Renewable Natural Gas

The City of Stratford (City) is considering an upgrade to the existing Water Pollution Control Plant (WPCP) located at 701 West Gore Street. In addition to the municipal wastewater that is currently being treated at the site, the upgrade would allow the facility to accept and treat organic waste.

The facility would treat solid and liquid organic waste from both residential and commercial sources and "co-digest" this waste with the existing sewage sludge being treated onsite in the plant’s two existing anaerobic digesters.
That digestion process creates two products:

1. Biogas – which would be converted into Renewable Natural Gas and fed back into Stratford’s natural gas distribution system for use by the community. It would not be stored on site.

2. Digestate – the nutrient-rich leftover material, which can be used as fertilizer on area farms.

What is solid and liquid organic waste? 

Organic solid waste is derived from household, commercial, institutional and industrial establishments including factories, plants, wholesalers, catering and restaurant establishments, shops and offices. This mainly includes kitchen food waste such as vegetable cuttings, meat trimmings and expired or spoiled goods from grocery stores. Solid organic waste materials are often disposed of in landfills and enter the environment with specific health hazards if they are not properly treated. Since they are biodegradable, a large portion of organic waste is suitable for anaerobic digestion and/or composting and fertilizer.

Liquid organic waste material is made up of wastewater, fats, oils and grease from a variety of sources, including food-processing plants, as well as expired or spoiled goods such as milk, yogurts and juices.

Anaerobic digestion is the process of using fermentation to break down organic material in the absence of oxygen to manage waste while generating a renewable fuel. The material that is left is called “digestate”, which is rich in nutrients and can be land applied for crop production. Biogas, which is rich in methane and high in energy, is also generated through this process.

Co-digestion is a means of processing organic matter in sewage sludge with solid and liquid organic wastes at the same time, in the same location. This process would use the existing anaerobic digesters on-site. 

Renewable Natural Gas is the methane portion of biogas (greater than 60%) that results from the fermentation of organic matter using anaerobic digestion. Currently, biogas produced at the Plant is used to heat the boiler, and any excess is flared (burned) into the environment. However, due to the high content of methane in biogas, it can be used as an energy source and distributed through the existing natural gas pipeline for use by the surrounding community instead of being released into the atmosphere. 

There are a number of dedicated organic waste anaerobic digestion facilities in Ontario that operate a similar process and generate Renewable Natural Gas.  The proposed Stratford facility would be the first co-digestion facility of its kind in Canada, but mixing sewage and organics is a common practice throughout the United States and Europe as the preferred method for treating organic waste.

 Example #1 – United Kingdom

A prime example of this is the Bristol Sewage Treatment Works in Avonmouth, UK.  At Bristol, the sewage treatment works maintains the highest level of wastewater treatment, at the same time importing both sewage sludge as well as solid organic waste for digestion in the plants’ anaerobic digesters.  The technology being used in Bristol is very similar to the proposed solution for Stratford.  See videos below for more detail.

• Video 1
• Video 2
• Video 3

Example #2 – Toronto, Ontario

The City of Toronto has developed two source separated organic material processing facilities within the City. The Disco Road Organics Processing Facility receives and processes 75,000 tonnes and the Dufferin Organics Processing Facility receives and processes 55,000 tonnes per year, both using similar pre-processing operations and anaerobic digestion. Both sites have been designed with negative pressure inside the building space to contain fugitive odours and many of the same engineering controls will be implemented within the design of the Stratford project. Neither Toronto site have received significant odour complaints during operations.

Example #3 – London, Ontario

The Orgaworld London composting facility is a different process when compared to anaerobic digestion. Compost is loaded into concrete tunnels where air and water is added to aerobically decompose organic waste. Biogas is not produced, and air from within the tunnels is treated before exhausted through a stack to the environment.

There is currently an ongoing odour monitoring program that includes Orgaworld, City of London W12A Landfill Site and Ingredion Canada Corporation

Should the Minister of Environment, Conservation and Parks approve the project, the final decision will be made by Stratford’s City Council. Council has been involved in the process to date and a final decision is expected early in 2020. The matter is on the agenda for the January 13, 2020 meeting of City Council.

The initial route includes routes along O’Loane Ave, Lorne Ave West, Lorne Ave East, Erie Street, and West Gore Street. In response to the community feedback received at the Public Information Session that took place on June 13, 2019, additional routes are being examined and will be posted to the website in the future.
Please see the Trucking Route Map for a visual of the original proposed route that could be used by the biosolids haulers along John St. and Lorne Ave. 

The average number of trucks per day travelling along the proposed route is expected to be 12-13, and the intent is to limit that truck traffic to the time period between 9 a.m. and 3 p.m. The maximum daily number of trucks would not exceed 16. This maximum number would only be reached in the event that the facility is functioning at maximum capacity, which is not anticipated for several months. The 16 trucks includes trucks introduced by the City’s anticipated green bin program, which may be a couple of years away.

Solid waste would be delivered in “walking floor trailers”, which are enclosed with drip trays to capture any liquid, as well as “tip trailer trucks”, which are typically a completely sealed container. The City of Stratford has spoken with the trucking company about the public’s concerns. All trucks transporting material will be licensed and registered with Ministry of Environment, Conservation and Parks to handle and transport waste material and will adhere to stringent regulations.

•      The intent is to minimize truck travel through the City as much as possible

•      Deliveries would be staggered to minimize a line-up of trucks 

•      Trucks delivering solids organic waste would be washed prior to exiting the site to minimize odours along the route

•      The City of Stratford's anti-idling by-law would be enforced for trucks servicing the site

•      Deliveries on-site would be accepted between 9 a.m. and 3 p.m., limiting traffic outside of those hours

•      The current seasonal sludge hauling would be spread throughout the year, reducing peak truck traffic in the Spring/Summer.

How long would the trucks delivering solid organic waste take to offload at the site?

Once a truck arrives onsite, it would be weighed on a truck scale to ensure the amount of waste being dropped off is closely monitored. Once the weight was recorded, the truck would proceed into the receiving building where the waste would be accepted and prepared for processing. The estimated time for an average visit is expected to be 20 minutes, which includes the washing of trucks in the new building prior to departure. The inside of the truck containers would be washed to ensure that any waste stuck on the sidewalls is removed. Truck tires would also be washed to ensure all waste is removed before leaving the facility. 

The public comment period for the Ministry of Environment, Conservation and Parks (MECP) is still open, and that feedback will be considered by the Minister when examining the proposal. City Council would have to approve the project before the City can request approvals to construct.  City Council has not yet made a decision.
If Provincial approval is granted, Stratford’s City Council will make the final decision on whether to proceed. 

In 2018, the provincial government approved a "Food and Organic Waste Framework" as part of its Strategy for a Waste-Free Ontario. A ban on food and organic waste in landfill sites is being considered within that framework.

There is an excess of residential and private material that is being collected that does not have a home.  The project being proposed provides a solution that offers an alternative to sending the waste to landfill, and is intended to be a more economical solution, regardless of whether the organics ban is put in place.  

The facility would be permitted to accept organic waste generated in Ontario, however the priority would be to accept the City of Stratford’s organics collected from business and residents through a possible green-bin program. Considering trucking distances for this material, other potential sources would most likely be in Southern Ontario. The receiving building could accept up to 20,900 tonnes per year of solid organic waste and 5,000 tonnes per year of liquid waste. Stratford currently produces approximately 1,000 tonnes of organic waste per year.

Why don’t we ship the waste somewhere else? 

Shipping Stratford’s organic waste to another processing plant in Ontario is not a simple solution. This approach comes with a great financial cost due to dependency on other municipalities to process our waste. Upgrading the Water Pollution Control Plant would allow the City to take ownership over our own waste, and would set us apart as a leader in the field of waste management and sustainability. In addition, the financial revenue generated by Renewable Natural Gas distribution and fertilizer sales would be invested back into the local community. 

The total cost of the project is currently estimated at $22.7 million. The City of Stratford received a grant from the Province of Ontario for a total of $5M, which would contribute to the upfront cost for facility upgrades. The grant was awarded for this proposed project because of the greenhouse gas emission reductions it generates, diversion of waste from landfill, and the offsetting of utilizing fossil fuel Natural Gas. 

The City of Stratford would initially fund $1.5 million, with $1.5 million from the Ontario Clean Water Agency. Longer term financing of $15 million would also be required by the City of Stratford.

Where would the revenue come from?  

Revenue would be generated from receiving tipping fees from waste providers, as well as from the sale of the RNG. A revenue sharing arrangement would also need to be finalized with the City's partners.

If the project is approved, the preferred partnership model would be a Municipal Services Corporation, with the City of Stratford and the Ontario Clean Water Agency (OCWA) as the partners. 

It is not expected that there would be any relationship between the value of your home and its proximity to the site and/or trucking route. 

The existing site is the optimal location since it would be using existing infrastructure and plant operations staff, and there is room to expand at the facility. 

What capacity is the site currently working at?

The existing Water Pollution Control Plant is currently running at an estimated 60% capacity.

The existing digesters are a relatively young infrastructure compared to other sites across Ontario. The existing storage tank was built in 1957 and the new Primary and Secondary digesters were built in 1982. The last inspection of the Primary digester was completed in in 2012. Yes, the site would be able to handle the additional material. It is estimated that the site would accept up to 20,900 tonnes per year of solid organic waste and 5,000 tonnes per year of liquid waste.

Can the pre-processing be done somewhere else? 

Stratford does not currently have a local pre-processing plant to prepare the organics, so pre-processing material on site is the most viable option to ensure the safety and proper treatment of materials.  Pre-processing off-site would result in additional truck traffic to haul the now liquid waste to the WPCP.  Based on design flows this would require six trucks/day to the site vs. the proposed three trucks/day delivering unprocessed solid waste.

The majority of the proposed equipment would be located within the existing fenced-in area of the Water Pollution Control Plant. The only expansion outside of that fenced area would be for the proposed building to process the incoming organic waste.

Currently, the tallest structure on the site is 10.5 metres in height. The proposed receiving building would be 13 metres in height, with a single 16.2-metre stack to exhaust treated air after going through UV and carbon filters.

Please see the Display Panels presented at the Public Information Session for a map of where the specific upgrades are proposed.

Yes, process tanks would be totally covered in order to maximize the capture of biogas being generated through the digestion process. 

The cost for a purpose-built facility to handle the proposed 25,900 tonnes of solid and liquid organics has been estimated at approximately $38.8 million.

Growth predictions have been included as part of the project assessment and have been incorporated into the expected tonnage data. The City of Stratford is committed to planning for growth and making sustainable decisions as part of the process.

Spills at anaerobic and/or co-digestion sites are very uncommon. All material would be contained and processed inside the engineered buildings, and the receiving building would be kept under negative pressure to prevent fugitive odour emissions. The Ontario Clean Water Agency (OCWA), the agency in charge of site operations, has long-established contingency plans for safety on-site, which would be adhered to during operations of the co-digestion project. 

The City understands that residents are concerned about the impacts that this may have on the surrounding community. Strict safety and contingency plans would be put in place, and contact information would be made available to the public to report any issues. 

Would there be an increase in odour in the area? How would it be addressed? 

Studies have been conducted to examine this potential issue, and an Odour Baseline Data and Management Plan (Plan) has been developed. The Plan compares current site operations with how operations would change with the upgrade to co-digestion operations. The Plan concludes that concentrations of odour in the air on-site would not increase. The odour control system would treat air from inside the receiving building to remove all odours, and exhaust treated air through a single 16.2-metre stack.

Other odour mitigation measures would be set in place in accordance with guidelines outlined by the Ministry of Environment, Conservation and Parks (MECP) and would be monitored closely. Should you experience a problem with odour in the area, please contact the MECP Director appointed for the purposes of Part ll.1 of the Environmental Protection Act:

Ministry of the Environment, Conservation and Parks
135 St. Clair Avenue West, 1st Floor
Toronto, Ontario
M4V 1P5
Phone: (416) 314-8001 Toll Free: 1-800-461-6290

Would the waste trucks be diesel or electric? 

It is anticipated that trucks would be diesel fueled, however final details on this would be confirmed during the contracting phase as this may differ from contract to contract depending on the trucking practices of each individual partner. Greenhouse gas emissions produced from trucks would be insignificant compared to those produced from sending organic wastes to landfill.

Liquid waste would be transported in contained tanks, similar to trucks that carry fuel and other hazardous material. Liquid waste trucks are strictly engineered to prevent any spillage. As such, it is not anticipated that any material would escape.

Solid waste would be delivered in “walking floor trailers,” which are enclosed with drip trays to capture any liquid, as well as “tip trailer trucks,”, which are typically a completely sealed container. All trucks transporting material would be licensed and registered with MECP to handle and transport waste material and would adhere to stringent regulations. We agree that any such leaks would be unacceptable.

away? If so, where does it go?

Currently, the biosolids/digestate that is generated at the wastewater treatment plant is stored on-site and is hauled from site for land application in late spring and through the summer months.  Once upgraded, the site would generate a digestate that would be transported to a licensed waste disposal facility for land application or sold as a nutrient rich fertilizer. There would be less than one truck per week transporting outgoing materials.

The project would reduce GHG emissions by approximately 49,000 tonnes carbon dioxide equivalents per year and would divert 20,900 tonnes per year of solid organic waste from landfills. The estimated reduction in greenhouse gas emissions would be the equivalent of removing 10,800 cars from the road, or the ability to heat 9,100 homes per year. The site would produce over 2 million cubic metres of Renewable Natural Gas per year, to be sold and utilized in the natural gas pipeline. 

There are many community facilities that surround the site, including schools, hospitals, retirement homes, medical facilities and swimming facilities. What is being done to ensure the safety and compatibility of these facilities to the people nearby? 

If the project proceeds, the City will be seeking regular input from the community, and will be communicating regularly with the companies responsible for delivering materials to the site, to ensure any concerns with the operation of the plant are addressed in a timely manner.