Following are a number of back-translations as well as a sample translation for translators of Joel 3:14:

• Kupsabiny: “There are many people in
  the valley of judgments/decisions.
  Because the day of God is close to arriving
  to that place of the valley of judgments/decisions.” (Source: Kupsabiny Back Translation)
• Newari: “Crowds of people have gathered
  in the valley of judgment.
  Because the day of the LORD is near
  in the valley of judgment.” (Source: Newari Back Translation)
• Hiligaynon: “Very great-in-number (are) the people who make-noise in the Valley/Plains of Judgment, for the day of the LORD’s punishment (is) now soon to-reach there.” (Source: Hiligaynon Back Translation)
• English: “There will be huge crowds of people in that Valley of Judgment.
  It will soon be the time that Yahweh will punish them.” (Source: Translation for Translators)