A Covid-positive Coles staff member worked for two days while infectious, plunging colleagues into isolation and prompting an urgent alert for customers.
The infected worker was at Coles in Kareela in Sydney's south on July 2 and July 6 between 5pm and 10pm.
Coronavirus fragments have also been found in wastewater gathered from 32 north-western Sydney suburbs, putting thousands of residents on high alert.
A busy Coles and Vodaphone store at Stockland Wetherill Park in the city's south-west were also added to the relentlessly growing Covid exposure list on Thursday night, along with several food outlets and an Aldi in Menai.
The exposure list and sewage alert come amid growing fears the virus is rampantly spreading in Sydney's western suburbs, with lockdown failing to have contained it in the city's east.
Five of the seven new sites are in the three local government areas in Sydney's south-west, where residents have been ordered to stay at home due to a rapid rise in cases.
Anyone who visited Billy's Cars in Revesby on July 4 between 10am and 11.30am is regarded as a close contact.
They have been ordered to get tested and isolate for 14 days, regardless of the result.
Anyone who attended the car yard July 2, 9am-5pm and July 3, 9am-5pm were also previously ordered to self-isolate for 14 days.
Health officials are also concerned about fragments of the virus in the Boronia Park sewage network, which covers more than 30 suburbs across the city - with no known Covid cases.
Stockland Wetherill Park (pictured) has been listed as a casual contact exposure site after infected cases visited Coles and Vodafone at the busy shopping centre on July 4
A host of venues in Sydney's south and south-west were also listed as casual contact sites.
They include Charlie’s Grill Chicken and Seafood in Illawong, Youies Takeaway in Belmore, Aldi Menai, Vodafone and Coles Wetherill Park and Fred’s One Stop Shopping in nearby Edensor Park.
Anyone who attended these venues at the listed times must immediately get tested and isolate until a negative result is received.
Residents are urged to check the NSW government website regularly, as the list of venues of concern and relevant health advice will be updated as investigations continue.
Anyone who attended the Charlie’s Grill Chicken and Seafood Illawong, July 3, 2.50pm-3.10pm has been ordered to get tested and isolate until they return a
