Residents in Musselburgh and Wallyford have complained of discoloured water coming through their taps.
Scottish Water took 37 calls on the issue.
One Wallyford resident said her tap water was brown for a few hours from noon and then went cloudy.
A spokeswoman for Scottish Water said: "We repaired a valve on the drinking water network earlier today and this resulted in some of our customers across the Musselburgh area having discoloured water.
"We have flushed the network and normal supply should be restored. Any customers continuing to have discoloured water should run their cold water tap for a short period until it becomes clear. We apologise for any inconvenience."
She added that the water was safe to drink, adding: "When repairing things like valves/bursts there is a flow disturbance in the network which causes natural sediment in the pipes to shift which can make the water discoloured, for example brown, for a short period."
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