1  This dataset is named 'STORET.HELP.H2O.MODEL'
    and was last updated Dec. 13, 1984 by Tom Barnwell, from
    Athens, Georgia.



1                   CENTER FOR WATER QUALITY MODELING
                    ENVIRONMENTAL RESEARCH LABORATORY
                   U S ENVIRONMENTAL PROTECTION AGENCY
                                ATHENS, GA


      As  part of the national effort to implement the Clean Water  Act,
 water   quality  planners  and  managers  in  the  United  States  have
 increasingly   used  mathematical  models  to  analyze  water   quality
 problems.   These  models are used in conducting evaluations  of  waste
 loads from point and nonpoint sources and in pollutant exposure assess-
 ments.   To encourage the wider application of these techniques,  EPA's
 Office  of  Research and Development established the Center  for  Water
 Quality  Modeling  to provide a focal point for water quality  modeling
 activities.   The  Center supports models that range from simple  tech-
 niques for preliminary analysis to sophisticated techniques for detail-
 ed planning.   This paper describes the models supported by the  Center
 and gives an overview of the Center's activities, which include distri-
 bution  and maintenance of computer programs,  training of  users,  and
 sponsorship of a users group.

      The Center for Water Quality Modeling is located at EPA's Environ-
 mental Research Laboratory in Athens,  Ga, which has long been involved
 in the develop-ment and application of mathematical models that predict
 the transport and fate of water pollutants.  For selected water quality
 and  pollutant loading models,  the Center provides a central file  and
 distribution point for computer programs and documentation.    In addi-
 tion,  the  Center  sponsors workshops and seminars that  provide  both
 generalized  training in the use of models and specific instruction  in
 the application of individual simulation techniques.

 SUPPORTED MODELS

      The  modeling packages currently available through the Center were
 selected from many candidate models by experienced users in EPA regula-
 tory and regional offices and by the Center staff.   Selection criteria
 included  model  utility and effectiveness,  availability  of  adequate
 documentation,  degree of acceptance and application by users,  and the
 Center  staff's  experience with the software.  A  wide  collection  of
 analysis  techniques  is provided,  ranging from simple desk-top  tech-
 niques  suitable  for screening analysis through  computerized  steady-
 state models to sophisticated,  state-of-the-art continuous  simulation
 models.  Modeling packages currently supported by the Center are:

      Water  Quality  Assessment:  A Screening Procedure for  Toxic  and
 Conventional Pollutants (Mills et al.,  1982) -- a collection of formu-
 lae,  tables  and graphs for preliminary assessment of water quality in
 river basins.  These desk-top procedures are designed for hand calcula-
 tors.   The manual includes a discussion of the environmental chemistry
 of  synthetic organic chemicals and metals;  a chapter on waste  source
 estimation  techniques;  and simple methods for assess-ment of  conven-
 tional and toxic organic pollutant fate and transport in rivers,  lakes
 and  estuaries.   Procedures for assessment of heavy metal and  ground-
 water problems are currently under development.

1     Exposure Analysis Modeling System (EXAMS) (Burns, Cline and Lassi-
 ter, 1982) -- a steady-state model designed for rapid evaluation of the
 behavior of synthetic organic chemicals in aquatic ecosystems.   Start-
 ing from a description of the chemistry of a toxicant and the  relevant
 transport and physical-chemical characteristics of the ecosystem, EXAMS
 computes exposure,  the ultimate expect-ed environmental concentrations
 resulting from a long-term steady pattern of pollutant loadings;  fate,
 the distribution of the chemical in the environment and the fraction of
 the loadings consumed by each transport and transformation process; and
 persistence, the time required for effective purification of the system
 once  the loadings cease.   EXAMS is an interactive program and  allows
 the  user  to  specify and store the properties of chemicals  and  eco-
 systems,  modify the characteristics of either via simple  English-like
 commands, and conduct rapid, efficient evaluations of the probable fate
 of chemicals.

      Stream Quality Model QUAL-II (Roesner,  Gigure and Evenson,  1981)
 -- a  steady-state  model  for conventional pollutants in  streams  and
 well-mixed lakes.   It includes conservative  substances,  temperature,
 bacteria,  BOD,  DO, nitrogen, phosphorus and algae.  QUAL-II is widely
 used  for waste load allocations and discharge permit determinations in
 the United States and other countries.

      Storm  Water  Management Model (SWMM) (Huber et  al.,  1981)  -- a
 comprehen-sive  model for simulation of urban runoff quantity and qual-
 ity.   All aspects of the urban hydrologic and quality cycles are simu-
 lated including surface runoff, transport through the drainage network,
 and storage and treatment (including cost).   Alternate techniques  are
 available  for simulation in a sewer system  -- a kinematic wave proce-
 dure for most problem assessment and a full-equation routing method for
 surcharged systems.  It has been used in a planning context as well  as
 for  detailed design studies.   SWMM also has a long history of use  in
 the United States and Canada for urban drainage assessment and design.

      Agricultural  Runoff Management (ARM) (Donigian et al.,  1977) and
 Non Point Source (NPS) (Donigian and Crawford,  1976) -- techniques for
 assessing  agricul-tural and urban nonpoint source pollutant  loadings.
 The models use the Stan-ford Watershed Model for the water balance  and
 extend  this model to the assess-ment of nonpoint source pollution from
 agricultural and urban areas.  ARM can be used to study pollutants from
 agricultural  lands  such as sediment,  nutrients  and  pesticides  and
 includes  detailed process descriptions for nutrient and pesticide fate
 on the land surface.   NPS contains simpler algorithms and can be  used
 on both urban and agricultural lands.

1     Hydrological Simulation Program - FORTRAN (HSPF) (Johanson et al.,
 1984)  -- a model for simulation of watershed hydrology and water qual-
 ity for both conventional and toxic organic pollutants.   HSPF incorpo-
 rates the watershed-scale ARM and NPS models into a basin-scale  analy-
 sis  framework  that  includes fate and transport in  stream  channels.
 Simply  put,  the model uses such infor-mation as the time  history  of
 rainfall,  temperature,  and solar radiation; such land surface charac-
 teristics as land use patterns and soil properties; and land management
 practices  to  simulate the processes that occur in a  watershed.   The
 result of this simulation is a time history of the quantity and quality
 of runoff from an urban or agricultural watershed.  Flow rate, sediment
 load,  and  nutrient and pesticide concentration  are  predicted.   The
 program  takes these results,  along with information about the  stream
 channels, and simulates instream processes, producing a time history of
 water quantity and quality at any point in a watershed -- the inflow to
 a lake,  for example.  It has been used in such diverse applications as
 evaluation  of agricultural best management practices in Iowa and in  a
 National  Urban Runoff Program project near Washington,  DC.   A  user-
 friendly  editor  to aid in developing program input is also  available
 (Lumb  and Kittle,  1983) as well as a comprehensive application  guide
 (Donigian et al., 1984).

      Water Analysis Simulation Program (WASP) (Di Toro, Fitzpatrick and
 Tho-mann,  1983)  and  its extension to  toxic  contaminants,  TOXIWASP
 (Ambrose,  Hill and Mulkey,  1983) -- a generalized modeling  framework
 for  contaminant  fate and transport in surface waters.  A  variety  of
 problems  can  be addressed with the selection of  appropriate  kinetic
 subroutines.   WASP  is  designed to permit easy substitution of  user-
 written routines into the program structure.   Problems that have  been
 studied  using WASP include BOD-DO dynamics,  nutrients and eutrophica-
 tion,  bacterial contamination,  and toxic chemical movement.  TOXIWASP
 combines a kinetic structure adapted from EXAMS with the WASP transport
 struc-ture and simple sediment balance algorithms to predict  dissolved
 and  sorbed  chemical concentrations in the bed and  overlying  waters.
 WASP has been used in the Great Lakes and the Potomac estuary to assess
 eutrophication problems.   TOXIWASP has been applied in Mississippi and
 in the Delaware estuary to examine fate and transport of toxic contami-
 nants.

1SUPPORT ACTIVITIES

      In responding to requests for software, the Center provides a copy
 of  the  model documentation and a magnetic tape of the computer  code,
 which  is  to be copied and returned to the Center.   The  Center  also
 functions  as  a clearing house for correcting coding errors  or  other
 problems that are discovered as the techniques are applied.  New  soft-
 ware  releases  periodically document code up-dates and corrections  to
 known problems.  Model maintenance activities focus on overcoming prob-
 lems in the use of models;  further development,  refining,  and exten-
 sions of these models is a separate research and development activity.

      Instruction  in  the use of supported models is  provided  through
 workshops and technical seminars sponsored by the Center in cooperation
 with EPA's Center for Environmental Research Information  (CERI).   In-
 structors for these training activities are experts from the Athens and
 other ORD laboratories and from organizations that developed the models
 under EPA auspices.   Workshops are open to all model users on a space-
 available basis.

      The  Center also sponsors the Storm Water and Water Quality  Model
 Users Group (formerly SWMM Users Group).  The Users Group consists of a
 large  number of model users and developers in international,  federal,
 regional and state environmental management agencies and their  consul-
 tants,  and in private indus-try and academia.    The Users Group meets
 semi-annually  to  exchange information on applications and results  of
 model  use.   This forum enables the timely exchange of information  on
 model  refinements,  code changes,  and model adap-tations as  well  as
 identification  of problem areas and model use limitations.   The meet-
 ings alternate between the United States and Canada and proceedings  of
 the  U  S meetings are published by the Center.   Users  Group  members
 receive copies of these proceedings free of charge.  Proceedings of the
 Canadian  meetings are published on an ad hoc basis by the meeting host
 and there is usually a nominal charge for these proceedings.

      The Center periodically distributes, free of charge,  a newsletter
 to Users Group members.  The newsletter provides helpful hints to model
 users  and  communicates  information  on  scheduled  workshops,  model
 improvements  and devel-opments,  the availability of  technical  docu-
 ments,  and  planned meetings and conferences.   More information about
 the  Center is available from Tom Barnwell at the Athens  Environmental
 Research Laboratory (404/546-3175; FTS 250-3175)
1
 REFERENCES

 Ambrose,  R  B,  S I Hill,  and L A Mulkey (1983) Users Manual for  the
 Toxic  Chemi-cal  Transport and Fate Model TOXIWASP:  Version  I   EPA-
 600/3-83-005, U S EPA, Athens, Ga 30613.

 Burns,  L A, D M Cline and R R Lassiter (1982) Exposure Analysis Model-
 ing System (EXAMS)  EPA/600-3-82-023, U S EPA, Athens, Ga 30613.

 Di  Toro,  D M,  J J Fitzpatrick and R V Thomann (1983)  Water  Quality
 Analysis Simulation Program (WASP) and Model Verification Program (MVP)
 - Documentation EPA-600/3-81-044, U S EPA, Duluth, Mn 55804.

 Donigian,  A S et al. (1977) Agricultural Runoff Management (ARM) Model
 Version II:  Refinement and Testing  EPA-600/3-77-098, U S EPA, Athens,
 Ga 30613.

 Donigian, A S and N H Crawford (1976) Modeling Non Point Pollution from
 the Land Surface  EPA-600/3-76-083, U S EPA, Athens, Ga 30613.

 Donigian,  A  S et al.  (1984)  Application Guide for the  Hydrological
 Simulation Program - FORTRAN (HSPF)  EPA-600/3-84-065, U S EPA, Athens,
 Ga 30613.

 Huber,  W  C et al.  (1984) Storm Water Management Model User's  Manual
 Version III EPA-600/2-84-109a,b, U S EPA, Cincinnati, Oh 45268.

 Johanson,  R C et al.  (1984) Hydrological Simulation Program - FORTRAN
 (HSPF):  Users  Manual  for  Release 8.0  EPA-600/3-84-066,  U  S  EPA,
 Athens, Ga 30613.

 Lumb,  A M and J L Kittle (1984) "ANNIE - An Interactive Processor  for
 Hydrologic  Models," in Emerging Computer Technology in Stormwater  and
 Flood  Management,  American Society of Civil Engineers,  New York,  NY
 10017, pp 352-365.

 Mills,  W B et al.  (1982) Water Quality Assessment: A Screening Proce-
 dure for Toxic and Conventional Pollutants  EPA-600/6-82-004,  U S EPA,
 Athens, Ga 30613.

 Roesner,  L  A,  P  R Gigure and D E Evenson  (1981)  Computer  Program
 Documentation for the Stream Quality Model QUAL-II  EPA-600/9-81-014, U
 S EPA, Athens, Ga 30613.
