Sanitizing Fresh Water Tank

i also just drain sanitizing solution in my gravel TT parking spot

My driveway too.

Yup, I just let mine drain on the driveway.

Drive way is fine, use it yo water the grass

I drain my sanitized water on my gravel parking area.

I just empty the fresh water tank bleach water in the driveway. A 1/2cup of bleach to 30gal water isn't an environmental issue. The small amount of bleach dissipates quickly. A partially used bottle of bleach will lose it's strength over a few months so after sanitizing, I try to remember to take it to the laundry room to be used up.