To expand on the produced water issue:
C&EN magazine (produced by ACS) has had quite a few articles on fracking water and the issues surrounding it. One of their cover stories,
Volume 93 Issue 11 | pp. 8-12, talks about a few of the issues. To summarize, The Great Unknown (chemicals degrade into what?), the Less Unknown (stuff we know about, but how much comes up) and the Radioactive component (self-explanatory).
I can't link that article as it is a cover story; other shorter articles I can link to. I can try to find a pdf and drop it somewhere for others to read.
USGS report and summary of the injection wells and earthquakes
ArticleAnother issue is disposal and future use for drinking (or industrial water use)
ArticleA lot is due to lack of communication and understanding. Or relying on someone else to do the work.
Chemicals and how 'bad' they areBiocides might not be needed, but would require a case-by-case instead of a blanket use
ArticleSome hopefully interesting information about this process.
~egon