Emergency services were called after a mysterious bright green puddle materialised outside a takeaway in Leeds.
The YFC shop on Beeston Road, Beeston, was cordoned off after reports from the public about the substance on Tuesday afternoon.
West Yorkshire Fire and Rescue Service dispatched its detection, identification and monitoring (DIM) and hazardous materials teams.
A fire engine from Hunslet fire station also attended.
Investigations revealed there was no immediate danger to the public.
Yorkshire Water officials visited the site on Thursday morning and said that the discolouration of the water is thought to have been caused by a green dye.
Checks on pipes and manholes were carried out, but they were found to be clear.