Environmental Health say the source of the pollution at La Vallette has been traced and work is underway on a permanent fix.
The Ladies Pool at La Vallette was closed earlier this week after it was discovered that the cesspit for the cafe and changing block was overflowing into the surface water system, and then into the seawater pool.
Tobin Cook, who heads up Environmental Health and Pollution Regulation, says that leak has now been stopped:
"While measures have already been undertaken to prevent a recurrence, until Environmental Health has received the formal report, we’ve asked for the public and café toilets to remain out of use to allow the café to at least operate on a reduced capacity."
He says a further water sample has been taken and planned maintenance work will go ahead early next week:
"The Ladies’ Pool is currently scheduled to be emptied and cleaned on Tuesday, so the pool will remain closed until then as a precaution.
"This will also allow time for short-term mitigation to be reviewed while a permanent solution is arranged."
He is hopeful that if the water sample passes lab tests, then the popular all year round pool can re-open on Wednesday (9 September).
The Gents, Horseshoe Pool and Havelet Bay are unaffected and are open to swimmers.

"Catastrophic" engine failure stops Channel Island ferry
Fog causes major disruption at Guernsey Airport
Sark chef creates astronomy app
More women cycling in Guernsey after confidence booster classes
Toilet leak forces closure of popular Guernsey seawater pool
Alderney Children's Centre shortlisted for Nursery World Award
Hottest summer for Guernsey since records began
Guernsey considering funding requests following the disaster in Nepal