This document provides an outline for a project to design a water treatment system for agricultural irrigation from a reservoir. The system will filter algae and disinfect water from Lake Issaqueena in Clemson, SC to meet irrigation standards. Key objectives are to develop a multi-stage system to remove algae and deactivate E. coli via chlorination. Literature on water quality standards, initial conditions, filtration methods, and disinfection kinetics will inform the design of the algae filtration and pathogen disinfection components. A self-cleaning disk filter and trash pump will be selected for the initial design.

1. Engineering and Design of a
Water Treatment System for
Agricultural Irrigation
from a Reservoir
Wesley Cagle, Cody Eimen, Alexis McFadden, Colin Richter, and Michael Smith
Clemson University
Clemson, SC
November 30, 2021

2. Outline
• Introduction
• Background
• Rationale
• Objectives
• Approaches
• Deliverables
• Literature Review
• Materials and Methods
• Results
• Recommendations
• Acknowledgements

3. Introduction

4. Introduction
• Agriculture is an essential component of civilization
• Oftentimes, crops require supplemental watering in the
form of irrigation
• Irrigation directs water from nearby sources towards
cropland
• The availability of fresh water will remain an issue in arid or
frequently drought-stricken areas and regions subject to
extreme hydrological events stemming from climate change
• Water quality used for irrigation impacts the agricultural
practices and types of crops that can be grown in a region
Figure 2. There is a strong direct correlation between
irrigation and crop yield to a certain point. Irrigation
is an important part of ensuring food security.
Figure 1. South Carolina field that utilizes drip irrigation.

5. Introduction
• Water quality is defined by microbial activity, nutrient concentrations, turbidity, or—in systems
prone to clogging—suspended algae concentration, among other factors
• “The clogging of emitters is one of the more serious problems in drip/trickle irrigation systems
causing reduction in application uniformity and negative effects on crops production” (Yavuz et al,
2010)
• Clogging within pipes is also an issue
Figure 3. Sprinkler clogged by algae

6. Introduction
• Water for use in irrigation systems must be environmentally safe and mechanically practical
• It must meet Escherichia coli (E. coli) standards set by the South Carolina Department of
Health and Environmental Control (SCDHEC)
• It also must be free of nozzle-clogging solids
• A two-part system including algae removal and microbial disinfection must connect water
storage reservoirs and commercial irrigation systems
• Water must be chlorinated to ensure appropriate microbial levels
• Some water may need to be dechlorinated to ensure chemical safety

7. Need for Chlorination
• Water that is not disinfected may become a vector for E. coli transport
and infect susceptible crops
• As many fresh foods do not undergo thermal treatment, it is particularly
important for these crops to have a high level of water quality
• Examples of target crops include:
• Collards
• Cabbage
• Swiss chard
• Kale
• Spinach
Figure 4. Collards to be harvested and consumed
without heat treatment.

8. Background
Figure 5. GIS map of Lake Issaqueena and
the surrounding area (Zoomed Out)
Lake Issaqueena
Lake Hartwell
City of Clemson

9. Background
Figure 6. GIS map of Lake Issaqueena (Zoomed In)
Lake Issaqueena
Lake Hartwell
Issaqueena Dam
Testing site

10. Background
• Our project aims to use
engineering techniques that were
developed for an irrigation
reservoir in Southern California
to be used in the southeastern
United States
• Since California’s climate is different
than that of the southeastern US, we
will mirror AECOM’s approach of
designing a water treatment facility
using different technologies
Figure 7. Map of total irrigation withdrawals in each US state in 2015

11. Background
• Lake Issaqueena's water level is
maintained by the Issaqueena Dam,
which separates the reservoir from the
Keowee River portion of Lake Hartwell
• Lake Issaqueena has a capacity of 1207
acre-feet and a normal water storage of
around 600 acre-feet
• The dam, lake, and surrounding area
make up part of the Clemson
Experimental Forest
Figure 8. Photograph of Issaqueena Lake Dam taken by team

12. Rationale
The motive for undertaking this project is to:
• Ensure water security for local agricultural production
• Provide a product that meets irrigation standards and is environmentally safe
• Produce a product that can be used in existing water conveyance systems
• Establish food security though reliable water availability for local agriculture
• Sell a product that will eventually be able to pay for the treatment facility

13. Objectives
The objectives of this project are to:
• Develop a facility that will transform an influent flow from a reservoir into an effluent that meets
designated water quality standards
• Deliver water to agricultural consumers without clogging existing water conveyance and irrigation
systems

14. Approaches/Tasks
This project achieves the objectives through the following tasks:
• Task 1. Identify the primary impurities of the influent reservoir water
• Assess the characteristics of algae and its concentration in the reservoir
• Evaluate the initial microbial quality of the reservoir water
• Task 2. Determine and assign the water quality standards that must be met by the effluent
• Task 3. Research water filtration technologies
• Select feasible filtration methods and designs
• Evaluate the advantages and disadvantages of different filtration methods
• Task 4. Investigate water disinfection methods
• Research different pathogen disinfection techniques
• Select most applicable water disinfection technique
• Task 5. Design and model a multistage filtration and disinfection system to be housed in a facility
• Task 6. Devise a plan for maintaining the filtration and disinfection system after installation
• Task 7. Present findings and recommendations to AECOM

15. Deliverables
These are the products we will be delivering with this project:
• Description of water quality parameters that the designed system will meet
• Designs and models of algae filtration and pathogen disinfection methods
• Analysis of the selected algae filtration and pathogen disinfection methods
• Life cycle analysis of water from the reservoir to the irrigated field

16. NAE Grand Challenge
• "Providing access to clean water" is the
most applicable Engineering Grand
Challenges to this project.
• “The world's water supplies are
facing new threats; affordable,
advanced technologies could make a
difference for millions of people
around the world.” (National
Academy of Engineering)
Figure 10. United Nations food insecurity statistic
UN Sustainability Goal
• UN Sustainable Development Goal of
"achieving food security“
• 70% of water withdrawal in the
world is used for agriculture
(United Nations
Educational, Scientific and Cultural
Organization)​
Figure 9. NAE Grand Challenges logo

17. Venn Diagram
This diagram conveys how different fields interact within this project.
Figure 11. Venn Diagram of Project Topics

18. Literature Review

19. Literature Review: Water Quality Standards
• No garbage, cinders, ashes, oils, sludge, or other refuse
• No treated wastes, toxic wastes, deleterious substances, colored or other wastes allowed alone or
in combination with other substances or wastes
• Dissolved oxygen: daily average should not be less than 5.0 mg/L
• E. coli: not to exceed a geometric mean of 126 MPN/100 mL (CFU/100 mL) based on ≥ 4 samples
from a given site over a 30-day period, also a single sample should not exceed 349 MPN/100 mL
• pH: between 6.0 and 8.5
• Temperature: should not exceed 5 °F (2.8 °C) above natural conditions and shall not exceed a
maximum of 90°F (32.2°C)
• Turbidity: not to exceed 25 NTUs (≈8.33 mg/L)
• Algae: No sprinkler nozzle clogging algae present

20. Literature Review: Initial Water Quality
• Data was collected from the most recent SCDHEC Savannah River
Basin Watershed assessment (carried out in 2010)
• General trends in Lake Issaqueena and neighboring lakes/rivers show
decreasing "Total Phosphorus" levels, but increasing "Total
Nitrogen" levels
• The interplay of these nutrient levels is essential to understanding
the growth of algae in the lake
• The major concern of the original AECOM project is not large
filamentous algae, but small clogs in sprinkler heads

21. Literature Review: Present Algal Species
• Algal Species Present and their approximate sizes
Figure 14. Closterium Algae
Figure 12. Chlorella Algae Figure 13. Cladophora Algae
Species Name Diameter (µm) Length (µm)
Chlorella Vulgaris 5-10
Cladophora Glomerata 45-150 300-1000
Closterium Moniliferum 16-75 100-800

22. Literature Review: Filtration Theory
• Straining or Screening is the technique of separating a mixture of solid particles
based on size and shape differences
• Filtration is the prosses of physically or mechanically removing suspended solid
particles from a liquid
• “In filtration a pressure difference is set up and causes the fluid to flow through
the small holes of a screen or cloth which block the passage of large solid
particles” (Anand Agricultural University)
Figure 15. Large particles excluded by a
screen while small particles pass through

23. Literature Review: Dead-End Filtration
• Darcy's Law is a fundamental law describing fluid flow through porous media and
can be used for conventional dead-end filtration on a time basis with the
following equations:
• where:
• A = cross-sectional membrane area (m2)
• V = volume of filtrate (m3)
• µ0 = filtrate viscosity (Pa•sec)
• R = Rf + Rc is the sum of resistances (m-1)
• Rf = filter screen resistance
• Rc = filter cake solids resistance
• α = specific cake resistance (m/kg)
• ρc = density in terms of dry cake mass of solids per volume of filtrate liquid (kg/m3)
• Δp = change in pressure across the filtration membrane (Pa)
(Walker, 2021)
(Eq. 1) (Eq. 2)

24. Literature Review: Dead-End Filtration
• Combining the previous Darcy's Law equations and integrating based on the initial
conditions of volume = 0 at time = 0, the following equation is obtained
• Where all terms were established in the previous slide except:
• t = time (sec)
• This equation allows us to determine the filtration time it would take to reach a certain
pressure difference across the filter membrane
(Eq. 3)

25. Literature Review: Filtration Pore Sizing
• The biggest limiting factor for the size of algae particulate that can
safely pass through the system is irrigation nozzle size
• Spray irrigation systems use nozzles in the 5/32-inch to 7/32-inch diameter
range
• "Wheel move systems typically have 3/16-inch nozzles"(R. Hill, 2001)
• Drip irrigation systems use microtubes with inner diameters ranging from 2-4
mm or just over 1/16-inch to 5/32-inch

26. Literature Review: Disinfection with Chlorine
• Chlorination is a particularly powerful tool to use in water
treatment because it eliminates harmful pathogens and prevents the
growth of algae and slime molds
• Chlorine has been used to disinfect drinking water for almost 100
years in some regions of the US
• There are no proven health implications from low levels of chlorine intake
• Adding chloramine is one of the common ways to chlorinate water
• Some systems use chloramine because it gives off a less potent smell
• Chloramines are generally formed when ammonia is added to chlorine

27. Literature Review: Disinfection with Chlorine (Cont.)
• Hypochlorite bleach is a very common way that non-drinking water
systems are chlorinated
• For instance, many swimming pools utilize hypochlorite bleach
• Hypochlorite bleach is sometimes referred to as "liquid chlorine"
• The biological oxygen content (BOC) of the water system determines
the amount of hypochlorite that should be used
• It is important to exceed this level by about 2 mg/L to ensure satisfactory
disinfection
• Any residual chlorine in the water will prevent new microbial growth
in agricultural applications

28. Literature Review: Kinematics of Disinfectant Decay
• First-Order Kinetic Reaction in a batch reactor
• 1
• Where:
C(t)= concentration at time t (ppm)
= initial concentration (ppm)
K=decay constant (1/minute)
t = time (minute)
• Found acceptable for predicting chemical disinfectant decay
• Decay constant (k) decreased with initial disinfectant concentration
being increased
• When chlorine was used prior to disinfection it was found to increase
in efficiency of E. coli removal
(Eq. 4)

29. Literature Review: Chlorine Decay Constant
• There is an inverse relationship
between bulk decay rate and initial
chlorine dose
• Equation 5 is plugged into
Equation 6 to get Equation 7 which
is the bulk decay of chlorine in the
distribution system
• where: β and 𝐾0 are regression
parameters
(Eq. 5) (Eq. 6) (Eq. 7)
Figure 16. Plot of the bulk decay rate constant K against the
initial chlorine dose used

30. Literature Review: E. coli Disinfection
• First order reaction in a batch reactor
• k = 1.283 minutes-1 at a pH of 7.1
• As pH increases, the hypochlorite has
less disinfecting capacity and the k value
drops
• General characteristics​
• "99% [of E. coli] destroyed by 1.0 mg/liter hypochlorous acid at pH 6 in
less than 10 s and at pH 10 by 1.0 mg/liter hypochlorite ion in about 50 s"
(National Research Council (US) Safe Drinking Water Committee, 1980)
(Eq. 4)

31. Literature Review: Algae Kinetics
• Algal growth in environmental conditions
• Generic Chlorella strain doubles in about 1.75 hours at 20.5 oC when nutrients
are not a limiting factor
• The microalgae that makes it through the filtration will behave
similarly whether killed by the hypochlorite or not
• In a poorly-stirred system, it is reasonable to assume about 40% of algae will
settle to the bottom for a hydraulic retention time of about 2 hours

32. Literature Review:
Continuously Stirred Tank Reactor (CSTR)
• Must have a flow in and a flow out
• Must be well-mixed
• Impeller
• Shaking mechanism
• Jet mixing
• This is distinct from the batch reactor because
of the flow in and flow out
Figure 17. Generic CSTR model

33. Literature Review: CSTR Equation
Q = system flow rate (L/min)
V = system volume (L)
Cin = influent concentration (ppm)
C = system concentration (ppm)
r = rate of reaction (ppm/min)
(Eq. 8)
• The CSTR equation below describes the rate of change of
concentration at a time, t:
𝑄 ⋅ 𝐶𝑖𝑛
𝑉
−
𝑄 ⋅ 𝐶
𝑉
− 𝑟 =
𝑑𝐶
𝑑𝑡

34. Materials and Methods

35. Filtration Pore Size Selection
• Mesh sizing for filtration will be based on the standard minimum
diameter of nozzles used in spray irrigation systems
• From the literature review, nearly all spray irrigation systems use
spray nozzles with diameter larger than 1/16-inch
• 1/16-inch nozzle diameter is equivalent to 0.0625-inch mesh hole size
• A 250-micron filter, having 60 holes per linear inch, and a maximum hole size
of 0.01-inch diameter, will be more than fine enough to prevent algae
clogging in all spray irrigation systems

36. Filter Selection
• The single filter unit selected for our design is the
Tekleen LPF16-SP, which is part of their self-
cleaning Low Pressure Filter Series
• These filters are designed specifically to filter out
particles like sand as well as organic matter like
algae, can operate at a range of 15-150 psi, and
use a filter screen with an area of 24 square feet
• As the filter screen captures contaminates, the
pressure differential is tracked across the
membrane and triggers an automatic
flush cycle by reversing the pressure differential
across the filter screen
• Cleaning cycles take only 10-15 seconds, and the
filtration process continues uninterrupted
Figure 18. Vertically fixed Tekleen LPF in
operation, the water to be filtered enters
through the lower right inlet and the
filtered water exits through the
downward facing left outlet

37. Tekleen LPF Series
Figure 20. Large horizontally fixed Tekleen LPF
Figure 19. Tekleen LPF installation layout drawing

38. Trash Pump Selection
• A trash pump model Godwin CD400M will be
used as the first pump in the system, prior to
filtration
• This pump is often used for dewatering
reservoirs and can process water containing
solids up to 4.9 inches in diameter
• This pump operates with a 250 hp electric
motor that will only have to run at 60%
maximum capacity to produce the desired
6,000 gallons per minute (GPM) flowrate
Figure 21. 15 diesel powered CD400Ms used to move 1.7 billion
gallons of water in Panama canal lock system over 22 days in 2017
Figure 22. Godwin CD400M with electric motor rather than
diesel for long-term continuous applications

39. Processing Pump Selection
• The pump selected for moving water
through and out of the system is the Goulds
3196 i-FRAME
• These pumps are the ANSI standard in
industry, have over 1,000,000 installations
since their introduction, and are widely
available new or previously owned
• Two of these pumps and electric motors
will be used in the designed system
• These pumps are modular by design, and
the specific layout used to provide a stable
6,000 GPM flow rate will be the XLTi 8x10 –
16H configuration
Figure 23. Goulds 3196 i-FRAME atop a pallet for scale

40. Goulds 3196 i-FRAME XLTi 8x10–16H
Figure 24. Technical drawing of 3196 i-FRAME from Goulds
catalog, the Suction inlet is 10 inches in diameter while the
Discharge port is 8 inches in diameter, giving the pump the
8x10 designation
Figure 25. Outline of modularity of XLTi series of i-FRAME
pumps, each portion of the 8x10 - 16H is outlined
5.25 inch 27.87 inch 6.00 inch
19.00 inch
14.50 inch

41. Pipe Selection: 8 and 10-inch Galvanized Steel Pipe
• Galvanized steel pipes are less
expensive compared to stainless steel
• These pipes achieve rust free
protection for up to 30 years of use
• They are also compatible with the
pumps and filters selected for this
system
Figure 26. Picture of Galvanized steel pipe

42. Drip Chlorinator Selection:
Chlorinator Stenner 45MHP10
• This pump is capable of
injecting chlorine into the
system at a rate of 1.2 GPM
Figure 27. Chlorinator Stenner 45MHP10

43. Tank Selection
• LTT10000104 – 10,000 Gallon
Above Ground Steel Water
Tank
• 10,000-gallon steel tank
is required for the system
• The tank will hold the water
from the reservoir prior to
filtration
Figure 28. 10,000-gallon steel tank
(10'4" Diameter x 16' Height)

44. Tank Selection: Backwash Tank
• A 100-gallon vertical plastic tank will be
used to store water for the backwash
cycle of the filter
Figure 29. 100-gallon water tank
(2'4" Diameter x 3'9" height)

45. Chlorine Storage Tank
• Rotoplas 5,000 Gallon
Vertical Industrial Storage
Tank
• A vertical plastic storage
tank will keep the chlorine
solution that will be used
for our drip chlorinator
Figure 30. 5,000 Gallon chemical storage tank
(9'11" Diameter x 9'6" Height)

46. Final Storage Tank
Figure 31. 100,000 Gallon Exterior Storage Tank
(39'6" Diameter x 10'7"Height )
• Pioneer Water Tank:
Model XLE 50/03

47. Modeling
• The 3D design of our system was modeled using AutoCAD Civil 3D
• Chlorine concentration was modeled using Stella Architect
• E. coli concentration was modeled using Stella Architect
• A range of influent E. coli concentrations was considered
• A range of water pH values was considered
• The time between automatic flush cycles was calculated using
Microsoft Excel
• A range of influent algae concentrations was considered

48. Material and Methods: Initial Water Quality
• On September 23, 2021, water from Issaqueena Lake was tested to
obtain initial water quality information
Water Quality
Parameter
Materials Testing Method
Air Temperature • Thermometer • Placed thermometer in a shaded area
Water Temperature • Thermometer • Placed thermometer in water in a shaded area
pH
• Bromothymol blue pH indicator
• pH Octa-slide Bar 2
• pH Octa-slide Bar 2 viewer
• Collected water sample
• Added 8 drops of indicator into sample and inverted
• Placed tube in slide bar viewer and used slide bar to determine the value
Dissolved Oxygen
(amount of oxygen
present in a water
body)
• Manganous sulfate solution (1)
• Alkaline potassium iodide azide solution (2)
• Sulfuric acid 1:1 solution (3)
• Sodium thiosulfate 0.025N solution (4)
• Starch indicator solution (5)
• Collected water sample
• Added 8 drops of solutions 1 and 2 to the sample and inverted
• Allowed to settle
• Added 8 drops of solution 3 to the sample and inverted (oxygen is now fixed)
• Titrated with solution 4 until sample goes from dark yellow to light yellow
• Added 8 drops of solution 5
• Titrated until sample went from purple to clear
Conductivity
(ability of water to
pass an electrical
current)
• Conductivity meter
• Calibrated meter to 1413 µS/cm
• Inserted meter into water

49. Material and Methods: Initial Water Quality (Cont.)
Water Quality Parameter Materials Testing Method
Total Alkalinity
(ability of water to neutralize
acids)
• BCG-MR indicator tablet
• Alkalinity Titration Reagent B
• Titration
Turbidity (cloudiness of water) • Secchi disk
• Lowered and raised the Secchi disk into the water and took
measurements
Phosphate (can come from
surface runoff from man-made
sources)
• Test tube
• 1.0 mL pipet
• Plain pipet
• VM Phosphate Reagent
• Reducing Reagent (6405)
• Phosphate Octa-Slide Bar 2
• Phosphate Octa-Slide Bar 2 Viewer
• Filled test tube to the 5 mL line with water
• Used the pipette to add 1.0 mL of Phosphate Reagent to the tube
• The tube was capped and mixed several times, and we waited for 5
minutes
• The plain pipet was used to add 3 drops of Reducing Reagent
• The tube was capped and mixed (color developed)
• Placed tube in slide bar viewer and used slide bar to determine the value

50. Material and Methods: Initial Water Quality (Cont.)
Water Quality Parameter Materials Testing Method
Nitrate-Nitrogen (can come from
improper well construction)
• Sample bottle
• Test tube
• Mixed Acid Reagent (V-6278)
• 0.1g spoon (0699)
• Nitrate Reducing Reagent (V-6279)
• Nitrate-Nitrogen Octa-Slide Bar 2
• Nitrate-Nitrogen Octa-Slide Bar 2 Viewer
• Filled sample bottle with water
• Filled test tube to the 2.5 mL line with water from the sample bottle
• Diluted water to the 5 mL line with Mixed Acid Reagent
• The tube was capped and mixed, and we waited for 2 minutes
• The 0.1g spoon was used to add one level measure of Nitrate Reducing
Reagent
• The tube was capped and inverted 60 times in one minute, and we waited
for 10 minutes
• Placed tube in slide bar viewer and used slide bar to determine the value
E. coli
• Whirlpaks
• Petrifilm plates
• Incubator
• Collected water samples in Whirlpaks,
• Plated the samples on Petrifilm plates
• Incubated for 24 hours ± 1 hour at 35 °C ± 1°C

51. Top left: Figure 32. Michael testing for phosphate
Right: Figure 33. Team performing the dissolved oxygen test
Middle: Figure 34. Alexis performing the conductivity test
Bottom Left: Figure 35. Lake Issaqueena viewed from Testing Location

52. Results

53. Results: Initial Water Quality
Water Quality
Parameter
Trial 1 Results Trial 2 Results Trial 3 Results Average
Air Temperature 23 °C
Water Temperature 25 °C
pH 6.8 6.8 6.8
Dissolved Oxygen 6.0 mg/L 5.8 mg/L 5.9 mg/L
Conductivity 38 µS/cm
Total Alkalinity 28 ppm 26 ppm 27 ppm
Phosphate 0.5 ppm 0.5 ppm 0.5 ppm
Nitrate-Nitrogen 0.25 ppm 0.25 ppm 0.25 ppm
Turbidity
Down: 4.5 ft
Up: 4.6 ft
Down: 4.5 ft
Up: 4.5 ft
Down: 4.5 ft
Up: 4.55 ft
E. coli 1 colony 1 colony 1 colony 100 CFU/100 mL

54. Results: Initial Concentration of Algae
• Average SDV down: 4.5 ft, average SDV up: 4.55 ft
• Average SDV: 4.525 ft = 1.38 m
• Total Suspended Solids (TSS) calculation
• TSS = 𝑒(𝑆𝐷𝑉−0.9266)/0.169 = 14.56 mg/L (Eq. 9)
• This TSS concentration value encompasses all visible particles in the
water but will be used as an estimate for reservoir algae concentration.

55. Flow Chart
Figure 36. Path of water flow from the reservoir to consumers

57. Figure 37. Overall AutoCAD 3D Model

58. Figure 38. 3D Model of Sheltered Portion

59. Figure 39. 3D Model of Chlorinator

60. Figure 40. 3D Model of Final Holding Tank

61. Final Storage Tank: Stand Pipe
• A stand pipe is generally
used to regulate the flow
out of a system using
gravity
• Maintains a constant
water level
• Frequently implemented
in ponds
• Prevents short circuiting
Figure 41. Stand Pipe inside of Final Storage Tank
Water Level
Settled Algae

62. Final Storage Tank: Stand Pipe
• Covering the stand
pipe forces the effluent
to pull up from the
bottom of the tank
• Incorporating
this component will
ensure that settled algae
is not a concern
Figure 42. Stand Pipe inside of Final Storage Tank
Water Level
Settled Algae

63. Final Storage Tank: Angled Influent Flow
• Angling the flow of the water
will cause the final storage tank
to be well mixed
• This is one of the main
components that makes
modeling as a CSTR appropriate
Figure 43. Angled Inlet into Final Storage Tank

64. Modeling: Chlorine Concentration in Final Tank
Figure 44. Stella Architect model of the
concentration of chlorine in the
Continuously Stirred Tank Reactor (CSTR)
Figure 45. Length of time for 10 ppm
hypochlorite concentration to be
obtained from start

65. Modeling: Chlorine Decay during Delivery
Figure 46. Stella Architect model of the
concentration of chlorine in the pipes
after treatment
Figure 47. Decay of chlorine concentration
in the conveyance system

66. Modeling: E. coli Disinfection in Batch
Hypochlorite concentration= 10 mg/L (ppm)
k=2.73 1/min
Initial E. coli concentration = 1000 CFU/100 mL
Figure 48. Stella Architect model of E. coli used for theory Figure 49. E. coli response to hypochlorite in a
batch system

67. Modeling: E. coli Disinfection in System
Figure 50. Stella Architect model of E. coli concentration in drip chlorinator
• Modeled as a CSTR
• This model will be tested
for a range of water pH
values and influent E. coli
concentrations

68. Modeling: E. coli Disinfection for a Variety of pH's
Figure 51. E. coli response to
hypochlorite at pH of 5.6
Figure 52. E. coli response to
hypochlorite at pH of 7.1
Figure 53. E. coli response to
hypochlorite at pH of 8.2

69. Modeling: E. coli Disinfection for a Variety of
Influent Concentrations
100 CFU/100 mL 500 CFU/100 mL
Figure 54. E. coli responses to hypochlorite for influent
E. coli concentration of 100 CFU/100 mL
Figure 55. E. coli responses to hypochlorite for
influent E. coli concentration of 500 CFU/100
mL

70. Modeling: E. coli Disinfection for a Variety of
Influent Concentrations
1,000 CFU/100 mL
Figure 56. E. coli responses to hypochlorite for influent E.
coli concentrations 1,000 CFU/100 mL
5,000 CFU/100 mL
Figure 57. E. coli responses to hypochlorite for influent
E. coli concentrations 5,000 CFU/100 mL

71. Modeling: E. coli Disinfection for a Variety of
Influent Concentrations
10,000 CFU/100 mL
Figure 58. E. coli responses to hypochlorite for influent
E. coli concentrations 10,000 CFU/100 mL

72. Modeling: Summary of a Variety of Influent
Concentrations
Figure 59. Steady state E. coli concentration vs. influent E. coli concentration

73. Modeling: Time to Automatic Filter Flush
• The Darcy's Law equation for dead end filtration, (Eq. 3) , was
used in Excel to model how long it would take for automatic filter flush cycles to begin
Figure 60. Time for Automatic Filter Flush Cycle

74. Cost Analysis
Table 2. Table of recurring costs
Table 1. Total installation cost of facility components

75. Cost Analysis
• The cost of building the entire facility will be approximately $430,000.00
• This includes all materials, land clearing, and construction
• The processed water will be sold at $50/1000 m3
• (1000 m3 = 264172 gallons)
• At a rate of 6000 GPM for 8 hours per day for 8 months of the year the
facility will generate approximately $26,000.00 per year after operation
and maintenance
• After 16 years the facility will be paid for

76. Maintenance Plan
• Settling Tank
• Cleaning out algae precipitate
from bottom of tank through
maintenance tube
• Flush out with pressurized water
• Frequency: When tanks fills
halfway with algae
• Chlorine Dripper
• Refilling Chlorine tank with
hypochlorite bleach
• Frequency: Around every 2 weeks
Figure 61. Settling Tank Outlet Tube

77. Maintenance Plan
• Inlet Grate
• Remove large debris that has accumulated outside grate
• Clean out intake pipe if obstructed by accumulated debris with underwater
vacuum
• Repair pipes and tanks when necessary
• Storage Tank
• Due to the covered stand pipe, the tank will not have to be drained during the
season

78. CSTR Assumption Testing
• Introduce a tracer substance (dye) to the
system in multiple trials
• Use the CSTR equation to calculate several
expected effluent flows for given influent
concentration
• Ex. trial 1 influent = 1 ppm
• If the measured effluent concentrations are
achieved, it will be confirmed that modelling as a
CSTR is appropriate
• Check the hydraulic retention time
(component of CSTR equation) against 16.7
minutes
Figure 62. Final Storage Tank Model

79. Recommendations
• The designed facility should be installed below Lake Issaquena after
irrigation clientele are established to consume the filtered and disinfected
water
• Small adjustments could be made to the facility design to make it
applicable to other reservoir locations where irrigation water is in higher
demand
• This would increase the value of sold water and decrease facility payoff time
• A facility supervisor should always be on sight to monitor equipment and
perform regular influent and effluent water quality testing
• In areas where water flow is high, like below the
Issaqueena Dam, hydroelectric power should be considered to significantly
reduce operating costs

84. Acknowledgements
• Dr. Christophe Darnault
• Associate Professor, Clemson University
• Dr. Alex Franchi
• Project Correspondent with AECOM in California
• Dr. William Martin
• Clemson RiSE faculty and Adopt-a-Stream advisor, Clemson University
• Dr. Caye Drapcho
• Associate Professor, Clemson University
• Clemson University Biosystems Engineering faculty

85. Thank You