WERF Research Report
5 total works
Evaluation of WET Testing as an Indicator of Aquatic Health in Effluent-Dominated Streams
by Jerome M. Diamond
Published 1 January 2007
This project evaluated the quality of data needed to determine relationships between chronic Whole Effluent Toxicity (WET) test results and in-stream biological condition. A data quality objectives approach was used, which included several proposed measurement quality objectives (MQOs) that specified desired precision, bias, and sensitivity of methods used. Six facilities (four eastern and two western U.S.) participated in this study, all having design effluent concentrations > 60% of the stream flow. In accordance with a Quality Assurance Project Plan most of the facilities completed four quarters of chronic Ceriodaphnia dubia, and Pimephales promelas (fathead minnow) WET tests, and three quarters of Selenastrum capricornutum (green algae) WET testing following the most recent USEPA methods. Several other WET tests were conducted to address MQOs including splits, duplicates, and blind positive and negative controls. Macroinvertebrate, fish, and periphyton bioassessments were conducted at multiple locations up and downstream of each facility following the most recent USEPA Office of Water bioassessment protocols.
Test acceptance criteria were met for most WET tests, however, this study demonstrated the need to incorporate other MQOs in a full study (such as minimum and maximum percent significant differences and performance on blind samples) to ensure accurate interpretation of effluent toxicity. More false positives, lower test endpoint (i.e., higher toxicity), and more "failed" (non-compliant) tests were observed using No Observed Effect Concentrations (NOEC) as compared to IC25s (concentration causing >= 25% decrease in organism response compared to controls). Algae tests often yielded the most effluent toxicity in this study, however, this test was most susceptible to false positives and high inter-laboratory variability. WET test results exhibited few relationships with bioassessment results, even when incorporating actual effluent dilution. Neither frequency of WET non-compliance nor magnitude of WET were clearly related to differences in biological condition up and downstream of a discharge for the most part. Macroinvertebrate assessments were most able to discriminate small changes downstream of the effluent, followed by periphyton and then fish. The sampling methods used were robust but a full study should collect more field replicates up and downstream of each discharge to increase detection power. Macroinvertebrate and periphyton assessments together appeared to be sufficient to address project objectives. Fish assessments could be useful as well but would entail more effort and cost per site than expended in this project, to be useful.
Test acceptance criteria were met for most WET tests, however, this study demonstrated the need to incorporate other MQOs in a full study (such as minimum and maximum percent significant differences and performance on blind samples) to ensure accurate interpretation of effluent toxicity. More false positives, lower test endpoint (i.e., higher toxicity), and more "failed" (non-compliant) tests were observed using No Observed Effect Concentrations (NOEC) as compared to IC25s (concentration causing >= 25% decrease in organism response compared to controls). Algae tests often yielded the most effluent toxicity in this study, however, this test was most susceptible to false positives and high inter-laboratory variability. WET test results exhibited few relationships with bioassessment results, even when incorporating actual effluent dilution. Neither frequency of WET non-compliance nor magnitude of WET were clearly related to differences in biological condition up and downstream of a discharge for the most part. Macroinvertebrate assessments were most able to discriminate small changes downstream of the effluent, followed by periphyton and then fish. The sampling methods used were robust but a full study should collect more field replicates up and downstream of each discharge to increase detection power. Macroinvertebrate and periphyton assessments together appeared to be sufficient to address project objectives. Fish assessments could be useful as well but would entail more effort and cost per site than expended in this project, to be useful.
Diagnostic Tools to Evaluate Impacts of Trace Organic Compounds
by Jerome M. Diamond
Published 29 June 2011
With the recent advent of improved analytical and biomarker detection capabilities, a variety of organic chemicals have been found in trace amounts (Trace Organic Chemicals, TOrCs) in surface waters and fish tissue. TOrCs include pharmaceuticals, personal care products, surfactants, pesticides, flame retardants, and other organic chemicals, some with unknown modes of action or effects. Identifying or predicting ecological effects of TOrCs in typical aquatic multi-stressor situations is challenging, requiring a variety of epidemiological tools that together, can diagnose effects at multiple scales of ecological organization.
Five objectives were addressed in this research: (1) develop and apply a procedure to prioritize which TOrCs are of most concern; (2) develop and test a conceptual site screening framework; (3) evaluate and test diagnostic approaches to identify potential risks due to TOrCs using various case studies; (4) develop a relational database and user interface with which the water resource community can enter, store, and search TOrC exposure data in the U.S.; and (5) foster partnerships and transfer knowledge gained in this research to the water quality community. TOrC fate, effects, and occurrence data were compiled in a database for over 500 organic chemicals based on over 100 published studies representing more than 50 organizations and 700 sites. Alternative risk-based prioritization processes and draft lists of high priority TOrCs were developed. A preliminary site screening and diagnostic framework was developed and evaluated using seven different case study sites. EPA's causal analysis (stressor identification) procedures, Canada's Environmental Effects Monitoring (EEM) procedure, the ecosystem model CASM (Comprehensive Aquatic System Model), and several other specialized diagnostic tools were used and evaluated. A relational database based on Tetra Tech's EDAS2 was developed using the Microsoft platform. The modified version of EDAS2, built on the EPA WQX data model, provides web-based data queries using a combination of tabular data for downloads and a visual map interface that allows the user to view, query, and select sites from the map having chemical or biological data. The database is not discussed in this report but can be accessed through WERF.
This Final Report summarizes all other approaches used and results obtained in this research, discusses critical data gaps and other important uncertainties, and provides testable hypotheses and recommendations for Phase 2 testing and analyses.
Five objectives were addressed in this research: (1) develop and apply a procedure to prioritize which TOrCs are of most concern; (2) develop and test a conceptual site screening framework; (3) evaluate and test diagnostic approaches to identify potential risks due to TOrCs using various case studies; (4) develop a relational database and user interface with which the water resource community can enter, store, and search TOrC exposure data in the U.S.; and (5) foster partnerships and transfer knowledge gained in this research to the water quality community. TOrC fate, effects, and occurrence data were compiled in a database for over 500 organic chemicals based on over 100 published studies representing more than 50 organizations and 700 sites. Alternative risk-based prioritization processes and draft lists of high priority TOrCs were developed. A preliminary site screening and diagnostic framework was developed and evaluated using seven different case study sites. EPA's causal analysis (stressor identification) procedures, Canada's Environmental Effects Monitoring (EEM) procedure, the ecosystem model CASM (Comprehensive Aquatic System Model), and several other specialized diagnostic tools were used and evaluated. A relational database based on Tetra Tech's EDAS2 was developed using the Microsoft platform. The modified version of EDAS2, built on the EPA WQX data model, provides web-based data queries using a combination of tabular data for downloads and a visual map interface that allows the user to view, query, and select sites from the map having chemical or biological data. The database is not discussed in this report but can be accessed through WERF.
This Final Report summarizes all other approaches used and results obtained in this research, discusses critical data gaps and other important uncertainties, and provides testable hypotheses and recommendations for Phase 2 testing and analyses.
Testing Diagnostic Tools for Trace Organic Compounds and Multiple Stressors
by Jerome M. Diamond
Published 15 December 2010
Available as an eBook only.
The screening Trace Organic Chemical (TOrC) ecological risk approach, developed previously, was evaluated using seven case studies, located in Pennsylvania, Ohio, Colorado, California, and Ontario, Canada. Sites represented a range of complexity, types of biological impacts, and wastewater effluent dilution at low flow. Several different techniques for diagnosing potential effects of TOrCs were incorporated in these case studies including EPA's causal analysis framework, CADDIS; Canada's Environmental Effects Monitoring (EEM) approach; the consumer products ROUT model and the pharmaceutical model PhATE to predict concentrations of certain TOrCs at a wastewater-influenced site; and ecological modeling (Comprehensive Aquatic Systems Model, CASM).
Both prospective and retrospective assessments are represented in these case studies illustrating how various tools can be used to determine whether TOrCs are or could be a cause of biological impairment. At most sites, high priority TOrC data (using any of the TOrC prioritization approaches previously developed in this project) were unavailable. At five of the seven sites, the screening approach indicated a potential for risk due to TOrCs based on the type of wastewater treatment available (secondary treatment with little or no nutrient removal, potential input sources of TOrCs present in addition to domestic sources) and the relatively high effluent concentration under low flow conditions. Except for two sites, data were unavailable for at least one level of biological organization making it difficult to evaluate TOrCs as a cause of impairment.
The lack of diagnostic TOrC exposure data (i.e., suborganismal or organismal measures indicative of exposure to a certain class of TOrCs), or organism effects data (e.g., intersex, lesions) at most sites restricted our ability to diagnose whether certain TOrCs could have contributed to observed biological impairment at these sites. Our analyses confirm that the comprehensiveness and sensitivity of the population/ community assessment is a critical factor affecting the success of diagnostic analyses. Indices of biological integrity (IBI) and most metrics that constitute such indices, offered little definitive diagnostic information regarding risks due to TOrCs, but were useful in supporting or eliminating other types of stressors such as excess nutrients and habitat quality. None of the case studies examined had sufficient TOrC data with which to demonstrate linkages between concentrations of specific TOrCs or groups of TOrCs and organism effects.
However, results from two sites suggested that TOrC concentrations exceeding conservative screening threshold values may not result in observed effects at either the organism or population level based on the endpoints measured. While some of the case studies demonstrated apparent linkages between exposure to estrogenic chemicals and organism effects, none had sufficient information to definitively link organism and population/community level effects. Defining the conditions under which organism TOrC effects are likely to manifest as a population-level effect at a site should be a critical component of Phase 2.
The screening Trace Organic Chemical (TOrC) ecological risk approach, developed previously, was evaluated using seven case studies, located in Pennsylvania, Ohio, Colorado, California, and Ontario, Canada. Sites represented a range of complexity, types of biological impacts, and wastewater effluent dilution at low flow. Several different techniques for diagnosing potential effects of TOrCs were incorporated in these case studies including EPA's causal analysis framework, CADDIS; Canada's Environmental Effects Monitoring (EEM) approach; the consumer products ROUT model and the pharmaceutical model PhATE to predict concentrations of certain TOrCs at a wastewater-influenced site; and ecological modeling (Comprehensive Aquatic Systems Model, CASM).
Both prospective and retrospective assessments are represented in these case studies illustrating how various tools can be used to determine whether TOrCs are or could be a cause of biological impairment. At most sites, high priority TOrC data (using any of the TOrC prioritization approaches previously developed in this project) were unavailable. At five of the seven sites, the screening approach indicated a potential for risk due to TOrCs based on the type of wastewater treatment available (secondary treatment with little or no nutrient removal, potential input sources of TOrCs present in addition to domestic sources) and the relatively high effluent concentration under low flow conditions. Except for two sites, data were unavailable for at least one level of biological organization making it difficult to evaluate TOrCs as a cause of impairment.
The lack of diagnostic TOrC exposure data (i.e., suborganismal or organismal measures indicative of exposure to a certain class of TOrCs), or organism effects data (e.g., intersex, lesions) at most sites restricted our ability to diagnose whether certain TOrCs could have contributed to observed biological impairment at these sites. Our analyses confirm that the comprehensiveness and sensitivity of the population/ community assessment is a critical factor affecting the success of diagnostic analyses. Indices of biological integrity (IBI) and most metrics that constitute such indices, offered little definitive diagnostic information regarding risks due to TOrCs, but were useful in supporting or eliminating other types of stressors such as excess nutrients and habitat quality. None of the case studies examined had sufficient TOrC data with which to demonstrate linkages between concentrations of specific TOrCs or groups of TOrCs and organism effects.
However, results from two sites suggested that TOrC concentrations exceeding conservative screening threshold values may not result in observed effects at either the organism or population level based on the endpoints measured. While some of the case studies demonstrated apparent linkages between exposure to estrogenic chemicals and organism effects, none had sufficient information to definitively link organism and population/community level effects. Defining the conditions under which organism TOrC effects are likely to manifest as a population-level effect at a site should be a critical component of Phase 2.
Development of Diagnostic Tools for Trace Organic Compounds and Multiple Stressors
by Jerome M. Diamond
Published 15 December 2010
Available as an eBook only.
This WERF sponsored research presents a preliminary screening process and ecological diagnostic approaches that could be used to help prioritize and evaluate treated wastewater-influenced sites that may be most at risk from trace organic chemical (TOrC) exposure. This work builds on the TOrC prioritization research completed earlier in this research and demonstrates how current diagnostic approaches used in the U.S. (CADDIS) and Canada (Environmental Effects Monitoring) could be extended to evaluate potential risks due to TOrCs.
The screening process uses indicators in four categories: (1) wastewater influent and population served, (2) wastewater treatment characteristics, (3) ecological characteristics of the site, and (4) exposure or effects information from the site if available. The indicators included in the screening process are hypotheses, to be tested further using case studies in this research, and should not be taken as validated measures to be used to infer TOrC issues at a site.
The diagnostic approach described in this research could be applied prospectively (could ecological effects due to TOrCs occur at my site?) and retrospectively (I have observed ecological effects at my site; are TOrCs a contributing cause?). However, given our current lack of knowledge concerning modes of action for many TOrCs, as well as the factors that determine whether TOrC effects on individuals are translated to community-level ecological effects, the diagnostic approach in this research focuses on retrospective applications at this time. The screening process has been used with some modification for sites in the Ohio Erie Drift Plain ecoregion and some of these, as well as other sites, will be evaluated using diagnostic approaches in Task 3 (case studies) of this research.
A web-based database application (http://werf2.tetratech-ffx.com/) has been developed for this project to help end users eventually search and evaluate TOrC data collected by many organizations in the U.S. and to assist in screening and diagnosing risks due to TOrCs. Comments are welcome on the various search features and metadata available for TOrCs within the current database.
This WERF sponsored research presents a preliminary screening process and ecological diagnostic approaches that could be used to help prioritize and evaluate treated wastewater-influenced sites that may be most at risk from trace organic chemical (TOrC) exposure. This work builds on the TOrC prioritization research completed earlier in this research and demonstrates how current diagnostic approaches used in the U.S. (CADDIS) and Canada (Environmental Effects Monitoring) could be extended to evaluate potential risks due to TOrCs.
The screening process uses indicators in four categories: (1) wastewater influent and population served, (2) wastewater treatment characteristics, (3) ecological characteristics of the site, and (4) exposure or effects information from the site if available. The indicators included in the screening process are hypotheses, to be tested further using case studies in this research, and should not be taken as validated measures to be used to infer TOrC issues at a site.
The diagnostic approach described in this research could be applied prospectively (could ecological effects due to TOrCs occur at my site?) and retrospectively (I have observed ecological effects at my site; are TOrCs a contributing cause?). However, given our current lack of knowledge concerning modes of action for many TOrCs, as well as the factors that determine whether TOrC effects on individuals are translated to community-level ecological effects, the diagnostic approach in this research focuses on retrospective applications at this time. The screening process has been used with some modification for sites in the Ohio Erie Drift Plain ecoregion and some of these, as well as other sites, will be evaluated using diagnostic approaches in Task 3 (case studies) of this research.
A web-based database application (http://werf2.tetratech-ffx.com/) has been developed for this project to help end users eventually search and evaluate TOrC data collected by many organizations in the U.S. and to assist in screening and diagnosing risks due to TOrCs. Comments are welcome on the various search features and metadata available for TOrCs within the current database.
Diagnostic Tools to Evaluate Impacts of Trace Organic Compounds (Prioritization Framework for TOrCs)
by Jerome M. Diamond
Published 15 December 2010
Available as an eBook only.
With the advent of improved analytical detection capabilities, a variety of organic chemicals have been found in trace amounts (Trace Organic Chemicals, TOrCs) in surface waters, sediment, and fish tissue. These TOrCs include pharmaceuticals, personal care products, surfactants, and other currently unregulated chemicals.
This WERF sponsored research presents a preliminary screening process and ecological diagnostic approaches that could be used to help prioritize and evaluate treated wastewater-influenced sites that may be most at risk from trace organic chemical (TOrC) exposure. Identifying or predicting ecological effects of TOrCs in typical aquatic systems is challenging, requiring a variety of tools that can diagnose effects at multiple scales of ecological organization. Development of a prioritization process is the goal of Task 1 of this research and the focus of this report.
This research developed three approaches to prioritize TOrCs: 1) risk-based, 2) chemical persistence, bioaccumulation potential, and toxicity (PBT), and 3) a hybrid based on risk, persistence, and bioaccumulation potential. Using an occurrence database compiled from over 100 monitoring studies, the three prioritization approaches were applied to over 500 TOrCs that have been detected in water or effluent samples in the U.S. over the past 10 years. Types of TOrCs identified as high priority differed among approaches: steroids/hormones, pharmaceuticals, and surfactants comprised most of the high priority TOrCs based on risk while pesticides, industrial chemicals, and PAHs comprised most of the high priority TOrCs based on a PBT approach. Except for the synthetic hormones and steroids, results of all three prioritization approaches yielded only a few pharmaceuticals of high priority. Using a risk-based prioritization approach, predicted chronic toxicity endpoints were more sensitive than endpoints based on estrogenic activity for most TOrCs.
The prioritization list(s) resulting from this work is not necessarily intended to be viewed as a list of compounds to be monitored or for which water quality criteria should be developed. The process of developing the list(s) is as important as the list(s) itself and the appropriate use of any resulting list(s) will depend largely on the goals of the user.
With the advent of improved analytical detection capabilities, a variety of organic chemicals have been found in trace amounts (Trace Organic Chemicals, TOrCs) in surface waters, sediment, and fish tissue. These TOrCs include pharmaceuticals, personal care products, surfactants, and other currently unregulated chemicals.
This WERF sponsored research presents a preliminary screening process and ecological diagnostic approaches that could be used to help prioritize and evaluate treated wastewater-influenced sites that may be most at risk from trace organic chemical (TOrC) exposure. Identifying or predicting ecological effects of TOrCs in typical aquatic systems is challenging, requiring a variety of tools that can diagnose effects at multiple scales of ecological organization. Development of a prioritization process is the goal of Task 1 of this research and the focus of this report.
This research developed three approaches to prioritize TOrCs: 1) risk-based, 2) chemical persistence, bioaccumulation potential, and toxicity (PBT), and 3) a hybrid based on risk, persistence, and bioaccumulation potential. Using an occurrence database compiled from over 100 monitoring studies, the three prioritization approaches were applied to over 500 TOrCs that have been detected in water or effluent samples in the U.S. over the past 10 years. Types of TOrCs identified as high priority differed among approaches: steroids/hormones, pharmaceuticals, and surfactants comprised most of the high priority TOrCs based on risk while pesticides, industrial chemicals, and PAHs comprised most of the high priority TOrCs based on a PBT approach. Except for the synthetic hormones and steroids, results of all three prioritization approaches yielded only a few pharmaceuticals of high priority. Using a risk-based prioritization approach, predicted chronic toxicity endpoints were more sensitive than endpoints based on estrogenic activity for most TOrCs.
The prioritization list(s) resulting from this work is not necessarily intended to be viewed as a list of compounds to be monitored or for which water quality criteria should be developed. The process of developing the list(s) is as important as the list(s) itself and the appropriate use of any resulting list(s) will depend largely on the goals of the user.