ROCHESTER - In order to improve sewer service, Weston & Sampson will conduct smoke testing of the sewer between Aug 15 and Sept. 30. Testing will take place from 7 a.m. to 3 p.m., Monday through Friday, weather permitting.

The purpose of smoke testing is to locate sources of rainwater entering the sewer. During the test, white smoke is introduced to the sanitary sewer system via a smoke-generating machine. During this procedure, white smoke will be venting from holes in manhole covers located in the street and from plumbing vent pipes located on or near roof surfaces. This is normal and should not cause alarm.

Smoke should not enter premises unless there is either a dry trap in an unused fixture or a plumbing defect. You may wish to pour two gallons of water down your basement floor drain or unused plumbing fixture to ensure that the drain trap will be effective.

Should smoke be detected within your building, do not be alarmed. The smoke is non-toxic, won't stain anything and dissipates quickly through open windows.

People with lung ailments or respiratory conditions such as asthma or emphysema should stay away from the smoke.

Any smoke within a building should be immediately reported to the Weston & Sampwon personnel conducting the tests or by calling (603) 988-0143. To learn more about the smoke used, visit rochesternh.gov.

Weston & Sampson Engineers, Inc. company vehicles are black with the company name on the sides and their smoke testing personnel will be wearing shirts with the Weston & Sampson markings and a current Weston & Sampson ID card.

Any questions should be directed to Weston & Sampson at (603) 988-0143. Please leave a message including your name, address, and telephone number and you will get a prompt response.