PLC & SCADA based automation of Filter House, a section of Water Treatment Plant

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Abstract— Rajasthan is an arid state and hence making 
available drinking water is a government priority. Under 
Bhageri Ka Naka (Rajasthan) Rural water supply scheme, 
there is a transmission system of a capacity to produce and 
deliver 16.21 MLD of treated water in the clear water 
reservoirs near treatment plant. This water supply scheme is 
divided mainly into three sections namely: (1) Intake Pump 
House (IPH), (2) Water Treatment Plant (WTP) & (3) Clear 
Water Pump House (CWPH). Water Treatment Plant Section 
Involves: 
1. Turbidity Measurement and Alum Dosing. 
2. PH Measurement and Lime Dosing 
3. Clarifloculator for Clarifying the Alum dosed and Lime 
dosed Raw Water 
4. Filter House for further filtering the Clarified Water. 
5. Chlorination 
This paper describes how automation of Filter House (section 
4 of Water Treatment Plant) is done for this project using 
PLC & SCADA. 
I. INTRODUCTION 
PLCs (programmable logic controllers) are the control hubs 
for a wide variety of automated systems and processes. 
They contain multiple inputs and outputs that use 
transistors and other circuitry to simulate switches and 
relays to control equipment. They are programmable via 
software interfaced via standard computer interfaces and 
proprietary languages and network options. 
 
Available inputs for programmable logic controllers 
include DC, AC, analog, thermocouple, RTD, frequency or 
pulse, transistor, and interrupt inputs. Outputs for PLCs 
include DC, AC, relay, analog, frequency or pulse, 
transistor, and triac. Programming options for PLCs 
include front panel, hand held as well as computer. 
 
PLCs can also be specified with a number of computer 
interface options, network specifications and features. In 
addition to controlling output functions, programmable 
logic controllers are good for compiling data from many 
sources and uploading this data into a computer network. 
PLCs are generally more durable, and less expensive, than 
computer systems and as a result can be placed in remote or 
rugged industrial locations, and perform at a high level for 
many years. 
 
A. Prof. Archana B. Yadav has completed M.Tech in Instrumentation 
from Devi Ahilya University, Indore. She is working as an Assistant 
Professor at Sardar Vallabhbhai Patel Institute of Technology, Vasad. She 
is having more than 3 years of Industrial Experience as well as more than 
3 years Teaching Experience. (email: archu.payal@gmail.com). 
 
 
SCADA stands for Supervisory Control And Data 
Acquisition. As the name indicates, it is not a full control 
system, but rather focuses on the supervisory level. As 
such, it is a purely software package that is positioned on 
top of hardware to which it is interfaced, in general via 
 
 
Programmable Logic Controllers (PLCs), or other 
commercial hardware modules. 
 
SCADA systems are used not only in industrial processes: 
e.g. steel making, power generation (conventional and 
nuclear) and distribution, chemistry, but also in some 
experimental facilities such as nuclear fusion. However, 
SCADA systems evolve rapidly and are now penetrating 
the market of plants with a number of I/O channels of 
several 100K SCADA systems used to run on DOS, VMS 
and UNIX; in recent years all SCADA vendors have moved 
to NT and some also to Linux 
III. WHY USE PLCS? 
Advantages offered by PLCs: 
ƒ Cost effective for controlling complex systems. 
ƒ Flexible and can be reapplied to control other 
systems quickly and easily. 
ƒ Computational abilities allow more sophisticated 
control. 
ƒ Trouble shooting aids make programming easier 
and reduce downtime. 
ƒ Reliable components make these likely to operate 
for years before failure. 
II PROJECT BACKGROUND 
Rajasthan is an arid state and hence making available 
drinking water is a government priority. Under Bhageri Ka 
Naka (Rajasthan) Rural water supply scheme, there is a 
transmission system of a capacity to produce and deliver 
16.21 MLD of treated water in the clear water reservoirs 
near treatment plant. The carrying capacity of the 
transmission main for clear water from Bhageri Ka Naka in 
gravity from Bhageri ka Naka to Khamnor shall be of 13.71 
MLD and that from Khamnor to Nathadwara of 10.96 
MLD. At Khamnor, approximately 3.75 MLD clear water 
shall be transferred to the Khamnor clear water reservoir, 
for onward boosting. 
Water shall be either taken through gravity or shall be 
pumped from the intake pump house at Banas River on 
which a Dam is constructed. Water from Intake shall be 
taken to treatment plant inlet chamber or sedimentation 
tank situated in Bhageri Ka Naka head works, 
approximately 500 meters from the proposed intake site. 
PLC & SCADA based automation of Filter 
House, a section of Water Treatment Plant 
A. Archana B. Yadav 
Sardar Vallabhbhai Patel Institute of Technology, Vasad (Gujarat). 
e-mail: archu.payal@gmail.com 
2012 1st International Conference on Emerging Technology Trends in Electronics, Communication and Networking
978-1-4673-1627-9/12/$31.00 ©2012 IEEE
 
A treatment plant of output capacity 16.21 MLD, two clear 
water reservoirs each of capacity 1.25 MLD are 
constructed at Bhageri Ka Naka head works. 
 
In short, the plant located at Bhageri ka Naka, Rajasthan is 
divided mainly into three sections namely: 
1. Intake Pump House (IPH) 
2. Water Treatment Plant (WTP) 
3. Clear Water Pump House (CWPH) 
 
Water Treatment Plant (WTP) 
Intake Chamber raw water flows to Water Treatment Plant 
through Raw water Gate valve. In manual mode operator 
has to give Open command to this valve through SCADA 
or Panel View screen while in Auto or Semi Auto mode it 
gets Open command after a specified time of getting ON 
Feedback from at least any one pump of Intake Pump 
House. Operator can give this lead-time from SCADA or 
PanelView screen. 
 
Water Treatment Plant Section Involves: 
• Turbidity Measurement and Alum Dosing. 
• PH Measurement and Lime Dosing 
• Clarifloculator for Clarifying the Alum dosed and 
Lime dosed Raw Water 
• Filter Beds for further filtering the Clarified 
Water. 
• Chlorination 
This paper describes how automation of Filter House 
(section 4 of Water Treatment Plant) is done for this project 
using PLC & SCADA. 
 
IV. SYSTEM CONFIGURATION 
In Bhageri Ka Naka Project all I/Os related to process 
control are scattered across the plant. So RIO (Remote 
Input Output) communication scheme is adopted in order to 
minimize the field device wiring up to control room. 
RIO (Remote Input Output) is implemented on RS 485 
multi-drop networking concept. Basically it is two-wire 
loop running across the plant to communicate between PLC 
(master) and RIO Adapters (slaves). RIO is capable of 
communicating over 25 Kilometer long network. In short, 
RIO Networking is used to gather all the remote Input and 
Outputs (Digital and Analog) into a one SLC (PLC). 
In this project for Online Graphical Interfacing, in each 
plant section individual MMIs (Panel View Terminal or 
PC) are used. To communicate all these MMIs of all the 
sections of plant, DH-485 data highway (RS 485 multi-
drop networking) is established. DH-485 data highway is 
established using Advanced Interface converters (RS-232 
to RS-485 Isolators). Panel View Terminals and PC support 
only RS-232 protocol. So to established communication of 
these devices Advance interface converters are used in 
system configuration. 
 Printer is connected to PC, which scatters the facility to 
print the online parameters printouts (Daily, Monthly, 
Yearly Report) of the plant as per operator’s requirement. 
Hardware Used 
All the devices used in this project are of Rockwell 
Automation (Allen Bradley) make. The Hardware 
components used in this project arelisted below: 
1. Programmable Logic Controller (SLC 5/03) 
2. Racks for modules 
3. Power Supply for SLC 
4. Digital Input Modules 
5. Digital Output Modules 
6. Analog Input Modules 
7. Basic Module 
8. Remote I/O Scanner Module 
9. Remote I/O Adapter Module 
10. Network Interface Module 
11. Graphical User interface (Panel View Terminal) 
12. PC for SCADA 
13. Cables 
 
 
 Figure 1. System Configuration 
 
IV. OPERATION PHILOSOPHY 
Filter House: 
The clarified water from the Clarifloculator enters into the 
filter House for filtering. Total three filter beds are there in 
water treatment plant for filtering operation. Each filter bed 
contains two compartments. In each compartment 
Differential pressure transmitter is mounted. Also there are 
two Air blowers for filtering operation. 
 
Nine pneumatic control valves are provided for the filtering 
process in each filter bed. These valves are listed below: 
1. Clarified Water Inlet Valve – 1 no., which is common 
between two compartments of filter bed. 
2. Air Scour Inlet Valve – 2 Nos., one for each 
compartment. 
3. Wash Water Inlet Valve – 2 Nos., one for each 
compartment. 
4. Dirty Water Outlet Valve – 2 Nos., one for each 
compartment. 
5. Clear Water Outlet Valve – 1 No., which is common 
between two compartments of filter bed. 
 
In each Filter Bed following two main operations are 
performed: 
1. Filter operation 
2. Backwash operation 
A. Filter Operation 
Prerequisite for filter operation: 
2012 1st International Conference on Emerging Technology Trends in Electronics, Communication and Networking
978-1-4673-1627-9/12/$31.00 ©2012 IEEE
 
 
 
 
ƒ Differential pressure across the filter bed should not 
high than the specified set point by the operator 
through MMI screen 
ƒ Filter is not selected as OFF from the MMI screen 
ƒ Air Blower should be in Remote mode 
ƒ Any valve out of all the valves related to the filter bed 
should not be in trouble (Open or Close) 
ƒ Both air blowers should not be tripped 
Sequence of Filter Operation: 
1. The filter operation is performed for the programmed 
time, which is adjustable from MMI screen. 
2. In this operation, the clarified water coming from the 
Clarifloculator enters into the selected filter bed 
through the Clarified Water Inlet Valve. 
3. When this valve opens, at the same time Clear Water 
Outlet Valve of selected filter bed also opens and all 
other valve (Air scour inlet, Wash water inlet, Dirty 
water outlet) remains closed. 
 
The water is thus filters through sand bed and filtered water 
from filter house flows into the Chlorine Contact Tank. 
B. Backwash Operation 
To clean the filter bed back wash operation is performed. 
The backwash operation is performed in either of the 
following condition: 
• When differential pressure across filter bed goes High 
than the specified set point given through the MMI 
screen. 
• All four filter beds get back washing sequentially at a 
fixed time given by operator through MMI screen. 
In Auto mode, out of the two above conditions whichever 
condition occurs first governs for the particular Filter Bed 
to go in Backwash. The PLC is programmed such that not 
more than one Filter Bed undergoes Backwash operation at 
a time. In case the DP across two and more Filter Beds 
becomes high at the same time, priority will be defined in 
the PLC program so that the Filter Bed having priority 1 
undergoes backwash first. 
The fixed interval of time for filter backwashing in 
Auto/Semi auto mode will be selectable from the PC based 
MMI (SCADA). 
 
Pre-requisite for Backwash operation: 
• The level in the Wash water tank should be above a 
setpoint given by operator through MMI screen. 
• Any valve out of all the valves related to the filter bed 
should not be in trouble (Open or Close) 
 
Sequences of Back wash Operation: 
Backwash operation is performed automatically through 
PLC in following sequence: 
1. Draining 
2. Air scouring 
3. Back-Washing 
4. Rinsing 
5. Filtering 
 
The status of all valves in all the above steps of Backwash 
operation is shown below: 
 
TABLE I 
STATUS OF VALVES IN BACKWASH OPERARTION 
 
In manual mode of back wash operation operator has to 
give open command to the related valve according to the 
above table. 
In Auto/Semi auto mode above sequence of Back washing 
takes place automatically when Auto sequence is started. In 
Auto mode if Filter House section gets tripped than all the 
sections preceding this section also gets tripped. In any 
abnormal condition alarm sounds through hooter and it also 
comes in MMI’s alarm list. 
 
ANALYSIS AND RESULTS: 
 
MAIN SCREEN: 
 
 Figure 2. SCADA Main Screen (*Refer page no.5 for Enlarged view) 
 
SCADA Main Screen for Filter House section is shown in 
Figure 2. Operator can able to view status of each & every 
valve, pump as well as blower i.e. ON/OFF or Open/Close 
by color animation. In bottom of the SCADA main screen 
alarm summary is also displayed, which is showing details 
of any alarm occurred in the process. Operator can 
acknowledge any alarm from this window. By clicking on 
the individual Filter Bed, operator can able to view detailed 
screen of that Filter Bed. Figure 3 shown below shown one 
of that screen. 
 
 
Backwash 
Operation 
Steps 
 
Service 
Water 
Inlet 
Valve 
 
Air 
Inlet 
Valve 
 
Wash 
Water 
Inlet 
valve 
 
Dirty 
Water 
Outlet 
Valve 
 
Clear 
water 
Outlet 
Valve 
 
Air 
Blower 
Draining Close Close Close Open Close OFF 
Air 
scouring Close Open Close Open Close ON 
Back 
Washing 
Close Close Open Open Close OFF 
Rinsing Close Close Close Open Close OFF 
Filtering Open Close Close Close Open OFF 
2012 1st International Conference on Emerging Technology Trends in Electronics, Communication and Networking
978-1-4673-1627-9/12/$31.00 ©2012 IEEE
 
 
Figure 3. SCADA Filter BED Screen (*Refer page no.6 for Enlarged 
view) 
 
Operator can able to view status i.e. ON/OFF of each & 
every pump of Fiter Bed. This screen also shows time left 
for each sequence of filtering operation or backwashing 
operation whichever is running. Alarm summary window 
like that of SCADA Main screen is also shown in this 
display. 
 
Operator can enter time period for all these sequences of 
filtering or backwashing operation through set point screen. 
I. CONCLUSION 
In this paper we have presented a PLC-SCADA based 
automation of Filter house which is a part of Water 
Treatment Plant. The trend in automated water treatment 
plants is to use SCADA systems based on PLCs, advanced 
communication systems, and PC-based software. PLC has 
been widely used and played an important role in the 
automation industry today. Due to advantages of low cost 
and high reliability, many automation machine 
manufactures still prefer to use PLC at the time being. The 
SCADA provides multipurpose utility management and 
operating flexibility for the monitoring system. 
 
VIII. REFERNCES 
 
[1] Archana B.Yadav & Pooja S.Shukla, Paper on “Augmentation to Water 
supply schme using PLC & SCADA”, IEEE digital library. 
[1] L.A.Brayan & E.A.Brayan, Programmable Controllers Theory & 
Implementation; 2nd Edition, (1997-01). 
[2] Madhuchhanda Mitra & Samarjit Sen Gupta, Programmable Logical 
Controllers & industrial Automation;2nd Edition,Penram Intrnational 
Publishing Pvt.Ltd. 
[3]http://literature.rockwellautomation.com/idc/groups/public/documents/w
ebassets/browse_category.hcst 
[4] Rockwell Automation SCADA System Selection Guide Allen-Bradley, 
Publication AG-2.1. 1998. 
[5] Boyer, Stuart, A. SCADA: Supervisory Control and Data Acquisition, 
Instrument Society of America, Research 
Triangle, NC. 1993. 
 
Prof. Archana B. Yadavhas completed M.Tech (Instrumentation) in 
2005 from Devi Ahilya University, Indore. She is working as an Assistatnt 
Professor at Sardar Vallabhbhai Patel Institute of Technology, Vasad. She 
is having 3 years of Industrial Experience as a Project Engineer in 
Automation Industries and 3 years of teaching Experience at SVIT, 
VASAD. Email: archu.payal@gmail.com. 
 
2012 1st International Conference on Emerging Technology Trends in Electronics, Communication and Networking
978-1-4673-1627-9/12/$31.00 ©2012 IEEE
 
 
 
 
 
 
 
2012 1st International Conference on Emerging Technology Trends in Electronics, Communication and Networking
978-1-4673-1627-9/12/$31.00 ©2012 IEEE
 
 
2012 1st International Conference on Emerging Technology Trends in Electronics, Communication and Networking
978-1-4673-1627-9/12/$31.00 ©2012 IEEE