How do we establish a diversion rate for recycled batteries when tracking recycling batteries is easy, but tracking batteries thrown in the trash is extremely difficult?

There really is no perfect way we know of to accurately track the diversion rate of batteries. In general you are expected to maintain a collection of batteries for recycling, and then recycle 100% of those batteries. Performing regular tenant outreach and training custodial staff on recycling programs can also help you achieve a 100% recycling rate for batteries.