United States
Environmental Protection Office of Water	EPA 811-B-94-001
Agency	4601	April 1994
vEPA WATER TREATMENT PLANT MODEL
FOR MS WINDOWS 3.1
VERSION 1.51

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Water Treatment Plant Model
for MS Windows 3.1
Version 1.51/
The Water Treatment Plant Model (WTP) was originally developed in support
of the Disinfectant/Disinfection Byproducts Rule. It was prepared with the
understanding that the predictions should reflect the central tendency for
treatment. It is not to be construed that the results from the model will
necessarily be applicable to individual raw water quality and treatment
effects at unique municipalities. This model does not replace sound
engineering judgement based on site-specific treatability data to evaluate
the best manner in which to address the requirements of the SWTR or
potential D/DBP Rule.
It is understood that one limitation of the model is the extent of the data
base available to verify model predictions. In a desire to systematically
improve the overall predictive capability, the intent of this release is to
solicit public comment on the usefulness and relative accuracy of the
predictions on a case-by-case basis. To this end, WTP model includes a
method to enter laboratory analysis so that a comparison can be made to the
model predictions.
The USEPA encourages constructive comments on methods to improve the model,
results from verification efforts, and utility data that can be used to
enhance the overall applicability of the model. Please forward comments
to:
Michael D. Cummins
Water Supply Technology Branch
Technical Support Division
Office of Ground Water and Drinking Water
United States Environmental Protection Agency
Cincinnati, Ohio 45268
513-569-7979
Updates to the model can be obtained by calling the Safe Drinking water Act
Hot Line 1-800-426-4791.
The guidance provided herein may be of educational value to a wide variety
of individuals in the water treatment industry/ but each individual must
adapt the results to fit their own practice. The USEPA shall not be liable
for any direct, indirect, consequential, or incidental damages resulting
from the use of the WTP model.

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The user manual for version 1.5 is in preparation and is expected to be
available January 1994 by calling the Safe Drinking Water Act Hot Line.
The following contains information on installing WTP and using the model.
Hardware requirements:
WTP will run on any system equipped with MS-Windows 3.1 or later
however due to the intensity of the calculations a numerical
coprocessor is recommended.
Hard Disk Installation:
The distribution disk contains a simple 'Install' program which will
create a directory named C:\WTPWIN and copy the distribution files
into the directory.
1)	Insert the distribution disk into drive A or B and, from the c
prompt, type in the following.
C:\> A:Install A
or
C:\> B:Install B
2)	If you have been using a previous DOS version of WTP and have process
train data files that you wish to use with the windows version of WTP
then copy the process train data files to the WTPWIN directory as
follows.
C:\>copy C:\WTPDOS\*.WTP C:\WTPWIN
where C:\WTPDOS is the name of the directory containing your dos
version of WTP.
3)	The following procedure is preformed in MS-Windows and will create a
group icon for WTP and create an item icon for WTP.EXE model. Start
MS-Windows as follows.
C:\> win
You should now be in windows 'Program Manager'
First Time Windows Users:
MS-Windows has an on-line tutorial which covers the
basics of using windows. The tutorial is accessed from
the 'Program Manager' by clicking (left mouse button) on
the menu selection 'Help' and then clicking on 'Windows
Tutorial'. If you feel uncomfortable using the following
procedure then use the tutorial to get an overview of
using windows.
a)	Using the mouse, click (left button) on the Program
Manager menu selection 'File' located at the top left of
the screen. A drop down menu will appear.
b)	Using the mouse, click on the drop down menu selection
'New'. A 'New Program Object' requester will appear.
c)	Select 'Program Group' by clicking on it. The black dot
should be located to the left of 'Program Group'.
d)	Click 'OK' in the 'New Program Object' requester. A
'Program Group Properties' requester will appear.
e)	In the Description box type in WTP. This is the title
that will appear below the group icon. Note: the title
no relation to the name of the WTPWIN directory.
f)	Click on 'OK' in the 'Program Group Properties'. The
requesters will disappear and a program group window
titled WTP will appear.
g)	Using the mouse, click on the Program Manager menu
selection 'File' and 'New' as done in step a) and b).
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The 'New Program Object' requester will reappear.
h)	This time select 'Program Item' by clicking on it. The
black dot should now be located to the left of 'Program
Item'.
i)	Click on 'OK' in the 'New Program Object' requester. A
'Program Item Properties' requester will appear.
j) In the 'Description' box type in WTP.
k) Move the cursor to the next box by using the mouse to
click on the 'Command Line' box. The cursor should now
be in the 'Command Line' box.
1) In the 'Command Line' box type in the following:
C:\WTPWIN\WTP.EXE
m) Click on 'OK' in the Program Item Properties. The
requester will disappear and the WTP item icon will
appear in the WTP group window,
n) Re-size the WTP group window to a reasonable small size,
o) Close the WTP group window by double clicking the system
close button located in the upper left of the WTP group
window. The window will close and the WTP group icon
will appear at the bottom of the screen.
Water treatment plant model is now installed.
Starting WTP Model:
1)	Double click on the WTP group icon.
2)	Double click on the WTP item icon.
3)	First time use of WTP Model:
At this point the main screen of WTP will fill the monitor. Across
the bottom of the window is a series of buttons that can be clicked
using the mouse. The user interface is designed such that the
buttons across the bottom control most of the action. A menu is at
the top which contains additional selections for 'File', 'Display',
and 'Edit'.
4)	In the following guided tour a conventional water treatment plant is
made up which is out of compliance with the THM MCL. The plant is
brought into compliance by improving coagulation, adjusting pH, and
changing the point of chlorination.
Using the mouse, click (left button) on the 'Edit' button. The 'Edit
Process Train' screen will appear. On the left half of the screen is
the process train  at the moment there is only an 'Influent'. At
the bottom of the left half of the screen are four buttons to
manipulate the process train. The four buttons are labeled 'Move',
'Edit', 'Delete' and 'Clear'. Use of these buttons are described
later in this guided tour.
On the right half of the screen are three lists of "Available
Selections" that can be added to the process train. The three lists
are 'Unit Processes', 'Chemical Feeds' and 'Sample Points'.
Now generate a conventional treatment process train by clicking on
the following selections in the "Available Selections" section of the
screen.
Alum
Rapid Mix
Flocculation
Settling Basin
Filtration
Contact Tank
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Clearwell
WTP Effluent
End of System
The left half of the screen should now show 'influent' followed by
above unit processes, chemical additions, and sample points.
5)	Chlorine was purposely not included in the above so that moving the
point of chlonnatior could be demonstrated. On the right side of
the screen, click on 'Chlorine' in the Chemical Feeds list. Chlorine
will appear at the end of the process train list on the left side of
the screen. To move the point of chlorination to follow the Influent
is a three step process. First click on 'Chlorine' in the process
train. A highlight will appear on Chlorine. Second, click on the
'Move' button. A small check mark will appear next to the 'Move'
button to indicate that the process train editor is in the move mode.
The move mode can be canceled by clicking the 'Move' button a second
time. Try it, when finished set the check mark to move mode. Third,
with "Chlorine" highlighted and the check mark next to the 'Move'
button, click on "Influent". The point of chlorine addition will
move to follow Influent.
The 'Move' button is designed to be intuitive and will respond to
other combinations of mouse clicks. The fundamental logic is that
the highlighted unit process will be moved to FOLLOW the next click.
The highlight can be placed on anything in the process train and any
unit process can be moved to any point in the process train except
before the Influent. Influent will always be first. Experiment
with the "Move" button until you feel comfortable with its operation.
6)	Now challenge this plant with a poor water quality. Click an the
'Edit' button at the bottom left of the 'Process Train' screen. The
"Influent Parameters" screen will appear. The default values shown
in the "Influent Parameters" screen (and all other parameter screens)
are generally believed to be national averages. Index through the
parameters using the tab key on the keyboard to go forward, shift tab
to go backward, or using the mouse to click (left button) directly on
any parameter. The 'Enter' key does nothing.
Challenge this plant by changing the following:
TOC	12.0
UV	1.0
Turbidity 50.0
This plant now has a challenge!
In the lower right of the screen are buttons labeled 'Next' and
'Prev'. These buttons accept any changes made and index to the next
or previous unit process in the process train. Click on the 'Next'
button at the lower right of the Influent Parameters screen and the
parameters for the next unit process -will appear. It should be
"Chlorine Parameters". Experiment with 'Next' and 'Prev' until you
feel comfortable. If you happen to drop back to the "Edit Process
Train" screen, click "Edit" to return to the Influent Parameters
screen.
Bring up the Chlorine Parameters screen and change the chlorine dose
to 10 mg/L.
Many of the screens have buttons labeled 'OK' and 'Cancel'. The 'OK'
button will accept any changes made and return to the parent screen.
The 'Cancel' button will cancel any changes made and return to the
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parent screen. Each screen also has a system close button located at
the top ]ift of the screen which functions identically to the
'Cancel' button.
After changing the chlorine dose to 10 mg/L on the Chlorine
Parameters screen click the 'OK' button and return to the "Edit
Process Train" screen.
On the Edit Process Train screen, click "OK" to return to the main
screen.
7) Predicting water quality:
One of the objectives of WTP is to predict water quality through the
treatment process train and distribution system using water chemistry
and correlation equations. The calculations are performed by
clicking on the 'Run' button (Run for the lack of a better name) on
the main window.
Now click on the 'Run' button and the display is filled with the
predicted water quaLity. Note: on a 336-SX this takes about 5
seconds.
There are a total of 5 tables of which Table 1 is now fully visible.
The scroll bar at the right will scroll the display through the other
tables. Try scrolling the display now by using the mouse left button
to press and hold the small down arrow at the bottom right of the
screen. The screen scrolls down until the button is released. Now
try the up arrow at the top of the scroll bar. The scroll bar also
has a knob between the two arrows which can be "dragged" using the
mouse. Drag the knob now using the mouse left button to hold down
the knob and move the mouse down the screen. The screen scrolls as
the knob is moved. The screen can also be scrolled by clicking
inside the scroll bar between the arrow and knob. The screen will
scroll by about 8 lines each time the scroll bar is clicked. (The
smoothness of the scrolling is dependent on the processor and video
board).
Table 1 includes pH, TOC, UV, Bromide, Temperature, free chlorine
residual (C12), monochloramine (NH2C1) and ammonia (NH3-N). These
parameters are the major inputs to disinfection byproduct formation.
Now scroll to Table 2. Table 2 includes pH, Alk, Ca and Mg hardness,
and sludge production. This table would illustrate softening if it
occurred.
Table 3 and 4 contain the predicted trihalomethane (THM) and
predicted haloacetic acid (HAA) formation. This plant has problems
with both the THM and HAA.
The predictions in Tables 1 through 4 are at the average operating
conditions. Specifically, the average temperature and average flow.
Table 5, however, is disinfection/inactivation and is at the minimum
temperature and maximum flow which is the worst case condition for
disinfection. Of interest is the column labeled "Inactivation
Ratio". The Inactivation Ratio is the disinfection/inactivation
achieved divided by the inactivation goal. For surface water plants
the inactivation goal is based on the influent Giardia cysts
concentration as described in the SWTR guidance manual. For
groundwater plants the inactivation is based on 4 log (99.99%)
inactivation of virus. The inactivation ratio is estimated through
the treatment plant up to the first customer. Inactivation Ratios
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greater than 1.0 have sufficient disinfection and values less than
1.0 do nop-have sufficient disinfection.
This plant is meeting the inactivation goal, but not meeting the
current TTHM MCL (Table 3). The plant will also probably be out of
compliance with any potential HAA MCL (Table 4).
8) Enhance Coagulation:
Now increase the alum doses to 50 mg/L and add sulfuric acid after
alum addition to lower the pH to achieve better removal in the
coagulation/settling unit processes and better inactivation with free
chlorine. Also move the point of chlorination to after the settling
basin to cut down on byproduct formation. A general guide is to add
sufficient sulfuric acid to lower the pH to about 6. The amount of
sulfuric acid to add is a trial and error procedure. Try it on your
own before reading the following detailed directions.
a)	From the main window, click on the 'Edit' button and the Edit
Process Train screen will appear.
b)	Move the point of chlorination to after the settling tank by
clicking on Chlorine in the process train list, clicking on
move, and clicking on Settling Basin in the process train list.
c)	Here is a new trick. Insert Sulfuric Acid after Alum in the
process train by first clicking on Alum. The highlight is now
on Alum. New additions to the process train are inserted after
whatever is highlighted. Now click on Sulfuric Acid in the
Chemical Feed list. Sulfuric acid is inserted into the process
train following Alum. There are many ways to accomplish the
above objective.
d)	Here is another new trick. Change the Alum dose by double
clicking (left mouse button twice, quickly) on Alum in the
Process Train screen. The Alum Parameters screen will appear.
Double clicking on any unit process m the process train will
activate its parameter screen. Change the alum dose to 50
mg/L.
e)	In the Alum Parameters screen, click on the 'Next' button to
look at the sulfuric acid dose. How much sulfuric acid is
needed to achieve a pH of 6.0? It's try and error, don't worry
about it now. Leave the sulfuric acid dose at 1.0 mg/L for
now. (Note: if the influent pH was accidentally changed, the
original value was pH 7.7).
f)	Click 'OK' on the sulfuric acid screen and the Edit Process
Train screen will appear. The process train should be as
follows:
Influent
Alum
Sulfuric Acid
Rapid Mix
Flocculation
Settling Basin
Chlorine
Filtration
Contact Tank
Clearwell
WTP Effluent
End of System
g)	Click 'OK' on the Edit Process Train screen and the main window
will appear with Table 1 updated to reflect the changes. On a
386-SX this will take about 5 seconds.
h)	In Table 1, note the pH at the point of sulfuric acid addition.
We want a pH of about 6.0 at this point thus, more sulfuric
acid is needed to lower the pH. On the main window click
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'Edit', on the Edit Process Train screen double click Sulfuric
AcicL and on the Sulfuric Acid Parameters screen make a new
guess for the proper sulfuric acid dose. Click 'OK' on the
Sulfuric Acid Parameters screen and 'OK' on the Edit Process
Train screen and note the pH at the point of sulfuric acid
addition on Table 1. Repeat this step until pH 6.0 is obtained
at the point of sulfuric acid addition. (The sulfuric dose
should be about 10 mg/L).
Coagulation has now been enhanced. Examine the 5 tables and observe the
effect on the various parameters.
9)	OBP and Disinfection display.
On the main window click on the 'DBPs' button and Table 6 will be
displayed. Table 6 is a summary table which contains the pH, free
chlorine residual, monochloramine, Inactivation Ratio, TTHM and THAA.
The Inactivation Ratio is at the minimum temperature and maximum flow
while the other parameters are at average conditions.
Now lower the chlorine dose such that 2.0 mg/L or less is at the WTP
Effluent and the Inactivation Ratio is 1.0 or greater. This is a
trial and error procedure similar to the sulfuric acid dose. The
chlorine dose should be about 3.0 mg/L.
On the main window examine the Inactivation Ratio, TTHM and THAA at
the WTP Effluent. The plant is now in compliance with the
disinfection requirements of the SWTR and in compliance with the
current TTHM MCL. But there is more to be done, the pH in the
distribution system is too low and there is no chlorine residual at
the "End of System".
10)	Add Ammonia after the clearwell to convert the free chlorine to
monochloramine and maintain a residual in the distribution system.
The proper amount of ammonia is about 0.4 mg/L. Observe Table 1, at
the point of ammonia addition the free chlorine (C12) has been
converted to monochloramine (NH2C1) and there is a small ammonia
residual.
11)	Add sodium hydroxide after ammonia to adjust the pH to about 8. The
proper amount is a trial and error procedure and should be about 30
mg/L. Again observe Table 1 to see the effect. Note: Soda Ash could
be used in place of sodium hydroxide.
This completes the guided tour of using WTP. The following describes the
menu functions, control buttons and other features of WTP.
Main Window:
Mam Title and Working File Name
The title at the top of the main window is generally:
"U.S. Environmental Protection Agency - Water Treatment Plant Model"
The title at the top of the main window is replaced with the working
file name when WTP model is working with process train data that is
stored on disk. As an example save the guided tour process train (or
any process train) as follows.
From the main window menu select 'File | SaveAs'. A "Save Process
Train & Unit Process Data" file requester will appear. In the
"Filename" box type in test.wtp and click 'OK'. The process train
data are saved to the disk and the title at the top of the window
will change to reflect the working file name.
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Menu
File
New
Open
Save
This selection will prepare WTP model to start a new process
train. Any existing process train data are cleared from WTP
along with the name of the working file. Data stored in a disk
file are not cleared.
This selection will read process train data from a disk file
and track the working file name. Internally the Open function
preforms a 'New' operation before reading in data.
This selection will write process train data to the working
file without prompting the user. If a working file name does
not exist then a SaveAs selection is automatically preformed.
SaveAs
This selection will prompt the user for a working file name
then save the process train data to the data file. This
selection provides an opportunity to change the working file
name.
Print
This selection will print the main window display on the system
printer.
Print To File
This selection will save the main window display to a disk file
in ASCII format. Any previous contents of the disk file are
LOST. The user is prompted to supply a file name with a .1st
extension. The disk file can then be loaded into word
processor for further use.
Append To File
This selection will append the main window display to the end
of a disk file thus not loosing the previous contents of the
disk file. The user is prompted to supply a file name with a
.1st extension. The disk file can then be loaded into a word
processor for further use.
Exit
Quit WTP and return to MS-Windows.
Display
Process Train
This selection will display the names of the unit processes,
chemical feeds, and samples points in the process train. The
display is in the main window display area.
Unit Process Data
This selection is similar to "Display \ Process Train" but
includes the unit process data.
Water Quality
This selection will run the model and display 5 tables of water
quality parameters.
Disinfection & DBPs
This selection will run the model and display one summary table
containing worst case disinfection and average byproduct
formation.
Edit
Process Train
This selection will open the 'Edit Process Train' screen. See
'Edit Process Train' for details.
Control Buttons
Open: Same as menu selection File j Open
Edit: 	 "	Edit ! Process Train
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Run :
DBPs:
Save:
Exit:
Disp	]	Water Quality
Disp	|	Disinfection & DBPs
File	J	Save
File	!	Exit
Edit ProcesB Train
The "Edit Process Train" screen is used to configure the
process train. Unit processes, chemical feeds and sample
points can be inserted, repositioned or deleted in this screen.
Process Train
The left half of the screen is the process train and control
buttons.
List Box
This section of the Process Train display illustrates the
current process train which can consist of any number of unit
processes, chemical feeds and sample points (collectively
referred to as items). Any of the items in the process train
can be highlighted by clicking with the mouse. The highlighted
item is the point where new items are inserted into the process
train. The highlighted item is also used with the 'Move'
button. Double clicking an item will open the parameter data
entry screen starting with the selected item. A scroll bar is
on the right side of the list box and will become active if the
process train contains more items than will fit in the display.
Move button
This selection will reposition an item in the process train.
The procedure is to first highlight an item, click the move
button, and click on the point in the process train where the
highlighted item should be repositioned. The 'Move' operation
will reposition the highlighted item such that the highlighted
item will follow the clicked item in the process train.
Edit button
This selection will open the Parameter data entry screen
starting with the Influent. Note: double clicking any item in
the process train list box will open the parameter data entry
starting at the selected item.
Delete button
This selection will delete the highlighted item from the
process train. Any data associated with the item are lost.
Clear button
This selection will delete all items from the process tram. Be
careful, 'Clear' may appear to be similar to the main window
'File | New' selection but there are differences. The
difference is that the 'Clear' button will retain the working
file name while the main window menu 'File | New' selection
will also clear the working file name. With 'Clear', WTP
considers the now empty process train to be associated with the
working file name. Clicking the 'Save' button on the main
window will overwrite the working file without a second
warning. Please use 'File | New' if a new disk data file is
desired.
Available Selections
Unit Processes
Chemical Feeds
sample Points
These three list boxes contain selections that can be added to
the process train. Clicking on any selection will insert the
selection into the process train following the highlighted item
in the process train or, if no highlight, append the selection
to the end of the process train.
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Cancel button
Thi9 button will cancel all changes made to the process train
and also cancel all changes made in the parameters data entry
screens. Control is returned to the main window.
OK button
This is the normal method of return to the main window. All
changes are passed back to the main window and the display area
of the main window is updated.
Data Entry Screen
There are many data entry screens for unit process data,
chemical feed doses, location of sample points, and laboratory
analysis collectively referred to as data entry screens. All
the data entry screens have the following features and control
button.
Screen Title
The title at the top of the data entry screen indicates the
name of the unit process, chemical feed, sample point, or
laboratory analysis that the data entry screen is associated
with.
Next button
Prev button
OK button
The 'Next' and 'Prev' buttons will index through the data entry
screens associated with the process train. 'Next' indexes to
the next data entry screen while 'Prev' indexes to the previous
data entry screen. The 'OK' button will return to the Edit
Process Train screen. When clicked, 'Next', 'Prev' and 'OK'
check for valid data in each data element, pass new data back
to Edit Process Train, and then index to the next data entry
screen. Both 'Next' and 'Prev' will return to the Edit Process
Train screen if the data entry screen is the first or last data
entry screen in the process train.
Cancel button
The 'Cancel' button will cancel changes made in the current
data entry screen and return to the Edit Process Train screen.
Note: changes made on other data entry screens are passed back
to Edit Process Train when 'Next' and/or 'Prev is pressed. If
changes are made on other data entry screens and the current
data entry screen is arrived at via 'Next' and/or 'Prev' then
pressing 'Cancel' will cancel only the current data, not
changes made to the other data entry screens.
As stated at the beginning of this document, it is desired to
systematically improve the user interface and predictive capability of WTP.
The intent of this release is to solicit comment on the usefulness and
relative accuracy of the prediction. Please forward constructive comments,
results from verification efforts, and utility data to the name and address
shown at the beginning of this document. Thank you.
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