LIV GRoup - The company responsible for safety at 277 flats at Manor Mills on Ingram Street in Holbeck - said the water supply was temporarily cut off on Wednesday September 15.
Connor Scherer, building safety manager for LIV Group, said: “LIV Group received results from a regularly planned, quarterly testing on Wednesday, 15 September and immediately shared the results with water provider Yorkshire Water.
"As per their recommendations, we have temporarily cut off the water system while both Yorkshire Water and water safety experts further investigate the water hygiene levels at the property.
"We are monitoring the situation daily, and will continue to update residents as the situation progresses.
Leeds Festival road closures: Aberford village will be closed to festival traffic after being used as a 'rat run'
Man dead after a paragliding accident near to Leeds
'Highly organised' Leeds thieves caught by own technology after tracking movement of business owners
Leeds United supporters issued warning not to walk on M621 after minibus drops fans off on motorway slip road
'I'll throw acid over you': Leeds dad high on cocaine made vile threats to ex
"We expect work to be completed early next week.
"In the meantime, LIV Group has installed portaloos and water delivery to all 277 units at Manor Mills.
"We will continue to liaise with the water provider to resolve the matter as soon as possible.”
Mr Scherer wrote in a letter to Manor Mills residents: "We sample and test the water supply every three months to make sure you are drinking and using clean and fresh water.
"One of these results has come back with a higher reading than normal and - on advice - we have taken the precautions necessary to protect you while the issue is investigated.
"There could be a variety of reasons for the adverse result."