993 

Chapman 1993 

Chapman 1993 

7.6 Adelnan and Smith 1976 

7.4 Spehar and Fiandt 1986 

42 54 3 DH R Yes 206 166 

114 61 ? DN R Yes 52 45 

16840 26 3 DM S No <51 9 

26267 32 ? OH S No 110 9 

27416 27 7 DH S No 96 10 

58665 23 ? Dl4 S No 190 25 

CHROMIlJM(VI~ (Freshwater: CCC = 11 Ug/L; CMC = 16 ug/L) 

>25,000 100 1 FH,GF F Yes 220 214 

43,300 99.5 4 Fn F No 44 43 

CQPPEB (Freshwater: 

10-30 

40-200 

30-100 

100-200 

20-200 

40-300 

lo-80 

74 3 

78 ? 

79 ? 

02 ? 

06 3 

87 ? 

89 ? 

ccc = 6.5 to 21 ug/L; CHC = 9.2 to 34 ug/L)' 

CT F No 27 20 7.0 Chakoumakos et al. 1979 

CT F No 154 20 6.8 Chakoumakos et al. 1979 

CT F No 74 23 7.6 Chakourakos et al. 1979 

CT F No 192 72 7.0 Chakoumakos et al. 1979 

CT F No 31 78 8.3 Chakounakos et al. 1979 

CT F No 83 70 7.4 Chakoumakos et al. 1979 

CT F No 25 169 8.5 Chakoumakds et al. 1979 

7 
300-1300 

100-400 

92 ? 

94 ? 

125-167 2 

CT 

CT 

3-4J 

12-91' 

18-19 

20’ 

50 

175’ 

79-84 3 

95 2 

95 1 

96 2 

91 2 

CD 

CD 

DA 

DA 

FBI 

F?l 

5-52 >82’ ? Fn 

6-80 83O ? cs 

6.7 57 3 Dn 

35 43 ? D?l 

13 73 3 DM 

16 57 ? DH 

51 39 ? Dl4 

32 53 ? DI4 

33 52 3 Dn 

39 64 ? DH 

25-84 96 14 El4,GM 

17 91 6 DM 

120 88 14 SC 

15-90 74 19 

12-162 80’ 3 

28-58 85 6 

26-59 79 7 

56,101 86 2 

? 

BG 

DBl 

Dn 

DM 

F 

F 

R 

R 

S 

R 

S 

R 

F 

F 

S 

S 

R 

R 

R 

S 

S 

S 

S 

S 

S 

S 

F 

R 

R 

R 

No 195 160 7.0 Chakoumakos et al. 1979 

No 70 174 8.5 Chakoumakos et al. 1979 

Yes 31 38 7.2 Carlson et al. 1986a,b 

Yes 31 38 7.2 Carlson et al. 1986a,b 

No 52 55 7.7 Carlson et al. 1986b 

No 31 38 7.2 Carlson et al. 1986b 

No 52 55 7.7 Carlson et al. 1986b 

No 31 38 7.2 Carlson et al. 1986b 

Ye& 47 43 8.0 Lind et al. 1978 

No 21 19 7.1 Finlayson and Verrue 1982 

No 49 37 7.7 Chapman 1993 

Yes 48 39 7.4 Chapman 1993 

Yes 211 169 8.1 Chapman 1993 

Yes 51 44 7.6 Chapman 1993 

Yes 104 83 7.8 Chapman 1993 

No 52 45 7.8 Chapman 1993 

No 105 79 7.9 Chapman 1993 

No 106 82 8.1 Chapman 1993 

No 50 

No 52 

No 48 

No 48 7.7 Call et al. 1982 

Ye& 45 

168 

168 

168 

40 

43 

47 

47 

43 

117 

117 

117 

7.0 Hammermeister et al. 1983 

7.3 Hauermeister et al. 1983 

7.3 Hamermeister et al. 1983 

7-8 Benoit 1975 

No 

Ye&’ 

YesN 

8.0 Lazorchak 1987 

8.0 Lazorchak 1987 

8.0 Lazorchak 1987 

8 
96 86 4 

160 94 1 

230-3000 >69->79 3 

17 

181 

193 

612 

952 

1907 

7-29 

34 

58 

119 

235 

474 

4100 

2100 

(Freshwater: CCC = 1.3 to 

9 ? 

18 ? 

25 ? 

29 ? 

33 -38 I 

10 3 

62’ 3 

68H ? 

71H 

75n 9 

81” ? 

82’ 3 

79 7 

DM 

DM 

DM 

DM 

DH 

D?4 

EZ 

BT 

BT 

BT 

BT 

BT 

BT 

Fn 

220-2700 96 14 Fn,GM,DH 

580 95 14 SG 

FM 

FH 

CR 

m (Freshwater: C&K = 2.4 ug/L) 

F No 

S No 

F No 

7.7 ug/L; CMC 

R Yes 

R Yes 

R Yes 

S No 

S No 

S No 

R No 

F Yes 

F Yes 

F Yes 

F Yes 

F Yes 

F No 

F- No 

S No 

S No 

172 73 1 FM F No 

44 

203 

17 

= 34 

43 7.4 Spehar and Fiandt 1986 

171 8.2 Geckler et al. 1976 

13 7.6 Rice and Harrison 1983 

to 200 ug/L)F 

52 47 7.6 Chapman 1993 

102 86 7.8 Chapman 1993 

151 126 8.1 Chapman 1993 

50 

100 

150 

22 

44 

44 

44 

44 

44 

44 

44 

49 

51 

44 

-- -w- Chapman 1993 

-- --- Chapman 1993 

-- --- Chapman 1993 

a- --s JRB Associates 1983 

43 7.2 

43 7.2 

43 7.2 

43 7.2 

43 7.2 

43 7.2 

43 7.4 

44 7.2 

48 7.2 

Holcombe et al. 1976 

Holcombe et al. 1976 

Holcombe et al. 1976 

Holconbe et al. 1976 

Holcombe et al. 1976 

Holcombe et al. 1976 

Spehar and Fiandt 1986 

Hammermeister et al. 1983 

Hamermeister et al. 1983 

43 7.4 Spehar and Fiandt 1986 
(Freshwater: CCC = 88 to 280 ug/L; CMC = 790 to 2500 ug/L)' 

DH R Yes 51 49 7.4 Chapman 1993 

on R Yes 107 87 7.8 Chapman 1993 

DH R Yes 205 161 8.1 Chapman 1993 

21 

150 

578 

81 

76 

87 ? 

645 88 DM 

1809 93 9 DM 

1940 92 

3 

Dl4 

2344 100 DH 

S No 54 43 7.7 Chapman 1993 

S No 51 44 7.7 Chapman 1993 

S No 104 04 8.2 Chapman 1993 

S No 100 84 7.9 Chapman 1993 

4000 90 3 PK R No 21 -- --- JRB Associates 1983 

m (FRESHWATER: CCC = 5 ug/L; cwc = 20 ug/L) 

No data are available. 

sILvER (Freshwater: CK = 1.2 t0 13 ug/L; a CCC is not available) 

0.19 74 ? DM S No 

9.98 13 3 DU S Yes 

4.0 

4.0 

DM S No 

DU S Yes 

3 

2-54 

2-32 

4-32 

5-89 

6-401 

41 11 ; 

79 3 

793 ; 

91 1 

90 ? 

93 ? 

FM S No 

FM S Yes0 

Fn S No 

FM S No 

Fn S No 

FH S No 

47 37 7.6 Chapman 1993 

47 37 7.5 Chapman 1993 

36 25 7.0 Nebeker et al. 1983 

36 25 7.0 Nebeker et al. 1983 

51 49 8.1 uws 1993 

49 49 7.9 uws 1993 

50 49 8.1 uws 1993 

48 49 8.1 uws 1993 

120 49 8.2 uws 1993 

249 49 8.1 uws 1993 

10 
ZINC (Freshwater: CCC = 59 to 190 ug/L; cnc 65 to 210 ug/L)F 

52 31 

62 77 

191 77 

356 74 

551 78 

741 76 

7' 71-129 

18-273' 81-107 

167' 

180 

99 

94 

188-393' 

551 

100 

100 

40-500 95O 

1940 100 

5520 83 

<4000 

>4000 

90 

70 

160-400 103 

240 96 

? ? 3 

? 

P 

2 

2 

2 

1 

2 

1 

? 

? 

? 

3 

3 

13 

13 

DM 

DM 

DM 

DM 

DU 

Dn 

CD 

CD 

CD 

CD 

FM 

Fn 

cs 

AS 

AS 

F?! 

FH 

FI¶,GM,DH 

SG 

R 

R 

R 

S 

S 

S 

R 

R 

R 

S 

R 

S 

F 

F 

F 

F 

F 

S 

S 

Yes 211 169 8.2 Chapman 1993 

Yes 104 83 7.8 Chapman 1993 

Yes 52 47 7.5 Chapman 1993 

No 54 47 7.6 Chapman 1993 

No 105 85 8.1 Chapman 1993 

No 196 153 8.2 Chapman 1993 

Yes 31 38 7.2 Carlson et al. 1986b 

Yes 31 38 7.2 Carlson et al. 1986b 

No 31 38 7.2 Carlson et al. 1986b 

No 52 55 7.7 Carlson et al. 1986b 

No 31 38 7.2 Carlson et al. 1986b 

No 52 55 7.7 Carlson et al. 1986b 

No 21 19 7.1 Finlayson and Verrue 1982 

No 20 12 7.1 Sprague 1964 

No 20 12 7.9 Sprague 1964 

No 204 162 7.7 Mount 1966 

No 204 162 7.7 Mount 1966 

No 52 43 7.5 Hammermeister et al. 1983 

No 49 46 7.2 Haamermeister et al. 1983 

A Total recoverable concentration. 

B Except as noted, a 0.45-pa membrane filter was used. 

11 
Y 0) Ll 

3 

f 

co 

a 

u 0 

t-l 

d 

0 

d 

d 

4 

-4 

a 

a: & 
References 

Adelman, I.R., and L.L. Smith, Jr. 1976. Standard Test Fish 

Development. Part I. Fathead Minnows (PimeDhales promelag) and 

Goldfish (Carassiu guratus) as Standard Fish in Bioassays and 

Their Reaction to Potential Reference Toxicants. EPA-600/3-76- 

061a. National Technical Information Service, Springfield, VA. 

Page 24. 

Benoit, D.A. 1975. Chronic Effects of Copper on Survival, 

Growth, and Reproduction of the Bluegill (Lepomis macrochims). 

Trans. Am. Fish. Sot. 104:353-358. 

Brungs, W.A., T.S. Holderman, and M.T. Southerland. 1992. 

Synopsis of Water-Effect Ratics for Heavy Metals as Derived for 

Site-Specific Water Quality Criteria. 

Call, D.J., L.T. Brooke, and 0.0. Vaishnav. 1982. Aquatic 

Pollutant Hazard Assessments and Development of a Hazard 

Prediction Technology by Quantitative Structure-Activity 

Relationships. Fourth Quarterly Report. University of 

Wisconsin-Superior, Superior, WI. 

Carlson, A.R., H. Nelson, and 0. Hammsrmeister. 1986a. 

Development and Validation of Site-Specific Water Quality 

Criteria for Copper. Environ. Toxicol. Chem. 5:997-1012. 

Carlson, A.R., H. Nelson, and D. Hammermeister. 1986b. 

Evaluation of Site-SpedLiz Crft.eria for Capper and Zinc: An 

Integration of Metal Addition Toxicity, Effluent and Receiving 

Water Toxicity, and Ecological Survey Data. EPA/600/S3-86-026. 

National Technical Information Service, Springfield, VA. 

Carroll, J.J., S.J. Ellis, and W.S. Oliver. 1979. Influences of 

Hardness Constituents on the Acute Toxicity of Cadmium to Brook 

Trout (Salvelinus fontinalis). 

Chakoumakos, C., R.C. Russo, and R.V. Thurston. 1979. Toxicity 

of Copper to Cutthroat Trout (Salmo clarki) under Different 

Condition8 of Alkalinity, pH, and Hardness. Environ. Sci. 

Technol. 13;213-219. 

Chapman, G.A. 1993. Memorandum to C. Stephan. Junm 4. 

Davies, P.H., J.P. Goettl, Jr., J.R. Sinley, and N.F. Smith. 

1976. Acute and Chronic Toxicity of Lead to Rainbow Trout SaLmo 

gairdneri, in Hard and Soft Water. Water Re8. 10:199-206. 

Finlayson, B.J., and K.M Verrue. 1982. Toxicities of Copper, 

Zinc, and Cadmium Mixtures to Juvenile Chinook Salmon. Trans. 

Am. Fish. Sot. 111:645-650. 

13 
Geckler, J.R., W.B. Horning, T.M. Neiheisel, Q.H. Pickering, E.i,. 

Robinson, and C.E. Stephan. 1976. Validity of Laboratory Tests 

for Predicting copper Toxicity in Streams. EPA-600/3-76-116. 

National Technical Information Service, Springfield, VA. Page 

118. 

Grunwald, 0. 1992. Metal Toxicity Evaluation: Review, Results, 

and Data Base Documentation. 

Hammermeister, D., C. Northcott, L. Brooke, and 0. Call. 1983. 

Comparison of Copper, Lead and Zinc Toxicity to Four Animal 

Species in Laboratory and ST. Louis River Watrr. University of 

Wisconsin-Superior, Superior, WI. 

Hansen, D.J. 1993. Memorandum to C.E. Stephan. April 15. 

Holcombe, G.W., D.A. Benoit, E.N. Leonard, and J.M. McKim. 1976. 

Long-Term Effects of Lead Exposure on Three Generations of Brook 

Trout (SalveLinus fontfnalfs). J. Fish. Res. Bd. Canada 33:1731- 

1741. 

Holcombe, G.W., and R.W. Andrew. 1970. The Acute Toxicity of 

Zinc to Rainbow and Brook Trout. EPA-600/3-78-094. National 

Technical Information Service, Springfield, VA. 

Horowitz, A.J., K.A. Elrick, and M.R. Colbsrg. 1992. The Effect 

of Membrane Filtration Artifacts on Dissolved Trace Element 

Concentrations. Water Res. 26:753-763. 

Howarth, R.S., and J.B. Sprague. 1978. Copper Lsthality to 

Rainbow Trout in Waters on Various Hardness and pH. Water Res. 

12:455-462. 

JRB Associates. 1983. Demonstration of the Site-specific 

Criteria Modification Process: Selser's Creek, Ponchatoula, 

Louisiana. 

Lazorchak, J.M. 1987. The Significance of Weight Loss of 

ehz Straus During Acute Toxicity Tests with Copper. 

. . . 

Lima, A.R., C. Curtis, D.E. Hammermeister, T.P. Markee, C.E. 

Northcott, L.T. Brooke. 1984. Acute and Chronic Toxicities of 

Arsenic(II1) to Fathead Minnows, Flagfish, Daphnids, and an 

Amphipod. Arch. Environ. Contam. Toxicol. 13:595-601. 

Lind, D., K. Alto, and S. Chatterton. 1978. Regional CopperNickel Study. Draft. 

Mount, 0.1. 1966. The Effect of Total Hardness and pH on Acute 

Toxicity of Zinc to Fish. Air Water Pollut. Int. J. 10:49-56. 

14 
Nebeker, A.V., C.K. McAuliffe, R. Msher, and D.G. Stevens. 1983. 

Toxicity of Silver to Steelhead and Rainbow Trout, Fathead 

Minnows, and Daphnia magna. Environ. Toxicol. Chem. 2:9S-104. 

Pickering, Q.P., and M.H. Gast. 1972. Acute and Chronic 

Toxicity of Cadmium to the Fathead Minnow (Pimephales promelas). 

J. Fish. Res. Bd. Canada 29:1099-1106. 

Rice, D.W., Jr., and F.L. Harrison. 1983. The Sensitivity of 

Adult, Embryonic, and Larval Crayfish Procambarus clarkii to 

Copper. NUREG/CR-3133 or UCRL-53048. National Technical 

Information Service, Springfield, VA. 

Schuytema, G.S., P.O. Nelson, K.W. Malueg, A.V. Nebeker, D.F. 

Krawczyk, A.K. Ratcliff, and J.H. Gakstatter. 1984. Toxicity of 

Cadmium in Water and Sediment Slurries to Daphnia magna. 

Environ. Toxicol. Chem. 3:293-308. 

Spehar, R.L., R.L. Anderson, and J.T. Fiandt. 1978. Toxicity 

and Bioaccumulation of Cadmium and Lead in Aquatic Invertebrates. 

Environ. Pollut. lS:l95-208. 

Spehar, R.L., and A.R. Carlson. 1984. Derivation of SiteSpecific Water Quality Criteria for Cadmium and the St. Louis 

River Basin, Duluth, Minnesota. Environ. Toxicol. Chem. 3:6Sl665. 

Spehar, R.L., and J.T. Fiandt. 1986. Acute and Chronic Effects 

of Water Quality Criteria-Based Metal Mixtures on Three Aquatic 

Species. Environ. Toxicol. Chem. S:917-931. 

Sprague, J.B. 1964. Lethal Concentration of Copper and Zinc for 

Young Atlantic Salmon. J. Fish. Res. Bd. Canada 21317-9926. 

Stevens, D.G., and G.A. Chapman. 1984. Toxicity of Trivalent 

Chromium to Early Life Stages of Steelhead Trout. Environ. 

Toxicol. Chem. 3:125-133. 

University of Wisconsin-Superior. 1993. Preliminary data from 

work assignment l-10 for Contract No. 680Cl-0034. 

15 
ATTACHMENT #3 

GUIDANCE DOCUMENT 

ON DYNAMIC MODELING AND TRANSLATORS 

August 1993 

Total Maximum Daily Loads (TMDLs) and Permits 

o Dynamic Water Quality Modeling 

Although not specifically part of the reassessment of water quality criteria for metals, 

dynamic or probabilistic models are another useful tool for implementing water quality 

criteria, especially those for protecting aquatic life. Dynamic models make best use of the 

specified magnitude, duration, and frequency of water quality criteria and thereby provide a 

more accurate calculation of discharge impacts on ambient water quality. In contrast, steadystate modeling is based on various simplifying assumptions which makes it less complex and 

less accurate than dynamic modeling. Building on accepted practices in water resource 

engineering, ten years ago OW devised methods allowing the use of probability distributions 

in place of worst-case conditions. The description of these models and their advantages and 

disadvantages is found in the 1991 Technical Support Document for Water Quality-based 

Toxic Control (TSD). 

Dynamic models have received increased attention in the last few years as a result of 

the perception that static modeling is over-conservative due to environmentally conservative 

dilution assumptions. This has led to the misconception that dynamic models will always 

justify less stringent regulatory controls (e.g. NPDES effluent limits) than static models. In 

effluent dominated waters where the upstream concentrations are relatively constant, 

however, a dynamic model will calculate a more stringent wasteload allocation than will a 

steady state model. The reason is that the critical low flow required by many State water 

quality standards in effluent dominated streams occurs more frequently than once every three 

years. When other environmental factors (e.g. upstream pollutant concentrations) do not 

vary appreciably, that the overall return frequency of the steady state model may be greater 

than once in three years. A dynamic modeling approach, on the other hand, would be more 

stringent, allowing only a once in three year return frequency. As a result, EPA considers 

dynamic models to be a more accurate rather than a less stringent approach to implementing 

water quality criteria. 

The 1991 TSD provides recommendations on the use of steady state and dynamic 

water quality models. The reliability of any modeling technique greatly depends on the 

accuracy of the data used in the analysis. Therefore, the selection of a model also depends 

upon the data. EPA recommends that steady state wasteload allocation analyses generally be 

used where few or no whole effluent toxicity or specific chemical measurements are 

available, or where daily receiving water flow records are not available. Also, if staff 

resources are insufficient to use and defend the use of dynamic models, then steady state 
models may be necessary. If adequate receiving water flow and effluent concentration data 

are available to estimate frequency distributions, EPA recommends that one of the dynamic 

wasteload allocation modeling techniques be used to derive wasteload allocations which will 

more exactly maintain water quality standards. The minimum data required for input into 

dynamic models include at least 30 years of river flow data and one year of effluent and 

ambient pollutant concentrations. 

o Dissolved-Total Metal Translators 

When water quality criteria are expressed as the dissolved form of a metal, there is a 

need to translate TMDLs and NPDES permits to and from the dissolved form of a metal to 

the total recoverable form. TMDLs for toxic metals must be able to calculate 1) the 

dissolved metal concentration in order to ascertain attainment of water quality standards and 

2) the total recoverable metal concentration in order to achieve mass balance. In meeting 

these requirements, TMDLs consider metals to be conservative pollutants and quantified as 

total recoverable to preserve conservation of mass. The TMDL calculates the dissolved or 

ionic species of the metals basal on factors such as total suspended solids (TSS) and ambient 

pH. (These assumptions ignore the complicating factors of metals interactions with other 

metals.) In addition, this approach assumes that ambient factors influencing metal 

partitioning remain constant with distance down the river. This assumption probably is valid 

under the low flow conditions typically used as design flows for permitting of metals (e.g., 

7Q10, 4B3, etc) because erosion, resuspension, and wet weather loadings are unlikely to be 

significant and ever chemistry is generally stable. In steady-state dilution modeling, metals 

releases may be assumed to remain fairly constant (concentrations exhibit low variability) 

with time. 

EPA’s NPDES regulations require that metals limits in permits be stated as total 

recoverable in most cases (see 40 CFR §122.45(c)). Exceptions occur when an effluent 

guideline specifies the limitation in another form of the metal or the approved analytical 

methods measure only the dissolved form. Also, the permit writer may express a metals 

limit in another form (e.g., dissolved, valent, or total) when required, in highly unusual 

cases, to carry out the provisions of the CWA. 

The preamble to the September 1984 National Pollutant Discharge Elimination System 

Permit Regulations states that the total recoverable method measures dissolved metals plus 

that portion of solid metals that can easily dissolve under ambient conditions (see 49 Federal 

Register 38028, September 26, 1984). This method is intended to measure metals in the 

effluent that are or may easily become environmentally active, while not measuring metals 

that are expected to settle out and remain inert. 

The preamble cites, as an example, effluent from an electroplating facility that adds 

lime and uses clarifiers. This effluent will be a combination of solids not removed by the 

clarifiers and residual dissolved metals. When the effluent from the clarifiers, usually with a 
high pH levei, miXcS with receiving water having significantly lower pH level, these solids 

instantly dissolve. Measuring dissolved metals in the effluent, in this case, would 

underestimate the impact on the receiving water. Measuring with the total metals method, on 

the other hand, would measure metals that would be expected to disperse or settle out and 

remain inert or be covered over. Thus, measuring total recoverable metals in the effluent 

best approximates the amount of metal likely to produce water quality impacts. 

However, the NPDES rule dots not require in any way that State water quality 

standards be in the total recoverable form; rather, the rule rcquircs permit writers to consider 

the translation between differing metal forms in the calculation of the permit limit so that a 

total razoverable limit can bc established. Therefore, both the TMDL and NPDES uses of 

water quality criteria require the ability to translate from the dissolved form and the total 

recoverable form. 

Many toxic substances, including metals, have a tendency to leave the dissolved phase 

and attach to suspended solids. The partitioning of toxics between solid and dissolved phases 

can be determined as a function of a pollutant-specific partition coefficient and the 

concentration of solids. This function is expressed by a linear partitioning quation: 

Cf % 

1 +K,W10-‘ 

where, 

C - dissolved phase metal conocntration, 

C, = total metal concentration, 

TSS = total suspended solids concentration, and 

I& = partition coefficient. 

A key assumption of the linear partitioning quation is that the sorption reaction 

reaches dynamic quilibrium at the point of application of the criter& that is, after allowing 

for initial mixing the partitioning of the ~llutant between the adsorbed and dissolved foms 

can be used at any location to predict the fraction of pollutant in each respective phase. 

SuccesW application of the linear partitioning equation relies on the selection of the 

partition coefficient. The use of a partition coefficient to rcprcmt the degree to which 

toxics adsorb to solids is most readily applied to organic pollutants; partition coefficients for 

metals are more difficult to define. Metals typically exhibit more complex speciation and 

complexation reactions than organics and the degree of partitioning can vary greatly 

depending upon site-specific water chemistry. Estimated partition coefficients can be 

detcrmincd for a number of metals, but waterbody or site-specific observations of dissolved 

and adsorbed concentrations arc prcferrcd. 
EPA suggests three approaches for instances where a water quality criterion for a 

metal is express@ in the dissolved form in a State’s water quality standards: 

1. Using clean analytical techniques and field sampling procedures with appropriate 

QA/QC, collect receiving water samples and determine site specific values of IC,, for 

each metal. Use these I(d values to “translate’ between total recoverable and 

dissolved metals in receiving water. This approach is more difficult to apply because 

it relies upon the availability of good quality mca&rcmcnts of ambient metal 

concentrations. This approach provides an accurate assessment of the dissolved metal 

fraction providing sufficient samples arc collected. EPA’s initial rccommcndation is 

that at least four pairs of total recoverable and dissolved ambient metal mcasurcmcnts 

bc made during low flow conditions or 20 pairs over all flow conditions. EPA 

suggests that the average of data collected during low flow or the 95th percentile 

highest dissolved fraction for all flows be used. The low flow average provides a 

representative picture of conditions during the rare low flow events. The 95th 

percentile highest dissolved fraction for all flows provides a critical condition 

approach analogous to the approach used to identify low flows and other critical 

environmental conditions. 

2. Calculate the total recoverable concentration for the purpose of setting the permit 

limit. Use a value of I unless the permittee has collected data (see #l above) to show 

that a different ratio should be used. The value of 1 is conservative and will not err 

on the side of violating standards. This approach is very simple to apply because it 

places the entire burden of data collection and analysis solely upon permitted 

facilities. In terms of technical merit, it has the same characteristics of the previous 

approach. However, permitting authorities may be faced with difficulties in 

negotiating with facilities on the amount of data necessary to determine the ratio and 

the necessary quality control methods to assure that the ambient data are reliable. 

3. Use the historical data on total suspended solids (TSS) in receiving waterbodies at 

appropriate design flows and & values presented in the Technical Guidance Manual 

for Performing Waste Lnad Allocations. Book II. SW and Rivers. EPA-440/4- 

84-020 (1984) to “translate’ bctwecn (total recoverable) permits limits and dissolved 

metals in receiving water. This approach is fairly simple to apply. Howcvcr, these 

& values are suspect due to possible quality assurance problems with the data used to 

develop the values. EPA’s initial analysis of this approach and these values in one 

site indiw that these K,, values generally overutimate the dissolved fraction of 

metals in ambient waters (see Figures following). Therefore, although this approach 

may not provide an accurate estimate of the dissolved fraction, the bias in the estimate 

is likely to be a conSerYative one. 

EPA suggests that regulatory authorities use approacha I1 and #2 where States 

express their water quality standards in the dissolved form. In those States where the 

standards arc in the total recoverable or acid soluble form, EPA recommends that no 
translation be used until the time that the State changes the standards to the dissolved form. 

Approach #3 may be used as an interim measure until the data are COktcd to implement 

approach # 1. 
ma8au.A VB. ~tobslad DitmolveA Coppar Concentrations 

3.5 

3 

2.5 

2 

Ii 

P 

- 1.5 

1 

0.5 

0 

-_-- -. -- 

0 5 10 IS 20 25 30 35 40 45 

SIlnplhlg station 
0.16 

0.14 

0.12 

0.1 

Ii 

2 0.08 

0.08 

0.04 

0.02 

0 

0 5 10 1s 20 2s 30 35 40 4s 

Sampling Station 

numard tm. Ilodolod Dissolved Cadmium Concontrrtioam 

_. 

.---- .- Modeled 

-- 0 Measured 
1.6 

1.4 

1.2 

1 

th j 0.6 

-- 

0.6 

0.4 

0.2 

no8mar.d V8 l Hodold Dio8olvob Lord Concentrations 

I- 

. Modeled 

II Measured 

0 

0 5 10 15 20 25 30 35 40 4s 

Sampling Shlion 
0.12 

0.1 

0.06 

s 

jj 0.06 

0.04 

0.02 

I 

I 

nu8wod va. 8toUrlod Dissolved Worcury Concentrrtfonr 

0 5 10 15 20 25 30 35 40 4s 

Samplittg Station 
7 

6 

S 

4 

ii 

=3 

2 

1 

Womurd vm. Mob.106 Dimolvod Nick.1 Cormcntrattonm 

O,----+ -+--------t-----------t0 S 10 lS e 20 2s 30 35 

Sampling Station 

-- l Modeled 

0 Measured 

L-- _- 

---t--- --- ---4 

40 . 4s 
30 

2s 

20 

3 15 

- 

10 

5 

@-aura VII. W~cslob Dim~olveb 2iac Concontratfons 

--+- _ 

0 s 10 15 20 25 30 

Smpldng SWlon 

Modeted 

Measured 

I 

- I 

35 

I 

40 

I 

45 
(i/W 
ATTACHMENT #4 

GUIDANCE DOCUMENT 

ON CLEAN ANALYTICAL TECHNIQUES AND MONITORING 

October 1993 

Guidance on Monitoring 

o Use of Clean Sampling and Analytical Techniques 

Appendix B to the WER guidance document (attached) provides some general guidance 

on the use of clean techniques. The Office of Water recommends that this guidance be used 

by States and Regions as an interim step while the Office of Water prepares more detailed 

guidance. 

o Use of Historical DMR Data 

With respect to effluent or ambient monitoring data reported by an NPDES permittee 

on a Discharge Monitoring Report (DMR), the certification requirements place the burden on 

the permittee for collecting and repotting quality data. The certification regulation at 40 

CFR 122.22(d) requires permittees, when submitting information, to state: “I certify under 

penalty of law that this document and all attachments were prepared under my direction or 

supervision in accordance with a system designed to assure that qualified personnel properly 

gather and evaluate the information submitted. Based on my inquiry of the person or persons 

who manage the system, or those persons directly responsible for gathering the information, 

the information submitted is, to the best of my knowledge and belief, true, accurate, and 

complete. I am aware that there are significant penalties for submitting false information, 

including the possibility of fine and imprisonment for knowing violations.” 

Permitting authorities should continue to consider the information reported in DMRs 

to be true, accurate, and complete as certified by the permittee. Under 40 CFR 122.41(1)(8), 

however, as soon as the permittee becomes aware of new information specific to the effluent 

discharge that calls into question the accuracy of the DMR data, the permittee must submit 

such information to the permitting authority. Examples of such information include a new 

finding that the reagents used in the laboratory analysis are contaminated with trace levels of 

metals, or a new study that the sampling equipment imparts trace metal contamination. This 

information must be specific to the discharge and based on actual measurements rather than 

extrapolations from reports from other facilities. Where a permittee submits information 
In addition to submitting the Information described above, the permittee also must 

develop procedures to assure the collection and analysis of quality data that are true, 

accurate, and complete. For example, the permittee may submit a revised quality assurance 

plan that describes the specific procedures to be undertaken to reduce or eliminate trace 

metal contamination. 
10-l-93 

Appendix B. Guidance Concerning the Use of "Clean T8chniquesoo and 

QA/QC in the Measurement of Trace Metals 

Recent information (Shiller and Boyle 1987; Windom et al. 1991) 

has raised questions concerning the quality of reported 

concentrations of trace metals in both fresh and salt (estuarine 

and marine) surface waters. A lack of awareness of true ambient 

concentrations of metals in saltwater and freshwater systems can 

be both a cause and a result of the problem. The ranges of 

dissolved metals that an typical in surface waters of the United 

States away from the immediate influence of discharges (Bruland 

1983; Shiller and Boyle 1985,1987; Trefry et al. 1986; Windom et 

al. 1991) are: 

Metal Salt water Fresh Water 

f UU/T,l (UU/f‘l 

Cadmium 0.01 to 0.2 0.002 to 0.08 

Copper 0.1 to 3. 0.4 to 4. 

Lead 0.01 to 1. 0.01 to 0.19 

Nickel 0.3 to 5. 1. to 2. Silver 0.005 to 0.2 -------w----- 

Zinc 0.1 to 15. 0.03 to 5. 

The U.S. EPA (1983,1991) has published analytical methods for 

monitoring metals in waters and wastewaters, but these methods 

are inadequate for determination of ambient concentrations of 

some metals in some surface waters. Accurate and precise 

measurement of these low concentrations requires appropriate 

attention to seven areas: 

1. 

2. 

3. 

use of “clean techniques e during collecting, handling, 

storing, preparing, and analyzing samples to avoid 

contamination. 

Use of analytical methods that have sufficiently low detection 

limits. 

Avoidance of interference in the quantification (instrumental 

analysis) step. 

4. 

5. 

6. 

7. 

In 

Use of blanks to assess contamination. 

Use of matrix spikes (sample spikes) and certified reference 

materials (CRMe) to assess interference and contamination. 

Use of replicator to assess precision. 

Use of certified standards. 

a strict sense, the term "clean techniques" rafmre to 

techniques that reduce contamination and enable the accurate and 

precise measurement of trace metals in fresh and salt surfaco 

waters. In a broader sense, the term also refers to related 

issues concerning detection limits, quality control, and quality 

assurance. Documenting data quality demonstrates the amount of 

confidence that can be placed in the data, whereas increasing the 

sensitivity of methods reduce the problem of deciding how to 

1 
interpret results that are reported to be below detection limits. 

. This auoenQirc 1s written for those analytical laboratories that 

want auidqace concerninu wavs to lower detection limits, increase 

. gr 1s~ n. and/ r increase accuracvL The ways to achieve these 

goE?s aze to i&ease the sensitivity of the analytical methods, 

decrease contamination, and decrease interference. Ideally, 

validation of a procedure for measuring concentrations of metals 

in surface water requires demonstration that agreement can be 

obtained using completely different procedures beginning with the 

sampling step and continuing through the quantification step 

(Bruland et al. 1979), but few laboratories have the resources to 

compare two different procedures. Laboratories can, however, (a) 

use techniques that others have found useful for improving 

detection limits, accuracy, and precision, and (b) document data 

quality through use of blanks, spikes, CR?&, replicates, and 

standards. 

In general, in order to achieve accurate and precise measurement 

of a particular concentration, both the detection limit and the 

blanks should be less than one-tenth of that concentration. 

Therefore, the term t'metal-free8t can be interpreted to mean that 

the total amount of contamination that occurs during sample 

collection and processing (e.g., from gloves, sample containers, 

labware, sampling apparatus, cleaning solutions, air, reagents, 

etc.) is sufficiently low that blanks are lese than one-tenth of 

the lowest concentration that needs to be measured. 

Atmospheric particulate8 can be a major source of contamination 

(Moody 1982; Adeloju and Bond 1985). The term nclase-lOOm refers 

to a specification concerning the amount of particulate8 in air 

(Moody 1982); although the specification says nothing about the 

composition of the particulates, generic control of particulates 

can greatly reduce trace-metal blanks. Except during collection 

of samples and initial cleaning of equipment, all handling of 

samples, sample containers, labware, and sampling apparatus 

should be performed in a class-100 bench, room, or glove box. 

. subtracts from w raw rewts set forth j,~ otm EPA 

documents concer&a metal anuses, The word nmuet* is used in 

this appendix merely to indicate items that are considered very 

important by analytical chemists who have worked to increase 

accuracy and precision and lower detection limits in trace-metal 

analysis. Some items are considered important because they have 

been found to have received inadequate attention in eoma 

laboratories performing trace-metal analyses. 

Two topics that are not addressed in this appendix are: 

1. The @'ultraclean techniques n that are likely to be necessary 

when trace analyses of mercury are performed. 

2. Safety in analytical laboratories. 

2 
Other documents should be consulted if these topics are of 

concern. 

Fvoidinu contamination bv use of "clean technicrues" 

Measurement Of trace metals in receiving waters rust take into 

account the potential for contamination during each step in the 

process. Regardless of the specific procedures used for 

collection, handling, storage, preparation (digestion, 

filtration, and/or extraction), and quantification (instrumental 

analysis), the general principles of contamination control must 

be applied. Some specific recommendations are: 

a. NoWtalc latex or class-100 polyethylene gloves must be worn 

during all steps from sample collection to analysis. (Talc 

seems to be a particular problem with zinc; gloves made with 

talc cannot be decontaminated sufficiently.) Gloves should 

only contact surfaces that are metal-free; gloves should be 

changed if even suspected of contamination. 

b. The acid used to acidify samples for preservation and 

digestion and to acidify water for final cleaning of labware, 

sampling apparatus, and sample containers must be metal-free. 

The quality of the acid used should be better than reagentgrade. Each lot of acid must be analyzed for the metal(s) of 

interest before use. 

c. The water used to prepare acidic cleaning solutions and to 

rinse labware, sample containers, and sampling apparatus may 

be prepared by distillation, deionization, or reverse osmosis, 

and must be demonstrated to be metal-free. 

d. The work area, including bench tops and hoods, should be 

cleaned (e.g., washed and wiped dry with lint-free, class-100 

wipes) frequently to remove contamination. 

e. All handling of samples in the laboratory, including filtering 

and analysis, must be performed in a class-100 clean bench or 

a glove box fed by particle-free air or nitrogen; ideally the 

clean bench or glove box should be located within a class-100 

clean room. 

f. Labware, reagents, sampling apparatus, and sample containers 

must never be left open to the atmosphere; they should be 

stored in a class-100 bench, covered with plastic wrap, stored 

in a plastic box, or turned upside down on a clean surface. 

Minimizing the time between cleaning and using will help 

minimito contamination. 

g. Separate sets of sample containers, labware, and sampling 

apparatus should be dedicated for different kind8 of samples, 

e.g., rec8iving water samples, effluent samples, etc. 

h. To avoid contamination of clean roeme, samples that contain 

very high concentrations of metals and do not require use of 

Itclean techniqueen should not be brought into clean rooms. 

i. Acid-cleaned plastic, such as high-density polyethylene 

(HDPE) 8 low-density polyethylene (LDPE), or a fluoroplaetic, 

must be the only material that ever contacts a sample, except 

possibly during digestion for the total recoverable 

3 
measurement. (Total recoverable samples can be digested in 

some plastic containers.) Even HDPE and LOPE might not be 

acceptable for mercury, however. 

j. ~11 labware, sample containers, and sampling apparatus must be 

acid-cleaned before use or reuse. 

1. Sample containers, sampling apparatus, tubing, membrane 

filters, filter assemblies, and other labware must be 

soaked in acid until metal-free. The amount of cleaning 

necessary might depend on the amount of contamination and 

the length of time the item will be in contact with 

samples. For example, if an acidified sample will be 

stored in a sample container for three weeks, ideally the 

container should have been soaked in an acidified metalfree solution for at least three weeks. 

2. It might be desirable to perform initial cleaning, for 

which reagent-grade acid may be used, before the items are 

allowed into a clean room. For most metals, items should 

be either (a) soaked in 10 percent concentrated nitric acid 

at SOOC for at least one hour, or (b) soaked in SO percent 

concentrated nitric acid at room temperature for at least 

two days; for arsenic and mercury, soaking for up to two 

weeks at 50°C in 10 percent concentrated nitric acid might 

be required. For plastics that might be damaged by strong 

nitric acid, such as polycarbonate and possibly HDPE and 

LDPE, soaking in 10 percent concentrated hydrochloric acid, 

either in place of or before soaking in a nitric acid 

solution, might be desirable. 

3. Chromic acid muet not be used to clean items that will be 

used in analysis of metals. 

4. Final soaking and cleaning of sample containers, labware, 

and sampling apparatus must be performed in a claee-100 

clean room using metal-free acid and water. The solution 

in an acid bath must be analyzed periodically to 

demonstrate that it is metal-free. 

5. After labware and sampling apparatus are cleanad, they may 

be stored in a clean room in a weak acid bath prepared 

using metal-free acid and water. Before use, the items 

should be rinsed at least three times with metal-free 

water. After the final rinse, the items should be moved 

immediately, with the open end pointed down, to a class-100 

clean bench. Items may be dried on a class-100 clean 

bench; items rust not be dried in an oven or with 

laboratory towels. The sampling apparatus should ba 

assembled in a class-100 clean room or banch and doublebagged in metal-free polyethylene zip-type bag8 for 

transport to the field; new bags are usually natal-free. 

6. After sample containers are cleaned, they should ba filled 

with metal-'free water that has been acidified to a pH of 2 

with metal-free nitric acid (about 0.5 mL per liter) for 

storage until use. At the time of S?&mpl@ collection, the 

sample containers should be emptied and rinsed at least 

twice with the solution being sampled before the actual 

4 
sample is placed in the sample container. 

k. Field samples must be collected in a manner that eliminates 

the potential for contamination from the sampling platform, 

probes, etc. Exhaust from boats and the direction of wind and 

water currents should be taken into account. The people who 

collect the samples must be specifically trained on how to 

collect field samples. After collection, all handling of 

samples in the field that will expose the sample to air must 

be performed in a portable class-100 clean bench or glove box. 

1. Samples must be acidified (after filtration if dissolved metal 

is to be measured) to a pH of less than 2, except that the pH 

must be less than 1 for mercury. Acidification should be done 

in a clean room or bench, and so it might bo desirable to wait 

and acidify samples in a laboratory rather than in the field. 

If samples are acidified in the field, Fetal-free acid can be 

transported in plastic bottles and poured into a plastic 

container from which acid can be removed and added to samples 

using plastic pipettes. Alternatively, plastic automatic 

dispensers can be used. 

HI. Such things as probes and thermometers must not be put in 

samples that are to be analyzed for metals. In particular, pH 

electrodes and mercury-in-glass thermometers rust not be used 

if mercury is to be measured. If pH is measured, it must be 

done on a separate aliquot. 

n. Sample handling should be minimized. For example, instead of 

pouring a sample into a graduated cylinder to measure the 

volume, the sample can be weighed after being poured into a 

tared container; alternatively, the container from which the 

sample is poured can be weighed. (For saltwater samples, the 

salinity or density should be taken into account when weight 

is converted to volume.) 

0. Each reagent used rust be verified to be metal-fres. If 

metal-free reagents are not commercially available, removal of 

metals will probably be necessary. 

p. For the total recoverable measursment, samples should be 

digested in a class-100 bench, not in a metallic hood. If 

feasible, digestion should be done in the sample container by 

acidification and hsating. 

q. The longer the time between collection and analysis of 

samples, the greater the chance of contamination, loss, etc. 

r. Samples must be stored in the dark, preferably between 0 and 

4OC with no air space in the sample container. 

Achievinu low detect&on w 

a. Extraction of the m&al from the sample can be l xtremsly 

useful if it simultaneously concentrates the metal and 

eliminates potential matrix interferenc88. For l xampla, 

ammonium 1-pyrrolidfnsdithiocarbamate and/or diethylammonium 

diethyldithiocarbamate can extract cadmium, copper, lead, 

5 
nickel, and zinc (Bruland et al. 1979; Nriagu et al. 1993). 

b. The detection limit should be less than ten percent of the 

lowest concentration that is to be measured. 

Avoidina interference3 

a. Potential interferences nust be assessed for the specific 

instrumental analysis technique used and each metal to be 

measured. 

b. If direct analysis is used, the salt present in high-salinity 

saltwater samples is likely to cause interference in most 

instrumental techniques. 

c. As stated above, extraction of the metal from the sample is 

particularly useful because it simultaneously concentrates the 

metal and eliminates potential matrix interferences. 

a. A laboratory (procedural, method) blank consists of filling a 

sample container with analyzed metal-free water and processing 

(filtering, acidifying, etc.) the water through the laboratory 

procedure in exactly the same way as a sampls. A laboratory 

blank must be included in each set of ten or fewer samples to 

check for contamination in the laboratory, and must contain 

less than ten percent of the lowest concentration that is to 

be measured. Separate laboratory blanks must be processed for 

the total recoverable and dissolved measurements, if both 

measurements are performed. 

b. A field (trip) blank consists of filling a sample container 

with analyzed metal-free water in the laboratory, taking the 

container to the site, processing the water through tubing, 

filter, etc., collecting the water in a sampls containar, and 

acidifying ths water the same as a field sample. A fisld 

blank must be processed for each sampling trip. Separate 

field blanks rust be processed for tha total recoverable 

measurement and for the dissolved measurement, if filtrations 

are performed at the sits. Field blanks must ba processed in 

the laboratory the same as laboratory blank8. 

Assessina acwacv 

a. A calibration curve must be determined for each analytical run 

and the calibration should be checked about every tenth 

sample. Calibration solutions must be traceable back to a 

certified standard from the U.S. EPA or ths National Institute 

of Science and Technology (NIST). 

b. A blind standard or a blind calibration solution wrt be 

included in each group of about twenty samples. 

6 
C. Ak least one of the following must be included in each group 

of about twenty samples: 

1. A matrix spike (spiked sample; the method of known 

additions). 

2. A CPM, if one is available in a matrix that closely 

approximates that of the samples. Values obtained for the 

CPM must be within the published values. 

The concentrations in blind standards and solutions, spikes, and 

CRMs must not be more than 5 times the Ledian concentration 

expected to be present in the samples. 

. . 

Fssessina Drecluan 

a. A sampling replicate must be included with each set of samples 

collected at each sampling location. 

b. If the volume of the sample is large enough, replicate 

analysis of at least one sample must be performed along with 

each group of about ten samples. 

Whereas the total recoverable measurement is especially subject 

to contamination during the digestion step, the dissolved 

measurement is subject to both loss and contamination during the 

filtration step. 

a. Filtrations must be performed using acid-cleaned plastic 

filter holders and acid-cleaned membrane filters. Samples 

must not be filtered through glass fiber filters, even if the 

filters have been cleaned with acid. If positive-pressure 

filtration is used, the air or gas must bs passed through a 

0.20um in-line filter; if vacuum filtration is used, it must 

be performed on a class-100 bench. 

b. Plastic filter holders must be rinsed and/,or dipped between 

filtrations, but they do not have to be soaked between 

filtrations if all the samples contain about the same 

concentrations of metal. It is best to filter samples from 

low to high concentrations. A membrane filter au8t sot be 

used for more than one filtration. After each filtration, the 

membrane filter must bo removed and discarded, and the filter 

holder w8t be either rinsed with metal-free water or dilute 

acid and dipped in a metal-free acid bath or rinsed at least 

twice with metal-free dilute acid; finally, the filter holder 

must be rinsed at least twice with metal-free water. 

C. For each sample to be filtered, the filter holder and membrane 

filter must be conditioned with the sample, i.e., an initial 

portion of the sample must be filtered and discarded. 

The accuracy and precision of the dissolved measurement should be 

7 
assessed periodically. A large volume of a buffered solution 

(such as aerated 0.05 N sodium bicarbonate) should be spiked so 

that the concentration of the metal of interest is in the range 

of the low concentrations that are to be measured. The total 

recoverable concentration and the dissolved concentration of the 

metal in the spiked buffered solution should be measured 

alternately until each measurement has been performed at least 

ten times. The means and standard deviations for the two 

measurements should be the same. All values deleted as outliers 

must be acknowledged. 

penortina regultp 

To indicate the quality of the data, reports of results of 

measurements of the concentrations of metals must include a 

description of the blanks, spikes, CRMs, replicates, and 

standards that were run, the number run, and the results 

obtained. All values deleted as outliers must be acknowledged. 

The items presented above are some of the important aspects of 

"clean techniques"; some aspects of quality assurance and quality 

control are also presented. This is not a definitive treatment 

of these topics; additional information that might be useful is 

available in such publications as Patterson and Settle (1976), 

Zief and Mitchell (1976), Bruland et al. (1979), Moody and Beary 

(1982), Moody (1982), Bruland (1983), Adeloju and Bond (1985), 

Berman and Yeats (1985), Byrd and Andreae (1986), Taylor (1987), 

Sakamoto-Arnold (1987), Tramontano et al. (1987), Puls and 

Barcelona (1989), Windom et al. (1991), U.S. EPA (1992), Horowitz 

et al. (1992), and Nriagu et al. (1993). 

Adeloju, S.B., and A.M. Bond. 1985. Influence of Laboratory 

Environment on the Precision and Accuracy of Trace Element 

Analysis. Anal. Chem. 573172801733. 

Berman, S.S., and P.A. Yeats. 1985. Sampling of Seawater for 

Trace Metals. CRC Reviews in Analytical Cbmistry 16:1-14. 

Bruland, X.W., R.P. Franks, G.A. Knauer, and J.H. Martin. 1979. 

Sampling and Analytical Methods for the Determination of Copper, 

Cadmium, Zinc, and Nickel at the Nanogram per Liter Level in Sea 

Water. Anal. Chim. Acta 105:233-245. 
Bruland, K.W. 1983. Trace Elements in Sea-water. In: Chemical 

Oceanography, Vol. 8. J.P. Riley and R. Chester, eds. Academic 

Press, New York, NY. pp. 157-220. 

Byrd, J.T., and M.O. Andreae. 1986. Dissolved and Particulate 

Tin in North Atlantic Seawater. Marine Chemistry 19:193-200. 

Horowitz, A.J., K.A. Elrick, and M.R. Colberg. 1992. The Effect 

of Membrane Filtration Artifacts on Dissolved Trace Element 

Concentrations. Water Res. 26:753-763. 

Moody, J.R. 1982. NBS Clean Laboratories for Trace Element 

Analysis. Anal. Chem. 54:1358A-1376A. 

Moody, J.R., and E.S. Beary. 1982. Purified Reagents for Trace 

Metal Analysis. Talanta 29:1003-1010. 

Nriagu, J.O., G. Lawson, H.K.T. Wong, and J.M, Azcue. 1993. A 

Protocol for Minimizing Contamination in the Analysis of Trace 

Metals in Great Lakes Waters. J. Great Lakes Res. 19:175-182. 

Patterson, C.C., and D.M. Settle. 1976. The Reduction in Orders 

of Magnitude Errors in Lead Analysis of Biological Materials and 

Natural Waters by Evaluating and Controlling the Extent and 

Sources of Industrial Lead Contamination Introduced during Sample 

Collection and Processing. In: Accuracy in Trace Analysis: 

Sampling, Sample Handling, Analysis. P.D. LaFleur, ed. National 

Bureau of Standards Spec. Publ. 422, U.S. Government Printing 

Office, Washington, DC. 

Puls, R.W., and M.J. Barcelona. 1989. Ground Water Sampling for 

Metals Analyses. EPA/540/4-89/001. National Technical 

Information Service, Springfield, VA. 

Sakamoto-Arnold, C.M., A.K. Hanson, Jr., D.L. Huizenga, and D.R. 

Kester. 1987. Spatial and Temporal Variability of Cadmium in 

Gulf Stream Warm-core Rings and Associated Waters. J. Mar. Res. 

45:201-230. 

Shiller, A.M., and E. Boyle. 1985. Dissolved Zinc in Rivers. 

Nature 317:49-52. 

Shiller, A.M., and E.A. Boyle. 1987. Variability of Dissolved 

Trace Metals in the Mississippi River. Geochin. Cosmochim. Acta 

51:3273-3277. 

Taylor, J.K. 1987. Quality Assurance of Chemical Measurements. 

Lewis Publishers, Chelsea, MI. 

Tramontano, J.M., J.R. Scudlark, and T.M. Church. 1987. A 

Method for the Collection, Handling, and Analysis of Trace Metals 

in Precipitation. Environ. Sci. Technol. 21:749-753. 
Trefry, J.H., T.A. Nelsen, R.P. Trocine, S. Metz., and T.W. 

Vetter. 1986. Raw l P.-v. Reun. Cons. int. Explor. Mer. 

186:277-288. 

U.S. Environmental Protection Agency. 1983. Methods for 

Chemical Analysis of Water and Wastes. EPA-600/4-79-020. 

National Technical Information Service, Springfield, VA. 

Sections 4.1.1, 4.1.3, and 4.1.4 

U.S. Environmental Protection Agency. 1991. Methods for the 

Determination of Metals in Environmental Samples. EPA-600/4-91- 

010. National Technical Information Service, Springfield, VP,. 

U.S. Environmental Protection Agency. 1992. Evaluation of 

Trace-Metal Levels in Ambient Waters and Tributaries to New 

York/New Jersey Harbor for Waste Load Allocation. Prepared by 

Battelle Ocean Sciences under Contract No. 68-C8-0105. 

Windom, H.L., J.T. Byrd, R.G. Smith, and F. Huan. 1991. 

Inadequacy of NASQAN Data for Assessing Metals Trends in the 

Nation's Rivers. Environ. Sci. Technol. 25:1137-1142. (Also see 

Comment and Response, Vol. 25, p. 1940.) 

Zief, M., and J.W. Mitchell. 1976. Contamination Control in 

Trace Element Analysis. Chemical Analysis Series, Vol. 47. 

Wiley, New York, NY. 

10