The ISIMET Water Controller for Drug Testing Labs (DLA) ensures the integrity of a drug test by shutting off the water supply and draining supply lines (optional) to ensure drug test is not contaminated. The controller visually indicates whether bathroom water is on or off. Keyed and non-key (push-button) versions are available. It complies with Department of Transportation (CDOT) 49 CFR collection security requirements. It is easy to retrofit a light switch with a DLA.