The Region of Halton

1
The Region of Halton Biosolids Management into
the Future
Regional Municipality of Halton Ontario, Canada
2
Current Status

• Ability to remove solids from WWTPs on demand
  is critical to maintain effluent quality
• Production in 2001
• 318,848 m3 liquid biosolids
• 8,216 m3 dewatered cake
• Liquid biosolids applied to land within Halton
• Dewatered cake stored and applied to land within
  and outside Halton
• Program operations under contract by Terractec
  Environmental Ltd.

3
Limitations of Current Strategy

• Insufficient land within Halton to apply 100 of
  biosolids currently produced
• Available agricultural land expected to decrease
  marginally in the future
• Biosolids quantities estimated to increase by
  60 over next 20 years
• Storage time at BMC estimated to decrease to
  less than regulation minimum 6 months by 2008
• Inability to access farmland during wet weather
  can result in inadequate storage at the BMC

4
Biosolids Projections

5
Required vs. Available Land

6
Considerations for Future Biosolids Management

• Continue land application to the extent that can
  be supported by land within the Region
• highly successful program
• continuing demand from farmers
• Regional investment in infrastructure
• Diversify biosolids management program to
  include one of the following options
• non-competing nutrient end use
• non-nutrient end use

7
Non-Competing Nutrient End Use

• Ontario Compost Guidelines compost from
  biosolids does not meet criteria for unrestricted
  utilization not an option
• MOEE/OMAF Guidelines pathogen free biosolids
  (US EPA Class A) not recognized at this time,
  crop restrictions in Ontario not an option
• Ag Canada Fertilizer Act biosolids marketed as
  fertilizer under the Act must meet certain
  requirements including metal content but no site
  or crop restrictions potential option

8
Non-Competing Nutrient End Use (contd)

• Halton biosolids meet metal requirements in
  Agriculture Canada Fertilizer Act and US EPA
  limits for Exceptional Quality biosolids
• Alkaline stabilization and drying/pelletization
  are producing products in Ontario that are being
  marketed, under the Fertilizer Act, for higher
  value end uses

9
Non-Nutrient End Use

• Thermal destruction of organic material leaving
  inert ash for disposal
• Potential energy recovery from combustion of the
  organics in biosolids
• Fluidized bed combustion considered
  state-of-the-art incineration technology based
  on
• energy efficiency
• air emission control

10
Existing Management Options

Biosolids Management Centre Storage
Liquid to Land
Digested Biosolids
Mobile Dewatering
Contingency
Dewatering
Cake to Land

Cake to Halton Landfill
Cake to Private Landfill
Diversification Options
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Diversification Options

Dewatered Cake
Temporary Storage
Incineration
Ash to Landfill
Alkaline Stabilization
Product to Market

Land Application Landfill Cover Disposal in
Landfill
Contingency
Thermal Drying
Product to Market
Land Application Landfill Cover Disposal in
Landfill
Contingency
12
Alkaline Stabilization

• Beneficial use option
• Inactivation of pathogens to produce Class A
  biosolids
• addition of alkaline mixture such as lime or
  cement kiln dust
• elevate pH gt 12 for 72 hours
• maintain temperature gt 52oC for 12 hours
• dry to gt 50 solids

13
Alkaline Stabilization (contd)

• Product
• fertilizer value
• acts as liming agent for low pH soil
• improves soil structure
• No site or crop restrictions on use
• Operating facilities approved in Ontario
• Product marketed under Fertilizer Act
• Experience with marketing product in Ontario

14
Thermal Drying/Pelletization

• Beneficial use option
• Inactivation of pathogens to produce Class A
  biosolids
• temperature of biosolids gt 80oC
• moisture reduced to lt 10
• Product
• used directly as a fertilizer
• component for the manufacture of commercial
  fertilizer

15

Thermal Drying/Pelletization (contd)

• No site or crop restrictions on use
• Operating facilities approved in Ontario
• Product marketed under Fertilizer Act
• Experience with marketing product in Ontario

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Incineration

• Complete destruction of pathogens, viruses and
  organics
• high temperature combustion gt800ºC
• Heat recovery possible for in-plant use
• Autogenous combustion at 28 solids
• no additional fuel required
• Majority of metals immobilized in ash
• Minimal volume of residue for ultimate disposal
• Can meet stringent air emission criteria

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Sites Visited by Halton Team

• Drying/pelletization
• Windsor
• Smiths Falls
• Toronto

• Incineration
• London
• Alkaline Stabilization
• Sarnia
• Leamington
• Syracuse

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Technology Rating Criteria

Environmental Sustainability Reliability Cost
Odours Changes in legislation Proven technology Capital
Air emissions Public opinion Complexity OM
Surface/ground water Ability to expand Dependence on weather
Soil Competition Waste on demand
Public exposure Contingency
Ease of permitting

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Rating of Acceptable Technologies

Incineration Alkaline Stabilization Thermal Drying
Environmental 2.5 2.83 2.83
Sustainability 1.5 2.25 1.75
Reliability 2.6 2.8 2.6
Cost 2 2.5 2.5
Total Score 8.6 10.38 9.68

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Preliminary Identification of Recommended
Solution

• Diversify Haltons biosolids management program
  to address land availability limitations by
• Building an alkaline stabilization facility to
  process the excess biosolids
• Developing a program to market the resulting
  product to end users outside the existing land
  application program

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Implementation Plan

• Public consultation process to present
  recommended solution to public and seek input
• Confirm preferred solution
• Submit Notice of Completion to review agencies
  and public
• Submit recommendation to Council for approval
• Select site for facility
• Complete pre-engineering and tender documents
• Call for tenders on the project
• Award contract
• Initiate construction