Water testing apparatus and methods of using the same

A test vial for detecting contaminants in a water sample comprising:

• a) a tamper evident cap comprising a separable top cap, an internal seal, and a bottom ring, and
• b) a vial consisting essentially of a single internal vial sample testing volume that is the sum of the air volume and a water sample test volume,
• wherein the air volume in the vial is at least 16.7% of the single internal vial sample testing volume,
• wherein the water sample test volume is at least 25 mls and consists of a water test sample and media, and
• wherein the media consists essentially of 4-methylumbelliferyl-b-D-glucuronide (MUG), 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (XGAL), or combinations thereof.