UV Case Studies: Small UV Applications

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UV Case Studies Small UV Applications

• Melissa Lubitz, B.Sc., CWS-VI
• Regulatory Affairs Coordinator/Corporate Trainer
• R-Can Environmental Inc
• [phone] ext 237
• lubitz_at_r-can.com

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Overview

• Four different small system UV applications
• Delawana Inn
• Household application deep well
• Trent Severn marina
• Household application shallow well
• Examine various aspects of each application
• Groundwater or Surface Water
• Water quality characteristics
• Application
• Applicable regulations
• Problems/Issues with each Application

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1. Delawana Inn

• Small resort located in Northern Ontario
• Resort can accommodate up to 200 guests
• Water supply is SURFACE WATER
• Water quality characteristics
• No hardness
• Trace amounts of iron
• High turbidity
• Low concentration of tannins
• Water is pulled from Georgian Bay to feed entire
  resort
• Restaurant
• Marina
• All resort rooms

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1. Delawana Inn

• Delawana Inn falls under Ontario drinking water
  regulations (REG 170/03)
• Category of DW System Large Non-Municipal
  Non-Residential
• Newly-affected group of private seasonal,
  commercial institutional systems capable of
  supplying drinking water at a rate of 2.9 L/s -
  resorts, service centers
• This is a SW system therefore must comply with
  REGS by July 1 2006
• Delawana Inn contracted a consulting engineer in
  order to determine what water treatment was
  necessary in order to comply with new DW REGS

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1. Delawana Inn

• Engineer recommended that facility install UV for
  their primary disinfection needs
• UV equipment must have third party validation in
  order to demonstrate sufficient dose levels
• Secondary disinfection deemed not necessary as
  water does not feed a distribution system
• 9 separate UV systems were installed in parallel
  in order to meet flow rate demand
• 5 micron filtration system was installed prior to
  UV to decrease turbidity of water supply
• Peak flow rate can be met as each system can
  handle in excess of 40 USGPM

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1. Delawana Inn
Problems?

• Initially system did not incorporate sufficient
  pre-filtration prior to UV system, allowing high
  turbidity levels to pass through system
  resulting in high bacteria counts
• Trace concentrations of tannins due to the
  surface water supply was causing dose levels to
  drop giving alarm conditions (which ultimately
  closes down solenoid valve)
• Customer installed finer filtration incorporated
  with KDF addition in order to remove feed-water
  contaminants

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1. Delawana Inn
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1. Delawana Inn
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2. Household Application deep well

• Private home located in rural Arthur, Ontario
• 2000 ft2 home accommodating three residents
• Water supply is well water well is
  approximately 180 ft deep
• Water Quality Characteristics
• Hardness 14 gpg (grains per gallon)
• Trace amounts of iron
• Low turbidity
• No evidence of tannin concentrations
• Customer did not want the added expense of a
  softener as recommended by manufacturer opted
  for a regular maintenance schedule

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2. Household Application deep well

• Homes which feed from a private well do not fall
  under Ontario DW regulations therefore are not
  required to comply
• It is up to home-owner to decide what type, if
  any, of disinfection they will implement on their
  drinking water supply
• When installing a UV system for the disinfection
  of potable water it can done two different ways
• Point-of-use water treatment applied to a
  single tap (often used to treat water for
  drinking cooking only)
• Point-of-entry full service water treatment
  applied to water entering a house or building

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2. Household Application deep well

• Disinfection for Arthur home is a point-of-entry
  application
• Before system was installed it was recommended by
  manufacturer that all water lines in home were to
  be disinfected
• It was also recommended that water be
  pre-filtered prior to disinfection
• System installed holds third party validation,
  therefore it is rated for a specific UV dose at a
  pre-determined flow rate
• A flow restrictor is incorporated into UV system
  based on third party validation protocol (NSF
  55A)

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2. Household Application deep well
Problems?

• (1)
• Upon installation customer noticed within first
  three months that UV intensity dropped to
  approximately 55
• this particular system had capability of
  displaying level of UV intensity at any given
  time with 50 intensity indicating alarm
  set-point of system which indicated a 40 mJ/cm2)
• After inspection customer found that there was
  evidence of a scale build-up on the quartz sleeve
  of the system, due to level of hardness in water
• By monitoring the UV intensity level customer was
  able to maintain a quartz cleaning schedule
• (2)
• Customer did experience a problem with
  condensation forming on inside of quartz sleeve
  in conditions of high humidity
• Ultimately it was found that o-ring seal was not
  tightened properly during install

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2. Household Application deep well
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3. Trent Severn lock station

• Trent Severn Waterway is run by Parks Canada
• Full length of Waterway can be traveled by boat
  through 36 different lock stations
• Along Trent Severn Waterway the needs of boaters
  are met at each lock station with overnight
  mooring, showers, washrooms, holding tank
  refills
• Some of these lock stations are supplied by
  municipal water while others use surface water
• All 36 lock stations fall under the Ontario DW
  regulations

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3. Trent Severn waterway
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3. Trent Severn lock station

• Stations supplied by municipal water are
  considered to be Small Municipal Non-Residential
  Serving community centers/town halls, for
  example, but not able to supply 2.9 L/s or 45
  USGPM
• Stations supplied by surface water are considered
  to be Small Non-Municipal Non-Residential Group
  of private seasonal, commercial institutional
  systems that supply drinking water to public but
  are not capable of supplying it at a rate of 2.9
  L/s)

Lock 28 Burleigh Falls, Ont.
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3. Trent Severn lock station

• One specific lock station under evaluation is one
  which feeds off surface water
• Water Quality Characteristics
• Hardness 3 gpg (51.3 ppm)
• Trace amounts of iron
• UVT of 76
• Tannin concentration of 0.4 ppm
• Consulting engineer was contracted to recommend
  treatment
• Recommendation included UV for primary
  disinfection with sufficient pretreatment
• Pretreatment included a mixed bed media filter,
  to remove all tannins decrease hardness level,
  along with a 1 micron pre-filter
• UV system holds third party validation is
  installed with an automatic solenoid valve
• Due to level of pretreatment no problems have
  been recorded in the 5 months since installation

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3. Trent Severn marina
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4. Household Application shallow well

• Private home located in Harriston, Ontario
• 2300 ft2 home accommodating 4 residents
• Home is located in a swamp-like area
• Water supply is well water well is
  approximately 50 ft deep
• Water Quality Characteristics
• Hardness 22 gpg (376.2 ppm)
• Iron concentration 3 ppm
• Tannin concentration 1.1 ppm
• Low turbidity
• Customer very willing to install all pretreatment
  necessary

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4. Household Application shallow well

• Homes that have their own private well do not
  fall under Ontario DW regulations therefore are
  not required to comply
• It is up to home-owner to decide what type, if
  any, of disinfection they will implement on their
  drinking water supply
• When installing a UV system for the disinfection
  of potable water it can done two different ways
• Point-of-use water treatment applied to a
  single tap (often used to treat water for
  drinking cooking only)
• Point-of-entry full service water treatment
  applied to water entering a house or building

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4. Household Application shallow well

• Customer installed a specific type of softener
  that has capability to remove high concentrations
  of iron as well as hardness
• Due to high level of organics in water supply, a
  tannin removal system had to be incorporated into
  pretreatment train
• Following tannin removal step, a large 5 micron
  filter was installed to catch any levels of
  turbidity
• UV was last piece of equipment
• High level of pretreatment has given customer
  piece of mind as well as trouble-free drinking
  water treatment

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4. Household Application shallow well
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Delawana Inn
Harriston
Trent Severn Waterway
Arthur
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Conclusion

• Small UV applications do not have to be
  residential installations, there are several
  different types of applications
• Key issues before installing UV for primary
  disinfection
• Type of water supply groundwater or surface
  water
• Water quality characteristics
• Type of application Home, small facility etc.
• Applicable drinking water regulations
• Sufficient pre-treatment