Lesson Seven

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Indiana Water Operator Training
Lesson Seven
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Indiana Water Operator Training
Indiana Department of Environmental Management
Indiana Rural Water Association
American Water Works Association
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Lesson Seven WT3 Operators

• WT3 systems and operators
• Filtration
• Gravity filters
• Pressure filters
• Lime soda softening
• Reverse osmosis
• Advanced ion exchange softening

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Classification of water distribution systems and
water treatment plants
Water treatment plants
WT3 Class WT3 includes systems that meet the
following (A) Acquire water from one (1) of the
following (i) Ground water (ii) Purchase (B)
Utilize chemical feed (C) Have one (1) of the
following (i) Pressure or gravity
filtration (ii) Ion exchange processes if the
population served is greater than five
hundred one (501) (iii) Lime soda (iv) Reverse
osmosis
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Classification of water system operators
Water operator certification qualifications
WT3 Grade WT3 is a certified operator qualified
to operate a Class WT1, WT2 and WT3 water
treatment plant after having fulfilledthe
following requirements (A) Possess a high school
diploma or its equivalent (B) Meet the
qualifications of the certification rule (C) Must
be able to (i) maintain inventories (ii) order
supplies and equipment and (iii) interpret
chemical and bacteriological sample reports
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Classification of water system operators
Water operator certification qualifications
WT3 (continued from previous slide) (D) Attain
the following acceptable work experience at a
minimum (i) Two (2) years in the operation of a
Class WT3 water treatment plant (ii) Successful
completion of educational work at college level
in (AA) engineering (BB) chemistry, or (CC)
science related to water treatment may be
substituted for work experience required
according to item (i) at the ratio of four
(4) semesters or six (6) quarters of schooling
for a maximum substitution of one (1) year of
experience
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Classification of water system operators
Water operator certification qualifications
Operator-in-Training (OIT) Grade
Operator-in-Training (OIT) is available under the
following guidelines (1) to a person meeting the
following (A) Currently employed at a public
water system with facilities classified as
a Class WT 3, Class WT 4 or Class WT 5 water
treatment plant or a DSL water distribution
system (B) has fulfilled the qualifications of
the certification rule
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Classification of water system operators
Water operator certification qualifications
Operator-in-Training (OIT) (continued from
previous slide) (2) In accordance with the
following (A) Until the OIT meets the experience
requirement needed for the classification
of treatment plant or distribution system where
the OIT is accumulating work experience (B)
Operating work must be accomplished under the
supervision of a certified
operator-in-responsible-charge who must verify to
the Commissioner the satisfactory
achievement of acceptable experience by the
OIT
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Classification of water system operators
Water operator certification qualifications
Operator-in-Training (OIT) (continued from
previous slide) (C) An OIT may not (i) serve as
a certified operator in responsible charge (ii)
transfer an OIT certification to a water
treatment plant or distribution system with
a public water system identification number
(PWSID) different than the PWSID for which the
certification was issued (iii) hold two (2)
treatment plant or distribution system OIT
certifications concurrently or (iv) renew the
OIT certification
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Filtration
Adsorption
Mechanical
Small particles attachedto media
Large particles trappedbetween media
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Gravity filters Normal operation
Influent
Surface washers
Backwash trough
Optional cap AnthraciteIron (Fe) removal
Air Gap
Filter media
To waste
Barrier media
Dispersion media
Underdrain system
To clearwell
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Gravity filters Backwash operation
Influent
Surface washers
Media expansionof at least 20
Backwash trough
Optional cap Anthracite
Air Gap
Filter media
To waste
Barrier media
Dispersion media
Underdrain system
To clearwell
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Pressure filters Vertical
Courtesy USFilter

• Often found at smaller treatment plants
• Additional tanks can be added as needed

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Pressure filters Horizontal
Courtesy USFilter

• Large capacities
• Sometimes installed with tank outside valves
  pipes inside
• May have multiple filter cells in one tank

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Pressure filtersGravity filters
Pressure filters Gravity filters

• Pressurized
• Flow rates of 612 GPM/Ft2
• Follow manufacturersbackwash recommendations

• Open to atmosphere
• Flow rate of 2 GPM/Ft2
• Media expansion key to backwash

Operator Tip
Cold water denser
Both kinds of filters Lower water temperatures
require lower backwash rates Higher water
temperatures require higher backwash rates
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Softening

• Whats hard water?Practically speaking,
  measurement of
• Calcium (Ca) ions
• Magnesium (Mg) ions

Hardness as calcium carbonate mg/L
GPG Soft 0-17 0-1.0 Moderately
hard 60-120 3.5-7.0 Very hard 180 over 10.5
over 1 GPG 17.1 mg/L
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Softening

• Two types of hardness
• Carbonate (temporary hardness)
• Heating water causes precipitation
• It is why water heaters get deposits at the
  bottom
• Non-carbonate (permanent hardness)
• Heating water does not affect it

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Lime soda softening

• Used to reduce hardness of very hard water
• 35-40 grains per gallon can be reduced to 5-10
  GPG
• Slake lime Ca(OH)2 added to hard water
• Carbonate hardness precipitates
• Removed by filtration
• Soda ash (Na2C03) added
• Non-carbonate hardness precipitates
• Removed by filtration
• Raises pH of the water above 10

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Lime soda softening

• Requires large settling tanks
• Advantages include
• No salt added
• Reduction of some total dissolved solids
• Taste and odor improvements
• Removal of
• Iron
• Arsenic
• Heavy metals
• Disadvantages include
• Requires pH adjustments
• Systems hard to operate and control
• Sludge disposal a problem
• Tail that wags the dog

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Reverse osmosis Osmosis
Diffusion of fluid through a semipermeable
membrane from a solution with a low solute
concentration to a solution with a higher solute
concentration until there is an equal
concentration of fluid on both sides of
the membrane
Curtsey Pure-Pro Corp.
According to Dictionary.com
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Reverse osmosis
A method of producing pure water by forcing
saline or impure water through a semipermeable
membrane across which salts or impurities cannot
pass
Curtsey Pure-Pro Corp.
According to Dictionary.com
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Reverse osmosis

• Reverse osmosis can reduce
• Arsenic
• Asbestos
• Fluoride
• Herbicides
• Lead
• Mercury
• Nitrate
• Pesticides
• Radium
• Salt

• Semipermeable membranes
• are fragile
• Hard water can clog membrane
• Chlorine can destroy membrane
• Membrane must be rinsed regularly to prevent
  scaling
• Prefiltration usually required

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Advanced ion exchange softening
How does ion exchange work?
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Advanced ion exchange softening
Residential Water softener
Municipal Water softener
Courtesy USFilter
Courtesy Canature
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Advanced ion exchange softening

• Best applied for additional softening
  followinglime-soda softening, or
• Softening water that is not too hard to begin
  with, say lt10 GPG
• Little effect on pH of water
• May add salt to water
• Undesirable for people with certain health
  conditions
• Ion exchange should not be used when the
  concentrationof Fe, Mn, or the combination
  exceeds 0.3 mg/L
• Ion exchange should not be used on raw or wash
  waterscontaining (high) dissolved oxygen

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Advanced ion exchange softening Problems with
Iron (Fe) Manganese (Mn)

• Most deep well waters are fairly low in dissolved
  oxygen (DO)
• Shallow wells may have higher DO
• In low DO water, Fe and Mn are soluble and remain
  dissolved in the water
• Water softeners will remove some soluble Fe and
  Mn
• In high DO water, Fe and Mn become insoluble, are
  no longer dissolved, and become visible as red
  colored and staining
• Water softeners will clog from insoluble Fe and
  Mn
• Prefilters ahead of the softener are necessary to
  remove Fe and Mn in high DO situations

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Advanced ion exchange softening Problems with
Iron (Fe) Manganese (Mn)
Operator Tip
Do customers complain of a thin black sludge or
oilysheen on top of their coffee or tea? It is
often caused by Fe and/or Mn reacting with
thetannins and acids in the beverages You have
Fe and/or Mn slipping through thetreatment system
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Ok, there is a light at the end of the
tunnel. Were about done. Are there any
questions?
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Lesson Seven WT3 Operators
Self Graded Examination
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Lesson Seven WT3 Operators
Self Graded Examination
10 Minutes
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Lesson Seven WT3 Operators
Self Graded Examination
5 Minutes
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Lesson Seven WT3 Operators
Self Graded Examination
Times Up
OK
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Lesson Seven WT3 Operators
Answers
X
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Lesson Seven WT3 Operators
Answers
X
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Lesson Seven WT3 Operators
Answers
X
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Lesson Seven WT3 Operators
Answers
X

• Used to reduce hardness of very hard water
• 35-40 grains per gallon can be reduced to 5-10
  GPG
• Slake lime Ca(OH)2 added to hard water
• Carbonate hardness precipitates
• Removed by filtration
• Soda ash (Na2C03) added
• Non-carbonate hardness precipitates
• Removed by filtration
• Raises pH of the water above 10

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Lesson Seven WT3 Operators
Answers
X

• Reverse osmosis can reduce
• Arsenic
• Asbestos
• Fluoride
• Herbicides
• Lead
• Mercury

• Nitrate
• pesticides
• Radium
• Salt

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Lesson Seven WT3 Operators
Answers
X

• Semipermeable membranes
• are fragile
• Hard water can clog membrane
• Chlorine can destroy membrane
• Membrane must be rinsed regularly to prevent
  scaling
• Prefiltration usually required

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Lesson Seven WT3 Operators
Answers
X
If you said B., ion exchange, you would be
correct in sayingthat it might not be as good of
choice as C., lime-soda forsoftening very hard
water. But, A., reverse osmosis, is definitely
the worse choice(best answer), because RO units
are quickly fouledby hard water.
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Lesson Seven WT3 Operators
Answers
X
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Lesson Seven WT3 Operators
Answers
X

• Ion exchange should not be used on raw or wash
  waterscontaining (high) dissolved oxygen
• In high DO water, Fe and Mn become insoluble, are
  no longerdissolved, and become visible as red
  colored and staining
• Water softeners will clog from insoluble Fe and
  Mn
• Prefilters ahead of the softener are necessary to
  removeFe and Mn in high DO situations

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Lesson Seven WT3 Operators
Answers
X
Do customers complain of a thin black sludge or
oilysheen on top of their coffee or tea? It is
often caused by Fe and/or Mn reacting with
thetannins and acids in the beverages You have
Fe and/or Mn slipping through thetreatment system
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Thank you for your participation

• Are there any other questions or comments?
• Please turn in your
• Self-graded examinations
• Training course evaluation forms
• Continuing education credit reports

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Indiana Water Operator Training
Indiana Department of Environmental Management
Indiana Rural Water Association
American Water Works Association
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Contact Information
Instructor For additional information
concerning this water operatortraining course,
please contact Indiana Rural Water
Association Odetta Cadwell, Executive
Director 317-402-7349