Water test samples from St Aubin's Bay have come back as 'excellent' but advice against swimming there will remain.
The government initially blamed 'technical problems' but now say that the recent warm, dry weather has contributed to the 'lower than usual quality'.
"I understand that people will be concerned, but I want to reiterate that this isn’t raw sewage going out into the sea. Our team at the Sewage Treatment Works are working incredibly hard, as you’d expect, to rectify the issues." - Infrastructure Minister Deputy Tom Binet.
Samples of sea water taken at La Haule and Victoria Pool came back as excellent. However, an 'undiluted sample' from the First Tower outfall was poor.
Environment Minister Deputy Johnathan Renouf says he's pleased about the results.
"They provide reassurance that although the quality leaving the Sewage Treatment Works isn’t of the standard we’d normally expect, the water quality in the bay generally remains high.
This suggests that the water from the STW is being quickly dispersed and diluted in the bay. However, I remain concerned about the poor findings from the undiluted outfall sample, which confirms that water coming from the STW is not yet up to standard.
We need to wait for colleagues in the Infrastructure team to confirm that the issues have been resolved at the plant itself, before we can change the advice around swimming. We also need to do more testing of sea water to back up the findings from this week’s samples."
The advice has thrown doubt over the Jersey triathlon this weekend.
Organisers say that they will continue to plan for a full event, but are ready to change it to a 'duathlon' if final results say it is unsafe to swim.
Results of further sea water and from the SWT itself are expected back tomorrow morning (17 June).