# APPENDIX E

AnApproach

# forEvaluating NumericWaterQualityCriteria forWetlandsProtection

WATERQUALITY STANDARDS HANDBOOK

SECONDEDITIONANAPPROACH FOREVALUATING NUMERIC WATERQUALITY CRITERIA FORWETLANDSPROTECTION

by Cynthia A. Hagley and Debra L. Taylor

Asci Corporation Duluth, Minnesota 55804

Project Officer
William D. Sanville Project Leader Environmental Research Laboratory Duluth, Minnesota 55804

DU: BIOL ISSUE: A PPA: 16 PROJECT: 39 DELIVERABLE: 8234
July 8, 1991ABSTRACT

Extension of the national numeric aquatic life criteria to wetlands has been recommended aspart of aprogram to develop standards and criteria for wetlands. This report provides an overview of the need for standards and criteria for wetlands and adescription of the numeric aquatic life criteria. The numeric aquatic life criteria are designed to be protective of aquatic life and their uses for surface waters, and are probably applicable to most wetland types. This report provides a possible approach, based onthe site-specific guidelines, for detecting wetland types that might not be protected bydirect application of national numeric criteria. The evaluation can be simple and inexpensive for those wetland types for which sufficient water chemistry and species assemblage data are available, but will be less useful for wetland types for which these data are not readily available. The site-specific approach is described and recommended for wetlands for which modifications to the numeric criteria are considered necessary. The results of this type of evaluation, combined with information on local or regional environmental threats, can beused to prioritize wetland types (and individual criteria) for further site-specific evaluations and/or additional data collection. Close coordination among regulatory agencies, wetland scientists, and criteria experts will be required.

iUNITEDSTATESENVIRONMENTAL PROTECTIONAGENCY WASHINGTON,D.C.20460



## MEMORANDUM OFFICEOF WATER

SUBJECT: Numeric Water Quality Criteria for Wetlands FROM: William R. Diamond, Director

Standards and Applied Science Division Office of Science and Technology TO: Water Management Division Directors (Regions I-X)

Environmental Services Division Directors (Regions I-X) State Water Pollution Control Agency Directors

The purpose of this memorandum is to provide you with acopy of areport entitled "An Approach for Evaluation of Numeric Water Quality Criteria for Wetlands Protection", prepared by EPA’s Environmental Research Laboratory in Duluth, Minnesota. This report was requested in the early stages of planning for wetland water quality standards to assess the applicability of EPA's existing numeric aquatic life criteria methodology for wetlands. This report was prepared by the Wetlands Research Program and is part of the Agency's activities to assist States with developing water quality standards for wetlands.
The report evaluates EPA's numeric aquatic life criteria to determine howthey can beapplied to wetlands. Numeric aquatic life criteria are designed to beprotective of aquatic life for a wide range of surface water types. The report suggests that most numeric aquatic life criteria are applicable to most wetland types.However, there are somewetland types where EPA's criteria are not appropriate. This report presents an approach that States mayuse as ascreening tool to detect those wetland types that maybeunder- or overprotected by EPA's criteria. The proposed approach relies ondata readily available from EPA's 304(a) criteria documents, aswell asspecies assemblages and water quality data from individual wetland types. The results of this type of simple evaluation can beused to prioritize wetland types where further evaluation maybeneeded prior to setting criteria. Twoexample analyses of the approach are included in the report. EPA's site-specific criteria development guidelines can then beused to modify criteria if appropriate.This report compiles existing information from EPA's 304(a)

criteria guidance documents and site-specific criteria methodologies and does not contain newguidance or policy. The report has been peer reviewed by ERL/Duluth scientists who develop EPA's 304 criteria. The report also has been reviewed by the Standards and Applied Science Division and the Wetlands Division. If you have additional questions onthe information contained in this report or its applications, contact the following persons: David Sabock, Water Quality Standards Branch, at 202-475-7315 regarding designated uses and water quality standards policies; BobApril, Ecological Risk Assessment Branch, at 202-475-7315, regarding EPA's aquatic life criteria: or Bill Sanville, Environmental Research Laboratory/Duluth, at 218-720- 5500, regarding the research for this report.

Attachment

cc: Water Quality Branch Chiefs (Regions I-X) Water Quality Standards Coordinators (Regions I-X) Wetlands Coordinators (Regions I-X) David Sabock BobApril Bill Sanville

2CONTENTS

Abstract i Tables iii Acknowledgements iv
1.

2.

3.

4.

5.

6. Introduction

Need for standards for wetlands Proposed approach to development of wetland standards Purpose of this document Current Surface Water Standards and Criteria Description of standards and criteria Development of national aquatic life numeric criteria Site-specific guidelines The Need for Evaluating Numeric Water Quality Criteria: Use of the Site-Specific Guidelines Overall relevance of criteria to wetlands Wetland variability Use of the site-specific guidelines for wetlands Aquatic plants Evaluation Program Classification Evaluating the appropriateness of direct application of criteria Developing site-specific criteria Example Analyses Example 1 Example 2 Summary of the example analyses Conclusions
References Appendices
A. Sources used in species habitat identification

for Minnesota marshes B. Sources used in species habitat identification

for prairie potholes 1 1
3 4 6 6
7 8

9 9 10
10 14 16 16
17 18 19 19 21 24 26
28

31 32

iiTABLES

Number Page 1
2

3

4
5 6

7

8

9 Freshwater numeric aquatic life criteria Suitability of wetland species to fill minimum family requirements for six criterion chemicals Someconditions recommended for dilution water for water quality criteria testing Effects of cofactors oncriterion chemical toxicity Water chemistry for selected Minnesota marshes Comparison of test species with Minnesota marsh biota for six criterion chemicals Number of species tested for acute criteria and percentage of test species that are not found in Minnesota marshes or oligosaline prairie potholes Water quality characteristics for oligosaline prairie potholes Comparison of test species with prairie pothole biota for six criterion chemicals 33

34

35 36 37

38

40

41

42

iiiACKNOWLEDGEMENTS

Preparation of this document has been funded bythe U.S. Environmental Protection Agency. This document has been prepared at the EPAEnvironmental Research Laboratory in Duluth, Minnesota, through Contract #68033544 to AScI Corporation. This document has been subjected to the Agency's peer and administrative review. Excellent reviews and assistance were received from C. Stephan, R. Spehar, C. Johnston, E. Hunt, D. Robb, and J. Minter.

ivSECTION 1 INTRODUCTION

NEEDFORSTANDARDS FORWETLANDS Wetlands have been studied and appreciated for arelatively short time in relation to other types of aquatic systems. The extent of their value in the landscape has only recently been recognized: in fact, afew decades ago government policies encouraged wetland drainage and conversion. Wetlands traditionally have been recognized as important fish and wildlife habitats, and it is estimated that over one-third of U.S. endangered species require wetland habitat for their continued existence. Someof their many other values, however, have become apparent only recently. These include attenuation of flood flows, groundwater recharge, shoreline and stream bank stabilization, filtering of pollutants from point and nonpoint sources, unique habitats for both flora and fauna, and recreational and educational opportunities.1 Impacts to Wetlands Despite new appreciation of the valuable functions that wetlands perform in the landscape, they continue to bedestroyed and altered at arapid pace. Since pre-settlement times over half of the wetlands in the continental U.S. have been destroyed, and losses over the last few decades have remained high.2 These figures only represent actual loss of acreage and do not account for alterations to or contamination of still-extant wetlands. The causes of wetland destruction and degradation include:3 * Urbanization - Resulting in drainage and filling, contamination, and ecological isolation of wetlands. * Agriculture Conversion - Drainage, cropping, and grazing which change or destroy wetland structure and ecological function. * Water Resource Development -Water flow alterations to wetlands from diking, irrigation diversions, alterations to rivers for navigation, diversions for

1water supply, and groundwater pumping. These result in changes in the hydrology that sustains the wetland system. * Chemical Pollution - From point and nonpoint sources, hazardous waste sites, mining, and other activities. These can overwhelm the assimilative capacity of wetlands or betoxic to wetland organisms. * Biological Disturbances - Introduction or elimination of plant and animal species that affect ecosystem processes. GapsinFederalRegulatoryPrograms Existing Federal regulatory programs intended to reduce some of the impacts described above leave major gaps in the protection of wetlands. Section 404 of the Clean Water Act (CWA) requires a permit to beobtained from the Army Corps of Engineers, in cooperation with the U.S. Environmental Protection Agency (EPA), before dredged material or fill can bedischarged into waters of the United States. Alterations such asdrainage, water diversion, and chemical contamination are not covered by Section 404 unless material will bedischarged into the wetland in association with such alterations. The Resource Conservation and Recovery Act, which regulates the disposal of hazardous wastes, and the CWA,which regulates contamination from waste-water discharges and nonpoint-source pollution, could provide protection from certain impacts, but they have not been used consistently to regulate impacts to wetlands. Programs designed to protect endangered species, migratory birds, and marine mammals have also been used to reduce impacts to wetlands, "the application of these programs also has been uneven."4 but
Gaps in State Regulatory Programs Wetland regulations vary greatly among States. SomeStates are nowdeveloping narrative standards for wetlands (e.g. Wisconsin, Rhode Island, and others). Onthe other hand, although wetlands are included in the Federal definition of "waters of the United States" and are protected by Section 101(a) of the CWA,not all States include them as "waters of the State" in their definitions. Areview conducted in 1989 by the EPA Office of Wetlands Protection and the Office of Water Regulations and Standards found that only 27of 50States mentioned wetlands in definitions of State waters. The review verified that there generally is alack of consideration given to water quality standards for wetlands.'

2EffectiveUseofExistingRegulatoryOptions Although some impacts (e.g. excavation, most drainage, and destruction of vegetation) are not addressed by the current implementation of existing regulations and programs, much of the chemical contamination of wetlands could becontrolled through existing Federal and State water pollution control laws.‘ The National Wetlands Policy Forum recommended that EPAand State water pollution control agencies review the implementation of their water quality programs to ensure that the chemical integrity of wetlands is adequately protected. The Forum stressed the need to develop water quality standards designed to protect sensitive wetlands.4 Under Section 401 of the CWA,States have authority to authorize, condition, or deny all Federal permits or licenses in order to comply with State water quality standards, including, but not limited to, Sections 402 and 404 of the CWA,Sections 9 and 10of the Rivers and Harbors Act, and Federal Energy Regulatory Commission licenses. States with water quality standards that apply to or are specifically designed for wetlands can use 401 certification much more effectively asaregulatory tool. Aswetlands receive more recognition as important components of State water resources, the need for testing the applicability of some existing guidelines and standards to wetlands regulation becomes more apparent.

PROPOSEDAPPROACHTODEVELOPMENT OFWETLANDSTANDARDS
The EPAOffice of Water Regulations and Standards and Office of Wetlands Protection recently completed adocument entitled, "National Guidance: Water Quality Standards for Wetlands."6 It recommends atwo-phased approach for the development of water quality standards for wetlands. In the first 3-year phase of this program, standards for wetlands would bedeveloped using existing information in order to provide protection to wetlands consistent with the protection afforded other State waters. Technical support for this initial phase will beprovided through documents such asthis one, which focuses onthe application of existing numeric criteria to wetlands. These criteria are widely used. Applying them to wetlands requires asmall amount of effort and can beaccomplished quickly. The development of narrative biocriteria is also required in the initial phase of standards development. The long-term goal (3-10 years) of this program is to develop numeric biocriteria for wetlands. It is anticipated that both narrative and numeric

3biocriteria can provide amore integrative estimate of wholewetland health and better identification of impacts and trends than can beattained bytraditional numeric chemical criteria. Field-based, community-level biosurveys can be implemented to complement, and help validate, laboratory-based conclusions. Results of such surveys can beused to monitor wetlands for degradation and establish narrative or numeric biocriteria or guidance which take into account "real world" biological interactions and the interactions of multiple stressors. More information onthe development of numeric biocriteria will be available in aguidance document in coming years. Technical guidance to support the development of biological criteria for wetlands has also been prepared.' This guidance provides asynthesis of technical information on field studies of inland wetland biological communities.

PURPOSEOFTHIS DOCUMENT
Anumber of steps are needed to develop wetland standards. The document, "National Guidance: Water Quality Standards for Wetlands," mentioned above, provides general guidelines to the States for each of the following steps: the inclusion of wetlands in definitions of State waters, the relationship between wetland standards and other water-related programs, use classification systems for wetlands, the definition of wetland functions and values, the applicability of existing narrative and numeric water quality criteria to wetlands, and the application of antidegradation policies to wetlands. The technical document for biological criteria7 and this report are companions to the guidance document described above. This report is directed primarily toward wetland scientists unfamiliar with water quality regulation and is intended to provide abasis for dialogue between wetland scientists and criteria experts regarding adapting numeric aquatic life criteria to wetlands. More specifically: 1) It provides background information and anoverview of water quality standards and numeric chemical criteria, including application to wetlands. 2) The need for evaluating numeric water quality criteria is discussed. The site-specific guidelines are introduced and discussed in two contexts: a) as an initial screening tool to ensure that water quality in extreme wetland types is adequately protected by criteria, and b) in terms of using the site-specific guidelines to modify criteria for wetlands where criteria might beover or underprotective.

43) Anapproach is described that uses information available

from criteria documents and is designed to: a) detect wetland types where water quality is not clearly protected by existing criteria, and b) help prioritize further evaluations and research efforts.4) Asimple test of the approach is presented with two examples. Results are not considered conclusive and are presented only as anexample of the procedure. Most of the data and examples are based onthe freshwater acute criteria. Asimilar approach should be equally applicable to the saltwater acute criteria and to both saltwater and freshwater chronic criteria.

5SECTION 2 CURRENTSURFACEWATERSTANDARDSANDCRITERIA

This section describes howcriteria are used in State standards, how national numeric criteria are derived, and what options are currently available for modifying national aquatic life criteria.

DESCRIPTION OFSTANDARDS MD CRITERIA Surface waters are protected by Section 101(a) of the CWA with the goal: "to restore and maintain the chemical, physical, and biological integrity of the nation's waters." State water quality standards are developed to meet this goal. State Standards There are two main components to establishing astandard: 1) The level of water quality attainable for aparticular waterbody, or the designated use of that waterbody (e.g. recreational, fishery, etc.) is determined; 2) Water quality criteria (usually acombination of narrative and numeric) are established to protect that designated use. Water quality standards also contain anantidegradation policy "to maintain and protect existing uses and water quality, to provide protection for higher quality waters, and to provide protection for outstanding national resource waters."8 State standards for a particular waterbody must bemet when discharging wastewaters. The "National Guidance: Water Quality Standards for Wetlands"6 outlines abasic program to achieve these goals for wetlands. Aquatic Criteria Narrative Criteria-- Narrative criteria are statements, usually expressed in a "free from

..." format. For example, all States have anarrative statement in their water quality standards which requires that their waters not contain "toxic substances in toxic amounts." Narrative criteria are typically applied at the State level when combinations of pollutants must becontrolled or when pollutants are present which are not listed in State water quality

6standards.8 States must document the process bywhich they

propose to implement these narrative criteria in their standards. Numeric Criteria-- Pollutant-specific numeric criteria are used by the States when it is necessary to control individual pollutants in order to protect the designated use of awaterbody. Fate and transport models commonly are used to translate these criteria into permit limits for individual dischargers. Somecriteria apply Statewide and others are specific to particular designated uses or waterbodies. National numeric criteria are developed by EPAbased onbest available scientific information. They serve as recommendations to assist States in developing their own criteria and to assist in interpreting narrative criteria.9 These include human health and aquatic life pollutant-specific criteria and whole effluent toxicity criteria. Sediment criteria are nowbeing developed. States can adopt national numeric criteria directly. Alternatively, site-specific criteria maybedeveloped using EPAspecified guidelines, and State-specific criteria can bederived using procedures developed by the State.8

DEVELOPMENT OFNATIONAL AQUATIC LIFE NUMERIC CRITERIA National aquatic life criteria are usually derived using single-species laboratory toxicity tests. Tests are repeated with awide variety of aquatic organisms for each chemical. The criteria are designed to protect against unacceptable effects to aquatic organisms or their uses caused by exposures to high concentrations for short periods of time (acute effects), to lower concentrations for longer periods of time (chronic effects), and to combinations of both.9 EPAcriteria are composed of 1) magnitude (what concentration of apollutant is allowable): 2) duration of exposure (the period of time over which the in-stream concentration is averaged for comparison with criteria concentrations): and 3) frequency (how often the criterion can be exceeded without unacceptably affecting the community).10 Separate criteria are determined for fresh water and salt water. Field data are used when appropriate.
All acceptable data regarding toxicity to fish and invertebrates are evaluated for inclusion in the criteria. Data ontoxicity to aquatic plants are evaluated to determine whether concentrations of the chemical that do not cause unacceptable effects to aquatic animals will cause unacceptable effects to plants. Bioaccumulation data are examined to determine if residues in the organisms might exceed FDAaction levels or cause known effects onthe wildlife that consume them. For aComplete

7description of the procedures for deriving ambient criteria,

consult the "National Guidelines" (1985).9 Numeric water quality criteria are designed to protect most of the species inhabiting asite.9 Awide variety of taxa with a range of sensitivities are required for deriving criteria. Guidelines are followed to determine the availability of sufficient experimental data from enough appropriate taxa to derive acriterion. For example, to derive afreshwater Final Acute Value for achemical, results of acute tests with at least one species of freshwater animal in at least eight different families are required. Acute and chronic values can bemade to beafunction of awater quality characteristic such as Ph, salinity, or hardness, when it is determined that these characteristics impact toxicity, and enough data exist to establish the relationship. Table 1lists the chemicals for which freshwater aquatic life criteria have been developed and indicates which of those criteria are pH, hardness, or temperature dependent.

SITE-SPECIFIC GUIDELINES
Anoption for modifying national aquatic life water quality criteria to reflect local conditions is presented in the sitespecific guidelines. States maydevelop site-specific criteria by modifying the national criteria for sites where 1)water quality characteristics, such as pH, hardness, temperature, etc., that might impact toxicity of the pollutants of concern differ from the laboratory water used in developing the criterion; or 2) the types of organisms at the site differ from, and maybemore or less sensitive than, those used to calculate the criterion; or 3) both maybe true. Site-specific criteria take local conditions into account to provide anappropriate level of protection. They can also beused to set seasonal criteria when there is high temporal variability.8
Atesting program can beused to determine whether sitespecific modifications to criteria are necessary. This program may include water quality sampling and analysis, abiological survey, and acute and chronic toxicity tests.11 If site-specific modifications are deemed necessary, 3separate procedures are available for using site-specific guidelines to modify criteria values, including the recalculation procedure, the indicator species procedure, and the resident species procedure. These will bediscussed more fully in the next section.

8SECTION 3 THENEEDFOREVALUATING NUMERICWATERQUALITY CRITERIA:

USEOFTHESITE-SPECIFIC GUIDELINES

OVERALL RELEVANCE OFCRITERIA TOWETLANDS
The national aquatic life criteria have been developed to provide guidance to the States for the protection of aquatic life and their uses in avariety of surface waters. They are designed to beconservative and "'... have been developed onthe theory that effects which occur onaspecies in appropriate laboratory tests will generally occur onthe same species in comparable field situations. All North American bodies of water and resident aquatic species and their uses are meant to betaken into account, except for afew that maybetoo atypical ..."9 A wide variety of taxonomic groups sensitive to many materials are used in testing, including many taxa common to both wetlands and other surface waters. In order to ensure that criteria are appropriately protective, water used for testing is low in particulate matter and organic matter, because these substances can reduce availability and toxicity of some chemicals. For these reasons, the "National Guidance: Water Quality Standards for Wetlands" states that, in most cases, criteria should be protective of wetland biota.6 Although the water quality criteria are probably generally protective of wetlands and provide the best currently available tool for regulating contamination from specific pollutants, there are many different types of wetlands with widely variable conditions. There might besomewetland types where the resident biota or chemical and physical conditions are substantially different from what the criteria were designed to protect. These differences could result in underprotection or overprotection of the wetland resource. This section discusses the use of sitespecific guidelines for wetland types for which certain criteria might beover or underprotective, but its primary focus is to provide amechanism to identify wetland types that might be underprotected by certain criteria and that might require further research.

9WETLANDVARIABILITY

Wetlands are usually located at the interface between terrestrial systems and truly aquatic systems, and socombine attributes of both." They are intermediate between terrestrial and aquatic systems in the amount of water they store and process and are very sensitive to changes in hydrology.'* Their chemical and physical properties, such as nutrient availability, degree of substrate anoxia, soil salinity, sediment properties, and pHare influenced greatly by hydrologic conditions. Attendees at a Wetlands Water Quality Workshop (held in Easton, Maryland in August, 1988) listed the most commonways in which wetlands differ from "typical" surface waters: higher concentrations of organic carbon and particulate matter, more variable and generally lower pH, more variable and generally lower dissolved oxygen, more variable temperatures, and more transient availability of water." There is also high variability among wetland types. Wetlands, bydefinition, share hydrophytic vegetation, hydric soils, and awater table at or near the surface at some time during the growing season. Beyond these shared features, however, there is tremendous hydrological, physical, chemical, and biological variability. For example, an early classification system for wetlands "Circular 39", listed 20 distinctly different wetland types 14 and the present "Cowardin" system lists 56classes of wetlands.15 This variability makes it important to evaluate different wetland types individually.

USEOFTHESITE-SPECIFIC GUIDELINES FORWETLANDS
The site-specific guidelines outlined in Section 2are designed to address the chemical and biological variability described above. Determining the need for site-specific modifications to criteria requires acomparison of the aquatic biota and chemical conditions at the site to those used for establishing the criterion. This comparison is useful for identifying wetland types that might require additional evaluation. The three site-specific options are discussed in the context of their general relevance to wetlands and are used in this discussion to provide aframework for evaluating the protectiveness of criteria for wetlands.
In most cases, because of the conservative approach used in the derivation of the criteria, use of the site-specific guidelines to modify criteria results in no change or in their relaxation, provided that anadequate number of species are used in the calculations. However, criteria can also become more
10restrictive. Newly tested species could beespecially sensitive

to certain pollutants, or extreme water conditions found in some surface waters or wetland types might not reduce the toxicity of achemical. Disease, parasites, predators, other pollutants, contaminated or insufficient food, and fluctuating and extreme conditions might all affect the ability of organisms to withstand toxic pollutants.9 Appropriateness of Testing Organisms: Recalculation Procedure . The first option given in the site-specific guidelines is the recalculation procedure.8,11 This approach is designed to take into account differences between the sensitivity of resident species and those used to calculate acriterion for the material of concern. It involves eliminating data from the criterion database for species that are not resident at that site. It could require additional resident species testing in laboratory water if the number of species remaining for recalculating the criterion drops below the minimum data requirements. "Resident" species include those that seasonally or intermittently exist at asite.11,16 Use of the recalculation procedure will not necessarily result in ahigher acute criterion value (less restrictive), even if sensitive species are eliminated from the dataset and minimum family requirements are met. The number of families used to calculate Final Acute Values is important. If anumber of nonwetland species are dropped out of the calculation without adding asufficient number of newspecies, alower (more restrictive) Final Acute Value can result, because data are available for fewer species." Similarity of Required Taxa and Typical Wetland Species-- The variety of test species required to establish the national numeric criteria was chosen to represent awide range of taxa having awide range of habitat requirements and sensitivity to toxicants. Establishment of afreshwater Final Acute Value for achemical requires aminimum of 8different types of families to betested. These include: 1) the family Salmonidae; 2) asecond family of fish, preferably awarmwater species: 3) a third family in the phylum Chordata (fish, amphibian, etc.): 4) a planktonic crustacean: 5) abenthic crustacean: 6) an insect: 7) afamily in aphylum other than Arthropoda or Chordata; and 8) a family in any order of insect or phylum not already represented.9 Whenarequired type of family does not exist at asite, the guidelines for the recalculation procedure specify that substitutes from asensitive family, resident in the site, should be added to meet the minimum family data requirement. should it happen that all resident families have been tested and the

11minimum data requirements still have not been met, the acute

toxicity value from the most sensitive resident family that has been tested should beused asthe site-specific value. Most of the required families are probably well-represented in most wetland types. Sometypes of wetlands, however, seldom or never contain fish, and most wetland types do not support salmonids or aquatic insects requiring flowing water. General Evaluation of Species Suitability-- Table 2presents six criterion chemicals chosen as examples and the eight taxonomic groups required to establish criteria. The chemicals include two organochlorines: polychlorinated biphenyls (PCBs -used in industrial applications, environmentally-persistent, bioaccumulate) and pentachlorophenol (widely used fungicide and bactericide); one organophosphate: parathion (insecticide); two metals: zinc and chromium(VI); and cyanide. The species used for acute toxicity testing for each of the six chemicals have been broken down by taxonomic group and evaluated based onthe likelihood that those species can be found in wetlands. Except for the unsuitability of the Salmonidae to most wetland types, most of the taxonomic groups are wellrepresented for the six chemicals used as examples. Wetland species were not present in the list of species used to calculate the Final Acute Value for the "non-arthropod/non-chordate" and "another insect or newphylum" groups for afew of the criteria. This is not because these groups are not represented in wetlands. These are very general classifications. For example, the "nonarthropod/non-chordate" group can include rotifers, annelids, and mollusks among other phyla, all of which should have many representatives in most types of wetlands. There is alarge degree of variation in the total number of species tested for the six chemicals used asexamples, ranging from 10fish and invertebrates for polychlorinated biphenyls (PCBs) to 45 for zinc (Table 7). Criteria based onsmaller numbers of species are less likely to include asufficient number of wetland species to fulfill the minimum family requirements. Additional toxicity testing, using laboratory water and wetland species from the missing families, can bedone to fill these gaps. While the general taxonomic groups required for toxicity testing are fairly well represented in wetlands, the similarity between the genera and species inhabiting individual wetland types and those used for criteria testing varies widely among criteria and wetland types. Species chosen for toxicity testing were seldom or never chosen with wetlands in mind. In addition, relatively little is known about species assemblages in some types of wetlands (particularly in those lacking surface waters,

12

### suchaswetmeadowsorbogs). Defining typical 

### wetland taxa is

difficult. 

### Forexample, while most

### m ofwetlands donot support salmonids, Cohosalmon 

### arehighly dependent onwetlands in

### Alaska, where there is

### ahigher 

### percentage andacreage of wetlands than inanyother State. Part of the utility ofthe evaluation proposed here is in identifying where significant gaps indata exist.

. 

### . uence ofCofactors. -or Species Proca Thesecond of the three site-specific procedures, the indicator species procedure, accounts for differences in biological availability and/or toxicity of amaterial 

### causedby physical and/or chemical characteristics of the site 

### water, or cofactors. Forthe acute test, the effect of site water is compared tothe effect of laboratory water, using at least two resident species oracceptable non-resident species (onefish and oneinvertebrate) asindicators. A

### ratio is determined, which is usedtomodify the Final Acute Value. SeeCarlson et al. (1984) for information andguidelines for determination of site-specific chronic values." Suitability of Standard Testing Conditions-- Standard aquatic toxicity tests are performed using natural or reconstituted dilution water that should not of itself affect the results of toxicity tests. Forexample, organic carbon and particulate matter are required to belowto avoid sorption or complexation of toxicants, which might lower the toxicity or availability 

### of somecriterion chemicals. Recommended acute test conditions for certain water quality characteristics of fresh 

### and salt water are listed inTable 3. Wetlands, aswell 

### assome types of surface waters, canhavevalues far outside the ranges used for standard testing for someofthese characteristics (most notably total organic carbon, particulate matter, pH,and dissolved oxygen). Wetland types canbeevaluated to identify these extremes. Wetland Cofactors-- Manywater quality characteristics can 1)act ascofactors to affect the toxicity of pollutants (e.g. alkalinity/acidity, hardness, ionic strength, organic matter, temperature, dissolved oxygen, suspended solids); 2)canbedirectly toxic to organisms (e.g. un-ionized ammonia, high or lowpH,hydrogen sulfide, low dissolved oxygen); or 3)caninterfere mechanically with feeding andreproduction (e.g. suspended solids). Thecriteria for some ofthese water quality characteristics canbenaturally exceeded in manywetland types, aswell asin somelakes andstreams. Hardness, pH, andtemperature adjustments built into afew of the criteria account for effects from these cofactors inafew
13ca8es, 

### but noother cofactors are nowincluded inthe criteria,

despite someknowneffects. 

### Forexample, alkalinity, salinity, 

### andsuapendedsolids, inaddition topH

### andhardness, areknown to affect the toxicities of heavy metals 

### andammonia. These cofactors are not included inthe criteria primarily because there are insufficient data.' Forexample, most toxicity tests havebeenperformed under conditions of loworhigh salinity, so 

### that estuaries, where salinity 

### values canvary greatly, may require 

### metals." salinity-dependent site-specific criteria for some

Aninitial evaluation ofthe adequacy of protection provided to

### awetland type by

### acriterion should 

### take possible cofactor effects into account.

.

. 

### e&nt mcies Procew Theresident species procedure accounts for differences in both species sensitivity andwater quality characteristics." This procedure is costly, because it requires that acomplete minimum dataset bedeveloped using site water 

### andresident species. It is designed tocompensate concurrently for differences inthe sensitivity range ofspecies represented in the dataset usedto derive the criterion andfor site water differences which maymarkedly affect the biological availability and/or toxicity of the chemical."

AQUATICPLANTS Oneofthe most notable differences between wetlands and other types of surface waters is the dominance (and importance) of aquatic macrophytes andother hydrophytic vegetation in wetlands. Aquatic plants probably constitute the majority ofthe biomass inmostwetland types. Fewdata concerning toxicity toaquatic plants are currently required for deriving aquatic life criteria. Traditionally, procedures for 

### aquatic toxicity tests onplants havenot beenas well developed 

### asfor animals. Although national numeric criteria development guidelines state that results of atest with afreshwater alga orvascular plant "should beavailable" for establishing 

### acriterion, they donot require that information.' TheFinal Plant Value is the lowest (most sensitive) result from tests with important aquatic plant species (vascular plant or alga), inwhich the concentrations oftest material weremeasured andthe endpoint wasbiologically important. Plant values are compared toanimal values todetermine the relative sensitivities of aquatic plants andanimals. If plants are "amongthe aquatic organisms that are most sensitive tothe material," results ofa second test with aplant from another phylum are included.9

14

### Results of tests with plants usually indicate that criteria

which protect aquatic animals andtheir uses also protect aquatic plants andtheir uses.' As

### criteria are evaluated for their suitability for wetlands, however, plant values should be examined carefully. Additional plant testing maybeadvisable in somecases. If site-specific adjustments are madeto some criteria, they could result in less restrictive acute andchronic values for animals. Someplant values could then beassensitive or 

### moresensitive than the animal values. Chemicals with fairly sensitive plant values include: aluminum, arsenic(III), cadmium, 

### chloride, chromium(VI), cyanide, andselenium(V1). Forexample, fish are generally muchmoresensitive to cyanide than invertebrates. If the recalculation procedure wasused to develop asite-specific cyanide criterion for awetland type containing nofish, values for these sensitive species would be replaced inthe calculation, possibly byless sensitive species. A

### less restrictive criterion could result, possibly making the plant value moresensitive than the animal value. Therefore, additional consideration should begiven to plant toxicity data for wetland systems.

15SECTION 4 EVALUATION PROGRAM

The direct application of existing aquatic life criteria to wetlands is assumed to bereasonable in most cases. It provides apractical approach towards protecting the biological integrity of wetlands. The following evaluation program offers apossible strategy to identify extreme wetland types that might be underprotected by some criteria, to prioritize wetland types and criterion chemicals for further testing or research, and to identify gaps in available data. The approach can behelpful for identifying those instances where modifications to existing criteria might beadvisable. The proposed evaluation program offers ascreening tool to begin to answer the following questions: 1) Are there somewetland types for which certain criteria are underprotective? 2) For criteria in wetland types that cannot beapplied directly, can site-specific guidelines be used to modify the criteria to protect the wetland? 3) Will additional toxicity testing under wetland conditions and with wetland species be necessary in some cases in order to establish site-specific criteria? The proposed approach relates species and water quality characteristics of individual wetland types to species and water quality characteristics important in deriving each criterion. It involves identifying wetland types of concern, identifying cofactors possibly affecting toxicity for the criteria of interest, gathering data onthe biota and water quality characteristics of the wetland type, and comparing to data used to derive the criterion.

CLASSIFICATION
The proposed program for the evaluation of the suitability of aquatic life criteria discussed in this section can bedone separately for individual wetland types. These can bedefined in the classification process, which is the first step in developing standards for wetlands. The classification process requires the identification of the various structural types of wetlands and identification of their functions and values.6 The classification should provide groups of wetlands that are similar

16enough structurally and functionally sothat they can reasonably

beexpected to respond in kind to inputs of toxic chemicals.

EVALUATING THEAPPROPRIATENESS OFDIRECT APPLICATION OFCRITERIA Information Needed
1. Identification of cofactors. Cofactors potentially affecting mobility and biological availability for each criterion chemical should be identified. Cofactors known to affect each criterion chemical are listed in individual national criteria documents and are summarized in Table 4. The absence of a relationship between acofactor and achemical onTable 4does not ensure that no relationship exists, merely that none was discussed in the criteria document. The chemistry of the effects of the cofactors onthe chemicals is often very complicated, and limited data are available regarding some of the relationships. The approach presented here is simplistic and is geared toward directing further efforts. Other sources of information, in addition to the criteria documents, should be consulted when actually applying this approach. Criteria that include hardnessor pH-dependent correction factors (Table 1) should apply directly to wetlands unless the wetland type has extremes of pH or hardness well outside the ranges used in toxicity testing. For example, the pHof acid bogs can beas low as 3.5, well below the 6.5 lower limit for toxicity testing (Table 3).
2. Comparison to wetland water chemistry. Natural levels and variability of those cofactors should be identified aswell as possible for each major wetland type of interest. Wetlandsrelated information can beaccumulated through consultation with wetland researchers, through literature searches, and from monitoring agencies.
3. Comparison of species lists. Species lists of fish, invertebrates, and plants should becompiled for each wetland type and compared to lists of species used for testing each criterion. Lists should beevaluated ontwo levels: a) Species level -Are the species used for toxicity testing representative (the same species or genera, or "similar" in terms of sensitivity to toxicants) of the species found in the wetland type? b) Family level - Does the wetland contain suitable representatives for each of the families listed in the minimum family requirements?8,11 Consultation with fish and invertebrate specialists, plant ecologists, and wetlands experts will be necessary to do this comparison.

17Adoption of Existing Water Quality Criteria The existing water quality criterion should besuitable for that wetland type if the following are true:
1. Important cofactor levels are not naturally exceeded in the wetland to adegree that might seriously affect toxicity or availability of the chemical. Would toxicity likely behigher, lower, or not influenced bytypical levels or extremes of a particular cofactor in aparticular wetland type?
2. Sufficient species or genera used for aquatic toxicity testing are found in the wetland type sothat the minimum family requirements can be met by resident wetland species. Consultation between wetland scientists and criteria experts will be necessary in many cases to make judgements on howwellrepresented somewetland types are. 3. The criterion itself is not naturally exceeded in the wetland.

DEVELOPING SITE-SPECIFIC CRITERIA Whenone or more of these stipulations is not true or when insufficient data are available, more evaluation is advisable. Again, consultation between wetland scientists and criteria experts might behelpful in prioritizing those wetland types for which additional protection, or additional research, might be needed for some chemicals. Once apriority list for further evaluation is established, anapproach to obtaining the additional required data can bedetermined. It might bepossible to group wetlands by type, and possibly bydesignated use, and then develop site-specific criteria for all wetlands of that type in the State.

18SECTION 5
EXAMPLE ANALYSES

Evaluations of the applicability of the six criteria listed in Table 2will bemade for two sets of wetland data, including shallow marshes and prairie potholes. The analyses in these examples were made with limited data for each wetland type and are preliminary. They have been compiled to beused only as illustrations of the usefulness of this approach.

EXAMPLE1 The first example is based onawetland study taking place in southcentral Minnesota. The wetlands are being studied to evaluate the effects of disturbance onwater quality, aswell as the effects of pesticides onwetland communities. Therefore chemical and biological data have been collected." Classification The wetland study sites are primarily shallow marshes (freshwater palustrine, persistent emergent, semi-permanently or seasonally-flooded, according to Cowardin15), dominated by Phalaris (reed canary grass) andTypha (cattails), but also include asmall number of wet meadow/seasonally-flooded wetlands, deep marsh, shrub/scrub +woody wetlands, and ponds. Steps1and2:Identificationof Cofactors and Comparisonto Wetland Water Chemistry Cofactors are identified for criteria chemicals in Table 4. Somewater quality characteristics averaged for 5seasons for the Minnesota wetlands are summarized in Table 5. Although somewater chemistry conditions in the shallow marshes were within the ranges of the aquatic toxicity testing conditions, others were exceeded (Table 3). Wetland values for pHwere well within the 6.5-9.0 range allowed for testing, so criteria having pHasapossible cofactor affecting toxicity and/or biological availability should not be underprotective because of pHeffects. AsTable 4shows, PCP, chromium(VI), zinc, and cyanide can bemore toxic at low pHvalues, soavery
19acidic wetland might require additional evaluation in regard to

PH. The PCPcriterion has anadjustment factor for pH, which indicates that enough suitable data are available to allow this relationship to be incorporated into the criterion. Hardness values were not available for these marshes, but were probably fairly low since alkalinity was low. Table 4lists hardness as acofactor for zinc and chromium(VI). Table 1 reveals that the zinc criterion has anadjustment factor for hardness, soany effect of hardness on zinc toxicity and/or biological availability is already included in the criterion and does not have to beconsidered further. Chromium(VI) is more toxic at low alkalinity and hardness, but the criterion was derived using soft water and should beprotective for the wetlands. Total organic carbon (TOC) was highly variable in the wetlands and generally well above the 5mg/L limit for toxicity testing. However parathion and zinc, the two criteria with TOC cofactor effects, have reduced toxicity and/or biological availability at high levels of organic matter (Table 4), so criteria should beprotective. Dissolved oxygen (DC) was highly variable in the wetlands and reached very low levels in late summer. The shallow waters of the marshes were extremely warm on hot summer days. Toxicity and/or biological availability is increased by low DOand high temperatures for PCBs, PCP, and cyanide. These relationships will require further evaluation. Step 3: Comparisons of Species Lists
In Step 3, fish, invertebrates, and plants inhabiting the wetlands are compared to species used in testing each criterion. For these examples, only the acute toxicity lists have been consulted. Alist of genera common to both the marshes and to the toxicity tests was compiled for each criterion. When identical species were not found, species from the samegenus were compared to determine whether habitat requirements are suitable enough to include them as representative species for these wetlands. The shortened list of marsh species the same as, or similar to, species used for toxicity testing was examined to determine whether the minimum family requirements for acute toxicity tests could bemet for each criterion. Table 6contains alist of marsh genera that could be used to fulfill minimum family requirements for each criterion. Appendix Acontains a list of the sources that have been consulted in making this comparison.

20The aquatic species found in the Minnesota wetlands were

fairly well-represented bythe acute toxicity test species for the six chemicals used in this example. The percentages of total species tested that have not been found in these wetlands were below 50%for all six criteria (Table 7). Except for PCBs, for which noplant value is available, plant species tested overlapped with species occurring in the wetlands. The absence of salmonids in wetlands was the only consistent omission. Ofall the species tested, the salmonids are the most sensitive to PCPand cyanide and are much more sensitive than most invertebrate species. The inclusion of highly sensitive salmonid data in the criteria calculations probably ensures that these two criteria are adequately protective when applied to wetlands not containing this sensitive family (not considering cofactor effects). It would perhaps bemore important to consider the effects of the absence of salmonids in Minnesota marshes for criteria where salmonids are among the least sensitive species, including parathion and chromium(VI). In this case, the presence of salmonid toxicity data in the criterion calculation, despite their absence from the wetlands, could possibly cause the criterion to be less restrictive than is appropriate for the wetland. Salmonids do not occur in the wetlands included in this example. Three criteria were missing anadditional required taxonomic group (from Table 6: PCBs, chromium(VI), and cyanide). There are certainly representatives of this taxonomic group (nonarthropod/nonchordate) inhabiting the wetlands, but the genera used for toxicity tests did not correspond to the wetland genera. These three criteria have the least species onthe acute toxicity list, so there are less species to compare to, in relation to the other criteria (Table 7). Toxicity experts and wetland biologists might beable to fill some of these data gaps by reaching conclusions onthe suitability of wetland species to fulfill the minimum family requirements.

EXAMPLE2 This example is based ondata for anumber of oligosaline prairie pothole wetlands in southcentral North Dakota.19,20 Oligosaline is defined as ranging from 0.5-5 g/kg salinity, or specific conductance of 800-8,000 μS/cm at 25°C.15 The chemical types of the majority of wetlands used in this example include magnesium bicarbonate, magnesium sulfate, and sodium sulfate."

21

### Wetlands included inthis example are semipermanent (cover

type 4ofthe classification system develo edbyStewart and Kantrud for the glaciated prairie region) 2Pcontaining wet meadow, shallow marsh, anddeepmarsh. ClAssification ofthese wetlands based onthe Cowardin system can be

### found in

### Kantrud et a1.20

.. .

. DS land 

### 2. Identtiication of 

### Cofpctors QDdCo-on to WetLgnd Water Chew Cofactors are identified for criteria chemicals inTable 4. Water quality data 

### for the prairie pothole 

### wetlands are summarized inTable 8. Acomparison ofwater chemistry conditions for the prairie potholes with standard toxicological testing conditions (Table 3)reveals anumber of differences. Thesewetlands are extremely alkaline 

### andsaline compared to water usedfor freshwater toxicity testing. Salinity (reported asspecific conductance) canvary 

### greatly over 

### theyearandis concentrated by

### the high rates ofevaporation andtranspiration that take 

### place in the summer. Anumberofthe wetlands havepH values abovethe 6.5-9.0 range that the criteria are designed to protect. Nodata were available for total organic carbon (TOC), but dissolved organic carbon values from other prairie pothole systems weregeneral1 4;well above the TOClimit of 5mg/Lused for toxicity testing. Asin Example 1,hardness canbe eliminated from consideration 

### asacofactor, because toxicity and/or biological availability is 

### decreased 

### ashardness increases. Similarly, the probable high TOClevels would decrease toxicity and/or biological availability for zinc and chromium(V1). Thehigh pHvalues should cause decreased toxicity and/or biological availability. Bioavailability of zinc is reduced in high ionic strength waters suchasthese. Dissolved oxygen (DO)levels drop inthe winter andin middle to late summer, allowing anoxic conditions todevelop. Although noaquatic temperature data wereavailable, the Dakotas havemoderately hot summers (meanJuly temperature of 22.3°C).20 Theshallow waters of the prairie potholes probably becomevery 

### warmin late summer, corresponding with low DOlevels. Toxicity and/or biological 

### availability is increased bylow DOandhigh temperatures for PCBs, PCP,andcyanide. These relationships will require further evaluation. Steb 3: Comndsons of Species Listg Semi-permanent prairie pothole wetlands are generally shallow andeutrophic. Water levels fluctuate greatly, asdoes
22

### salinity. Thecold winters 

### cancausesomeofthe wetlands to

freeze to the bottom. Bothwinterkill andsummerkill, caused by the effects of 

### lack ofoxygen, canoccur. Fish 

### cansurvive only insemipermanent wetlands that have connections to deeper water 

### habitat. Theonly native fishes 

### knowntooccur insemi-permanent prairie potholes are fathead minnow LXQW&LS) and brook stickleback 

### (Culaeg inconstam Theinvertebrate 

### taxaofprairie potholes aretypical of other eutrophic, alkaline systems inthe United States. Macroinvertebrate species assemblages 

### arehighly influenced 

### by hydroperiod andsalinity inthese systems, andspecies diversity drops assalinity increases.20 

### Caremust

### betaken in

### aggregating large salinity ranges into onewetland type (i.e. "oligosalinem maybetoo 

### broad aclass interms of

### species representativeness). Comparisons of species typical of the wetlands with the criteria species lists reveals somemajor differences. For

### example, a large proportion ofthe aquatic insects tested for eachcriterion are found in flowing water, andtherefore might not be characteristic of prairie pothole aquatic insects. Although many species of aquatic insects are found inthese wetlands", there are not manysuitable aquatic insects onthe criteria species lists to compare to resident wetland species. Prairie pothole wetlands donot harbor Decapods (crayfish andshrimp), another commongroup for testing. Eubranchiopods (fairy, tadpole, and clam shrimp) are commonly found in prairie pothole wetlands", but only onerepresentative of this group hasbeenused to establish criteria, andthat species wasnot onthe list for any ofthe criteria usedasexamples here. Except for PCBs, for which noplant value is available, plant species tested do overlap with species occurring in the wetlands. Appendix B contains sources used inmaking comparisons. The above 

### discussion hasobvious implications for determining applicability ofcriteria based onsuitability of species. AsTable 7shows, the percentages of species tested for 

### eachcriterion that havenot been found in prairie potholes are rather high (upto 67%). There are moregaps inthe minimum family requirements for fish 

### andchordates (Table 9)than were found for the Minnesota marsh example. Thelack of fish inthese wetlands dictates that amphibians orother chordates beused to fill these family requirements. Thepaucity of fish inthese wetlands again 

### hasrelevance to the protectiveness of the criteria. Fish are the most sensitive group tested 

### for PCP

### and cyanide, sothese criteria mayhave anadded "buffer" of protection (in relation tothe other criteria usedasexamples) whenapplied with nomodifications to this 

### wetland type.

23SUMMARYOFTHEEXAMPLEANALYSES

The conclusions discussed below should be considered as examples only. They should not be considered final for these wetland types. Cofactor Effects Based onthis simple analysis, the only cofactors that potentially could cause criteria to be underprotective were DO and temperature. The low DOand high temperatures common in both wetland types in mid to late summer could cause increased toxicity and/or biological availability for PCBs, PCP, and cyanide. Cofactor effects for chromium(VI), zinc, and parathion were either not important under the chemical conditions encountered in these wetlands or should result in criteria being more, rather than less, protective for the wetland biota. Based onwater quality characteristics, it can beconcluded that chromium(VI), zinc, and parathion criteria are probably adequately protective of these wetland types with noacute modification.
The importance of the DOand temperature relationship requires further evaluation for PCBs, PCP, and cyanide. Chemists and wetlands experts should beconsulted and further literature reviews should becompleted to evaluate the need for additional toxicity tests. If it is determined that amodification to a criterion is warranted, seasonal site-specific criteria might be appropriate in this case. The indicator species procedure could beused, requiring toxicity tests using site water onone fish and one invertebrate. The tests could bedone at the high temperatures and low DOfound in late summer in the wetlands. Species Comparisons The Salmonidae are arequired family group for establishing aFinal Acute Value and yet are not present in either of the wetland types used asexamples. This evaluation is most concerned with ensuring that criteria are adequately protective, sothe absence of this family in the wetlands should only be considered aproblem if the unmodified criterion (which includes the Salmonidae) might beunderprotective. This would most likely betrue for parathion and chromium(W).
For several criteria, some family requirements are not fulfilled because the available toxicity data for that taxonomic group do not include wetland species or genera ("NT" in Tables 6 and 9). While this document made comparisons at the genus level, others have made comparisons at the family level to determine if the species listed in the criteria document is amember of a
24family that exists at the site.16 Issues related to species

comparisons should be addressed through discussion with criteria experts and wetlands ecologists and through further literature review.The absence of fish in prairie potholes to fill the "other

chordates" category for cyanide, zinc, chromium(VI), and PCBsmay warrant additional toxicity tests and site-specific modifications. The only other fish likely to be present in these wetlands is the brook stickleback (Culaea inconstans)20 which was not tested for any of the six criteria. Nonon-fish chordates were tested either, so noevaluation of the probable sensitivity of other chordates to these criteria can bemade based onthe criteria documents. If it is decided upon more rigorous evaluation that these differences in taxonomic groups warrant additional efforts and development of site-specific criteria, the recalculation procedure can be used. Asuitable family, resident in the wetlands, can be added to the list to replace the Salmonidae and/or other missing groups, either through additional toxicity tests or by including additional available data.
Further Evaluation This approach helps to prioritize wetland types and criteria for further evaluation. It was concluded that zinc, chromium(VI), and parathion criteria require nomodification with regard to cofactor effects. PCBs, PCP, and cyanide, however, should beevaluated further in regard to the effects of high temperatures and low DOontoxicity, for both wetland types. The absence of salmonids maybemost important for parathion and chromium(VI) in both wetland types. Further consideration should begiven to the need for additional tests with chordates from prairie pothole wetlands for cyanide, zinc, chromium(VI) and PCBs, although there is noevidence to suggest that the absence of representative wetland chordates from the test species will result in underprotective criteria. This type of evaluation, done for anumber of wetland types and criteria, can be combined with information onthe types of pollutants that threaten particular wetland types. In this way wetland types requiring additional evaluation and perhaps eventually some additional toxicity testing for particular pollutants can be prioritized based onadequacy of existing criteria, potential threats to the system, and resources available for testing. These examples illustrate the need for wetland scientists to work closely with criteria experts. Expert judgement is needed to evaluate the significance of the gaps in the available data.

25SECTION 6 CONCLUSIONS

The efficient use of limited resources dictates that criteria and standards for wetlands bedeveloped by making good use of the wealth of data that has been accumulated for other surface waters. This report focused onthe application of numeric aquatic life criteria to wetlands. The numeric aquatic life criteria are designed to protect aquatic life and their uses. The criteria are conservative, and for most wetland types are probably protective or overprotective.
Asimple, inexpensive evaluation technique has been proposed in this document for detecting wetland types that might be underprotected for some chemicals by existing criteria. The approach relies on information contained in criteria documents, data regarding species composition and water quality characteristics for the wetland types of interest, and consultation with experts. It is intended to be used asa screening tool for prioritizing those wetland types that require additional evaluations and research. Twotests of the approach demonstrated that it can beused to identify cases in which criteria might be underprotective, but further evaluation and close coordination among regulatory agencies, wetland scientists, and criteria experts are needed to determine when actual modifications to the criteria are necessary. Site-specific guidelines for modifying the numeric criteria should beappropriate for use onwetlands in cases where additional evaluations reveal that modifications are needed. The approach described in this document can beused to compile lists of the most commonly under-represented species and the most frequently encountered chemicals. Aquatic toxicity tests can then beconducted which would apply to anumber of wetland types. Information obtained with this approach can beused to prioritize further evaluations and research, identify gaps in data, and make further testing more efficient, but has some limitations. It does not adequately address the importance of plants in wetland systems and applies only to the aquatic component of wetlands. It relies onspecies assemblage and water

26quality data that are not available for somewetland types. For

these reasons, ameeting of wetland scientists and criteria experts is recommended to discuss the need for this type of evaluation, the utility of this approach, and possible alternative approaches. The application of numeric criteria to wetlands is just one part of alarge effort to develop wetland standards and criteria. The development of biocriteria, sediment criteria, and wildlife criteria will help to ensure that all components of the wetland resource are adequately protected.

27REFERENCES

1.

2.

3.
4.

5.

6.

7.

8.

9.

10. U.S. Fish and Wildlife Service. 1984. AnOverview of Major Wetland Functions and Values. Tiner, R.W., Jr. 1984. Wetlands of the United States: Current Status and Recent Trends. U.S. Fish and Wildlife Service. U.S. EPA, Office of Water. 1989. The Water Planet. The Conservation Foundation. 1988. Protecting America's Wetlands: AnAction Agenda: The Final Report of the National Wetlands Policy Forum. U.S. EPA, Office of Water Regulations and Standards, Office of Wetlands Protection. 1989. Survey of State Water Quality Standards for Wetlands. Internal report. U.S. EPA, Office of Water Regulations and Standards, Office of Wetlands Protection. In Review. Draft National Guidance: Water Quality Standards for Wetlands. Adamus, P.R., K. Brandt, and M. Brown. 1990. Use of Biological Community Measurements for Determining Ecological Condition of, and Criteria for, Inland Wetlands of the United States -ASurvey of Techniques, Indicators, Locations, and Applications. U.S. EPA, Corvallis, Oregon. U.S. EPA, Office of Water Regulations and Standards. 1986. Quality Criteria for Water. EPA-440/5-86-001. U.S. EPA, Washington, D.C. Stephan, C.E., D.I. Mount, D.J. Hansen, J.H. Gentile, G.A. Chapman, and W.A. Brungs. 1985. Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses. PB85-227049. National Technical Information Service, Springfield, Virginia. U.S. EPA, Office of Water. 1985. Technical Support Document for Water Quality-based Toxics Control. EPA-440/4- 85-032.

2811.

12.

13.

14.

15.

16.

17.

18.

19.

20. Carlson, A.R., W.A. Brungs, G.A. Chapman, and D.J. Hansen. 1984. Guidelines for Deriving Numerical Aquatic SiteSpecific Water Quality Criteria by Modifying National Criteria. EPA-600/3-84-099. U.S. EPA, Duluth, Minnesota. Mitsch, W.J. and J.G. Gosselink. 1986. Wetlands. New York: Van Nostrand Reinhold. Phillip, K. 1989. Review of Regulated Substances and Potential Cofactors in Wetland Environments. Draft internal report submitted to U.S. EPA. Shaw, S.P., and C.G. Fredine. 1956. Wetlands of the United States, Their Extent, and Their Value for Waterfowl and Other Wildlife. U.S. Fish and Wildlife Service, Circular 39. Washington, D.C., 67p. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. FWS/OBS-79/31. U.S. Fish and Wildlife Service. Hansen, D.J., J. Cardin, L.R. Goodman, and G.M. Cripe. 1985. Applicability of Site-Specific Water Quality Criteria Obtained Using the Resident Species Recalculation Option. Internal report, U.S. EPA, Narragansett, Rhode Island and Gulf Breeze, Florida. American Society for Testing Materials. 1988. Standard Guide for Conducting Acute Toxicity Tests with Fishes, Macroinvertebrates, and Amphibians. Standard E729-88a, ASTM, Philadelphia, Pennsylvania. Detenbeck, N.E. 1990. Effects of Disturbance onWaterQuality Functions of Wetlands: Interim Progress Report: January 1990. Natural Resources Research Institute. Internal report submitted to U.S. EPA, Duluth, Minnesota. Swanson, G.A., T.C. Winter, V.A. Adomaitis, and J.W. LaBaugh. 1988. Chemical Characteristics of Prairie Lakes in South-central North Dakota -Their Potential for Influencing Use by Fish anWildlife. U.S. Fish and wildlife Service Technical Report 18. Kantrud, H.A., G.L. Krapu, and G.A. Swanson. 1989. Prairie Basin Wetlands of the Dakotas: ACommunity Profile. U.S. Fish and Wildlife Service Biological Report 85(7.28).

2921. Stewart, R.E., and H.A. Kantrud. 1971. Classification of

Natural Ponds and Lakes in the Glaciated Prairie Region. U.S. Fish and Wildlife Service Resource Publication 92. 57p.
22. LaBaugh, J.W. 1989. Chemical Characteristics of Water in Northern Prairie Wetlands. Pages 56-90In A.G. van der Valk, ed., Northern Prairie Wetlands. Iowa State University Press.

30APPENDIX A SOURCESUSEDINSPECIES HABITAT IDENTIFICATION

FORMINNESOTA MARSHES

Fishes:Eddy, S., and J.C. Underhill. 1974. Northern Fishes. 3rd edition. University of Minnesota, Minneapolis. Nelson, J.S. 1984. Fishes of the World. 2nd edition. New York: John Wiley and Sons. Niering, W.A. 1987. Wetlands. NewYork: Alfred A. Knopf. Personal Communications: P. DeVore and C. Richards of the Natural Resources Research Institute, Duluth, Minnesota. G. Montz, Minnesota Dept. of Natural Resources. Macroinvertebrates: Nierinq, W.A. 1987. Wetlands. NewYork: Alfred A. Knopf. Pennak, R.W. 1978. Fresh-water Invertebrates of the United States. 2nd edition. NewYork: John Wiley and Sons. Williams, W.D. 1976. Freshwater Isopods (Asellidae) of North America. U.S. EPA, Cincinnati. Personal Communications: P. DeVore and A. Hershey of the Natural Resources Research Institute, Duluth, Minnesota. P. Mickelson of the University of Minnesota, Duluth.

31APPENDIX B SOURCESUSEDINSPECIES HABITAT IDENTIFICATION

FORPRAIRIE POTHOLES

Fishes:Kantrud, H.A., G.L. Krapu, and G.A. Swanson. 1989. Prairie Basin Wetlands of the Dakotas: ACommunity Profile. U.S. Fish and Wildlife Service Biological Report 85(7.28). Swanson, G.A., T.C. Winter, V.A. Adomaitis, and J.W. LaBaugh. 1988. Chemical Characteristics of Prairie Lakes in South-central North Dakota -Their Potential for Influencing Use by Fish anWildlife. U.S. Fish and Wildlife Service Technical Report 18. Macroinvertebrates: Broschart, M.R. and R.L Linder. 1986. Aquatic invertebrates in level ditches and adjacent emergent marsh in aSouth Dakota wetland. Prairie Nat. 18(3):167-178. Eddy, S. and A.C. Hodson. 1961. Taxonomic Keys to the CommonAnimals of the Northcentral States. Minneapolis: Burgess Publishing Co. Krapu, G.L. 1974. Feeding ecology of pintail hens during reproduction. The Auk 91:278-290. Pennak, R.W. 1978. Fresh-water Invertebrates of the United States. 2nd edition. NewYork: John Wiley and Sons. Swanson, G.A. 1984. Invertebrates consumed bydabbling ducks (Anatinae) onthe breeding grounds. Journal of the Minnesota Academy of Science 50:37-45.

van der Valk, A., ed. 1989. Northern Prairie Marshes. Ames: Iowa State University Press.

32TABLE 1. FRESHWATERNUMERICAQUATIC LIFE CRITERIA*

Chemical H, T, or pH**

Dependent Chemical H, T, or pH** Dependent Organochlorines: Aldrin Chlordane DDT Dieldrin Endosulfan Endrin Heptachlor Lindane PCBs Pentachlorophenol Organophosphates: Chlorpyrifos Parathion PH Metals: Aluminum Arsenic(III) Cadmium Chromium(III) Chromium(VI) Copper Lead Mercury Nickel Selenium Silver Zinc Others: Ammonia Chloride Chlorine Cyanide Dissolved oxygen H H H H H
H H

PH, T

T * Summarized from individual criteria documents. Chemicals that have adjustment factors built into the criteria are indicated. ** H= Hardness, T=Temperature.

33

### TABLE2. SUITABILITY OFWETLANDSPECIESTOFILL MINIHUHFAMILY REQUIREMENTSFORSIXCRITERIONCHEMICALS Required Taxonomic Group Para- ChromPCBs thion PCP Cyanide Zinc ium(VI)

Salmonid NP* NP NP NP NP NP Other Fish Y.. Y Y Y Y Y Other Chordate Y Y Y Y Y Y Planktonic Crustacean Y Y Y Y Y Y Benthic Crustacean Y Y Y Y Y Y Insect Y Y Y Y Y YNonarthropodNonchordate NT*** Y Y Y Y Y Another Insect Y Y Y NT Y Y orNewPhylum
l

### NP Notpresent: Taxonomic group not present in mostwetland types. **y Wetland genera represented adequately. ***NT Nottested: Available toxicity data does not include sufficient wetland species.

34

### TABLE3. SOMECONDITIONSRECOMMENDED FORDILUTION 

### WATER FORWATERQUALITYCRITERIA TESTING" Characteristic Freshwater Saltwater Total organic carbon <5mg/L ~20mg/L' Particulate matter <5mq/L ~20mg/L' PH 6.5-9.0 Stenohaline 8.0 Euryhaline 7.7 Range~0.2

Hardness (mg/L asCaC03) Salinity Soft water 40-48 Range~5mg/Lb Stenohaline 34g/kg Euryhaline 17q/W Range~2g/kg' Dissolved oxygen 60-100% saturationd 60-100% saturationd
Temperature +/- 5OCof water' oforigin '~5mg/L for tests other than saltwater bivalve molluscs. bOr10%of average, whichever is higher. 'Or20%of average, whichever is higher. dFor flow-through tests (40-100% for static tests).

l

### For invertebrates only.

35

### TABLB4. BrrBCTB or cformrom3 OHCRITBRIOM CEBMICAL

### TOXICITY

Corwroast 

### Bffoat of Qreator 

### Value PH Tot TIJRBTRWDO l? IONICB BKJTR/ORQ 

### Organoahlorines: Aldrin Chlordane DDT Dieldrin Endrin Heptachlor Lindane Endosulfan PCBs Pentachlorophenol Toxaphene + + +



### 0

+ + - + - + 

### Organophoaphatos: Parathion Chlorpyrifos 

### not81#: Arsenic (III) ium L. nium(VI) ,mium (III) Copper Lead Mercury Nickel Selenium Silver Zinc Aluminum + + 7 0

+

+ - +

+


### Other: Chlorine Cyanide Ammonia Chloride Do 0

+ 

### 0

-? 3 0

0 + - - + - +?

+: 

### increased toxicity/mobility ?: tested andfound inconclusive 0: noeffect ontoxicity/mobility : not discussed incriteria document -t decreased toxicity/mobility +: short-term increase/long-term 

### decrease TOC:total organic carbon DO:dissolved oxygen H:hardness TURB:turbidity NUTR/ORG:nutrients/organic acids m*ionic strength/cations -. S:salinity

36

### TABLE5. WATERCHEMISTRYFORSELECTEDMINNESOTAMARSHES.

Water Quality Characteristic MeanValue Comparison with Standard Testing Range Conditions pH(pHunits) Total organic carbon (mg/L) Dissolved oxygen (w/L) Hardness (mg/L asCaCO,) Alkalinity (mg/L asCaCO,) Temperature ("C) Turbidity (NTU) 7.1

20

8.2 Nodata 6.1 -7.6 Within range

5-60 High

0.4 -15.4 Seasonally low

8 4-14

11.9 0.3 -31.0 Seasonal extremes 33 1-412

l 

### Data taken from Detenbeck (1990), n=42wetlands.18

37

### TABLE6. COMPARISONOFTESTSPECIESWITH MINNESOTAMARSHBIOTAFORSIXCRITERIA Required Taxonomic Group PCBs Parathion PCP

Salmonid Npd NP NP Other Fish' Micropterus Lepomis Micropterus Other Chordate Pimephales Pimephales Rana Planktonic Crustacean Daphnia Daphnia Daphnia Benthic Crustacean unknown

amphipod Orconectes Orconectes Insect Ishnurab Chironomus Tanytarsus Nonarthropod- unknownC unknow+ Nonchordate NTe nematodes/ nematodes/ annelids annelids Another unknown Insect Tanytarsus Ishnura amphipod/ orNewPhylum isopod Aquatic Plant NT alga Lemna continued

38

### TABLE6, CONTINUED

Required Taxonomic Group Cyanide Zinc Chromium(V1)

Salmonid NP Other Fish' Perca Other Chordate Lepomis Planktonic Crustacean Daphnia Benthic Crustacean unknownC

amphipod/ isopod Insect TanytarsusNonarthropodNonchordate Physa Another Insect orNewPhylum NT
Aquatic Plant Lemna NP Lepomis
Pimephales
Daphnia unknownc amphipod/ isopod Argiab
Physa unknownC annelid/ nematode

Lemna NP

Lepomis
Pimephales
Daphnia

Orconectes

Chironomus
Physa

NT

alga

a Fish were sampled inwater bodies associated with someof the wetlands, not inthe wetlands themselves. b Probable orseenasanadult. C 

### Unknown species from these taxa found inwetlands. May 

### or maynot besimilar interms of habitat requirements, etc. to species used intoxicity tests. d Not present: Taxonomic group not present inwetland type. e Nottested: Available toxicity data does not include sufficient wetland species.

39

### TABLE7. NUMBER OFSPECIESTESTEDFORACUTE

### CRITERIAAND PERCENTAGE

OF

### TESTSPECIESTHATARENOTFOUNDIN 

### MINNESOTAMARSHES

OROLIGOSALINEPRAIRIEPOTHOLES* Species Usedto Not Present Not

### Present in Chemical Establish FAV" 

### inMarshes Prairie Potholes

(Total Number) (Per cent) (Per cent) PCBs 10 30% 40% Parathion 37 43% 64% PCP 37 22% 43% Cyanide 17 29% 65% Zinc 45 45% 67% Chromium(V1) 33 27% 64*
t 

### Remainder of percentage includes both those 

### species that are knownto occur inthese wetlands andthose species 

### that may 

### occur inthe wetlands, but insufficient 

### dataareavailable.
l+ 

### Final Acute Value.

40

### TABLE8. WATER QUALITY CHARACTERISTICS FOR 

### OLIGOSALINEPRAIRIEPOTHOLES'

Water Quality Characteristic 

### MeanValue Comparison with Standard Testing Range Conditions pH(pHunits) 8.9 7.4 -10.3b High Total organic 

### carbon (mg/L) Nodata' Dissolved oxygen (wm) No

### datad Hardness Nodata' (mg/LasCaC03) Alkalinity (mg/L 

### asCaCO,) 650 230-1300 High
Temperature ("C) Nodata‘ Specific conductance 3568 750-8000 (bS/cm at 25'C)

;: Data summarized from Swansonetal. (1988)." N=27wetlands. C 

### Dissolved organic carbon 

### data for Manitoba 

### prairie potholes ranged from 0.4-102 mg/L, 

### andfor 

### Nebraska, from 20-60 mg/L inonestudy and 139-440 mg/L inanother study.22 d Winterkill, caused bylow

### dissolved oxygen under ice, occurs inmanyof these lakes. e Anestimate of hardness based onalkalinity values gives a meanof 760mg/L

### asCaCO. f Region is characterized byvery cold winters andwarm summers.

41TABLE 9. COMPARISONOFTESTSPECIES WITH PRAIRIE 

### POTHOLEBIOTAFORSIXCRITERIA Required Taxonomic Group PCBs Parathion PCP

Salmonid NP NP NP Other Fish Pimephales Pimephales Pimephales Other Chordate NT Pseudacris' Rana' Planktonic Crustacean Daphnia Daphnia Daphnia Benthic Crustacean Gammarus' Gammarud 

### Hyalella Insect damselflyb Peltodytes Tanytarsusb Nonarthropod- tubificid tubificid Nonchordate NT WOrmb WOrmb Another Insect Tanytarsusb Chironomus Physa orNewPhylum Aquatic Plant NT Microcystis Lemna

42

### TABLE9, CONTINUED



### Required Taxonomic Group Cyanide Zinc Chromium(V1)
Salmonid Other Fish Other Chordate Planktonic Crustacean Benthic Crustacean Insect

### NonarthropodNonchordate Another Insect orNewPhylum 

### Aquatic Plant NP

Pimephales NP Pimephales


### NT NT 

### Daphnia
Gammarus' Tanytarsusb 

### Physa'

NT

Lemna Daphnia

Gammartd Argiab
Physa'


### tubificid wormb

Lemma NP



### Pimephales

NT Daphnia Hyalella Chironomus' Physa' damselflyb

Nitzschia

;: Genus is present inthe

### wetlands; maynotbesamespecies. Species representative of

### that taxonomic group from 

### criteria testing lists probably present 

### inprairie potholes, but no actual 

### data available.

43