The plea follows the recent discovery of a large amount of illegally-dumped fat, oil and grease which is causing blockages along a 100-metre stretch of sewer pipe under Dalrymple Street, the town's main street.
The substances have massively reduced the circumference of the pipe and could lead to flooding and pollution in the street, where most of the town's shops are located, and also nearby streets.
Scottish Water is continuing to investigate to find the source of the fat and has urged the community to bag and bin any cooking fat and oil, rather than pouring it down plugholes and into the waste water system.
Waste water from the town flows towards the harbour pumping station, from where it is pumped towards the waste water treatment works at Girvan Mains.
Scottish Water will work to clear the fat from the affected stretch of pipe and Dalrymple Street will be closed from 8am to 4pm this Sunday (April 27) and next Sunday (May 4) while this work is carried out.
Alex Milligan, Scottish Water's trade effluent adviser for South Ayrshire, said: "This is a serious problem, which could lead to flooding and pollution in the centre of Girvan.
"Scottish Water would really appreciate help from the community to prevent it happening in the first place.
"I would urge householders to bag and bin any cooking fats, rather than pouring them down plugholes and drains, and businesses such as B&Bs, hotels, cafes and takeaway outlets should have proper catering fat traps installed.
"If those responsible are traced, they could end up having to pay the cost of our clean-up effort, which could run into tens of thousands of pounds."
When warm fat cools, it solidifies. This can cause sewage to back-up, flooding homes and gardens.
Disposing of fats, oils and greases into the sewer system is illegal and can have disastrous environmental consequences, creating a health hazard. It is also a serious drain on Scottish Water's resources.
Businesses should know that there are specialist collection companies that can take away large quantities of fat and, in some cases, recycle it to make bio-diesel fuel.
Householders can turn cooking fats into cakes for garden birds, or can simply bag it and bin it.
Anyone who wants to know more information can call Scottish Water on 0845 601 8855 or visit www.scottishwater.co.uk