The City of Natchez will be &uot;blowing smoke&uot; for the next few months in an attempt to find leaks in its sanitary sewer system.

The work began Tuesday and will last about 200 days. The smoke is nontoxic and will show Natchez Water Works what sections of the sewer lines need to be repaired.

&uot;You have a town that is as old as Natchez, you are going to have some pipes that need replacing,&uot;&160;said City Engineer David Gardner.

The work will begin in the Highland Boulevard area and will concentrate on the city’s main sewer lines.

The city will use several hundred &uot;smoke grenades&uot; during the project.

&uot;The smoke is very valuable because it rises,&uot; Gardner said. &uot;If you have a crack in there, smoke will find the crack.&uot;

During this process, called infiltration and inflow, residents may notice the smoke spill out into their yards or into their homes.

The smoke indicates where gases and odors from the sewer also may enter and could cause a health hazard.

&uot;Location identification and correction of the source of smoke that enters your house is urgently advised,&uot; said a Natchez Water Works press release.

If residents notice any leaks in or around their homes, they should contact the Natchez Water Works so it can determine the location of the leak.

All repairs to private systems are the owner’s responsibility but residents are not required to fix private systems.

If they decide to do so, they are advised to contact a professional plumber, the press release said.

The city is paying Georgetown Construction Company of Natchez $500,000 to perform the job.

Company president G. Stephen Guido said one of the dangers of methane gas, a byproduct of sewage, is explosion.

But Gardner thinks the amount of gases leaving the system is small.

The cracks may not leak sewage but still may not be airtight, he said.

The real problem occurs when the cracks allow rainwater to enter the sewer system. All the additional water then has to be treated with the actual sewage, making the process much more difficult and expensive, Gardner said.

A crew of about eight will do the tests and will repair the damaged areas as the job progresses, Guido said.

The company plans to use several hundred smoke bombs and will also use video cameras to look for damaged lines. This will prevent workmen from having to dig up lines to look for damaged areas, Gardner said.

The city has been doing some of its own sewer system checks each year but decided to contract the job out this time so it could check a larger area.

&uot;It’s just good business,&uot;&160;Gardner said. &uot;It’s in everybody’s best interest to do this.&uot;