Unconventional Applications of Wastewater Effluent Reuse

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Unconventional Applications of Wastewater
Effluent Reuse
By Brian J. Ambrogi, E.I., Wilson Company,
Inc. And Dan Campbell, Raton Water
Works Presented to Rocky Mountain WEA/AWWA
Annual Conference, Casper, Wyoming September 17,
2003
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Raton, New Mexico
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Raton, New Mexico
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Background

• Existing system serves approx. 7,400 residents
• WWTP design capacity 0.9 MGD
• WWTP existing discharge points
• Doggett Creek - Year round
• Existing reuse sites (golf course athletic
  fields) - irrigation season only

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Initial Problems

• Effluent to Doggett Creek does not comply with
  water quality standards.
• Unidentified toxin in effluent
• Only occurs in Doggett Creek
• Not found in effluent at golf course

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Approach

• Need to identify additional reuse locations
• Golf course
• Median irrigation
• Irrigate range lands
• When is there demand for effluent reuse?
• Winter months no irrigation
• Summer months 100 of demand

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• What is to be done with effluent during winter
  months?
• Storage until irrigation season
• Impoundment of effluent for approx. 5 months
• Need to use all stored effluent by end of
  irrigation season.
• Unconventional reuse
• Once through cooling water in Co-generation
  electrical power plant.

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Course of Action

• Construct impoundment - retention lake located
  south of WWTP
• Improve tertiary treatment of effluent to
  publicly accessible locations
• to meet recently adopted NMED policy
• Allows more flexibility in reuse applications

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Construct Impoundment - Retention Lake Located
South of WWTP

• Surface area 24 acres
• Volumetric capacity 410 ac-ft per year
• Storage depth 20 ft
• Earthwork volumes
• 654321 c.y. of fill
• 123456 c.y. of cut

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Proposed Lake Location
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Storage Consideration of Effluent In Open Lakes

• Potential problems
• Algae, Phytoplankton, re-growth of
  microorganisms, high levels of turbidity and
  color, and deterioration of water quality due to
  aquatic life.
• How to address problems
• Cleaner effluent into lake
• Flow through lake
• Development of lake management plan

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Improve Tertiary Treatment of Effluent to
Publicly Accessible Locations

• Replacement of disinfection system
• Addition of filtration System
• NMED policy, August 2003
• 4 classes of effluent, 1A, 1B, 2, 3
• 1A 1B publicly accessible
• 2 3 publicly restricted
• Allows more flexibility in reuse applications
• Difference between application of
• classes 1A 1B

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Tertiary Treatment Process Considered

• Use of disinfection
• chlorine generation, liquid feed chlorine
• ultraviolet application
• Addition of filtration for effluent used at golf
  course and athletic fields.
• consider gravity filters
• consider pressure filters

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Disinfection Design Consideration

• Ultraviolet Vs. Chlorine
• Chlorine residual advantage at filter building
• Lake effluent too turbid for U.V.
• No residual from U.V.
• Safety issues
• Chlorine generation Vs. chlorine gas
• Liquid feed possible alternative . . .

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Filtration Design Considerations

• 2. 3-filter types considered
• Gravity Sand Filter
• Tall profile
• High headloss
• Traditional process
• Pressure Filter
• Extremely high headloss
• Disc Filter
• Small foot-print
• Low profile, headloss
• High capacity

• 1. Site considerations
• Small elevation change
• Existing lines at capacity
• Filter following treatment, not storage

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Proposed Tertiary Treatment Processes

• Selected Disinfection System
• Chlorine Generation at Filter Building and Lake
  Disinfection Building
• Selected Filtration System
• Disc Filtration following treatment process.
• Initially Only Effluent to Golf Course and
  Athletic Fields Filtered

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Develop Infrastructure Versatile Enough to
Accommodate Future Changes

• Site Layout
• Filter/Disinfection building at WWTP
• Pumps to Reuse
• Pumps to Retention Lake/Co-Generation Electrical
  Plant
• Disinfection building at retention lake

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Schematic of Proposed Reuse System
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Unconventional Reuse Cooling Water for
Co-Generation Electrical Facility

• Cogeneration Electrical facility Described
• Considered Green Energy Process of electrical
  power production that is environmentally
  beneficial.
• Use of deadfall in regional national forests to
  provide fuel source.
• Deadfall to be mechanically cleared and
  transported to co-generation facility.

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Water Quality Issues

• Problems resulting in cooling water include.
• Scaling.
• Metallic corrosion.
• Biological growth.
• Fouling of equipment.
• Raton will provide effluent of high enough
  quality to reduce amount of biological growth and
  fouling.
• Agreed to provide NPDES quality effluent to
  co-generation facility.
• Co-generation facility will handle scaling and
  metallic corrosion treatment.

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Summary of Improvements

• Storage
• 410-ac ft. retention lake
• Tertiary treatment
• Chlorine generation
• Filtration
• Effluent to co-generation facility
• Effluent from Lake and/or by-pass line
• Disinfection of effluent from lake

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Proposed Timeline

• Reuse improvements design completed by December
  2003
• Reuse construction started by April 2004
• Co-generation facility construction started in
  2005

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Questions?