NOT Dumping Black and Gray Tanks

[TheGriz]

This weekend (Friday-Sunday), I boondocked during our 2019 Amateur Radio Field Day (Ham Radio). I was the only one in my TT, and have only four "loads" or so in the black tank, several "pees", and associated flush waters. So I can't imagine black tank exceeds a third full. Guessing 5 gallons in the galley gray tank and 10 gallons in the bathroom/shower gray tank. I was in water conservation mode for weekend.

Is there any harm in NOT dumping the tanks for several weeks??? I could go to a campground a couple miles from my house and dump if needed. They do charge $20 to dump, and I am not complaining about the charge. However, it would be nice to wait until the next time I go camping and connected to full-hooks up to dump. Probably in next one to two months.

BTW...gates valves on tanks are all in good shape/don't leak.

As long as it's not a LONG time, say 6 months or more, I can't foresee a problem. Thoughts???

Thanks,
Mike