The Wetland Biofilter System: A vertical flow constructed wetland for treatment of manure compost pile leachate water
What is the Wetland Biofilter System? Vertical flow constructed wetland Consists of two or more cells in series Each cell: lined with PVC liner filled with root-bed media planted with cattail plants (Typha sp.)
Currently used for treating: Domestic sanitary sewage (26) Winery wash water (7) Greenhouse leachate (2) Landfill leachate (4) Abattoir wastewater (2) Mushroom farm leachate (3) Bakery process water (1) Liquid swine manure (1 pilot project)
Wastewater discharge: Regulated by the Ontario Ministry of Environment via the Ontario Water Resources Act MOE issues a Certificate of Approval that regulates quantity and quality of wastewater discharge
MOE Certificate of Approval: Required for all systems > 10,000 L/day Surface or groundwater discharge Generally no approval is required if there is no discharge to the environment
Treatment of Mushroom Farm Leachate Water Compost consists of: clean straw horse bedding material (straw & horse manure) chicken manure
Manure pile leachate water
The system: To Wetland Biofilter flow balancing pond Treated water re-use or discharge Compost pad
1. excavation 4' deep with sloped walls
2. 30 mill PVC liner installed
3. drain pipe and pump tank installed
4. filling with gravel
5. cell filling continues
6. grading of sand layer
7. winter manifolds installed on top of sand
8. covering winter manifolds with gravel
9. summer manifolds on surface, cattails to be planted
10. manifolds flooding
11. Cattails planted
12. First winter
13. Late summer
14. Spring
Important wastewater parameters: BOD5 = Biochemical Oxygen Demand The amount of organic matter in water TSS = Total Suspended Solids The amount of visible solid material floating in water Nitrogen Phosphorous
Performance data, Rol-land Farms Limited, Blenheim, Sept. 3, 2003 to Dec. 30, 2004 Parameter (mg/l) Wetland influent (n =13) wetland effluent (n = 13) total % reduction BOD5 181.90 2.50 98.62 TSS 354.50 3.21 99.09 phosphorus 5.44 0.08 98.52 TKN 19.97 3.31 83.42 ammonia 12.29 0.77 93.73 nitrate 1.28 4.25 N/A E.coli (cfu/100 ml) 4409 2 99.95 Colour 225.88 60.83 73.06
Operation & maintenance: 10,000 gal / day requires one 3 cell system, each cell 30 X 30 Maintenance requirements: " check pumps weekly " change manifolds to winter & summer as required " requires 1 hr/week Operational costs: " 52 hrs/year " plus electrical costs to power pumps power usage = (115 V) (10.0 A) (8.0 hrs/day) 1000 W/kW = 9.2 kwh/day 9.2 kwh/day X 3 pumps = 27.6 kwh/day ~ $0.13/kWh = $3.58/day
Capital costs of construction: Dependant on size $1 1.25 / litre for large systems $4-5 / litre for small systems Other considerations: Site access Access to material inputs i.e. concrete sand
The End
The Certificate of Approval Process: Pre-submission Consultation Meeting Preparation of Application Documents MOE review Construction Maintenance & monitoring
Pre-submission Consultation Meeting Meeting between: local MOE, technical support staff Proponent Consultant Proposal is presented MOE input concerns etc. Proposal may be altered to reflect MOE concerns
Preparation of Application Documents Design brief Design drawings Surface water impact assessment Groundwater impact assessment Maintenance & monitoring proposal
The review process: Environmental Assessment and Approvals Branch Engineering review Technical support: Impact assessments (ground water, surface water) Establish discharge objectives and/or limits Local MOE input Operation & monitoring Reporting requirements
The Final Certificate of Approval: Enforceable agreement between the owner & MOE Provides terms & conditions for: operation maintenance Sampling reporting