United States Environmental Protection Agency Office of Water Washington D.C. EPA841-B-92-001 July 1392 EPA A Quick Reference Guide Developing Nonpoint Source Load Allocations for TMDLs Printed on Recycled Paper ------- A QUICK REFERENCE GUIDE Developing IMonpoint Source Load Allocations for TMDLs Prepared by Tetra Tech, Inc. Fairfax, VA Prepared for the U.S. Environmental Protection Agency Office of Wetlands, Oceans, and Watersheds Assessment and Watershed Protection Division ------- Table of Contents 1. Introduction and Purpose 1 2. The TMDL Process and Nonpoint Sources 1 3. Prioritization and Targeting 3 4. Tools to Assess Water Quality and Estimate Load Allocations 4 a. Identifying Impaired Water Bodies 5 • Survey of Existing Information 5 • Analysis of Water Quality Information 8 • The Role of Water Quality Monitoring 10 b. Analyzing Pollution Sources 12 • Watershed Characterization 13 • Watershed Simulation Models 16 • Receiving Water Quality Models 18 5. Best Management Practices 20 a. Agriculture 20 b. Forestry 21 c. Urban Areas 21 6. Follow-up Monitoring 22 7. Contacts and References 23 This synopsis was developed in response to the concerns and issues raised at the Section 303(d) Coordinators Conference in February 1992. ------- Page 1 1. INTRODUCTION AND PURPOSE This synopsis of existing guidance, technical manuals, and case studies is intended to assist EPA Regional Coordinators, State managers, and local agencies to develop load allocation estimates for total maximum daily loads (TMDLs). It is a preliminary guide to the information and tools that are currently available to assess and characterize nonpoint source problems within the TMDL framework. It can also help to determine the data and tools that are needed to calculate a load allocation as part of a TMDL, to indicate how sufficient and accurate information can be obtained, and to facilitate decisions regarding selection and implementation of pollution control measures. While none of the tools were explicitly developed to derive load allocations, they can be useful and are appropriate. This guide provides brief explanations of existing guidance and technical manuals that can best be used as part of the Clean Water Act (CWA) §303(d) process and in planning on a watershed level. Documents that are summarized include those that can assist with the establishment of a monitoring plan to support TMDL project objectives and creation of a data base to facilitate decision-making, among others. This document is not intended to be a guidance in the classic sense. No new material or procedures have been developed. In addition, this document is not intended to replace any future technical guidance on how to develop and/or implement TMDLs. Until such technical guidance is available, however, it is important to use the resources that do exist to our best advantage. The references that are listed and discussed within this document are by no means exhaustive. There are certainly numerous others that can and will be of use to assist with TMDL development. EPA Regional Coordinators, State managers, and local agencies are encouraged to use these other references, as well. Where possible, the name, address, and phone number of any individual, agency, and organization who can provide support are provided. 2. THE TMDL PROCESS AND NONPOINT SOURCES Guidance for water quality-based decisions: The TMDL process (EPA, 1991a) The TMDL process provides water quality managers with an analytical method to address more complex water pollution problems, such as nonpoint sources, and to adopt a more integrated approach in their analysis. The Guidance for Water Quality-based Decisions: The TMDL Process, also known as the TMDL Program Guidance (EPA, 1991a), and the Workshop on the Water Quality-based Approach for Point Source and Nonpoint Source Controls have set the stage for the watershed approach and re-emphasized the need for moving beyond the "chemical-by- chemical and permit-by-permit" point source approach. To facilitate adoption of the watershed approach, the TMDL Program Guidance (EPA, 1991a) defined it as five stages or steps. Steps one, two, and three make up the TMDL process. ------- Page 2 1. Identification of water quality-limited waters still requiring TMDLs 2. Priority ranking and targeting 3. TMDL development 4. Implementation of control actions 5. Assessment of water quality-based controls. The identification of water quality-limited waters and priority ranking and targeting are the focal steps of the TMDL process. Most of the decisions associated with the development of TMDLs and control programs are based on the information that is assembled during these two steps. The identification step was outlined in the TMDL Program Guidance (EPA, 1991a). It requires a review of applicable water quality standards and the analysis and interpretation of existing water quality information. Priority ranking and targeting requires evaluation of the perceived magnitude of the quality impairment of a receiving water in its geographic and economic context. The CWA requires that the priority ranking of water quality-limited waters take into account the severity of pollution and the uses to be made of such waters. The TMDL Program Guidance (EPA, 1991a) suggests additional factors, including risk to human health and aquatic life and the degree of public interest and support. To do this properly may require the development of monitoring and sampling programs or special projects, and the use of screening-level models to illustrate which pollution problems are the most serious. Once priority impaired or threatened waters are delineated, the TMDL must be developed and pollution controls implemented for point and nonpoint sources so that water quality ,is restored (or preserved) and State standards are attained. A TMDL is, essentially, the estimated assimilative capacity for a water body that tells water quality and land management agencies how much of a pollutant may enter a water body without affecting designated uses. More data and information are often necessary to make this estimation. Special monitoring programs may be needed to facilitate a more complete analysis of pollution sources, and the eventual application, if necessary, of watershed and/or water quality simulation models. The TMDL process distributes portions of a water body's assimilative capacity to various pollutant sources—including natural background sources and a margin of safety—so that the water body achieves its water quality standards. The analyst may use predictive modeling procedures to evaluate alternative pollution allocation schemes in the same water body. By optimizing alternative point and nonpoint source control strategies, the cost effectiveness and pollution reduction benefits of allocation tradeoffs may be evaluated. Mathematically, a TMDL is represented as the sum of the wasteload allocations (WLAs) for point sources, the load allocations (LAs) for nonpoint and natural background sources, and a margin of safety (MOS). TMDL = EWLA + ELA + MOS The MOS is included to account for scientific uncertainty about whether the TMDL reflects the actual assimilative capacity of the water body. This uncertainty can be caused by insufficient or poor quality data or a lack of knowledge about the resource and pollutant loadings. The MOS can also be used to save assimilative capacity for future growth that may contribute additional pollution to the water body. ------- Page 3 When you cannot be reasonably certain that a TMDL will attain water quality standards in a given water body—because there is not enough information about the water body itself, pollutant behavior within the water body, pollutant sources, the effectiveness of pollution controls, etc.— the TMDL should be developed in phases. This means that, using the information that is available, a TMDL should be developed and implemented, and then re-evaluated and revised, if necessary, when better information is at hand. This phased approach requires well-designed post monitoring programs and periodic re- assessments of the TMDL allocations. In addition to the allocations for point and nonpoint sources, a TMDL under the phased approach will establish the schedule or timetable for the installation and evaluation of point and nonpoint source control measures, data collection, the assessment for water quality standards attainment, and, if needed, additional predictive modeling. The scheduling with this approach should be developed to coordinate all the various activities (permitting, monitoring, modeling, etc.) and involve all appropriate local authorities and State and Federal agencies. The schedule for the installation and implementation of control measures and their subsequent evaluations should include descriptions of the types of controls, the expected pollutant reductions, and the time frame within which water quality standards will be met and controls re-evaluated. The phased approach is necessary to use when nonpoint sources contribute to the pollution problem because of the technical uncertainties of estimating nonpoint source loads, and the uncertainties about the effectiveness of nonpoint source controls at a specific site. The phased approach deals directly with these uncertainties by allowing for scheduled re-assessment and updating of the TMDLs and implementation of nonpoint source control programs. The TMDL Program Guidance (EPA, 1991a) contains more specific information on the phased approach on pages 22 and 23. 3. PRIORITIZATIONAND TARGETING Handbook on geographic targeting, Draft (EPA, 1991b) Selecting priority nonpoint source projects: You better shop around (EPA, 1989a) Setting priorities: The key to nonpoint source pollution (EPA, 1987a) EPA's Office of Water has made targeting of nonpoint pollution sources an integral component of the TMDL process. Guidelines for assisting in the development of a targeted nonpoint source program and establishment of priorities at the State and watershed level were defined in Setting Priorities: The Key to Nonpoint Source Control (EPA, 1987a). This document pinpoints the programmatic steps required to rank nonpoint source priority areas, describes the set of prioritization criteria to be considered, and presents several examples of water resources prioritization. The document also presents an approach for determining the pollutant reduction needed to achieve water quality goals. ------- Page 4 Many States currently use a formal process for prioritizing water quality-limited waters as part of their nonpoint source program. Six examples of State prioritization systems are described in Selecting Priority Nonpoint Source Projects: You Better Shop Around (EPA, 1989a). This document is intended to help water quality managers develop or refine their own process for ranking nonpoint source impaired or threatened water bodies, encouraging water quality managers to adapt these examples to their State nonpoint source management programs where appropriate. The manual does not provide a "cookbook" approach. The most common criteria used in the six State prioritization systems that were reviewed were identified and their use in deciding whether to obligate limited resources for water quality restoration or preservation efforts were discussed. This document also briefly reviews (1) the priority criteria for the State Clean Water Strategy which encompasses the Management of Nonpoint Sources of Pollution (CWA §319), the Individual Control Strategies for Toxic Pollutants (CWA §304), Clean Lakes (CWA §314), and the National Estuary Program (CWA §320), and (2) the priority grant criteria for CWA §319(h) funds. EPA is also preparing a handbook for targeting procedures and approaches for use by Federal, State, and local agencies in developing their TMDL program agendas. The Handbook on Geographic Targeting (in Final Draft) summarizes available approaches and recent experience with water quality targeting. This document describes the four components of geographic targeting: (1) assessment, (2) ranking, (3) public participation, and (4) selection. Several illustrative examples are presented to assist water quality managers by providing information on ongoing programs. The document also facilitates a more integrated approach to targeting by exploring the relationship among all of the existing water quality programs, including the Nonpoint Source, §303(d) TMDL, §314, and §319 programs. 4. TOOLS TO ASSESS WATER QUALITY AND ESTIMATE LOAD ALLOCATIONS In general, several activities are required to identify and examine the nature of impaired waters within a particular region, and to identify, examine, and assess the dimensions and causes (i.e., point and/or nonpoint sources) of impairment so that the impaired waters can be prioritized and targeted. Common objectives of a preliminary assessment include identifying the waters within a region that are water quality limited and characterizing the nonpoint sources, as well as their contribution to the total load, and their temporal and spatial distribution. To achieve these objectives, analyses usually begin with a general characterization of the watershed, its water quality, and the water impairment mechanisms. Analyses may then progress to a more specific understanding as it becomes necessary to quantify water quality problems by estimating pollutant loadings. Very often the tools that are used to make a general characterization of a watershed can also be used to conduct the more specific analyses. The central difference among the stages of watershed analysis is the amount of data needed and the intensity and rigor of modeling activities. Both increase as analyses become more complex. ------- Page 5 a. Identifying Impaired Water Bodies • Survey of Existing Information - STORE! assistance hotline: (800)424-9067 - EPA mainframe data and tools for watershed assessments. Appendix A in Workshop on the Water Quality-based Approach for Point Source and Nonpoint Source Controls Meeting Summary (EPA, 1991c) - PC Waterbody System User's Guide (Version 3.0) (EPA, 1991d) One of the most important activities in problem identification consists of a survey and analysis of existing information. Such information is usually composed of qualitative observations and quantitative measurements. Qualitative observations may include specific reports from water quality managers, water body users, and citizen complaints concerning water quality deterioration such as increased turbidity within a given season, reduced fishing resources, changes in the eutrophic level and algae proliferation, and stream bank erosion and channel displacement. These reports are well known to iocal and regional water managers and their analysis represents the initial steps in identifying problem waters, estimating the perceived magnitude of the pollution problem, and evaluating the public concerns. Quantitative water quality measurements, collected from various monitoring programs, are usually available on electronic systems and can be readily used in preliminary water quality assessments. The information may be retrieved from various sources and integrated into several reporting formats. EPA has several water quality and related information files for the United States which are available on its main frame computer. These files can be accessed by registered STORET users with a valid user identification. Analysis of the information contained within the STORET system can provide a quantitative estimation of water quality conditions and evaluation of their temporal and spatial variabilities. A brief summary of data bases and the type of water quality and related information they contain is presented in Table 1. More detailed descriptions of these files and their structure and use can be found in the corresponding data file manuals. Also, Appendix A, "EPA Mainframe Data and Tools for Watershed Assessments," in the Workshop on the Water Quality-based Approach for Point Source and Nonpoint Source Controls Meeting Summary (EPA, 1991c) summarizes the data bases that are available for use by the public and how they may be accessed. Example applications are also provided. Additional water quality information may be retrieved from the Waterbody System (WBS). The WBS is a PC-based system containing the water quality information that must be reported under §305(b), §303(d), §314, and §319 of the CWA. If the WBS is not used, the 305(b) Report contains much of the same information. Recently, a new version of the PC Waterbody System User's Guide (Version 3.0) (EPA, 199Id) was developed by the Assessment and Watershed Protection Division of EPA. The WBS uses a standard format and allows for large ------- Page 6 Table 1 - OWOW/AWPD Data Files Drinking Water Supply File - The Drinking Water Supply File contains information on 8,000 water supplies that utilize surface waters. Data covers FRDS number, utility name, city, state, basin, latitude and longitude, stream reach, population served, water volume used, and locations for plants, intakes, and sources. Gage - The Stream Gage Data File contains information on approximately 36,000 stream gaging locations throughout the United States. Information stored includes locations of gaged streams, stream reach identification, types of data collected, frequency of data collection, media in which the data is stored, identification of the collection agency, mean annual flow, and 7 day/10 year flow. The file also contains estimated flows for all ungaged streams. City - This file contains data on 53,000 cities, towns, and villages located in the United States and its possessions. Information on each city includes the city's unique identification code; the county, state, major and minor river basin, and congressional district within which ft is geographically located; stream reaches associated with the city; its latitude and longitude; and its census population data. Dam - Inventory of 68,000 dams produced by U.S. Army Corps of Engineers which provides type, ownership, purpose, height, volume, surface area, latitude-longitude, and stream reach. Industrial Facilities - The Industrial Facilities Discharge File contains information on 128,000 NPDES industrial and municipal facilities (active and inactive) useful for environmental analyses. Data consists of NPDES, DUNS, and Needs A/F numbers with name, address, basin latitude and longitude, stream reach, flow, SIC codes, discharge types for facility and pipe level, and industrial category. Indirect discharges to POTW systems are also included. CETIS - The Complex Effluent and Toxicity Information System contains bioassay results for NPDES discharges toxicity tests. SIWPCA - Streams reported in the Americas' Clean Water STEP report by the Associations of State and Interstate Water Pollution Control Administrators (ASIWPCA) covering water quality impairments for 1972, 1982, and 1984 and indexed to the version 1 reach file. ICAT - Industrial categories used in effluent guidelines studies are grouped with standard industrial classification (SCI) indexes. STORET PARM - Information on 13,000 STORET parameters indicating reporting units, media, CAS registry number, and chemical/biological type. ODES - The Ocean Data Evaluation System is an extensive system of software for managing and analyzing marine environmental monitoring data. PCS - The Permit Compliance System contains NPDES permit compliance, tracking, and discharge monitoring reports for active permitted facilities. ------- Page 7 Table 1 - OWOW/AWPD Data Files (continued) Reach File - The River Reach File provides hydrologic connectivity between geographic locations and historical data created for the express purpose of performing hydrologic routing for modeling programs. The Reach File, Version 1, contains 68,000 stream reaches covering 100% of the continental U.S. and is indexed with STORET, IFD, drinking water supplies, stream gages, and fish kills. Version 3 covers 80% of the U.S. and provides hydrologic linkages for 3.5 million reaches based on the USGSW DLG data. STORET-BIOS - A component of STORET containing distribution, abundance, physical condition, and habitat description of aquatic organisms. These are integrated with the water quality file and linked to the reach file, PCS, IFD, and Gage files. STORET-USGS Flow - Contains daily stream observations of stream flow and miscellaneous water quality at USGS gaging stations. These data represent more than 695,000 water years for over 29,000 gages. STORET-WQ - The agency's water quality system containing physical, chemical, and biological parameters. More than 800 monitoring organizations have provided 175 million parametric observations from 700,000 sampling locations for surface water, ground water, fish tissue, and sediment. The sample locations are indexed to the reach file IFD, GAGE, and drinking water file with a PCS interface. STORET-Tissue - Tissue sample results cover over 530 parameters including metals, organics, and pesticides specific to species, tissue types, length, weight, and sex. These data and stations are integrated with the water quality file and indexed to the reach file with indexes to IFD, Gage, drinking water files, and the PCS interface. STORET Form 2C - Priority pollutant data reported by NPDES second round permits are in STORET referenced by the permit number and can be integrated with the water quality data and PCS data with the PCS/STORET interface. WBS - The Waterbody System data base contains water quality assessment information collected by states for 305(b) reporting. These data serve as an inventory of each state's navigable waters that have been assessed. quantities of water quality information to be summarized and reported according to the requirements of CWA §305(b). The WBS User's Guide provides detailed information for operating the various system options, including new data entry, assessment updates, and report generation. The system was developed to improve the quality and consistency of water quality reporting and to reduce the burden of report preparation. It is also intended to enhance water quality analytical capabilities by making it possible to compare assessment data over time and space. ------- Page 8 Analysis of Water Quality Information Water quality analysis system: Seminar documentation (EPA Region III, 1991) PCS data base management system design, PCS Generalized retrieval manual (EPA, 1987b) Managers guide to STORET (EPA, 1982) Methodologies for estimating NPS impacts on water quality from development (EPA Region V, 1991) Statistical methods for environmental pollution monitoring (Gilbert, 1987) Evaluation of some approaches to estimating non-point pollutant loads for unmonitored areas (Richards, 1990) DESCON user's manual, Draft (Rossman, 1992) Developing a monitoring system (EPA, 1991e) Several technical tools are needed to analyze available water quality information as part of a water quality assessment within the TMDL framework. These tools may range from simple statistical summaries of water quality data to more complex graphical representation and trend and excursion analyses. In addition to water quality data files, several interactive analysis procedures were developed by EPA to enable users to access, retrieve, and analyze the water quality and related information contained in EPA's main frame computer. Table 2 lists the water quality analysis systems most commonly used. Several system user guides and operation manuals are available from EPA, including the Managers Guide to STORET (EPA, 1982), and the PCS Generalized Retrieval Manual (EPA, 1987b). Other system guides were compiled in the Water Quality Analysis System: Seminar Documentation (EPA Region III, 1991). The DESCON system is another tool that may be useful to water quality managers when analyzing various water quality parameters to identify impaired and/or threatened waters. It provides automatic linkages to EPA's STORET system for retrieving stream flow and water quality data. These data are necessary to perform a long-term simulation of the daily loading of a pollutant that a receiving water can accomodate without violating standards. DESCON's Option 1 retrieves daily stream flow data, compiled by the U.S. Geological Survey (USGS), from the EPA's STORET data base system. Option 2 retrieves water quality data from STORET. Option 3 can perform various statistical analyses on the water quality data extracted from STORET to indicate trends. This system cannot be used to perform nonpoint source load allocation studies at this time. The DESCON User's Manual (EPA, 1992) is currently being updated. It should be finalized by the summer of 1992. More information on this water quality package may be obtained directly from Lewis A. Rossman, EPA Risk Reduction Engineering Laboratory, Cincinnati, Ohio (513/569-7603). ------- Page 9 Two useful references on various methods and procedures for interpretation of water quality data include Statistical Methods and Procedures for Environmental Pollution Monitoring (Gilbert, 1987), and Evaluation of Some Approaches to Estimating Non-Point Pollutant Loads for Unmonitored Areas (Richards, 1990). Additional references can be found in Methodologies for Estimating NPS Impacts on Water Quality from Development (EPA Region V, 1991). Statistical Methods and Procedures for Environmental Pollution Monitoring summarizes the fundamental sampling design questions typically encountered in environmental studies and presents numerous statistical tools for data interpretation. It also presents statistical procedures for estimating sampling size, duration, and geographical coverage. Standard statistical methods for describing water quality conditions (e.g., mean, median) and evaluating the magnitude of temporal and spatial trends are presented along with selected specialized procedures for addressing problems related to the limitations common to environmental data sets (e.g., non- normality, seasonality, censoring). Table 2 - OW Mainframe Interactive Analysis Systems ASIWPCA Interactive program providing information on stream use impairment CITY Interactive program providing overview information on cities DAMR Interactive program providing information on dams in the U.S. DFLOW Interactive program providing daily flows at gages and selected flow statistics DXLIST Interactive program providing information on dioxin EDDM Interactive program for graphically displaying locations of monitoring activities, PCS, and WQ data FLOW Interactive program providing information on gage mean flow, 7Q10 low flows, and daily flows ICAT Procedure to list industrial categories and related SIC codes in IFD File used by ITD IFDPLOT Interactive program to set up graphical displays of Facility data IFDRET Interactive program for generating standard tables of information from IFD IPS5 Interactive procedure for generating reports from STORET, PCS, and IHS files ISR Interactive, generates selected STORET and IFD reports and DO model using PCS DMR data MDDM Interactive mapping system for the Reach File, Facility, WQ, and WBS data PARM Interactive program for providing information on STORET parameters PATHSCAN Retrieval of information on hydrological streampaths from NPDES discharge locations RCHDAT Interactive program for retrieving reach, streamflow, and discharger data RCHRET Interactive procedure for generating reach trace Auxfiles for plotting or export RPA3 Reach pollutant assessment software providing reports using STORET, PCS, TRIS, and IHS data SIC Interactive program to obtain SIC codes and descriptions used in the IFD File SITEHELP Interactive graphical and text retrieval of stream referenced data using IHS, STORET, and PCS files STRAUX Procedure which generates a STORET AUXFILE for selected reach number USE Interactive program for summarizing WQAB procedure usage for given user ------- Page 10 Evaluation of Some Approaches to Estimating Non-Point Pollutant Loads for Unmonitored Areas examines data extrapolation techniques. Six extrapolation procedures and their application to unmonitored sites were evaluated using the Heidelberg College Water Quality Laboratory data sets. In general, three procedures (inter-basin ratios, C-factor, and discharge) were found to be more reliable than the regression-based approaches. However, the accuracy of these procedures was found to decrease significantly when applied to watersheds different in size from the control. The author also suggests that a paired watershed approach, not evaluated in this study, might be useful for extrapolating nonpoint source loads to unmonitored sections of a drainage basin. The latter approach is addressed in "Developing a Monitoring System," a paper that was presented at the Nonpoint Source Watershed Workshop (EPA, 1991e). The Role of Water Quality Monitoring Surface water monitoring program guidance, draft (EPA, 1990a) Rapid bioassessment protocols for use in streams and rivers: Benthic macroinvertebrates and fish (EPA, 1989b) Nonpoint source monitoring and evaluation guide, draft (EPA, 1987) Methodologies for estimating NPS impacts on water quality from development (EPA Region V, 1991) Biological criteria for the protection of aquatic life: Volume III standardized biological field sampling and laboratory methods for assessing fish and macroinvertebrate communities (Ohio EPA, 1989) The nonpoint source manager's guide to water quality monitoring (Coffey and Smolen, 1990) Guidelines for the monitoring of urban runoff quality (Sonnen, 1983) Methods for evaluating stream, riparian, and biotic conditions (Platts et al., 1983) Information from monitoring programs may be used at various stages of the TMDL process, including identification of impaired or threatened waters, estimation of nonpoint source loadings, calibration and verification of watershed and water quality models, and evaluation of the effectiveness of pollution management practices. Analysis of available water quality data usually reveals data gaps and needs for additional monitoring activities. It also assists in defining the objectives of the monitoring programs, the spatial distribution of monitoring stations, the set of parameters to be monitored, and the frequency and duration of the monitoring program. While it may be unnecessary to collect additional data for a preliminary assessment of impaired waters, special monitoring activities may be required to properly quantify nonpoint source ------- Page 11 loadings to a water body, to calibrate and verify models, and to verify the effectiveness of best management practices to control nonpoint source pollution. In addition, once TMDLs have been established for a given water body, monitoring programs are recommended to document changes in water quality and provide basic information for future reviews and updates of existing TMDLs. This type of follow-up monitoring is required for a phased TMDL. Well-designed ambient water quality monitoring can indicate when and where water quality is impaired by providing the general chemical, physical, and biological data that reflect the water and habitat quality conditions of a water body. There are several useful publications regarding the development and design of monitoring programs for watershed management and nonpoint source pollution assessment projects. References, in addition to those described below, can also be found in Methodologies for Estimating NFS Impacts on Water Quality from Development (EPA Region V, 1991). The Nonpoint Source Manager's Guide to Water Quality Monitoring (Coffey and Smolen, 1990), discusses monitoring objectives and water quality variables, presenting guidelines to help decision makers plan for and design an appropriate monitoring program. Two levels of nonpoint source monitoring, which may be designed according to the objectives, time and resources, and equipment necessary, are presented. Level 1 monitoring focuses on the general condition of water bodies monitored in terms of easily measured variables. Such a program may be used to identify or confirm general problems and determine violation frequencies. Level 2 monitoring builds on information obtained in Level 1 and consists of more comprehensive data collection, often requiring greater resources. Guidelines for the Monitoring of Urban Runoff Quality (Sonnen, 1983) presents storm water monitoring requirements as they relate to project objectives. The key objectives that are reviewed include problem identification, alternative solutions, design, regulatory compliance, operational performance, and research monitoring. This document reviews a number of monitoring programs (Denver, Houston, Chicago, San Francisco, and the National Urban Runoff Program), examines practical design and management considerations, and evaluates the associated costs. Monitoring program components include field sampling, laboratory analysis, data interpretation, and inflation costs. Rudimentary statistical guidance for selecting sample size and analyzing data is also provided. The Surface Water Monitoring Program Guidance (EPA, 1990a) was developed by the EPA in response to increasing needs and demands for improved water quality monitoring. This document targets EPA and State decision makers and provides both technical and programmatic considerations for surface water monitoring. Some of the key topics reviewed include screening for existing and emerging problems and analysis of effective monitoring. Numerous case studies from across the United States are provided to demonstrate typical examples of current monitoring programs. The Nonpoint Source Monitoring and Evaluation Guide (EPA, 1987) makes recommendations on nonpoint source pollution monitoring programs, assessing data needs, and collecting data. It analyzes water quality monitoring activities according to four objectives: (1) develop baseline information, (2) generate sufficient data for trend analysis, (3) develop/verify models, and (4) investigate single incidents or events. This draft document provides an overview of NPS pollution problems as well as a summary of sampling requirements and basic statistical procedures. ------- Page 12 The Rapid Reassessment Protocols for use in Streams and Rivers: Benthic Macroinvertebrates and Fish (EPA, 19895), was developed by EPA to assist State programs in conducting cost-effective biological assessments. Three macroinvertebrate and two fish protocols are presented. Benthic Rapid Bioassessment Protocol I and Fish Rapid Bioassessment Protocol IV are cost-effective screening procedures that provide some supporting data; Benthic Rapid Bioassessment Protocol II can help set priorities for more intensive evaluations; and Benthic Rapid Bioassessment Protocol III and Fish Rapid Bioassessment Protocol V are progressively more rigorous and provide more confirmational data, but also require more resources. The protocols advocate an integrated assessment, comparing habitat and biological measures with empirically defined reference conditions. They can be used to determine if a stream is supporting its designated life use, characterize the existence and severity of use impairment, help identify the sources and causes of impairment, evaluate the effectiveness of control actions, support use attainability studies, and characterize regional biotic components. A procedure for evaluating habitat is also presented in this document. The Ohio Environmental Protection Agency has developed a biosurvey program that includes biological sampling of macroinvertebrates and fish, and subsequent habitat evaluation as it relates to the fish community. Biological Criteria for the Protection of Aquatic Life: Volume III. Standardized Biological Field Sampling and Laboratory Methods for Assessing Fish and Macroinvertebrate Communities (Ohio EPA, 1989) address monitoring of resident biota as part of the water quality assessment program to increase the probability of detecting sporadic events (e.g., spills, nonpoint sources) or other highly variable impacts missed by traditional chemical and toxicological monitoring. The Invertebrate Community Index is a measure used by Ohio EPA to accurately evaluate water quality effects in rivers and streams. The ICI is comprised of ten community metrics or attributes including total number of taxa, total number of mayfly taxa, total number of caddisfly taxa, total number of dipteran taxa, percent mayflies, percent caddisflies, percent tribe Tanytarsini midges, percent other dipterans and non-insects, percent tolerant organisms, and total number of EPT (Ephemeroptera, Plecoptera, and Trichoptera) taxa. The scoring system evaluates each sample against a reference database of 247 undisturbed sites throughout Ohio. The U.S. Forest Service has also developed standardized techniques and methods for measuring stream, riparian, and biotic conditions for stream and river analysis. These techniques are compiled in the Methods for Evaluating Stream, Riparian, and Biotic Conditions (Plaits, et al., 1983). This report also addresses the validity of the recommended measurements and information based on their expected accuracy. b. Analyzing Pollution Sources The water quality monitoring and data interpretation methods presented in the previous section are intended to facilitate the identification of water quality-limited'waters. Once problem waters have been identified, the next steps are to survey potential pollution sources and analyze pollution causes and delivery mechanisms. This may include characterizing/assessing the watershed, simulating point and nonpoint pollution sources on a watershed basis, and modeling receiving water quality response. ------- Page 13 Watershed Characterization U.S. Geological Survey National Cartographic Information Center, 507 National Center, Reston, VA 22092, phone: 703/860-6045 Watershed screening methodology - Savannah River Basin application (EPA Region IV, 1992) Workshop proceedings on remote sensing and GIS applications to nonpoint source planning (EPA, 1991g) Introductory digital image processing (Jensen, 1986) A land use land cover classification system for use with remote sensor data (Anderson et al., 1976) Spatial analysis using GIS: Seminar workbook (Goodchild and Brusegard, 1989) Integration of GIS, digital elevation data, and remote sensing for a hydrologic model (Lee et al., 1990) The use of a GIS to track the impact of Virginia Chesapeake Bay Agricultural Nonpoint Source Program (Shanholtz et al., 1988) BMP effectiveness evaluation using AGNPS and GIS (Hession et al., 1989) Annual estimation of nitrogen in agricultural runoff (Yagow et al., 1990) Hydrologic/water quality modeling in a GIS environment (Shanholtz et al. 1990) VirGIS, Dr. Vernon Shanholtz, phone: 703/231-5843 EPA monitoring systems laboratory, phone: 702/798-2100 Agricultural nonpoint source pollution (AGNPS) model (Dr. Robert Young, phone: 612/589-3411) Compendium of watershed-scale models for TMDL development (EPA, 1992a) Airphoto inventories for pinpointing nonpoint sources (Perchalski, 1989) Watershed characterization includes delineating hydrologic boundaries, identifying soil and topographic features, mapping the type of land use/land cover, defining population patterns, surveying point and nonpoint sources of pollution, etc. Several data sources may need to be ------- Page 14 consulted to retrieve all of the necessary information. If possible, in addition to any site-specific information that is available at State and local agencies, U.S. Geological Survey (USGS) topographic maps, local zoning maps, agricultural reports on crop type and area, hydrologic information from USGS gaging stations (on EPA's main frame computer files), National land use data files (USGS and the Soil Conservation Service NRI land use data files), the National Weather Service weather data, demographic information from U.S. Bureau of Census, water supply and other usage (local surveys, EPA STORET files), and the characteristics and geographical distribution of permitted dischargers in the watershed (STORET) should be used. The U.S. Geological Survey National Cartographic Information Center, 507 National Center, Reston, VA 22092, phone: 703/860-6045, provides a nationwide information service for cartographic data of the United States. Information about maps and charts, aerial and satellite photographs, and map data in digital form is available at the center. The EPA main frame can meet many of the needs and goals of watershed analysis and nonpoint source characterization, taking advantage of available national data bases on stream flow and hydrologic parameters, land use distribution, point sources, and water quality measurements. Recent and ongoing system enhancements of several interactive procedures provide significant capability to conduct integrated point and nonpoint source assessments on a regional and watershed level. Preliminary testing of these procedures for application in the TMDL development process are summarized in a draft report Watershed Screening Methodology - Savannah River Basin Application (EPA Region IV, 1992). The techniques employed by this methodology can produce a snapshot of water quality conditions at a regional and watershed level. The regional assessment addresses river basin systems and examines watershed characteristics, general hydrology and water resources, and statistical summaries and trends of water quality indicators. This assessment relies on readily available information stored on EPA's computer system. The methodology is designed to assist in identifying, on a large scale, areas where water bodies are impaired or threatened and to provide a preliminary evaluation of potential point and nonpoint pollution sources. The watershed assessment focuses on water quality-limited areas or sub- watersheds identified at the regional assessment level. It uses simple simulation models to generate area or sub-watershed wide pollutant loadings and evaluates the contribution of each pollution source to the total load. To facilitate application of the watershed assessment, procedures for linking the pollution load simulation model to data bases on the EPA main frame are under development. This screening methodology was developed to assist the water quality manager perform a rapid screening application of water quality problems at a regional and watershed level. The key benefit is the integration of all pollution sources and related factors in the analysis and the optimum usage of readily available data. In addition to identification of water quality-limited waters, analysis of pollution sources, and development of decision criteria for the prioritization and targeting process, the methodology can assist in defining additional data needs and designing monitoring programs. Several TMDL development activities rely on spatial analyses, especially when investigating the significance of nonpoint source pollution loads from specific land uses or activities, or assessing the impacts of temporal changes in land use patterns on water quality. Spatial information, such as land use/land cover and its changes over time may be easily generated from aerial photography or satellite imagery. Although most applications of aerial photographic methods and satellite- based remote sensing techniques were directed toward inventory and assessment of natural ------- Page 15 resources to derive information for management decisions, current technological advances in these methods can provide valuable supplementary data sources to rapidly perform screening level assessments for TMDL development. Airphoto Inventories for Pinpointing Nonpoint Sources (Perchalski, 1989) describes and illustrates the techniques used to develop a nonpoint source inventory in an application to the Tennessee River watershed to derive animal waste, soil loss, and agricultural chemical information. The approach used in this application consists of (1) project planning, (2) material acquisition, (3) information extraction, (4) field checks, (5) data transfer, and (6) data interpretation and reporting. The cost of applying the six-step approach to a one million acre watershed was evaluated at about 20 cents per acre. Example applications of remote sensing techniques to surface mapping (i.e., the creation of a land cover map for Lake County, Illinois, wetland delineation, and analysis of the spatial distribution of suspended sediment within lakes and reservoirs) were presented through other papers in the Workshop Proceedings on Remote Sensing and GIS Applications to Nonpoint Source Planning (EPA 1991g). The EPA Monitoring Systems Laboratory (EMSL), Las Vegas, has extensively employed remote sensing techniques to assess lake water management problems. These techniques are used by EMSL to produce a wide range of management products, such as aerial photography prints, digital image maps, and geographical information systems data bases, that may be used in the TMDL development process. Remote sensing information can be converted into vector-based GIS system data bases for further data processing and modeling to evaluate nonpoint source pollution loadings. It should be noted, however, that the application of remote sensing and GIS techniques to watershed analysis requires both specialized software and hardware, in addition to well-trained personnel to set up and operate the system, process watershed information, and interpret the results. EMSL can provide some guidance with these applications (phone: 702/798-2100). Researchers at the Illinois State Water Survey have used satellite images, scanned aerial photos, and other spatial analysis techniques, including the geographical information system and digital elevation data, to run the Agricultural Nonpoint Source Pollution (AGNPS) Model. Application of this approach to two Illinois watersheds indicated that the approach is technically and economically feasible. Dr. Robert Young (phone: 612/589-3411) can provide more information on applications of the AGNPS model throughout the country. A brief summary of the model itself is also available in the Compendium of Watershed-Scale Models for TMDL Development (EPA, 1992a), which was recently compiled. The Virginia Division of Soil and Water Conservation (DSWC) has used a geographical information system (VirGis) as a component of its nonpoint source pollution control program. The objectives of the VirGis application are to develop (1) procedures to identify, prioritize and target land areas needing improved nonpoint source pollution control measures, (2) procedures to evaluate the effectiveness of nonpoint source pollution control programs and management strategies, and (3) an Information Support System to assist in state wide management of natural resources. Researchers at the Virginia DSWC have published numerous reports, which are listed in the box on page 13, describing experience, assessment procedures, and applications of VirGis to meet the three objectives above. To obtain information on the VirGIS effort, contact Dr. Vernon Shanholtz (ISSL), Department of Agricultural Engineering, 106-A Faculty Street, Blacksburg, VA 24061-0535 (phone: 703/231-5843). ------- Page 16 The Workshop Proceedings on Remote Sensing and GIS Applications to Nonpoint Source Planning (EPA 1991g) also addresses the application of remote sensing and GIS techniques to watershed management and nonpoint source pollution assessment. This document is a collection of selected papers regarding specific applications of remote sensing, GIS, and other techniques (i.e., the Digital Elevation model and watershed simulation models) to nonpoint source problems. Other references that can provide basic remote sensing and GIS fundamentals are cited in the various papers. Watershed Simulation Models Compendium of watershed-scale models for TMDL development (EPA, 1992a) Modeling of nonpoint source water quality in urban and non-urban areas (EPA, 19905) River basin validation of the water quality assessment methodology for screening nondesignated 208 areas. Volume II: Chesapeake Sandusky Nondesignated 208 screening methodology demonstration (Dean et al., 1982) Watershed simulation models may be used in the TMDL process to support a number of objectives and decisions. Typical project objectives that would require application of a watershed-scale model include (1) identifying problem areas or potential nonpoint sources in the watershed and characterizing the magnitude and variability, in time and space, of these sources; (2) comparing watersheds and assisting in the prioritization and targeting process; (3) providing the information necessary for receiving water quality analysis and modeling; (4) providing information for siting and designing control practices; (5) estimating the cost and performance of nonpoint pollution control alternatives; and (6) evaluating their relative impacts on water quality. A wide variety of simulation models are available to evaluate both point and nonpoint pollution loads from watersheds containing multiple point and nonpoint sources and land uses. Although these models were not specifically designed to work within the TMDL process, many of their capabilities can be directly applied to comprehensive water quality-based assessments. Several of these models are Federally supported and can be acquired from the following agencies: • Center for Exposure Assessment Modeling, U.S. EPA, College Station Road, Athens, Georgia, phone: 404/546-3549. . • National Center, U.S. Geological Survey, Reston, Virginia 22092, phone: 703/648-4000. • The Hydrologic Engineering Center (HEQ, U.S. Corps of Engineers, 609 Second Street, Davis, California 95616, phone: 916/756-1104. ------- Page 17 Grassland, Soil and Water Research Laboratory, U.S. Department of Agriculture, Temple, TX 76502, phone:. 817/770-6502. North Centra] Laboratory, U.S. Department of Agriculture, Morris, Minnesota 56267, phone: 612/589-3411. Federally Distributed Watershed-scale Models Dept. of Agriculture Agriculture Research Service Geological Survey Corps of Engineering AGNPS (Agricultural Nonpoint Source Pollution Model) DR3M-QUAL (Distributed Routing Rainfall Runoff Model - Quality) STORM (Storage, Treatment, Overflow, Runoff Model) Potential applications of watershed models in the TMDL process were briefly discussed at the Workshop on the Water Quality-based Approach for Point and Nonpoint Source Controls, held in Chicago in June, 1991. In response to a number of recommendations formulated in this workshop, the EPA's Office of Water compiled a Compendium of Watershed-Scale Models for TMDL Development (EPA, 1992a). This compendium reviews 22 watershed models which can be used to assist in the TMDL development process. Simulation capabilities, modeling performance, data requirements, and ease of use are described for each model. In addition, an exhaustive fact sheet for each model was prepared containing information on the model developer and distributor and a description of model components, limitations, and published applications. The compendium presents a brief comparison of each model's characteristics and discusses pertinent criteria to consider in selecting a watershed model for screening applications. EPA's Office of Research and Development has also sponsored a review of selected watershed- and field-scale models with potential application in water quality analysis and TMDL development. This review is entitled Modeling of Nonpoint Source Water Quality in Urban and Non-urban Areas (EPA, 1990b) and describes 11 computer-based models, in addition to several other simple nonpoint source evaluation methodologies. Several case studies where simulation models have been used to assess nonpoint source pollution problems are described and recommendations for urban nonpoint runoff quality modeling are presented. Earlier EPA-sponsored work developed a screening methodology to assess water quality problems in areas not covered under Section 208 of the Federal Water Pollution Control Act Amendments of 1972. The ensuing write up was entitled River Basin Validation of the Water Quality Assessment Methodology for Screening Nondesignated 208 Areas (Dean et al., 1982). The study incorporates nonpoint source loading factors developed by the Midwest Research Institute (MRI) to estimate the quantities of different diffuse loads entering receiving water bodies from various nonpoint sources. The report demonstrates how a combination of simple techniques could be used to identify water quality problems. It also describes the successful application of the nondesignated 208 screening methodology under field conditions in five river basins (Sandusky River, Chester River, Patuxent River, Ware River, and Occoquan Reservoir). ------- Page 18 Receiving Water Quality Models Water Quality Assessment: A Screening procedure for Toxic and Conventional Pollutants in Surface and Ground Water: Part I (Revised 1985) (EPA, 1985a) Water Quality Assessment: A Screening procedure for Toxic and Conventional Pollutants in Surface and Ground Water: Part II (Revised 1985) (EPA, 1985b) Watershed-scale models allow estimation of pollutant loadings to a receiving waterbody and the analysis of pollution source characteristics, magnitudes, and variability over time and space. Receiving water quality models, on the other hand, examine the transport and fate of pollutant loadings in river, lake, and estuarine environments. Although the majority of water quality models were developed for a wide range of applications, dealing primarily with point sources, waste load allocations, and evaluation of assimilative capacity of receiving water bodies, their use in analyzing nonpoint source pollution load allocations and assisting in TMDL development is well accepted. They are a valuable tool for assessing the causal relationships between changes in nonpoint source pollution loads due to alterations of land use patterns, implementation of watershed management programs, or point source control and the effects on receiving water quality. The results of water quality models provide pollutant distributions in time and space that may be compared to a specific water quality standard or criterion to determine whether violations are likely to occur. For nonpoint source load allocation studies, water quality models rely on inputs from the watershed analysis to properly account for nonpoint source loadings. It is common practice to couple a watershed model and a water quality model to provide an integrated analysis of point and nonpoint source pollution and facilitate comprehensive watershed management. Several water quality models are currently supported by EPA's Athens Environmental Research laboratory (see box). These include, among others, QUAL2E, the Water Quality Simulation Program (WASP4), EXAMS, and SMPTOX. The QUAL2E model can be applied for temperature, oxygen demand, nutrients, phytoplankton, and other user defined problems in rivers and well-mixed lakes. The WASP4 model is a general numeric model intended to provide a flexible temporal and spatial transport of pollutants in rivers, lakes, estuaries, and coastal waters. SMPTOX and EXAMS are particularly appropriate for screening application and identification of potential water quality problem areas. CEAM Supported Models Model Name Version No. DYNTOX EXAMSII HSPF MINTEQA2/PRODEFA2 PRZM QUAL2E-UNCAS SWMM WASP4/TOXI/EUTRO DYNHYD5 GCSOLAR FGETS CORMIX1 CORMIX2 DBAPE CLC Database RUSTIC MULTIMED HYDRO2D-V SED2D-V HYDR03D RTVMOD .1.0 2.94 9.01 3.00 1.00 3.11 4.2 4.22 5.02 1.10 1.00 1.00 2.00 1.05 2.00 . - - - - ------- Page 19 Book II. ill. IV. Among the simple models or methodologies that are supported by EPA are those found in Parts I and II of Water Quality Assessment: A Screening Procedure for Toxic and Conventional Pollutants in Surface and Ground Water (EPA, 1985a and b). These models can be used to compute pollutant levels in rivers, streams, estuaries, and surface impoundments. Computations can be applied to assess dissolved oxygen, toxic substances, metals, sediment accumulation in impoundments, eutrophication, and estuarine flushing time. It should be noted that it is preferable to use the simplest water quality model that can account for the governing mechanisms affecting the targeted water body. However, selection of a model that is too simple may result in inaccurate predictions of water quality conditions, especially when examining pollution load reduction scenarios. These inaccuracies may exist even if the model is properly calibrated using existing data. On the other hand, selection of a model that is too complex can misdirect study resources, delay the study, and be unnecessarily expensive. Also, uncertainty may increase because of • extra "free" model parameters that cannot be estimated with available data. General guidelines and specific procedures for selecting a water quality model for a given application are addressed in the Technical Guidance Manuals for Performing Waste Load Allocations, a set of nine volumes describing approaches for allocating waste loads in rivers, streams, lakes and impoundments, and estuaries. The pollutants addressed are biochemical oxygen demand/dissolved oxygen, nutrients, and toxic substances. Several case studies illustrating model selection and applications are also presented. In contrast with watershed-scale models, no specific reviews and evaluation of water quality models are available; readers may refer directly to any model documentation which can be procured from the EPA Environmental Research Laboratory in Athens, Georgia (a full address is on page 16 of this document). VII. VIII. IX. Technical Guidance Manuals for Performing Waste Load Allocations Title General Guidance Streams and Rivers Biochemical Oxygen Demand/Dissolved Oxygen N utrient/Eutrophication Toxic Substances Simplified Analytical Method for Determining NPDES Effluent Limitations for POTWs Discharging into Low-Flow Streams Estuaries Estuaries and Waste Load Allocation Models Application of Estuarine Waste Load Allocation Models Use of Mixing Zone Models in Estuarine Waste Load Allocations* Critical Review of Estuarine Waste Load Allocation Modeling* Lakes and Impoundments Biochemical Oxygen Demand/Dissolved Oxygen N utrient/Eutrophication Toxic Substances Technical Support Document for Water Quality-Base Toxics Control Design Conditions Design Flow Design Temperature, pH, Hardness, and Alkalinity Permit Averaging Screening Manual Biochemical Oxygen Demand/Dissolved Oxygen Toxic Organics Toxic Metals N utrients/Eutrophication Innovative Waste Load Allocations* * not yet available ------- Page 20 5. BEST MAN A CEMENT PRA CTICES (BMPs) Guide to Nonpoint Source Pollution Control (EPA, 1987) CZARA Guidance working drafts The user's Guide to Nonpoint Source Pollution Control (EPA, 1987) outlines the techniques that are now available for controlling nonpoint source pollution. Additional guidance on nonpoint source management measures is currently being drafted to comply with the requirements of the Coastal Zone Act Reauthorization Amendments (CZARA). Chapters two through six, in working draft form, specify management measures that represent the most effective systems of practices to prevent or reduce nonpoint source pollution from agriculture, forestry, urban areas, marinas and recreational boating, and hydromodification. Chapter seven, also in working draft form, specifies management measures that apply to the protection and restoration of wetlands and riparian areas, and the use of vegetated treatment systems. Compiled within these drafts is effectiveness data and cost information about the application of best management practices (BMPs) across the United States. Numerous Federal and State agencies and programs, such as the Soil Conservation Service and Cooperative Extension Offices, and universities were the source of this information. The cost and effectiveness data, for the most part, has not been synthesized. Nevertheless, these documents could be a valuable reference for making management decisions about the relative merits of various nonpoint source management options and for providing a bibliography of additional information sources when they become available. The Nonpoint Source Control Branch of AWPD will be able to provide copies. Agriculture Financial cost effectiveness of point and nonpoint source nutrient reduction technologies in the Chesapeake Bay Basin - Draft (Camacho, 1991) Agricultural BMP nutrient reduction efficiencies: Chesapeake Bay Watershed Model best management practices (Camacho, 1990) Rural clean water program (EPA, 1990c) Information on the suitability and design of agricultural BMPs is usually available from County Soil Conservation Field Offices. Each Field Office has a Field Office Technical Guide that provides specifications for installation and maintenance of BMPs suitable to that area. Studies on the costs and pollutant-reduction effectiveness of BMPs are site-specific. Camacho (1991 and 1990) studied the cost-effectiveness and pollutant reduction abilities of BMPs in the Chesapeake Bay Area. Hallberg and others at the University of Iowa have extensively examined the effects ------- Page 21 of BMPs on nitrate and pesticide leaching. The USDA-EPA Cooperative Rural Clean Water Program (RCWP) has also developed information on the costs and effectiveness of BMPs implemented in various regions across the country. Forestry Water Quality Management Guidelines and Best Management Practices for Alabama Wetlands (Alabama Forestry Commission, 1989) California Forest Practice Rules (California Department of Forestry and Fire Protection, 1991) A Practical Guide for Protecting Water Quality while Harvesting Forest Products (Connecticut Resource Conservation and Development Forestry Committee, 1990) Forestry Best Management Practices for Delaware (Delaware Forestry Association, 1982) Predicted Erosion Rates for Forest Management Activities and Conditions in the Southeast (Dissmeyer, 1980) Economic impacts of erosion control in forests (Dissmeyer, 1986) Most States with commercial Forestry operations have developed Forestry BMP manuals. These manuals are generally available to the public and can be obtained from State Forestry Divisions. A few States, particularly in the West, have Forest Practices Acts which require the implementation of Forestry BMPs on harvest operations. The list above presents several of these BMP manuals. The references section of the CZARA working draft guidance chapter on Forestry provides many more. Again, the cost and effectiveness of Forestry BMPs are highly site-specific. However, the Forest Service has initiated a Stewardship Incentives Program (SIP) that provides cost-share for BMP implementation. • Urban Areas Urban targeting and BMP selection (EPA, 1990d) is an information and guidance manual for State nonpoint source program staff engineers and managers. It consolidates existing information and describes a methodology for targeting urban areas for control. It is designed to assist State and local agency personnel in targeting areas within their jurisdiction for priority in the development and implementation of nonpoint source management programs. It addresses the following topic areas: (1) the nature and characteristics of urban runoff, and the types of water quality problems that are most likely to occur; (2) the types of best management practices that are appropriate for control of nonpoint source pollutant loads from urban and developing areas, and ------- Page 22 A current assessment of urban best management practices: Techniques for reducing non-point source pollution in the coastal zone (COG, 1992a) Watershed restoration sourcebook (COG, 1992b). Urban targeting and BMP selection (EPA, 1990d) guidance for their selection; and (3) a procedure for prioritizing urban areas for the application of controls beyond the baseline measures initially applied on a jurisdiction-wide basis. Cost and effectiveness of urban BMPs is usually site specific and depends on a variety of factors, such as land use, soil type, percent of impervious surfaces, and treatment methods already in existence. Nevertheless, some urban BMP information is transferable and the successes and ideas of one urban area's experience can be helpful to another. The Metropolitan Washington Council of Governments has collected effectiveness information for a variety of structural and nonstructural nonpoint source controls. The Watershed Restoration SourceBook is a manual on urban watershed restoration techniques. It includes the details of the Six Point Action Plan to clean up Washington D.C.'s Anacostia River, and contains 14 other papers including Mitigating the Adverse Impacts of Urbanization on Streams, Developing Effective BMP Systems for Urban Watersheds, Finding Retrofit Opportunities in Urban Watersheds, and Riparian Reforestation, among others. The report, A Current Assessment of Urban Best Management Practices (COG, 1992), is intended to define the capabilities and limitations of the current generation of BMPs in order to provide effective stormwater quality management within the coastal zone. It can help to answer many of the questions that arise when decision makers must choose a particular BMP or combination of BMP options. Can the BMP reliably remove urban pollutants? How well does the BMP operate over time? When and where is BMP use feasible? -How much will it cost? Many States have developed their own BMP guidance for controlling urban stormwater runoff. This document can be especially useful for those States that have not. 6. FOLLOW-UP MONITORING Once best management practices have been implemented so that the load allocations specified within a TMDL can be met, the water quality-based approach requires follow-up monitoring to ensure that water quality standards are attained. The technical requirements for this type of monitoring will not differ greatly, if at all, from those described by the references cited in "The Role of Water Quality Monitoring." The objectives for follow-up monitoring should include (1) evaluation of water quality, (2) evaluation of BMP effectiveness, and (3) calibration and verification of any models that were used. Operational performance monitoring would typically involve long term monitoring, perhaps over the lifetime of the BMP to ensure that its performance meets the specified design criteria. Long term monitoring would also serve to document new emerging problems that may arise because of changing conditions in land use upstream. Paired basin monitoring may also be useful for evaluating the effectiveness of BMPs. ------- Page 23 7. CONTA CTS AND REFERENCES THE TMDL PROCESS AND NONPOINT SOURCES EPA. 1991a. Guidance for water quality-based decisions: The TMDL process. U.S. Environmental Protection Agency, Office of Water, Washington, D.C. EPA 440/4-91- 001.' PRIORITIZA TION AND TARGETING EPA. 1991b. Handbook on geographic targeting. Draft. U.S. Environmental Protection Agency, Office of Wetlands, Oceans, and Watersheds, Washington, D.C. Prepared by Research Triangle Institute.2 EPA. 1989a. Selecting priority nonpoint source projects: You better shop around. U.S. Environmental Protection Agency, Office of Water and Office of Policy, Planning and Evaluation, Washington, D.C. EPA 506/2-89/003.' EPA. 1987a. Setting priorities: The key to nonpoint source pollution. U.S. Environmental Protection Agency, Office of Water, Washington, D.C. Prepared by the Biological and Agricultural Engineering Department at North Carolina State University.1 TOOLS TO ASSESS WATER QUALITY & ESTIMATE LOAD ALLOCATIONS a. Identifying Impaired Water Bodies • Survey of Existing Information STORE! assistance hotline 800/424-9067. EPA. 199 Ic. EPA mainframe data and tools for watershed assessments. Appendix A in Workshop on the Water Quality-based Approach for Point Source and Nonpoint Source Controls Meeting Summary. June 26-28, 1991. U.S. Environmental Protection Agency, Office of Water. Washington, D.C. EPA 503/9-92-001.' EPA. 199Id. PC waterbody system user's guide (Version 3.0). U.S. Environmental Protection Agency, Office of Water, Assessment and Watershed Protection Division, Washington, D.C. [Contact Jack Clifford, phone: 202/260-3667] 1 Copies of the document can be obtained by calling the Office of Water, phone: 202/260-9112. - Copies of the document can be obtained by calling Karen Guglielmone, Tetra Tech, Inc. at 202/260-7058. ------- Page 24 Analysis of Water Quality Information EPA Region III. 1991. Water quality analysis system: Seminar documentation. U.S. Environmental Protection Agency, Region III, Philadelphia, PA. [ATTN: Publications, EPA Region III, 841 Chestnut Building, Philadelphia, PA 19107, phone: 215/597-9800] EPA. 1987b. PCS' data base management system design, PCS Generalized retrieval manual. U.S. Environmental Protection Agency. [PCS hotline: 202/260-8529] EPA. 1982. Managers guide to STORET. Washington, D.C., Government Printing Office Publication 1982-373-096. [STORET assistance hotline 800/424-9067] EPA Region V. 1991. Methodologies for estimating NFS impacts on water quality from development. U.S. Environmental Protection Agency, Watershed Management Unit, Water Division, Region V. by Tetra Tech, Inc.2 Gilbert, R.O. 1987. Statistical methods for environmental pollution monitoring. Van Nostrand Reinhold Company, New York, -[phone: 212/254-3232 or 1800/926-2665 for purchase, pricing, and availability] Richards, R.P. 1990. Evaluation of some approaches to estimating non-point pollutant loads for unmonitored areas. Water Resources Bulletin, 25(4): 891-904.2 Rossman, L.A. 1992. DESCON user's manual. Draft. Water and Hazardous Waste Treatment Research Division. Risk Reduction Engineering Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH. [phone: 513/569-7603] EPA. 1991e. Developing a monitoring system. In: Nonpoint Source Solutions, Nonpoint Source Watershed Workshop, Section 6, Seminar Publication. U.S. Environmental Protection Agency, Washington, D.C. EPA 625/4-91/027.2 • The Role of Water Quality Monitoring EPA. 1990a. Surface water monitoring program guidance. Draft. U.S. Environmental Protection Agency, Office of Water, Washington, D.C. EPA. 1989b. Rapid bioassessment protocols for use in streams and rivers: benthic macroinvertebrates and fish. U.S. Environmental Protection Agency, Office of Water. EPA/444/4-89-001, by James L. Plafkin, Michael T. Barbour, Kimberly D. Porter, Sharon K. Gross, and Robert M. Hughes, [phone: 202/260-7021] EPA. 1987. Nonpoint source monitoring and evaluation guide. Draft. U.S. Environmental Protection Agency, Office of Water, Assessment and Watershed Protection Division, Nonpoint Source Branch. Washington, D.C. ------- Page 25 EPA Region V. 1991. Methodologies for estimating NFS impacts on water quality from development. U.S. Environmental Protection Agency, Watershed Management Unit, Water Division, Region V. by Tetra Tech, Inc.2 Ohio Environmental Protection Agency. 1989. Biological criteria for the protection of aquatic life: volume III. standardized biological field sampling and laboratory methods for assessing fish and macroinvertebrate communities. Division of Water Quality Planning and Assessment, Columbus, Ohio. [Ecological Assessment Section, 1685 West Belt Drive, Columbus, OH 43228, phone: 614/777-6264] Coffey, S.W. and M.D. Smolen. 1990. The nonpoint source manager's guide to water quality monitoring. Water Quality Group, Department of Biological and Agricultural Engineering, North Carolina State University, Raleigh, NC. For U.S. Environmental Protection Agency, Region VII, Kansas City, KS.2 Sonnen, M.B. 1983. Guidelines for the monitoring of urban runoff quality. U.S. EPA, Municipal Environmental Research Laboratory, Office of Research and Development, Cincinnati, OH. [phone: 513/569-7562] Plans, W.S., W.F. Megahan, and G.W. Minshall. 1983. Methods for evaluating stream, riparian, and biotic conditions. Gen. Tech. Rep. INT-138. Ogdon, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station, [phone: 801/625-5437 publications] b. Analyzing Pollution Sources • Watershed Characterization Anderson, J.R., E.E. Hardy, J.T. Roach, and W.E. Witmer. 1976. A land use land cover classification system for use with remote sensor data. U.S. Geological Survey Professional Paper 964. EPA Environmental Monitoring Systems Laboratory. Las Vegas, phone: 702/798-2100. EPA Region IV. 1992. Watershed screening methodology - Savannah River Basin application. U.S. Environmental Protection Agency, Region IV, Water Management Division, Atlanta, GA.2 EPA. 199If. U.S. Environmental Protection Agency - Region V and Northeastern Illinois Planning Commission. Remote sensing and CIS applications to nonpoint source planning. Workshop Proceedings. Chicago, Illinois. October 1-3, 1990. [Distributed by The Terrene Institute, Washington, D.C., phone: 202/833-8317.] Goodchild, M.F. and D. Brusegard. 1989. Spatial analysis using CIS: Seminar Workbook. Seminar presented April 10, 1989, AM/FM Conference XII, New Orleans, LA. [Available from: National Center for Geographic Information and Analysis, University of California, Santa Barbara, CA 93106.] ------- Page 26 Hession, W.C., K.L. Huber, Mostaghimi, S., V.O. Shanholtz, and P.W. McClellan. 1989. BMP effectiveness evaluation using AGNPS and CIS. Written for presentation at the 1989 International Winter Meeting sponsored by the American Society of Agricultural Engineers, New Orleans, LA, December 12-15, 1989. Paper No. 89-2S66.2 Jensen, J.R. 1986. Introductory digital image processing. Prentice-Hall Publishers, New Jersey. (Order Processing Center, P.O. Box 11071, Des Moines, IA 50336, phone: 201/592-2000] Lee, M.T., J.J. Kao, and Y Ke. 1990. Integration of CIS, digital elevation data, and remote sensing for a hydrologic model. Proceedings of 1990 ASCE Hydraulics Conference, San Diego, CA. August 1990.2 Shanholtz, Dr. Vernon. VirGIS. Department of Agricultural Engineering, 106-A Faculty Street, Blacksburg, VA 24061-0535, phone: 703/231-5843. Shanholtz, V.O., C.J. Desai, N. Zhang, J.W. Kleene, and C.D. Metz. 1990. Hydrologic/Water Quality Modeling in a CIS Environment. Written for presentation at the 1990 International Summer Meeting sponsored by the American Society of Agricultural Engineers, Columbus, OH, June 24-27, 1990. Paper No. 90-3033.2 Shanholtz, V.O., N. Zhang, E.R. Yagow, C.J. Desai, and J.M. Flagg. 1988. The use of a CIS to track the impact of Virginia Chesapeake Bay Agricultural Nonpoint Source Program. Written for presentation at the 1988 International Winter Meeting of the American Society of Agricultural Engineers, Chicago, IL, December 13-16, 1988. Paper No. S8-2535.2 EPA. 1992a. Compendium of watershed-scale models for TMDL development. Draft. U.S. Environmental Protection Agency, Office of Wetland, Oceans, and Watersheds, Washington, D.C. Prepared by Tetra Tech, Inc.2 Perchalski, F.R. 1989. Airphoto Inventories for Pinpointing Nonpoint Sources. In: Off- site Assessment Workshop - Proceedings of a National Workshop, November 15, 1988. St. Louis, Missouri. U.S. Environmental Protection Agency, Washington, D.C.2 Yagow, E.R., V.O. Shanholtz, and J.W. Kleene. 1990. Annual estimation of nitrogen in agricultural runoff. Written for presentation at the 1990 International Summer Meeting sponsored by the American Society of Agricultural Engineers, Columbus, OH, June 24- 27, 1990. Paper No. 90-2054.2 U.S. Geological Survey National Cartographic Information Center, 507 National Center, Reston, VA 22092, phone: 703/860-6045. Young. Dr. Robert. Agricultural Nonpoint Source Pollution (AGNPS) Model, phone: 612/598-3411. ------- Page 27 Watershed Simulation Models Dean, D.J., B. Hudson, and W.B. Mills. 1982. River basin validation of the water quality assessment methodology for screening nondesignated 208 areas. Volume II: Chesapeake Sandusky Nondesignated 208 screening methodology demonstration. Prepared for U.S. Environmental Protection Agency, Office of Research and Development, Environmental Research Laboratory, Athens, GA [phone: 404/546-3549]. EPA 600/3-82-057b. EPA. 1992a. Compendium of watershed-scale models for TMDL development. Draft. U.S. Environmental Protection Agency, Office of Wetland, Oceans, and Watersheds, Washington, D.C. Prepared by Tetra Tech, Inc.2 EPA. 1990b. Modeling ofnonpoint source water quality in urban and non-urban areas. U.S. Environmental Protection Agency, Office of Research and Development, Environmental Research Laboratory, Athens, GA., phone: 404/546-3549. Center for Exposure Assessment Modeling, U.S. EPA, College Station Road, Athens, Georgia, phone: 404/546-3549. Grassland, Soil and Water Research Laboratory, U.S. Department of Agriculture, Temple, TX 76502, phone: 817/770-6502. Hydrologic Engineering Center (HEC), U.S. Corps of Engineers, 609 Second Street, Davis, California 95616, phone: 916/756-1104. National Center. U.S. Geological Survey, Reston, Virginia 22092, phone: 703/648-4000. North Central Laboratory, U.S. Department of Agriculture, Morris, Minnesota 56267, phone: 612/589-3411. • Receiving Water Quality Models EPA. 1985a. Water quality assessment: A screening procedure for toxic and conventional pollutants in surface and ground water: Pan I (Revised 1985). U.S. Environmental Protection Agency, Environmental Research Laboratory, Athens, GA. EPA/600/6-85/002a.2 EPA. 1985b. Water quality assessment: A screening procedure for toxic and conventional pollutants in surface and ground water: Part II (Revised 1985). U.S. Environmental Protection Agency, Environmental Research Laboratory, Athens, GA. EPA/600/6-85/002b.2 ------- Page 28 BEST MANAGEMENT PRACTICES EPA. 1991: Proposed Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters. U.S. Environmental Protection Agency. Office of Water [Will be final in October. Contact Dov Weitman, phone: 202/260-7100] a. Agriculture Camacho, Rodolfo. 1991. Financial cost effectiveness of point and nonpoint source nutrient reduction technologies in the Chesapeake Bay basin (Draft). Interstate Commission on the Potomac River Basin.2 Camacho, Rodolfo. 1990. Agricultural BMP nutrient reduction efficiencies: Chesapeake Bay watershed model BMPs. Interstate Commission on the Potomac River Basin.2 EPA. 1990c. Rural clean water program. U.S. Environmental Protection Agency, Office of Water. EPA 440/4-90-012.2 b. Forestry Alabama Forestry Commission. 1989. Water quality management guidelines and best management practices for Alabama wetlands. California Department of Forestry and Fire Protection. 1991. California forest practice rules. Connecticut Resource Conservation and Development Forestry Committee. 1990. A practical guide for protecting water quality while harvesting forest products. Delaware Forestry Association. 1982. Forestry best management practices for Delaware. Dissmeyer, G.E. 1980. Predicted Erosion Rates for Forest Management Activities and Conditions in theSoutheast. In: U.S. forestry and water quality: What course in the 80's? Proceedings. Richmond, VA, June 19-20, 1980. Water Pollution Control Federation, pp. 42-49. Dissmeyer, G.E. 1986. Economic impacts of erosion control in forests. In Proceedings of the southern forestry symposium, November 19-21, 1985, Atlanta, GA., S. Carpenter (ed.) Oklahoma State University Agricultural Conference Series, pp. 262-287. c. Urban Areas COG. 1992 a. A current assessment ofurban best management practices: Techniques for reducing non-point source pollution in the coastal zone. Metropolitan Washington Council of Governments. Prepared by T.R. Schueler, P.A. Kumble, and M.A. Heraty. ------- Page 29 [COG Information Center, 777 N. Capital St., N.E. Suite 300, Washington, D.C., 20002-4201, phone: 202/962-3256] COG. 1992b. Watershed restoration sourcebook. Metropolitan Washington Council of Governments. [COG Information Center, 777 N. Capital St., N.E., Suite 300, Washington, D.C. 20002-4201, phone: 202/962-3256] EPA Region V. 1990. Urban targeting and BMP selection. U.S. Environmental Protection Agency, Region V, Chicago, IL. Prepared by Woodward-Clyde Consultants. [Distributed by The Terrene Institute, phone: 202/833-3380] FOLLOW-UP MONITORING (See "The Role of Water Quality Monitoring") ------- |