well i think technology sounds better, and so if we look at the meanings, technology also goes better :
Science Definition
The word science comes from the Latin "scientia," meaning knowledge.
How do we define science? According to Webster's New Collegiate Dictionary, the definition of science is "knowledge attained through study or practice," or "knowledge covering general truths of the operation of general laws, esp. as obtained and tested through scientific method [and] concerned with the physical world."
What does that really mean? Science refers to a system of acquiring knowledge. This system uses observation and experimentation to describe and explain natural phenomena. The term science also refers to the organized body of knowledge people have gained using that system. Less formally, the word science often describes any systematic field of study or the knowledge gained from it.
So pure water knowlege is what we have, but the technology is what we use = our systems
the knowledge gained by science has been very beneficial to this industry but the application of 'science' has helped us to develop technology, which is our tools / ro / di etc and mechanisms for producing what we need, or methods we use.
so it is better to say pure water technology