Hi Gabriel,
Thank you for your patience.
I don’t believe there is an insulation liner to prevent evaporation. Evaporation would be controlled by the enclosed design i.e. the lid.
Water tanks are usually lined with a food-grade liner to ensure the water stays fresh and to prevent contamination. However, there is no excess liner stored at the ranger base.
I hope this helps.
Kind regards,
Evelyn
Evelyn Todio