Best Management Practices for Food Waste Composting

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1 Best Management Practices for Food Waste Composting CWMA Information Luncheon Duncan, British Columbia June 13, 2014 Scott Gamble, P.Eng. Organic Waste Specialist

Food Waste as a Feedstock Food waste generally has a high moisture content, low C:N ratio and a high density. Pre-consumer food waste tends to be less contaminated than post-consumer food waste.

2 Food Waste as a Feedstock Food waste generally has a high moisture content, low C:N ratio and a high density. Pre-consumer food waste tends to be less contaminated than post-consumer food waste. Soiled paper products (e.g., paper towels, napkins, soiled or waxed cardboard, soiled newspaper, and tissues) are often included in food waste diversion programs. These materials are readily degradable, and they absorb liquids released by food waste.

3 Commercial Household

4 Contaminants Plastic bags Coffee creamers and stir sticks Aerosol cans Styrofoam Bags of garbage Shoes and slippers Rope and wire Carpet and floor mats Branches & stumps Plant pots Video cassettes Bathroom sinks Hockey sticks Engine parts Beer bottles 2 ton car jacks Toys

Peaking Factors The peaking factor is the ratio of the maximum flow to the average flow in a system. The concept of peaking factors have been used in potable water and wastewater design for decades.

5 Peaking Factors The peaking factor is the ratio of the maximum flow to the average flow in a system. The concept of peaking factors have been used in potable water and wastewater design for decades. A smart engineer will take peaking factors into account when designing a composting system. Designing a system based on average annual quantities may result in your system being undersized at certain times of the year. This may force you to reduce retention time and/or cut back on amendments. Food Waste Only Food Waste and L&YW

Managing Feedstock Deliveries Establish designated unloading areas with appropriate signage. Manage interaction between delivery vehicles and site equipment.

6 Managing Feedstock Deliveries Establish designated unloading areas with appropriate signage. Manage interaction between delivery vehicles and site equipment. Don t let public drop directly on composting piles unless they are supervised. Manage pedestrians around overhead doors. Drivers cant see while their eyes adjust to darker interior. Adjust shift schedules so that staff are present at least 30 minutes after the posted receiving hours.

Feedstock Inspections Generally, contaminants should be removed as soon as is practically possible. Load inspection or screening should be completed upon receipt.

7 Feedstock Inspections Generally, contaminants should be removed as soon as is practically possible. Load inspection or screening should be completed upon receipt. Requirements and methods vary from site-to-site depending on feedstocks, collection program, and tolerances of composting technology and markets. Non-compostables can be removed manually or mechanically (e.g. screening, magnets, air classifiers). Garbage in, garbage out

8 Feedstock Preparation Feedstocks needs to be prepared to establish optimal conditions for composting to proceed. Preparation may include: grinding to set particle size adding amendments to increase porosity or reduce moisture blending different feedstocks to optimize C/N ratio adding water inoculating the feedstock with microbes by recycling compost or screening overs.

Operators should always have a stockpile of amendments on site in case deliveries are disrupted.

9 Amendments (aka Bulking Agents) Wood chips are used primarily to adjust free air space and moisture. Oversized materials from screening operations can add free air space as well as microbes. Operators should always have a stockpile of amendments on site in case deliveries are disrupted. Too much amendment or improperly stored amendment can create fire hazards. Wood chips that will be added to food waste to adjust moisture downwards should be kept dry.

Windrow Turned mass bed Aerated Static Piles (uncovered and covered)

10 Appropriate Technologies Passively Aerated and Turned Actively Aerated Passively Aerated Static Piles Passively Aerated Windrows Bunker Windrow Turned mass bed Aerated Static Piles (uncovered and covered) Tunnels Containerized (static and agitated) Channel Agitated bed Rotating drum

Surface Water Management Surface water that has contacted feedstocks, composting piles and curing piles needs to be managed to prevent environmental impacts.

11 Surface Water Management Surface water that has contacted feedstocks, composting piles and curing piles needs to be managed to prevent environmental impacts. Separate high strength leachate from low strength leachate where possible. Buildings, enclosures and tarps are appropriate in high precipitation areas. Minimize the amount of water that enters your outdoor working areas (perimeter berms/ditches, designated snow dumps, plumbed roof drains). Ponds with controlled discharges are the normal practice. Use sediment knockouts (sumps, hay bales, bioswales) in ditches to prevent sediments from reaching and accumulating in detention ponds.

Vectors and Critter Control Vectors are animals, insects or other organisms that can carry pathogens from one host to another. Examples include rats, mice, flies, and birds.

12 Vectors and Critter Control Vectors are animals, insects or other organisms that can carry pathogens from one host to another. Examples include rats, mice, flies, and birds. Vectors can also contaminate finished compost with pathogens. Since many critters are attracted to the organic matter on the surface of compost pile it is important properly control the composting process. Critters may also be attracted to the heat from the composting piles. Eradication of pests may be necessary from time to time.

Install permanent litter control fences.

13 Litter Controls Enclose receiving and processing areas. Keep doors to tipping and processing areas closed. Install permanent litter control fences. Use temporary or portable litter fences. Regularly clean litter from fences and property.

Odour Management When it is done right, composting facilities can co-exist with their neighbors. Key requirements include: appropriate siting.

14 Odour Management When it is done right, composting facilities can co-exist with their neighbors. Key requirements include: appropriate siting. selecting the right composting system. good aeration rates. proper recipes. maintaining operations within the design envelope. following best management practices.

15 Use Appropriate Odour Control Technologies

16 Questions? Scott Gamble, P.Eng. CH2M HILL (Edmonton) Tel:

Solid Waste Treatment Facility Solid Waste Permit Application

Solid Waste Treatment Facility Solid Waste Permit Application Part One: Fees A check or money order for the appropriate fees must be submitted with the permit application. If the required fees are not included, the permit application will be returned to the applicant.