Warning signs had been up at the bay a month after problems with sewage from a cracked private sewer. Further investigations were then needed.
But a bathing water test this week showed the water was now classed as excellent.
Guernsey Water water quality risk manager Margaret McGuinness said resolving pollution incidents of this nature could be a challenge.
‘Working closely with our colleagues at Agriculture, Countryside & Land Management Services, the Office of Environmental Health and Pollution Regulation and, where necessary, private land owners, is essential to ensure incidents are dealt with as quickly as possible,’ she said.
‘This includes not only identifying the source of pollution and ensuring the issue is remedied, but also the monitoring and testing of both stream water, by Guernsey Water, and bathing water, by ACLMS.’
ACLMS principal environment services officer Andy McCutcheon said with any pollution incident of this nature, the greatest concern was ensuring the continued safety of islanders and preservation of the natural environment.
‘We appreciate everyone’s patience during the closure of Petit Bot bay to swimmers,’ he said.
‘Confirmation of consistent excellent bathing water quality test results was an essential requirement for us ahead of re-opening the bay.’
ACLMS confirmed that signage advising against swimming in the bay had now been removed.
The most recent bathing quality tests, taken from 13 beaches at the start of June, shows that all were classed as excellent water quality.