CMRN Home RTK or Left-To-Wonder? Recommended Reading
| Source: | Chapter Report, 02/17/94, GAO/PEMD-94-9 |
The Environmental Protection Agency (EPA) controls toxic pollutant discharges into waterways through seven "core" activities spread across several programs. GAO found that some of the information used to analytically support these activities may be of doubtful quality, raising questions about the effectiveness of these activities in controlling toxic pollutants. GAO also found that the current permit process does not limit the vast majority of toxics being discharged from the nation's factories and sewage treatment plants. Although most of these toxicants are "nonpriority" pollutants, they do pose risks to both human health and aquatic life. GAO tried to examine the implications of uncontrolled pollution cases identified in the facility sample population, but the majority of cases could not be evaluated because of a lack of criteria for assessing the health risks posed by the discharges. This is so for most toxicants discharged across the nation. --------------------------- Indexing Terms ----------------------------- REPORTNUM: PEMD-94-9 TITLE: Water Pollution: Poor Quality Assurance and Limited Pollutant Coverage Undermine EPA's Control of Toxic Substances DATE: 02/17/94 SUBJECT: Quality assurance Water pollution Water pollution control Wastewater management Toxic substances Environmental policies Monitoring Risk management Data bases Health hazards IDENTIFIER: Superfund Program EPA National Pollutant Discharge Elimination System EPA Permit Compliance System EPA Water Data Storage and Retrieval System EPA Toxics Release Inventory Program EPA Great Lakes Water Quality Initiative NPDES ************************************************************************** * This file contains an ASCII representation of the text of a GAO * * report. Delineations within the text indicating chapter titles, * * headings, and bullets are preserved. 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We are unable to accept electronic orders * * for printed documents at this time. * ************************************************************************** Cover ================================================================ COVER Report to the Chairman, Subcommittee on Superfund, Ocean, and Water Protection, Committee on Environment and Public Works, U.S. Senate February 1994 WATER POLLUTION - POOR QUALITY ASSURANCE AND LIMITED POLLUTANT COVERAGE UNDERMINE EPA'S CONTROL OF TOXIC SUBSTANCES GAO/PEMD-94-9 Water Pollution Abbreviations =============================================================== ABBREV ASTM - American Society of Testing and Materials BAT - Best available technology BOD - Biochemical oxygen demand EPA - Environmental Protection Agency GAO - General Accounting Office ICS - Individual control strategy NPDES - National Pollutant Discharge Elimination System PCS - Permit Compliance System POTW - Publicly owned treatment works QA/QC - Quality assurance/quality control STORET - STOrage and RETrieval TMDL - Total maximum daily load TRI - Toxic Release Inventory USGS - U.S. Geological Survey WET - Whole effluent toxicity Letter =============================================================== LETTER B-249852 February 17, 1994 The Honorable Frank R. Lautenberg Chairman, Subcommittee on Superfund, Ocean, and Water Protection Committee on the Environment and Public Works United States Senate Dear Mr. Chairman: In a January 6, 1992, letter, you asked us to evaluate the quality of the information EPA uses to control the discharge of toxic pollutants to surface water and the extent to which EPA controls these substances. This report presents our findings on these issues. In our evaluation, we identified the EPA activities that have a direct effect on controlling the release of toxics to surface water and the information requirements for these activities. We also evaluated the extent to which EPA takes steps to ensure that the information used to support these activities is of acceptable quality. In addition, we addressed the extent to which toxic pollutants are controlled through the NPDES permit process and examined the risk implications of discharged pollutants that are uncontrolled. If you have any questions or would like additional information, please call me at (202) 512-2900 or Kwai-Cheung Chan, Director of Program Evaluation in Physical Systems Areas, at (202) 512-3092. Other major contributors to this report are listed in appendix III. Sincerely yours, Eleanor Chelimsky Assistant Comptroller General EXECUTIVE SUMMARY ============================================================ Chapter 0 PURPOSE ---------------------------------------------------------- Chapter 0:1 Toxic pollutants threaten the biological integrity of the nation's water. State officials say that toxic pollutants affect the quality of more than 28,000 miles of the nation's rivers. Aquatic life has been affected and human health risk has increased. Contamination by toxic and conventional pollutants has resulted in fishing advisories or bans on more than 1,000 bodies of water. Pollutants discharged from the nation's factories and sewage treatment plants are a major cause of this water and fish contamination. To protect surface water from pollutants discharged from industrial facilities and sewage treatment plants, the Congress passed legislation in 1972 commonly referred to as the Clean Water Act. The Environmental Protection Agency (EPA) is responsible for setting national standards on the types and amounts of pollutants that industries and sewage treatment plants may discharge. EPA and the states enforce the standards by incorporating toxic limits on facilities' discharge permits. Many factors influence EPA's ability to implement programs authorized under the Clean Water Act. One critical variable is the quality of available information. EPA's program activities are analytical efforts, resulting in decisions about which toxic pollutants to control and at what levels. If its information is not of high quality, toxic pollutant control activities are weakened in consequence. The Chairman of the Subcommittee on Superfund, Ocean, and Water Protection of the Senate Committee on the Environment and Public Works asked GAO to evaluate the quality of the information EPA uses to control the discharge of toxics to surface water and the extent to which the EPA process controls toxic substances. GAO (1) identified EPA activities that directly affect the control of the toxic discharges and the information requirements of these activities, (2) determined EPA's steps to ensure that the information it uses to support these activities is of acceptable quality, (3) addressed the extent to which permits control toxic pollutants, and (4) examined the risk implications of uncontrolled discharged pollutants. BACKGROUND ---------------------------------------------------------- Chapter 0:2 For a number of years, EPA has been faced with reports by GAO and others that individual activities it administers to control toxic substances in surface water are producing information of suspect quality. Information about three specific types of entities--the environment, the facilities that discharge toxic pollutants, and the toxic substances themselves--is at the heart of any system for controlling toxics. Yet the quality of that information across EPA's approach as a whole has not been evaluated. To identify the critical activities that control the release of toxic substances into waterways, GAO submitted to EPA an extended list from the literature and agency documents. EPA identified activities that are directly related to controlling discharges of toxic substances into surface waters. A panel of experts reviewed and validated EPA's list. GAO then interviewed managers for each of the principal activities to identify information requirements as well as the principal sources of that information. Subsequently, GAO compiled data quality assurance criteria from the scientific literature and from EPA's quality assurance guidelines, assigning the relevant, critical quality assurance criteria to each information requirement for each EPA activity. (A criterion was considered critical if its absence, in and of itself, would compromise the quality of the information required by an activity.) GAO then reinterviewed managers and examined data to estimate the extent to which the relevant quality assurance criteria were followed in the design, collection, and analysis of the information. Finally, GAO obtained discharge permit files for 236 industrial facilities and compared a list of their toxic limits with information from three sources about the facilities' actual discharges. RESULTS IN BRIEF ---------------------------------------------------------- Chapter 0:3 EPA implements the control of toxic pollutant discharges into waterways through 7 "core" activities spread across a number of programs. GAO identified 13 types of information that are required to analytically support these 7 activities and found that 5 of the 7 fell short in implementing the quality assurance steps that are needed to produce accurate information. This raises questions not only about the quality of the information these 5 activities produced but also about their effectiveness within a strategy for controlling toxic pollutants. GAO also found that the current permit process does not limit the vast majority of toxics being discharged from the nation's facilities. Although most of these toxicants are "nonpriority" pollutants, they can and do pose human health and aquatic life risks (for example, ammonia and xylene). GAO attempted to examine the risk implications of uncontrolled pollution cases identified in the facility sample population, but the majority of cases could not be evaluated because the criteria were lacking by which to assess whether discharges posed a human health or aquatic life risk. This is so for most toxicants discharged across the nation. PRINCIPAL FINDINGS ---------------------------------------------------------- Chapter 0:4 "CORE" PROGRAMS AND THEIR CRITICAL INFORMATION REQUIREMENTS -------------------------------------------------------- Chapter 0:4.1 GAO initially identified 46 EPA water quality protection activities and then refined this list to the 7 that are directly related to the control of toxic pollutants. Taken together, these activities determine the toxic concentrations that are safe for human health and aquatic life, establish allowable discharge limits, identify impaired waterways, and monitor compliance infractions. Thirteen types of information are required to support these 7 core activities. (See figure 1.) Figure 1: Thirteen Types of Information A-M Required Within Activities 1-7 (See figure in printed edition.) ADHERENCE TO QUALITY ASSURANCE -------------------------------------------------------- Chapter 0:4.2 Two of the 7 activities (effluent guidelines development and water quality criteria development) have been exceptional in meeting quality assurance requirements, and confidence in the integrity of the information they have produced is thus relatively high. Collectively, these 2 activities have met approximately 93 percent of their related quality assurance requirements. However, the 5 other activities fell short of the criteria GAO used, meeting only 58 percent of their requirements. These activities (impaired water and point source identification, total maximum daily load development, water-quality-based permit issuance, local limits development, and compliance problem identification) are critical to the success of a standards-based toxics control program. EXTENT OF CONTROL OF TOXIC POLLUTANTS -------------------------------------------------------- Chapter 0:4.3 GAO reviewed the pollutants discharged from 236 facilities from three industrial sectors (pulp and paper, pharmaceutical, and pesticides manufacturing). The vast majority of the toxic pollutant cases GAO identified (77 percent) were not controlled through the permit process. Priority pollutants (for example, dichlorobenzene and carbon tetrachloride) made up 33 percent of these cases while the remainder were nonpriority pollutants. GAO found that, for the sample of facilities evaluated, the permit process rarely controlled nonpriority toxic pollutants (with the exception of acids, ammonia, and chlorine) and priority pollutants only partially. It should not be presumed that the former are innocuous: nonpriority pollutants can pose human health and aquatic life risks. In calculating the percentage of nonpriority pollutants reported in EPA's Toxic Release Inventory for 1989, GAO found that that group makes up 98 percent of the discharges by mass. These pollutants are reported in the inventory because they are used in commerce and because their release to the environment could pose human health risks. THE RISK IMPLICATIONS OF UNCONTROLLED TOXIC POLLUTANTS -------------------------------------------------------- Chapter 0:4.4 GAO used standard modeling methods to estimate the water concentration of uncontrolled toxic substances from the sample population of facilities mentioned above to determine what proportion presented human health or aquatic life risks. For cases that GAO could evaluate, only 8 percent did pose such risks. However, GAO could not evaluate many of the cases (62 percent) because the criteria needed for determining whether their discharge posed a risk had not been established. MATTER FOR CONGRESSIONAL CONSIDERATION ---------------------------------------------------------- Chapter 0:5 The Clean Water Act emphasizes a standards approach for controlling toxic pollutants. In its reauthorization of the act, the Congress should consider augmenting this approach with additional authority to allow EPA to emphasize pollution prevention as a way of managing toxic pollutant discharges. RECOMMENDATIONS ---------------------------------------------------------- Chapter 0:6 To improve EPA's efforts to control discharges of toxic water pollutants, GAO recommends that the Administrator of EPA initiate immediate efforts to address the information quality assurance problems GAO identified in the 5 toxic control activities where these problems occur and expand the use of the Toxic Release Inventory data base to identify nonpriority pollutants being discharged to water that should be considered for control through the permit process. AGENCY COMMENTS ---------------------------------------------------------- Chapter 0:7 GAO discussed the results of its work, including tentative findings, conclusions, and recommendations, with responsible EPA officials and has incorporated their comments where appropriate. Their major comments and GAO's responses are included in chapter 6. INTRODUCTION ============================================================ Chapter 1 Toxic pollutants pose a substantial threat to the biological integrity of the nation's water. Reports prepared by the states under section 304(l) of the Clean Water Act cite toxic discharges from 879 factories and sewage treatment plants around the nation as causing streams to violate water quality standards.\1 State governments have also identified toxic pollutants as affecting the quality of more than 28,000 miles of the nations' rivers.\2 Moreover, state officials have reported that 15 percent of monitored river miles and 39 percent of lake areas were contaminated by toxic substances.\3 Contamination by toxic and conventional pollutants resulted in more than 1,000 bodies of water around the country with fishing advisories or bans.\4 In an effort to control discharges of toxic pollutants from factories and sewage treatment plants, EPA, the agency with jurisdiction in matters of toxic pollution of waterways, has developed an approach that includes the collection of three different types of information. Under this approach, information about the environment, the facilities that dispose of toxic pollutants, and the toxic substances themselves provides the foundation for controlling toxics. Ensuring information of adequate quality about these elements, then, is critical to the approach's success. Adhering to information and data quality assurance standards is a requisite for attaining such quality. In short, decisions made within the EPA water quality programs can be only as good as the data on which they are based. At minimum, those data should be of high enough quality to appropriately and accurately characterize the event or object of interest. In the recent past, concerns have been raised about the quality of information EPA used in its water protection program.\5 The Chairman of the Subcommittee on Superfund, Ocean, and Water Protection of the Senate Committee on Environment and Public Works asked us to evaluate (1) how well EPA ensures information and data quality in the water toxic control program and (2) the extent to which the program controls toxic discharges. This report responds to that request. -------------------- \1 Bureau of National Affairs, Environment Reporter, June 23, 1989, p. 466. \2 Environmental Protection Agency, National Water Quality Inventory: 1990 Report to Congress (Washington, D.C.: 1992), p. 88. \3 Environmental Protection Agency, p. 86. \4 Environmental Protection Agency, p. 90. \5 U.S. General Accounting Office, Environmental Enforcement: EPA Cannot Ensure the Accuracy of Self-Reported Compliance Monitoring Data, GAO/RCED-93-21 (Washington, D.C.: March 31, 1993), and Water Pollution Monitoring: EPA's Permit Compliance System Could Be Used More Effectively, GAO/IMTEC-92-58BR (Washington, D.C.: June 22, 1992). BACKGROUND ---------------------------------------------------------- Chapter 1:1 As already noted, dealing with toxic discharges within the framework of the Clean Water Act requires information on the aquatic environment, the facilities that discharge the pollutants, and toxic substances. Collecting this information is not easy, because of both the complexity and variability of the subject matter and the technical and methodological challenges associated with measurement, data collection, and analysis. EPA has created a framework to collect data on all these elements, as described below. THE AQUATIC ENVIRONMENT -------------------------------------------------------- Chapter 1:1.1 The nation's surface-water resources are truly immense. They consist of more than a million miles of rivers and streams (enough to extend from the Earth to the Moon four times). There are 61,000 square miles of inland water bodies and 94,000 square miles of the Great Lakes. Taken together, this constitutes an area larger than the combined size of 12 states. Besides being vast, the aquatic environment is highly complex. It is composed of different "compartments," including the "water column," sediment, and aquatic life. Marshes, wetlands, lakes, rivers, streams, estuaries, and open oceans constitute greatly diverse habitats for aquatic life. Within both the water column and the sediment layers are varied collections of aquatic life, both animals and plants, with interdependent life cycles. Site-specific characteristics of a body of water (such as temperature, pH, and hardness) influence the areas in which different species reside and their sensitivity to stresses from toxic substances and other pollutants. DISCHARGES INTO THE AQUATIC ENVIRONMENT -------------------------------------------------------- Chapter 1:1.2 For as long as people have lived in villages and towns there has been pollution of rivers and streams. Many of the epidemics of the Middle Ages in Europe were caused by exposure to polluted waters. In the United States, the industrial revolution of the 18th and 19th centuries and the accompanying increases in manufacturing increased discharges, sowing the seeds of a water quality crisis for the nation's lakes, rivers, and streams. The chemical revolution of the 20th century dramatically increased the complexity of these discharges. These bodies of water serve as sources of drinking water for about half the nation's population and have recreational uses as well. They are also the repository for wastes from about 64,000 factories and sewage treatment plants. Of these dischargers, about 7,000 are considered "major dischargers" under federal legislation. Industrial processes have developed around the ability to dispose of industrial wastes into adjacent bodies of water. Disposing of wastes in this way is integral to modern industry. Billions of pounds of pollutants are released into the nation's waters every year from these "point sources" of pollution.\6 -------------------- \6 Discharges from specific locations are called point source discharges. Pollution that does not enter the water from a pipe is "nonpoint" pollution. Examples of sources of nonpoint pollution are farms, fields, and highways. TOXIC POLLUTANTS -------------------------------------------------------- Chapter 1:1.3 More than 65,000 chemicals are manufactured or used in the United States; over 1,000 new substances are introduced each year. A contrast is often drawn between "toxic" and "conventional" pollutants.\7 The short list of conventional pollutants, so-named because they were traditionally the objects of wastewater treatment and control, consists of the following: biochemical oxygen demand (BOD), coliform, oil and grease, pH, and total suspended solids. The toxic effects produced by conventional pollutants are usually immediately apparent. Too high a concentration of nitrogen or phosphorus in a lake can turn it green with algae. Too high a level of BOD in a lake or stream will deplete it of oxygen and suffocate the aquatic life residing in it. Toxic pollutants usually have more subtle effects on the health of the ecosystem and those who come into contact with it. These effects can range from harming the reproductive cycle of the wildlife in a stream to causing cancer in people who drink that water. In addition, these substances often produce their toxic effect at very low concentrations that may be beyond the capabilities of laboratory instruments to detect. Examples of toxic pollutants are some metals such as mercury and chromium; pesticides such as DDT and 2,4,5-TP; and organic chemicals such as PCBs and dioxins. Toxic substances can affect all organisms that dwell in water. When toxic substances settle, they can also harm the organisms that dwell in sediments. Further, there is variation in the amount of time it takes for toxic substances to produce harmful effects. Some toxic substances have an immediate action; others take a longer period of time. A long-term effect of some toxic substances is bioaccumulation, or the transfer of a substance from the environment into living tissues through feeding and bioconcentration (the passing of a substance from water into an organism). In fish, for example, bioconcentration occurs by absorption through the skin or by uptake through the gills. Living tissues reach higher concentrations than the surrounding water when a substance bioaccumulates. Thus, contaminated fish and shellfish present a health hazard to people who eat them. Determining the magnitude of risk associated with individual pollutants is a highly complicated task involving complex technical studies. -------------------- \7 Within this report, we define a water pollutant as any constituent or property of water that undermines the ability of the body of water to support the uses to which it is put. Thus, even fresh water can be a pollutant in a salt water ecosystem, where the organisms that reside there are adapted to highly saline water. CONTROLLING POLLUTANTS: THE CLEAN WATER ACT -------------------------------------------------------- Chapter 1:1.4 The Federal Water Pollution Control Act of 1972, known as the Clean Water Act, established the general framework for controlling these pollutants. Surface water can be characterized according to a number of uses. It is a source of drinking water for municipalities. It has recreational uses, such as boating, swimming, and fishing. It is the repository for wastes of numerous dischargers of pollutants such as factories and municipal sewage treatment plants. Much of the act is designed to provide a way to limit discharges in order to minimize the degree to which they interfere with the other uses of water bodies. In general, limits are placed on a pollutant if it is thought to threaten human health or aquatic life. The general framework of the 1972 Clean Water Act consists of a set of interrelated program activities based on provisions of the act and subsequent amendments to it. The process for controlling discharges of pollutants is administered through the National Pollutant Discharge Elimination System (NPDES). NPDES was created through the act as a way of controlling the pollutants discharged by the thousands of facilities releasing their wastes into surface waters. The cornerstone of the NPDES framework is a process for issuing permits to point source facilities: That is, discharging any substance into any body of water without a permit is forbidden. When a permit is issued, the pollutants requiring control are identified, limits for their discharge are established, and then through monitoring and enforcement EPA and the states are able to ensure compliance with the permit. So, placing a limit on a pollutant in a permit constitutes the first step in the Clean Water Act framework for controlling discharges from a particular point source. Permits are to be issued for every facility for up to 5 years. Prominent among the conditions contained within most permits are requirements that the total amount of a discharge be monitored by a discharging facility and that the amount of pollutants released be limited to values established through the permit process. For example, chloroform might be limited through a permit by requiring that it be monitored daily and that no more than 10 pounds be discharged each day. Other pollutants would have similar types of discharge requirements defined on the permit. Although issuing the NPDES permit is the centerpiece of the current approach for limiting discharges into surface waters, a related process uses information provided by several other activities (described in chapter 2). Implementation of NPDES rests with 39 delegated states and EPA's 10 regional offices. Each regional office retains implementation authority for nondelegated states in that region. Regions and delegated states issue permits with effluent limits and monitoring requirements, track compliance with the permit conditions, and carry out enforcement actions. Controlling toxic substances has been one of the major challenges for the Congress and EPA since the passage of the Clean Water Act. The number of toxic pollutants is large, the related risk is often difficult to demonstrate, and measurement is expensive or inconclusive at the low concentrations that pose a threat. In 1977 and 1987, the Congress passed amendments to the act focusing renewed attention on controlling toxics in surface water. In section 307 of the Clean Water Act as amended in 1977, the Congress directed EPA to focus its regulatory activities on a list (published elsewhere) containing 31 chemical groups (such as halomethanes and polynuclear aromatic hydrocarbons) and 38 individual substances (such as isophorone and thallium). From this requirement, the agency developed a list of 129 individual pollutants for priority attention, but this list has been reduced to 126. These pollutants are termed the "priority pollutants," and EPA has directed most of its attention with respect to toxics within the water protection framework to these 126. According to EPA, "The priority pollutant list identifies toxic pollutants of concern on a national basis. It has served as a basis for numerous EPA actions, including the selection of pollutants for development of water quality criteria under section 304(a) of the Clean Water Act; the development of technology-based effluent guidelines under section 301 of the Clean Water Act; the listing of impaired waters under section 304(l) of the Clean Water Act."\8 EPA has recently been augmenting its approach for controlling toxic pollutants under the Clean Water Act. An important initiative in this area is an approach called "whole effluent toxicity" (WET).\9 The agency has recognized that discharges from facilities often consist of a "chemical stew" of many different pollutants, each with its own "toxic signature," with a combined effect on a receiving water body that is impossible to deduce from the individual components. EPA has found that the toxicity of the "whole effluent" is what poses a human health risk and affects the environment and has, thus, decided that the "stew" itself, and not just the ingredients, is a proper subject for regulation and control through the NPDES process. In the view of the agency, a WET limit (a limit based on the results of testing the toxicity of the wastewater through a bioassay) "provides a way to evaluate an effluent in the absence of detailed information about the chemicals it contains."\10 However, because WET test results do not specify which substances in the effluent are toxic, they are not prescriptive: That is, by themselves, they do not indicate how to treat the effluent's toxicity to protect human health and aquatic life. Therefore, limits on individual pollutants remain a critical component of the water quality approach in spite of advances in WET testing.\11 Other initiatives EPA mentioned in this area are toxicity identification evaluations and toxicity reduction evaluations, which are intended to assist those holding permits to achieve compliance with WET limits.\12 -------------------- \8 Environmental Protection Agency, "Water Quality Guidance for the Great Lakes System and Correction; Proposed Rules," 58 Fed. Reg. 20801, at 20843 (April 16, 1993). \9 Environmental Protection Agency, Technical Support Document for Water Quality Based Toxics (Washington, D.C.: April 1991). \10 Environmental Protection Agency, Introduction to Water Quality Based Toxics Control for the NPDES Program (Washington, D.C.: March 1992), p. 6. \11 Environmental Protection Agency, Technical Support Document, p. 1-4. \12 Environmental Protection Agency, Technical Support Document, p. 114. OBJECTIVES, SCOPE, AND METHODOLOGY ---------------------------------------------------------- Chapter 1:2 OBJECTIVES -------------------------------------------------------- Chapter 1:2.1 In the winter of 1992, the Chairman of the Subcommittee on Superfund, Ocean, and Water Protection of the Senate Committee on Environment and Public Works asked us to evaluate EPA's effort to ensure the quality of the information used to control the discharge of toxics to surface water and the extent to which toxic substances that are discharged are listed on water quality permits. In responding to the request, we addressed four questions: 1. What are the EPA water quality activities that control discharges of toxic substances from point sources into surface waters and what are their critical information requirements? 2. To what extent do these activities meet critical information quality assurance requirements? 3. To what extent are limits for actual toxic substance discharges included on NPDES permits? 4. What are the effects on water quality of unlisted discharges of toxic pollutants? SCOPE -------------------------------------------------------- Chapter 1:2.2 For questions 1 and 2, we examined activities across programs administered by EPA's water quality office that are directly responsible for controlling discharges of toxics from point sources. A number of these activities are overseen by EPA and implemented at the state level. The scope for question 3 was comprised of facilities selected to include three industrial categories from which EPA's industrial technology division has recently gathered discharge monitoring data. These categories--pulp and paper, pharmaceutical manufacturing, and pesticide manufacturing--are among the most significant contributors of toxic substance discharges in the nation in terms of the amount of toxic pollutants discharged. We addressed question 4 using the same set of facilities. METHODOLOGY -------------------------------------------------------- Chapter 1:2.3 1. PRINCIPAL ACTIVITIES AND THEIR INFORMATION REQUIREMENTS ------------------------------------------------------ Chapter 1:2.3.1 To identify and characterize the activities that EPA has established to control toxic discharges to surface water and their critical information needs, we used program documents and literature reviews to develop a list of activities conducted across a number of water quality programs. We then submitted this list to EPA officials, asking them to identify those that directly affect the control of toxics. Our next step was to administer a structured interview to the managers of the "core" activities to determine (1) the types of information (for example, hydrology information about receiving bodies of water and information about pollutants discharged) that are required for conducting the activities and (2) the principal sources of the information. We validated our findings by asking an expert panel to review the core programs and information requirements identified (see appendix I for a list of the experts). 2. THE EXTENT TO WHICH INFORMATION MEETS QUALITY ASSURANCE CRITERIA ------------------------------------------------------ Chapter 1:2.3.2 We could not evaluate the quality of the EPA data directly, because of the diversity of data used and the amount of variation in the same type of information from case to case. Instead, we used commonly accepted standards of quality assurance to assess the degree to which the EPA process adhered to such standards in collecting, analyzing, and reporting the required information (identified in question 1). This evaluation approach was feasible because EPA's official policy for conducting studies requires that quality assurance criteria be established and followed by every agency data collection effort. According to agency documents, quality assurance is indispensable for producing valid data.\13 For these reasons, we were able to use an evaluation of the EPA quality assurance effort as a surrogate for directly examining data quality. We developed quality assurance criteria from a review of the scientific literature and EPA's quality assurance/quality control (QA/QC) guidelines. Members of EPA's quality assurance management staff then reviewed the list of criteria for relevance and completeness. We then determined which quality assurance criteria were relevant and critical to each information requirement (from evaluation question 1) for each of the core water quality protection program activities, resulting in separate sets of criteria from our overall set for each requirement. We asked our panel of experts to help us identify the quality assurance criteria relevant and critical to each information requirement. We then interviewed the managers of the activities to determine the extent to which the criteria assigned to each information type were met. We interviewed other individuals in EPA and the U.S. Geological Survey (USGS) to obtain responses to questions that program managers were unable to answer.\14 We obtained detailed explanations for each response during the interviews and independently reviewed supporting agency studies and data bases for particular responses. -------------------- \13 Environmental Protection Agency, Minimal Requirements for a Water Quality Assurance Program (Washington, D.C.: 1975), p. 1-3. \14 We obtained responses to a number of criteria from USGS staff. We also surveyed staff within EPA's 10 regional offices for responses to several criteria. 3. THE EXTENT TO WHICH THE NPDES PERMIT PROCESS CONTROLS TOXIC SUBSTANCES ------------------------------------------------------ Chapter 1:2.3.3 The third evaluation question addresses the extent to which toxic substances receive even the first level of control provided by the NPDES permit process. We answered this question by comparing reports of actual discharges against Permit Compliance System (PCS) permit files for a sample of facilities and identifying the "unlisted" pollutants--that is, toxic pollutants that were discharged but not listed on the permit and were thus not directly controlled.\15 We obtained the discharge data from (1) studies of discharges conducted by the industrial technology division of EPA, (2) reports of discharges by industrial facilities under section 313 of the Emergency Planning and Community Right-to-Know Act (otherwise known as the Toxic Release Inventory), and (3) NPDES permit applications listing pollutants identified in facilities' effluent. -------------------- \15 The Permit Compliance System is EPA's data storage and retrieval system for NPDES permit files. 4. THE IMPACT OF UNLISTED DISCHARGES ON WATER QUALITY ------------------------------------------------------ Chapter 1:2.3.4 To address our last evaluation question, we analyzed the human health and aquatic life risks associated with the uncontrolled toxic pollutant discharges identified in question 3. In order to determine these risks, we used a method similar to that employed by EPA regions and states when they review permit applications.\16 We developed in-stream concentrations of unlisted pollutants using a water quality model and used reported stream flow data. We obtained these from EPA. The model is a "static" water quality model in which the quantity discharged by the facility is diluted into the stream at either low flow or mean flow conditions.\17 We then compared the resultant concentrations against applicable water quality criteria to determine which of the discharges posed a risk to either human health or aquatic life. -------------------- \16 We reviewed our methodology with staff from EPA's office of water to ensure its similarity to that employed by permit authorities. \17 Whether we estimated concentration at low flow or mean flow conditions depended on whether we were comparing the value against an "aquatic life" or "human health" criterion. The general methodology for conducting this evaluation is presented in EPA's Technical Support Document and in Versar, Inc., ReachScan User's Manual (Springfield, Va.: September 1991). STRENGTHS AND LIMITATIONS ---------------------------------------------------------- Chapter 1:3 One strength of the work performed for this evaluation is the comprehensiveness of the effort to determine the principal activities EPA has designed to control toxic discharges. Our review of both literature and documentation was designed to ensure that we would identify every activity implemented in the overall EPA water quality program. Through indepth review of all activities identified, interviews with EPA staff to determine which activities were directly related to toxics control, and with the use of an expert panel to validate our results, we were certain to identify the activities that are absolutely essential to the toxics control program. To address EPA's steps to ensure data quality, our effort again was comprehensive. We used both EPA's quality assurance criteria and other criteria identified through a second literature review, this time in the specialized area of quality assurance. We asked the EPA staff who are responsible for the agency's quality assurance efforts to review our initial list of criteria for appropriateness. The use of an expert panel to examine whether criteria were both relevant and critical to ensure quality in the activities we identified served to further validate our work in establishing the normative framework. A limitation with regard to the measurement of data quality is that we could not assess that quality directly. As noted earlier, we looked at compliance with quality assurance criteria as a proxy for direct measurement, because the complexity of direct measurement far transcended the scope of this study. Although compliance with criteria for quality is an indirect measure, such compliance is a necessary (if not sufficient) condition for quality, and it is EPA's official policy concerning all agency data collection. Finally, our work in answering questions 3 and 4--determining the extent to which the permit process controls toxic discharges and determining the risk of uncontrolled discharges--has the strength of being a national level assessment. That is, the sample of facilities whose permits we reviewed was geographically dispersed across the country. Further advantages were the comprehensiveness of our three data bases (which defined the types of toxic pollutant discharges and their amounts) and the importance of the industrial sectors we chose to examine (pulp and paper, pharmaceutical, and pesticide manufacturing). These three sectors are among the most significant across the nation for discharging toxic pollutants, in terms of both the amount and types of pollutants discharged. However, although our sample was fairly large (236 facilities), our study was not designed to allow its conclusions to be generalized beyond that sample to the total population of the dischargers. EPA ACTIVITIES THAT LIMIT DISCHARGES OF TOXICS INTO SURFACE WATERS AND THEIR INFORMATION REQUIREMENTS ============================================================ Chapter 2 In this chapter, we address our first evaluation question: What are the EPA water quality activities that control discharges of toxic substances from point sources into surface waters and what are their critical information requirements? To answer this question, we refined the larger number of activities EPA conducts across a number of water quality programs to the 7 "core" activities that are fundamental to EPA's basic approach to control the discharge of toxic water pollutants from point sources. We then identified 13 types of information required by these activities. In this chapter, we describe each activity, the information it requires, and the roles and functions of the information collected and list the data sources for the various information types. ACTIVITIES TO LIMIT DISCHARGES OF TOXICS ---------------------------------------------------------- Chapter 2:1 EPA is responsible for many activities that are designed to limit discharges of pollutants into surface waters. Through a literature review, we identified 46 activities that EPA conducted within the agency's office of water. We first eliminated the 11 that deal with drinking water or groundwater issues and, therefore, have no direct relationship with controlling toxic discharges from point sources. We then administered a questionnaire and conducted a series of interviews with EPA officials to identify the activities from the remaining 35 that have a direct effect on controlling toxics. In this manner, we arrived at a set of 7 activities that form the nucleus of EPA's approach for controlling toxic discharges from point sources. Our panel of experts then validated this list of 7 activities. The 46 activities are presented in table 2.1, which distinguishes the 7 that we retained because of their direct influence on controlling discharges of toxic substances from the 39 others. The principal reasons for eliminating each of the 39 are also presented in the table. The 7 activities that are the focus of this chapter are then described in table 2.2. Table 2.1 Activities Conducted Within EPA's Office of Water Principal reason for No. Activity Status elimination -------- ----------------------------- -------- ----------------------------- 1 Assess progress in Eliminat Administrative activity implementing the Coastal Zone ed Management Act to control nonpoint source pollution in coastal waters 2 Assess toxicity control needs Eliminat Duplicates water-quality- for water-quality-based ed based permit activity number permits 28 3 Conduct water quality Eliminat Regulatory support activity standards triennial reviews ed 4 Demonstrate accomplishments Eliminat Not related to controlling in maintaining active state ed toxic discharges and federal enforcement programs for drinking water 5 Develop ecological criteria Eliminat Developmental activity guidance ed 6 Develop stormwater permit Eliminat General regulatory activity strategies ed with small need for data 7 Draft a strategy for Eliminat Developmental activity addressing contaminated ed sediment 8 Draft plans for stormwater Eliminat Administrative activity permits ed 9 Enforce state testing for Eliminat Not related to controlling lead in drinking water ed toxic discharges 10 Establish drinking water Eliminat Not related to controlling laboratory certification ed toxic discharges regulations 11 Establish national primary Eliminat Not related to controlling drinking water regulations ed toxic discharges 12 Establish total maximum daily Retained loads 13 Establish water quality Retained criteria 14 Focus on reauthorization of Eliminat Nonspecific regulatory Clean Water Act ed activity 15 Identify and track water Eliminat Administrative activity quality improvements of ed targeted water bodies 16 Identify compliance problems Retained 17 Identify priority issues in Eliminat General regulatory activity stormwater application ed with small need for data process 18 Implement nonpoint source Eliminat Not related to controlling watershed control programs ed toxic discharges from point sources 19 Improve effectiveness of Eliminat Regulatory developmental inspection activities ed activity 20 Improve quality and Eliminat Regulatory developmental timeliness of enforcement ed activity responses 21 Issue health advisories for Eliminat Not related to controlling drinking water ed toxic discharges 22 Issue administrative Eliminat Not related to controlling compliance orders for ed toxic discharges drinking water 23 Issue drinking water Eliminat Not related to controlling regulations ed toxic discharges 24 Develop effluent guidelines Retained 25 Issue fines and negotiate Eliminat Not directly related to consent decrees for permit ed toxics control violations 26 Issue lists of impaired Retained waters and related point sources 27 Issue regulations to control Eliminat Not related to point source pollutants in urban runoff ed control 28 Issue water quality permits Retained 29 Make revisions to permits Eliminat Duplicates number 28 codifying changes made by ed 1987 Clean Water Act amendments (antibacksliding provisions) 30 Manage state revolving funds Eliminat Administrative activity ed 31 NPDES regulatory revisions Eliminat Nonspecific regulatory contained in 1987 Water ed activity Quality Act 32 Prepare sewage sludge use and Eliminat Regulatory development disposal regulations ed activity 33 Propose revisions to Eliminat Not related to controlling monitoring requirements for ed toxic discharges drinking water 34 Reduce noncompliance with Eliminat Not related to controlling existing drinking water ed toxic discharges standards 35 Reduce exposure of population Eliminat Not directly related to to contaminants in drinking ed controlling toxic discharges water 36 Regulate sources of toxic Retained discharges to publicly owned treatment works from indirect dischargers 37 Regulate substances not on Eliminat Not related to controlling drinking water priority list ed toxic discharges 38 Revise stormwater Eliminat Program in development implementation rules ed 39 Revision of denial or Eliminat Not directly related to restriction of disposal sites ed controlling toxic discharges 40 Set federal NPDES fees in Eliminat Administrative activity states where EPA administers ed NPDES program 41 Strengthen the scientific Eliminat Not directly related to basis of water quality ed controlling toxic discharges standards to protect critical aquatic resources 42 Track fish consumption Eliminat Administrative activity advisories ed 43 Track pretreatment programs Eliminat Administrative activity ed 44 Track sludge facilities Eliminat Administrative activity ed 45 Track stormwater permit Eliminat Not directly related to activity ed controlling toxic discharges 46 Water quality standards Eliminat Not of national scope revisions for Indian tribes ed -------------------------------------------------------------------------------- Table 2.2 Activities Designed to Control Discharges of Toxic Substances No. Activity\a Objective -------- ------------------ ------------------------------ 1 Effluent Develop national standards, guidelines setting out baseline development (no. requirements for pollution 24) removal within individual industries 2 Water quality Develop statements of the criteria maximum permissible development (no. concentrations of individual 13) toxic pollutants in water that will not harm human health and aquatic life 3 Impaired water and Identify water threatened by point source point source discharges of identification\b toxic substances and the (no. 26) facilities causing the impairments 4 Total maximum Estimate the amount of a daily load pollutant that can be safely development (no. discharged from all sources 12) (including natural sources) into a body of water 5 Water-quality- Issue the legal documents based permit containing the conditions and issuance (no. 28) limits controlling a point source discharger's release of pollutants into a body of water based on the expected effect of the release on water quality 6 "Local limits" Restrict the amount of development (for pollutants that "indirect reducing dischargers" can release into discharges of sewer systems pollutants into sewage treatment plants) (no. 36) 7 Compliance problem Determine whether a discharger identification is meeting its permit (no. 16) conditions; used as a basis for possible future enforcement action ------------------------------------------------------------ \a Numbers in parentheses identify activities listed in table 2.1.\ \b This was a one-time exercise mandated by the Water Quality Act of 1987. Section 304(l) called for three lists to be prepared by each state. Only one of them featured streams with impairment primarily from toxic pollution from point sources (the others being broader delineations of impaired water bodies). We used the preparation of this list, and not the two others, as the activity. Across these 7 activities, the essential data for implementing EPA's approach are gathered and processed. In many cases, information that has been collected and decisions that have been reached within one activity are then used within another. For example, water quality criteria (activity 2) are used to generate water-quality-based permits (activity 5). In terms of their information function, the core program activities can be grouped into four categories by the role each plays in the overall process: (1) uniform guideline development, (2) geographic targeting, (3) permit development, and (4) compliance assessment. The overall process for controlling toxics from point sources begins with uniform guideline development: the development of general practices for making decisions with respect to the thousands of facilities subject to NPDES. In this first category, EPA develops national guidelines or criteria--specifically effluent guidelines and water quality criteria (activities 1 and 2 in table 2.2). They provide the rationale for determining what substances should be limited on permits and what those limits should be. The second step in the process is to identify specific facilities that require expedited review of their permit. The one time that geographic targeting was employed by the Congress within the Clean Water Act occurred in section 304(l) of the act as amended in 1987 (activity 3). The third category, permit development, uses the national criteria and standards (from the first category) along with site-specific information to determine the conditions and limitations needed on individual permits--specifically, total maximum daily load (TMDL) development, NPDES permit issuance, and "local limits" development (activities 4, 5, and 6). The fourth category, compliance assessment (that is, activity 7, compliance problem identification), uses information about patterns of discharges to determine whether facilities have complied with the conditions and limits of their permits. This activity compares actual monitoring and test data against the limits and conditions imposed in permits. If problems are found, the results of this comparison can lead to either an enforcement action against a facility for violating a permit condition or to a revision of its permit. INFORMATION REQUIRED WITHIN THE SEVEN CORE ACTIVITIES ---------------------------------------------------------- Chapter 2:2 We identified critical information needed to support the core activities through interviews with EPA program managers and others. "Critical" information was defined as having primary importance to conducting the activity with respect to meeting EPA's water quality goals for controlling point source discharges of toxics into surface water. Weaknesses in critical information clearly undermine the effectiveness of an activity. Each of the 13 information types we identified as required by the 7 activities is briefly described in table 2.3. Table 2.3 The Thirteen Types of Information Required Across the Seven Activities No. Information type Description -------- ------------------ ------------------------------ 1 Hydrology Characteristics of the properties of lakes and rivers such as stream flow 2 In-stream water The chemical properties of the quality receiving body of water (typically the concentration of the chemical constituents) 3 Concentration in Concentrations of chemical sediments constituents found within the sediments of receiving water bodies 4 Concentration in Concentrations of toxics biota within the aquatic creatures inhabiting the water body 5 Aquatic life The extent to which aquatic exposure life is exposed to pollutants 6 Discharges from Substances and amounts being individual sources discharged from specific plants and facilities 7 Removal Characterizations of the technologies technologies that are effective within the industry for removing pollutants from wastewater 8 Water use Characterizations of the reduction techniques that can be used to technologies reduce discharges of pollutants through water reuse in the industrial production process 9 Aquatic life The nature and extent of effects effects upon aquatic organisms that come into contact with substances in the environment\a 10 Human health The nature and extent of human effects effects associated with exposure to the substance in the environment 11 Fate and transport The mechanisms and rate at which a substance undergoes change and moves through the environment (or within a publicly owned treatment works) 12 Human health The extent and way in which exposure humans are exposed to water pollutants through drinking water and eating fish 13 Economic data The effect on an industry's profitability of changes in categorical technologically based effluent standards ------------------------------------------------------------ \a In connection with the section 304(l) exercise, this took on the meaning of assigning "biocriteria," or using indicator species, to measure environmental impairments. THE SEVEN CORE ACTIVITIES AND THEIR INFORMATION NEEDS ---------------------------------------------------------- Chapter 2:3 We found, as expected, that all 7 activities depend heavily on information. Each requires a different set of specific data for its implementation. As already noted, 13 different types of information in all are required across the 7 activities. The types of information listed as 1-13 in table 2.3 are labeled A-M in figure 1 and elsewhere in the report. The types of information used to support the 7 activities vary significantly. THE ROLES AND FUNCTIONS OF THE INFORMATION ---------------------------------------------------------- Chapter 2:4 In the series of summary tables 2.4 through 2.10, we present the reasons why the 13 types of information we identified in the preceding section (types A-M) are required across the 7 activities. Each table characterizes the determinations, within each activity, that the information is required to support (its purposes) and states the source of the information and how it is developed. In appendix II, we present a more detailed description of each activity, highlighting its statutory and regulatory basis in addition to the role and principal information sources of each information type. Table 2.4 The Purposes and Sources of Critical Information Within Activity 1: Effluent Guidelines Development Typical principal Information type Purpose source -------------------- ------------------ ------------------ Discharges from To identify the Questionnaire to a individual sources pollutants that sample of (F) are typical of facilities within facilities within industry; site an industry visits Removal technologies To identify the Questionnaire to a (G) most efficient sample of technologies facilities within available within industry; site an industry to visits remove pollutants Water use reduction To identify the Questionnaire to a technologies (H) most efficient sample of technologies facilities within available within industry; site an industry to visits reduce discharges through efficient water use Economic data (M) To identify and Questionnaire to a characterize the sample of economic effect on facilities within an industry of industry various alternatives ------------------------------------------------------------ Table 2.5 The Purposes and Sources of Critical Information Within Activity 2: Water Quality Criteria Development Typical principal Information type Purpose source -------------------- ------------------ ------------------ Concentration in To determine how Peer reviewed biota (D) pollutants scientific bioconcentrate in literature; EPA's the environment field studies Aquatic life To provide a Criteria from EPA exposure (E) measure allowing (on magnitude, the results of the duration, and effects studied to frequency of be related to exposure) "real world" exposures Aquatic life effects To identify the Aquatic toxicology (I) nature and studies, magnitude of the internally effects of developed or from exposure of the the scientific pollutant to literature; EPA aquatic species testing Human health effects To identify the Peer reviewed (J) nature and scientific magnitude of the literature; EPA's effects of field studies exposure of the pollutant to people Human health To provide a Peer reviewed exposure (L) measure allowing scientific the results of the literature; EPA's effects studied to field studies be extrapolated to the exposures of people ------------------------------------------------------------ Table 2.6 The Purposes and Sources of Critical Information Within Activity 3: Impaired Water and Point Source Identification Typical principal Information type Purpose source -------------------- ------------------ ------------------ In-stream water To identify areas State monitoring quality (B) that are programs; contaminated by STORET\a; state- toxics specific data bases Concentration in To identify areas State monitoring sediments (C) that have programs; STORET sediments state-specific contaminated by data bases toxics Concentration in To determine areas State monitoring biota (D) that have aquatic programs and life contaminated assessments by toxics Discharges from To identify areas Permit individual sources that may be applications and (F) contaminated by discharge toxics and the monitoring reports contributing sources Aquatic life effects To determine State monitoring (I) whether aquatic programs and life is being section 305(b) harmed by reports discharges Fate and transport To provide precise State section (K) estimates of in- 305(b) stream assessments; state concentrations surveys; state and EPA compliance monitoring for point sources ------------------------------------------------------------ \a STOrage and RETrieval (STORET). Table 2.7 The Purposes and Sources of Critical Information Within Activity 4: TMDL Development Typical principal Information type Purpose source -------------------- ------------------ ------------------ Hydrology (A) To estimate the USGS gaging "critical flow" of stations and the receiving regression water body equations from gages on neighboring streams In-stream water To estimate the State monitoring quality (B) background programs; STORET concentration of the substance being discharged Concentration in To determine State monitoring sediments (C) whether the programs; STORET sediment is contaminated Concentration in To determine State monitoring biota (D) whether there is a programs; STORET contamination problem Discharges from To estimate the Permit individual sources amount discharged applications and (F) by the facility discharge monitoring reports Fate and transport To provide precise Textbooks, journal (K) estimates of in- articles, EPA and stream U.S. Fish and concentrations Wildlife Service publications; EPA- supported water quality models ------------------------------------------------------------ Table 2.8 The Purposes and Sources of Critical Information Within Activity 5: Water- Quality-Based Permit Issuance Typical principal Information type Purpose source -------------------- ------------------ ------------------ Hydrology (A) To determine the USGS gaging dilution limits stations and for aquatic life regression and human health equations from effects gages on neighboring streams In-stream water To determine the STORET and state quality (B) background water quality data concentrations for bases the substances being considered Discharges from To determine the Permit individual sources amount discharged applications and (F) from the facility discharge monitoring reports Fate and transport To provide precise Textbooks, journal (K) estimates of in- articles, EPA and stream U.S. Fish and concentrations Wildlife Service publications; EPA- supported water quality models ------------------------------------------------------------ Table 2.9 The Purposes and Sources of Critical Information Within Activity 6: "Local Limits" Development Typical principal Information type Purpose source -------------------- ------------------ ------------------ Discharges from To determine the Monitoring of the individual sources substances and source's effluent, (F) amounts being by the indirect discharged discharger and the publicly owned treatment works Removal technologies To determine the Self-monitoring of (G) effectiveness of the publicly owned the publicly owned treatment works' treatment works at effluent removing the substance Fate and transport To determine the Self-monitoring of (K) amount of each the publicly owned substance treatment works' remaining in wastestream wastewater, volatilizing into the atmosphere, and precipitating in sludge as a result of treatment at the publicly owned treatment works ------------------------------------------------------------ Table 2.10 The Purposes and Sources of Critical Information Within Activity 7: Compliance Problem Identification Typical principal Information type Purpose source -------------------- ------------------ ------------------ In-stream water To compare against Self-monitoring by quality (B) permit limits in facility; data for order to evaluate major facilities compliance (in- entered into PCS stream monitoring is rarely included) Aquatic life To compare against Self-monitoring by exposure (E) permit limits in facility; data for order to evaluate major facilities compliance (WET entered into PCS limits) Discharges from To compare against Self-monitoring by individual sources permit limits in facility; data for (F) order to evaluate major facilities compliance entered into PCS ------------------------------------------------------------ SUMMARY ---------------------------------------------------------- Chapter 2:5 Seven activities across various EPA water quality programs form the core of the agency's effort to control toxic discharges from point sources into surface waters: effluent guidelines development, water quality criteria development, impaired water and point source identification, total maximum daily load development, water-quality-based permit issuance, "local limits" development, and compliance problem identification. A wide variety of information is employed within the 7 core activities. All 7 use several different types of information for making decisions. In all, 13 different types of information are used at 31 points across the 7 activities (tables 2.4 through 2.10). Information plays a critical role across these activities. From setting national standards to ensuring compliance with individual NPDES permits, information forms the basis for these efforts. Each one of the 13 types of information is critical to the activities. For example, without reliable information about efficient and feasible removal technologies, the effluent guidelines activity would not produce technological requirements that meet congressional objectives in the Clean Water Act. Without reliable information about the actual discharges of facilities with permits, the NPDES compliance program would not be able to identify the facilities that are not conforming to their permit requirements. Having established the core activities and their related information requirements, we now address our second evaluation question. In chapter 3, we evaluate the extent to which EPA ensures that critical quality assurance steps are taken in developing the required information. THE EXTENT TO WHICH REQUIRED INFORMATION MEETS QUALITY ASSURANCE REQUIREMENTS ============================================================ Chapter 3 In chapter 2, we identified the EPA activities that control toxic discharges to water and the types of information that support the activities. In this chapter, we address our second evaluation question: To what extent do these activities meet critical information quality assurance requirements? Here, we compare EPA's official policy for quality assurance in data collection with reported practice. INTRODUCTION ---------------------------------------------------------- Chapter 3:1 As we discussed in chapter 2, information is a critical component of the nation's approach for controlling discharges of toxics, and the quality of that information is central to the effectiveness of the 7 core activities. In general (that is, within each activity), information quality is promoted through adopting and practicing quality assurance standards. Quality assurance practices and standards control how data are collected, managed, and analyzed so as to ensure their reliability, validity, and completeness. These standards also regulate whether the information base is sufficient for drawing inferences and making decisions. We evaluated information quality according to two types of criteria. The first type concerns the methodological steps taken to ensure information quality.\1 The second type concerns the completeness of the data gathered vis-a-vis the envisaged purpose--that is, whether all the information required to support the activity was in fact acquired. EPA's policy is to protect information quality by incorporating quality assurance practices into individual studies. EPA order 5360.1 requires a quality assurance program for all environmentally related measurements performed by or for the agency. The primary goal of the program is to ensure that all such measurements yield data of known quality that can be verified as being reliable and appropriate to the program's objectives. The quality assurance management staff serves as the central management authority for this program within EPA. The staff is charged with developing quality assurance policy and training program managers in quality assurance practices. Program managers are responsible for specifying the quality of the data they require and for providing sufficient resources to ensure that an adequate level of quality assurance is performed. All routine or planned projects involving environmental measurement must begin with a "quality assurance project plan" that specifies acceptable quality goals. -------------------- \1 Concerning methodological adequacy, EPA and USGS have recently determined that the analytical methods used to collect and analyze the in-stream data for metals may be flawed. As a result, concerns have been raised about the soundness of the information on which the states have been basing their water quality programs. At a workshop that EPA convened to study the issue, an agency official raised the possibility that the numbers are problematic. A professional hydrologist suggested that much of the data collected in the past to determine whether water bodies are exceeding standards is "almost certainly useless" (Water Policy Report, February 3, 1993, p. 3). EPA and USGS, the two principal agencies involved in developing protocols for sample collection, are currently studying how to deal with these questions. EVALUATING QUALITY ASSURANCE PRACTICES ---------------------------------------------------------- Chapter 3:2 Each of the 7 activities we identified in our evaluation has resulted in a large number of program decisions and products. For example, dozens of effluent guidelines have been issued over the course of the clean water program and thousands of NPDES permits are issued and reissued each year. Because of the large number of decisions and products, which went far beyond the scope of our evaluation, we focused our evaluation at the level of the 7 activities. DEVELOPING CRITERIA STATEMENTS -------------------------------------------------------- Chapter 3:2.1 Through a review of the scientific literature on quality assurance, EPA's quality assurance guidelines, and interviews with experts in the field, we identified a set of 40 criteria that define a basis for ensuring both information quality and completeness for the toxic pollutant control activities we are addressing. Thirty-one of the 40 reflect consensus criteria developed by EPA itself or industrial groups such as the American Society of Testing and Materials (ASTM) relating to methodological adequacy. That is, they deal with how information collection activities should be planned and implemented and how the information should be reviewed. Most of them apply to whether safeguards were taken to ensure the validity and reliability of the information collected in the field and analyzed in the laboratory. The remaining 9 criteria relate to completeness--that is, whether the information base of all studies is sufficient (aside from data quality concerns of individual studies) to reach conclusions about the subject of interest, such as the in-stream concentration of dioxin (for setting a limit on an individual permit). We converted the 40 quality assurance criteria into a set of questions, using a response scale of frequency. The questions, presented in table 3.1, are divided into those dealing with methodological adequacy and those that ensure a complete information base. Table 3.1 Quality Assurance Criteria for Evaluating the Seven Core Toxic Pollutant Control Activities Criterio Type n Question ------------ -------- ------------------------------------ Methodologic 1 How often are data quality al adequacy objectives instituted at the initiation of a project? 2 How often is the design for data collection and analysis reviewed by an individual not directly associated with the program who is familiar with the methodological issues involved in data collection and analysis? 3 How often is a quality assurance project plan employed within the data collection process? 4 How often are standard operating procedures for field and laboratory sampling and reporting followed? 5 How often are QA/QC procedures for data storage and maintenance employed? 6 How often are questionnaires pretested? 7 How often are chemical analyses and bioassays conducted according to EPA-approved methods or other methods specified in the project plan? 8 How often are chemical analyses and bioassays performed by laboratories that follow good laboratory practices? 9 How often is an independent analysis conducted to assess the quality of the data that went into water quality criteria? 10 How often do assessments of environmental quality that are based on best professional judgment undergo quality control checks and independent verification? 11 How often were subject area experts consulted and drafts distributed for public review before the data were accepted? 12 How often are multiple, independent sets of data used to identify the toxic substances that were included within the data collection effort? 13 How often are multiple, independent sets of data used to identify the facilities to gather data from within the data collection effort? 14 Where sampling data were unavailable, how often were assessments, based on observations of water, biota, and sediment by an experienced professional? 15 How often do individual studies present missing data exceeding 10 percent of planned sample size? 16 How often is a probabilistic sampling scheme (a random sample) employed and documented? 17 How often are all requirements of the model, such as times and locations for in-stream or discharge monitoring, adhered to? 18 How often are the data checked for age and only those that are appropriately current retained and used in the analysis? 19 How often are data from different time periods gathered in such a way as to ensure that they are comparable? 20 How often are independent studies conducted to assess the degree to which self-reported samples represent discharges at different production and discharge levels? 21 How often is the critical flow based on data from gaging stations (whether on the reach itself or estimated from gaging stations on neighboring reaches)? 22 When substituting one variable for another within a model, how often were steps taken to ensure that the surrogate variable is correlated with the original with respect to the function it performs in the model? 23 For critical model parameters, how often were laboratory findings replicated with field studies? 24 How often are estimates of in- stream concentrations of discharges based on water quality models of proven validity with respect to local stream conditions? 25 How often do major externally published reports of findings discuss significant components of bias and measurement error? 26 How often was the laboratory "in control" during the period in which it performed the tests? 27 How often are field-derived data obtained under conditions that adequately represent the range and variability of biotic and abiotic conditions? 28 How often is the design for data collection and analysis reviewed by an individual within the organization who is familiar with the methodological issues involved in data collection and analysis? 29 How often is the survey design reviewed by an individual familiar with methodological issues involved in survey methods? 30 How often are manufacturers' specifications adhered to in calibrating gages? 31 How often was the laboratory instructed about detection and quantitation levels and how to report data below these levels? Completeness 32 How often is a judgment made that sampling and analysis included all pollutants that were likely to be present at measurable levels? 33 How often are data gathered on all relevant effects when developing criteria? 34 How often are there enough data of proven quality concerning the most likely effects to support the contention that criteria are based on the most sensitive effect? 35 How often are enough data of proven quality collected on a variety of representative species or cell lines to support the contention that criteria are based on impacts to the most sensitive species that will encounter the toxic substance in the environment? 36 How often is an assessment made downstream of each "major" discharger? 37 How often are sampling data available for waters on which "major" dischargers of toxics are situated? 38 How often are minimum data set size requirements stipulated? 39 How often are sampling frequency and size based on an assessment of the variability of discharge loads? 40 How often is the data set of adequate size to reflect variations and differences for this regulatory purpose? ------------------------------------------------------------ DETERMINING THE RELEVANCE OF THE QUALITY ASSURANCE CRITERIA -------------------------------------------------------- Chapter 3:2.2 The list of criteria for ensuring the methodological adequacy and completeness of information is broad. Whether a criterion is relevant to an information requirement depends on the activity that the information requirement supports. Consequently, our first task was to determine which criteria were relevant to and critical for each information requirement as it supports each specific activity. We did this with the assistance of a panel of five experts familiar with the information requirements of these activities. That is, for each of the 13 types of information used by the activities (figure 2.1), we identified the criteria that are both relevant and critical for ensuring information completeness and quality. We defined a critical criterion as one that, if not routinely met, would jeopardize the quality of the information and threaten EPA's ability to draw conclusions from it. The critical criteria are presented in table 3.2. Thirty-eight of the 40 criteria were applied to at least one information type. Table 3.2 Quality Assurance Criteria Applicable to Information Types Activity Information type Criteria ----------------------------- ------------------ ----------------------------- Effluent guidelines Discharges from 1-5, 7, 8, 12, 13, 19, 20, development individual sources 28, 39, 40 Removal 1-5, 7, 8, 10, 13, 19, 25, technologies 28, 39 Water use 1-5, 7, 8, 10, 13, 19, 25, reduction 28, 39 technologies Economic data 1, 3, 5, 6, 18, 28, 29 Water quality criteria Concentration in 1-5, 9-11, 26-28, 34 development biota Aquatic life 1-5, 9, 11, 26, 28 exposure Aquatic life 1-5, 7-9, 11, 26, 28, 33-35, effects 38 Human health 1-3, 5, 9-11, 18, 28, 33, 34, effects 38 Human health 1-3, 5, 9, 11, 28 exposure Impaired water and point In-stream water 1, 3-5, 7, 8, 18, 26, 28, 32, source identification quality 40 Concentration in 1, 3-5, 7, 8, 18, 25, 26, 28, sediments 40 Concentration in 1, 3-5, 7, 8, 18, 26, 28, 40 biota Discharges from 1, 3-5, 7, 8, 18, 26, 28, 32, individual sources 40 Aquatic life 1, 3-5, 7, 8, 28, 33, 40 effects Fate and transport 1-3, 5, 18, 21, 22, 24, 28, 37, 39, 40 Total maximum daily load Hydrology 21, 22, 24, 28, 38 development In-stream water 1-5, 7, 8, 18, 28, 37, 39 quality Concentration in 1-5, 7, 8, 18, 28, 32, 37, 39 sediments Concentration in 1-5, 7, 8, 28, 37 biota Discharges from 1-5, 7, 8, 18, 28, 39, 40 individual sources Fate and transport 1-5, 7, 8, 18, 21, 22, 24, 26, 28, 32, 37, 39, 40 Water-quality-based permit Hydrology 1-5, 19, 24, 25, 27, 28, 30, issuance 36, 40 In-stream water 1-5, 7-12, 17-19, 25-28, 31, quality 32, 36, 37, 40 Discharges from 1-5, 7-12, 15, 16, 18, 19, individual sources 25, 26, 28, 31, 32, 39, 40 Fate and transport 1-5, 7-9, 17-19, 24-28, 31, 32, 36, 39, 40 "Local limits" development Discharges from 1-5, 7, 8, 12, 15, 16, 18, individual sources 25, 26, 28, 31, 32, 39, 40 Removal 1-5, 7, 8, 10, 19, 25, 26, technologies 28, 39 Fate and transport 1-5, 7, 8, 10, 18, 19, 25, 26, 28, 39 Compliance problem In-stream water 1, 3-5, 7, 8, 18, 26, 32, 40 identification quality Aquatic life 1, 3-5, 7, 8, 18, 19, 26, 40 exposure Discharges from 1, 3-5, 7, 8, 18, 26, 32, 38, individual sources 40 -------------------------------------------------------------------------------- QUALITY ASSURANCE PRACTICES ---------------------------------------------------------- Chapter 3:3 To determine the extent to which the completeness and quality assurance criteria were employed within the 7 activities, we interviewed the relevant EPA managers, using our 40 criteria as a questionnaire with a five-point response scale rating the extent to which the activity is conducted "always," "usually," "sometimes," "seldom," and "never." A criterion should be met at least "usually" if quality assurance criteria are to be met. Therefore, we classified the responses by grouping them into two categories: met ("always" and "usually") and not met ("sometimes," "seldom," and "never"). We also asked for any supporting data and requested that each response be explained as we conducted our interviews. We examined the extent to which the quality assurance criteria were met from two different perspectives: first, from the overall perspective of the 7 activities, and, second, from the perspective of the information types (that is, to what extent were they supported by necessary quality assurance efforts?). A preliminary finding was that the officials we interviewed were aware of EPA's position concerning quality assurance policies and practices. From our review, it is clear that these managers recognize and have accepted the principle of quality assurance within their activities. Table 3.3 presents the results of our interviews with EPA officials concerning the degree of implementation of the quality assurance criteria. Table 3.4 summarizes our results for the activities and information types. As presented in table 3.4, 2 activities (those that establish effluent guidelines and water quality criteria) were exceptional in meeting quality assurance criteria that are critical to the effort. They met 93 percent of their quality assurance requirements. However, the 5 other activities fall short in taking the necessary steps to ensure information quality. That is, impaired water and point source identification, TMDL development, water-quality-based permit issuance, "local limits" development, and compliance problem identification are less than optimal in ensuring that the required quality assurance steps are taken in developing, collecting, or maintaining their needed information. Collectively, about 58 percent of their quality assurance criteria were met. Table 3.3 Responses to Individual Quality Assurance Criteria No.\ b F G H M D E I J L B C D F I K A B C D F K A B F K F G K B E F ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 1 5 5 5 5 5 5 5 5 5 4 4 4 2 3 2 4 4 4 4 4 5 4 5 4 4 4 4 3 4 4 2 4 4 4 5 5 5 2 2 2 3 2 2 2 3 5 3 4 4 4 3 3 3 5 5 5 4 5 5 5 4 4 4 4 4 2 3 2 4 4 4 4 4 5 4 3 4 4 4 4 3 4 5 4 5 5 5 5 5 5 5 4 4 3 4 4 4 4 4 4 5 4 4 3 4 4, 4, 4 4 3 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 3 4 4 4 4 4 4 4 5 4 4 3 2 2 2 1 3 3 6 5 7 5 5 5 5 4 3 4 5 4 4 4 3 4 4 4 4 4 4 4 4 2 4 4 8 5 5 5 5 4 4 4 3 4 4 4 4 4 4 4 4 4 4 4 4 3 4 4 9 5 5 5 5 5 3 3 3 10 5 5 5 5 3 2 3 3 11 5 5 5 5 5 4 4 12 5 3 2 3 13 4 4 4 14 15 2 2 16 2 1, 2 17 4 4 18 5 5 3 4 4 4 4 4 4 4 4 4 4 4 5 3 2 5 4 19 5 5 5 4 3 4 4 4 4 3 20 5 21 3 3 3 22 3 4 4 23 24 4 3 3 2 4 25 2 5 3 2 3 4 4 2 2 2 26 4 4 4 4 4 4 3 4 4 3 4 4 4 4 4 4 4 27 5 4 4 3 28 5 5 5 5 5 5 5 4,5 4,5 3 2 3 2 3 3 3 3 2 2 3 3 4 4 4 4 3 4 4 29 5 30 5 31 3 3 3 4 32 2 2 3 3 4 2 3 4 3 4, 5 33 5 5 3 34 3 3 3 35 3 36 3 4 5 37 4 4 3 2 4 3 38 5 5 2 5 39 5 5 5 3 3 2 3 3 3 3 3 4 4 40 5 2 2 3 2 2 2 3 2 4 2 3 4 3 2 3 3 ---------------------------------------------------------------------------------------------------------------------------------------------------- \a Letters in column headings under each activity refer to information types displayed in figure 1. Numbers in cells are 1, never; 2, seldom; 3, sometimes; 4, usually; 5, always. \b Criteria follow numbers in table 3.1. Table 3.4 The Number of Criteria Met Within Each Information Type Assign Not Activity Information type ed Met met ---------------- ------------------ ------ ------ ------ Effluent Discharges from 14 14 0 guidelines individual development sources Removal 13 12 1 technologies Water use 13 13 0 reduction technologies Economic data 7 7 0 Water quality Concentration in 12 11 1 criteria biota development Aquatic life 9 9 0 exposure Aquatic life 15 13 2 effects Human health 12 10 2 effects Human health 7 6 1 exposure Impaired water In-stream water 11 7 4 and point quality source identification Concentration in 11 7 4 sediments Concentration in 10 8 2 biota Discharges from 11 2 9 individual sources Aquatic life 9 4 5 effects Fate and transport 12 4 8 TMDL development Hydrology 5 1 4 In-stream water 11 8 3 quality Concentration in 12 7 5 sediments Concentration in 9 5 4 biota Discharges from 11 7 4 individual sources Fate and transport 17 9 8 Water-quality- Hydrology 13 10 3 based permit issuance In-stream water 23 14 9 quality Discharges from 22 12 10 individual sources Fate and transport 21 14 7 "Local limits" Discharges from 18 11 7 development individual sources Removal 13 9 4 technologies Fate and transport 14 9 5 Compliance In-stream water 10 2 8 problem quality identification Aquatic life 10 7 3 exposure Discharges from 11 8 3 individual sources ============================================================ Total 386 260 126 Percent 66% 34% ------------------------------------------------------------ \a Criteria numbers are in table 3.1. MEANINGFULNESS OF THE RESULTS ---------------------------------------------------------- Chapter 3:4 The work presented above shows that practice within 5 of the 7 core activities does not measure up to EPA's enunciated information quality assurance policies and principles. This raises questions about the quality of information generated and used within these 5 activities. We initiated a separate qualitative review of agency documents and information bases and were able to confirm at least some of these findings. For example, many of our EPA interviewees had noted that data on in-stream water quality for toxic pollutants are generally lacking (criterion 37). We were able to confirm the accuracy of these responses through a review of the data in STORET, EPA's principal repository of water quality data. For a group of streams around the nation on which large manufacturing facilities are situated, we found very few with any data for toxic pollutants.\2 In fact, we found that only 9 percent of these streams had had any in-stream data for organic toxic pollutants or pesticides entered in STORET since 1988, despite the presence of major industrial facilities discharging a variety of toxic pollutants into all these waterways. A lack of in-stream data can result in pollutants failing to be identified or limited on NPDES permits. For example, when there is no information about in-stream concentrations of pollutants being considered for a water-quality-based limit (activity 5), the in-stream concentration parameter is set to zero within the modeling routine used to derive permit limits. For streams in which the pollutant is present but is not reported, the absence of data signifies that a greater amount of pollutant discharge from facilities will be allowable than if valid in-stream data had been available.\3 It may also lead to facilities not receiving limits (restrictions) covering toxic pollutants although there is a water quality concern in the receiving body of water. EPA acknowledges some of these problems and has embarked on a program to modernize STORET to address them. -------------------- \2 These streams (river reaches) were selected because dischargers within three significant industrial categories (pesticide manufacturing, pharmaceutical manufacturing, and pulp and paper manufacturing) are situated on them. \3 Environmental Protection Agency, Technical Support Document for Water Quality Based Toxics (Washington, D.C.: March 1991), p. 130. SUMMARY ---------------------------------------------------------- Chapter 3:5 Our findings raise concerns about the quality of the information supporting EPA's core activities controlling toxic discharges into surface waters. Although 2 of the activities had strong quality assurance practices associated with them, the 5 others were much weaker, meeting about 58 percent of their critical quality assurance criteria. THE EXTENT TO WHICH LIMITS FOR TOXIC SUBSTANCES ARE INCLUDED ON NPDES PERMITS ============================================================ Chapter 4 In this chapter, we address our third evaluation question: To what extent are limits for toxic substance discharges included on NPDES permits? We answered this question by comparing information on actual toxic pollutant discharges from three data sources with a list of toxic pollutants controlled through NPDES permits for a sample of facilities. IDENTIFYING TOXICS TO BE LIMITED ON NPDES PERMITS ---------------------------------------------------------- Chapter 4:1 We based the development of our sample of facilities to examine on three industrial categories: pesticide manufacturing, pharmaceutical manufacturing, and pulp and paper manufacturing.\1 We reviewed the information on actual toxic effluent discharges for 236 facilities within these categories and compared them to the facilities' permits. Identifying which pollutants to control through the NPDES permit process is the critical step in issuing permits. As stated earlier, without an explicit permit limit on a pollutant, a facility is free to discharge any amount. Hence, identifying the range of pollutants that should be included on NPDES permits is essential for the toxic control program to succeed. It has been generally conceded that a discrepancy exists between the number of pollutants that are regulated through permits and the number that should be regulated.\2 However, this gap has not been systematically examined. We do so here and report our findings in this chapter for a sample of dischargers. It should be noted that the existence of such a gap would not in itself suggest problems with the permit process. That would be the case only if the discharge of uncontrolled toxicants resulted in unacceptable risks to human health and aquatic life. We address this issue in chapter 5. -------------------- \1 We selected these three because EPA's effluent guidelines program had recently conducted monitoring studies for facilities within these categories. \2 U.S. General Accounting Office, Water Pollution: Stronger Efforts Needed by EPA to Control Toxic Water Pollution, GAO/RCED-91-154 (Washington, D.C.: July 1991), p. 4. INFORMATION SOURCES ABOUT DISCHARGES ---------------------------------------------------------- Chapter 4:2 Our sources of information about toxic pollutant discharges for our sample of facilities were (1) each facility's permit application (EPA Form 2c); (2) EPA's Toxic Release Inventory (TRI), an annual inventory of discharges from the largest manufacturing facilities in the nation; and (3) discharge data collected under effluent guidelines.\3 We pooled these three sources of information to identify the toxic pollutants being discharged at the facilities in our sample.\4 Each of these sources employs a different data collection method. Consequently, using all three sources provides us a more comprehensive characterization of the toxic pollutant discharges from our sample of facilities. TRI in particular has a different data collection method than the permit applications. Much of the data it contains were derived from mass balance calculations or published emissions factors. These data collection methods complement the monitoring information contained within the other data sources. Table 4.1 presents the major attributes of the three data sources. Table 4.1 Major Attributes of Three Sources of Discharge Information Attribute Permit applications Effluent guidelines TRI ----------- ------------------- ---------------------- ---------------------- Primary To identify To identify pollutants To identify the purpose pollutants being and concentrations amounts of "hazardous discharged for discharged by the most chemicals" that are purposes of permit efficient facilities annually and routinely issuance within an industry discharged into the environment Data source Approximately 7,000 Small sample within Approximately 2,300 major and 57,000 selected industries facilities discharging minor facilities into surface waters Frequency Every 5 years No schedule Annually of reporting Time period Daily Daily and annually Annually covered by estimate Number of Varies Typically, a series No requirements samples for over 3 days each estimate Sampling Not applicable Individually selected All facilities meeting frame industries size requirements discharging toxics Pollutants Priority pollutants More than 450 Approximately 300 covered and pollutants pollutants and 80 others "if chemical groups expected to be present" Principal Monitoring for Monitoring Mass balance, basis of priority engineering estimate pollutants; calculations, or identification of monitoring 80 others "if expected to be present"\a Who Facility EPA Facility collects sample -------------------------------------------------------------------------------- \a Details of monitoring requirements are contained in section 122.21 of title 40 of the Code of Federal Regulations. -------------------- \3 We used the TRI responses from 1989, the most recent available when we conducted our analyses. \4 We included 234 facilities from TRI. Because of the difficulty of obtaining and reviewing permit applications, we drew a random sample of 72 facilities for data from that source. The third source of data, effluent guidelines studies, contributed data for approximately 32 facilities, which was the number of direct dischargers available within that data set. TOXICS DISCHARGED WITHOUT PERMIT LIMITS ---------------------------------------------------------- Chapter 4:3 We found a large number of different pollutants being discharged by one or more of the 236 facilities. One hundred and eighty-five different toxic pollutants were reported to have been discharged from the 236 facilities. Whereas some pollutants were discharged from a single facility, others were reported from numerous facilities. For example, chloroform, a common byproduct of industrial processes that EPA views as a "probable" carcinogen, was reported to be discharged by 91 of the 236 facilities. Table 4.2 presents the toxic pollutant discharges we identified, indicates whether they are priority pollutants or nonpriority pollutants, and shows the number of facilities they were discharged from and the number that were uncontrolled through the permit process across the 236 facilities in our sample. Because of the proprietary nature of some of the discharge data, we cannot present a facility-by-facility breakdown of our results. Table 4.2 The Extent of Discharge and Control of Individual Toxic Pollutants, Priority and Nonpriority Faciliti Faciliti es where Priority es listed pollutan releasin on Pollutant t g permit ------------------------------ -------- -------- -------- 1,1-dichloroethane No 1 1 1,1-dichloroethylene Yes 3 0 (vinylidene chloride) 1,1,1-trichloroethane Yes 7 3 1,1,2-trichloroethane Yes 1 1 1,1,2,2-tetrachloroethane Yes 1 1 1,2-dichloroethane Yes 12 6 1,2-butylene oxide No 2 0 1,2-dichlorobenzene Yes 1 1 1,2-dichloroethylene No 1 0 1,2-dichloropropane Yes 1 1 1,2,4-trimethylbenzene No 2 0 1,2,4-trichlorobenzene No 1 0 1,3-butadiene No 1 0 1,3-dichlorobenzene Yes 1 1 1,3-dichloropropylene Yes 1 0 1,4-dichlorobenzene Yes 1 1 2-hexanone No 1 0 2-phenylphenol No 1 0 2,3,7,8-TCDD (dioxin) Yes 5 1 2,4-D No 3 2 2,4-diaminotoluene No 1 0 2,4-dichlorophenol Yes 2 1 2,4-dimethylphenol Yes 1 0 2,4-dinitrophenol Yes 1 0 2,4,5-TP No 1 0 2,4,6-trichlorophenol Yes 1 0 3,3-dichlorobenzidine Yes 1 1 3,4,5-trichloroguaiacol No 1 0 3,4,5-trichlorocatechol No 2 0 4,4'-isopropylidene diphenol No 1 0 4,5-dichlorocatechol No 2 0 4,5-dichloroguaiacol No 2 0 4,5,6-trichloroguaiacol No 1 0 5,6-dichlorovanillin No 1 0 6-chlorovanillin No 1 0 Acetaldehyde No 5 0 Acetone No 108 1 Acetonitrile No 4 0 Acrolein Yes 1 0 Acrylamide No 2 0 Acrylic acid No 3 0 Acrylonitrile Yes 3 2 Alachlor No 1 1 Aluminum No 7 1 Ametryn No 1 0 Ammonia No 147 56 Ammonium nitrate No 7 0 Ammonium sulfate No 9 1\a Aniline No 4 0 Antimony Yes 3 1 Arsenic Yes 9 1 Asbestos Yes 1 0 Atrazine Yes 1 0 Barium No 6 0 Benomyl No 1 0 Benzene Yes 5 2 Biphenyl No 6 0 Bis(2-chloroethyl) ether Yes 1 1 Bis(2 ethylhexyl) phthalate Yes 9 1 Boron No 3 0 Bromacil No 1 1 Bromoform Yes 2 1 Bromomethane Yes 1 1 Butachlor No 1 1 Butylamine No 1 0 Cadmium Yes 1 0 Calcium No 3 0 Captan No 2 0 Carbaryl No 3 1 Carbon disulfide No 2 1 Carbon tetrachloride Yes 6 4 Catechol No 72 0 Chlorinated phenols No 3 1\b Chlorine No 44 19 Chlorine dioxide No 2 2\c Chloroacetic acid No 2 0 Chlorobenzene Yes\d 4 3 Chloroethane No 2 0 Chlorofluoromethane No 1 0 Chloroform Yes 91 28 Chloromethane Yes 5 0 Chlorothalonil No 1 0 Chromium Yes 22 4 Cobalt No 1 0 Copper Yes 17 4 Cresol No 1 0 Cyanide Yes 12 8 Cyclohexane Yes 2 0 Dacthal No 1 0 DDT Yes 1 1 DEET No 1 1 Di-n-butyl phthalate Yes 1 0 Dicamba