Sanchez questions Gajwani on co-digestion cost impacts and shared costs with partners
Sanchez asks how co-digestion impacts operating costs and about cost-sharing arrangements. Gajwani explains biogas processing is at no cost to the city through agreements with Waste Management and National Grid, but there are costs for heating food waste, biosolids disposal, and nitrogen management, offset by Waste Management payments.
How does co-digestion of organic waste impact operation costs?
Does the biogas processing facility contribute to cost?
And you've already spoken about how you've shared costs with waste management and National Grid.
Is there any other ways that you share costs with them as well?
So the actual processing of the biogas is similar to the contract that we have with waste management, where it's at no cost to the city.
We have an agreement with National Grid where it's also at no cost to the city.
However, within the processing itself, there are energy.
costs for kind of heating up the food waste.
It only makes up about 10% of the total mass that we're putting into the digesters, but there is, you know, heat associated with that.
And then in the actual processing, you know, the biogas itself is, you know, kind of not at additional cost to us, but the
the residual, the amount of the food waste that does not convert to biogas, it's about 25% of the incoming mass
that becomes biosolids, and then that has a disposal cost and recycling cost associated with it, as does, you know, there's different constituents of the food waste, such as nitrogen.
We have sensitive waterways from a nitrogen standpoint, and so we have to make sure that we're managing the nitrogen appropriately.
So there's costs associated with that.
We have a cost offset that we receive from waste management that covers the costs of the additional costs to DEP just in the processing of the additional food waste.