A photolithography system includes a variable-volume buffer tank, a dispensing system connected to the buffer tank, and a valve configured to release gas from a head space of the buffer tank while blocking the release of liquid from the head space. A storage container has an opening at the bottom and drains to the buffer tank through that opening. The buffer tank has a storage capacity sufficient to receive the full contents of the storage container. The system supplies chemical solutions to the dispensing system while keeping the chemical solutions from contact with air and other gases.