People in Great Yarmouth and Gorleston have reported their tap water turning green in recent days.
The tinge is most obvious in larger volumes of water such as when filling a bath.
Officials believe the tint is a consequence of recent heavy rainfall and insist the water is still safe to drink.
A spokesman from Essex and Suffolk Water said: "We were made aware of reports of discoloured water from customers in the Great Yarmouth area of Norfolk.
READ MORE: Why is my tap water coming out green in and around Norwich?
“We have investigated and believe this may have been caused by a change in the raw water quality at Ormesby Treatment Works, following the storms over the weekend.
“We would like to reassure customers that the change in the colour of the water is purely aesthetic only - this means that the water is absolutely safe to use and to drink, and has been thoroughly treated to its usual high standard."
Similar reports have emerged from homes in and around Norwich.
Anglian Water, which supplies the Norwich area, also blamed heavy rainfall and insisted the water was safe.
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