The Environment Protection Authority is investigating the sewage seep that occurred in Belmore Basin last month.
The sewage leak coming out of the rock wall at Belmore Basin was noticed on January 11 and led to Wollongong City Council closing Brighton Beach on January 17.
The source was eventually located and land manager Crown Lands informed the EPA on February 4 that repair work had stopped the seepage.
The beach remained closed until February 11 as a precaution.
From January 20 to February 5, the EPA conducted regular tests for faecal coliform, enterococci and ammonia at seven locations along the beach, including the area closest to the leak.
The EPA's Illawarra region manager Peter Bloem said the results showed that the effect on water quality was largely limited to the area closest to where the seep was occurring.
"There was, however, some increased enterococci readings at times in locations away from the sewage seep," Mr Bloem said.
"These tended to be in the north-western corner of Belmore Basin, adjacent to the large stormwater culvert and following rainfall.
"The maximum reading was 800cfu/100ml [colony forming units per 100 millilitres], suggesting that stormwater runoff may have been a key influence on water quality in the basin at the time of testing."
An enterococci level of 35cfu/100ml is enough for the EPA to deem a waterway as unsuitable for recreational use.
Levels of faecal coliform were also initially high, at 3600cfu/100ml - well above the 150cfu/100ml benchmark.
Test results this month show levels below those benchmarks.
"Now that the seep has been resolved, the EPA has requested a detailed incident report from Crown Lands and will be conducting further investigations to better understand the cause of the incident and the necessary measures to prevent a recurrence."
Mr Bloem said the EPA testing regime would continue throughout this month.
He also reminded people that beach swimming shortly after heavy rain, or while stormwater is present, should also be avoided due to the risk of pollution.
The summary of the test results is available on the EPA website.