I read a book by [Rabbi David Miller (1869 – 1939)][1] ( he had semicha from Rabbi Isaac Elchanan of Kovno ) , [The Secret of the Jew][2], which says you can fill an empty mikveh straight from a faucet (see pages 366 and 428).  [There is a copy of the book on Hebrew Books][3].

 Are there opinions that argue on Rabbi Miller? Who are they, and what is the basis of their disagreement?

  [1]: http://personal.stevens.edu/~llevine/david_miller_jp.pdf
  [2]: http://www.homemikveh.org/sotj/sotj.html
  [3]: http://www.hebrewbooksqa.org/934/rabbi-david-millers-the-secret-of-the-jew-vols-and-ii-is-where