Sanitary Sewer Smoke Testing Public Information

General Information / Purpose

The City of Suffolk has entered into a Special Order by Consent (SOBC) with the Virginia Department of Environmental Quality, the Hampton Roads Sanitation District, as well as 12 other Hampton Roads localities. The purpose of the SOBC is to reduce the occurrence of Sanitary Sewer Overflows (SSOs) in the sanitary collection system. As part of the SOBC, the City has implemented a program to identify and mitigate SSOs and to develop a long-term capital improvement plan that rehabilitates the system for the future prevention of SSOs.

Currently, the Department of Public Utilities operates and maintains the sanitary sewer system for the City of Suffolk. The sanitary sewer system is comprised of over 140 sewer pump stations, 289 miles of gravity sewer lines, 85 miles of sewer force mains, and conveys wastewater to the sewage treatment plants operated by the Hampton Roads Sanitation District.

Jacobs, a global leader in full-service engineering, construction, and operations is currently working with the City of Suffolk to implement a condition assessment program of the sanitary sewer system. An important goal of the condition assessment program is to address deficiencies which contribute to SSOs. A smoke testing program is being conducted as part of the condition assessment. Smoke testing is an effective way to locate and identify problems and defects that can contribute to SSOs and decrease the existing capacity and efficiency of the collection system infrastructure.

Public door hanger notification for smoke testing of sanitary sewer lines in the work area will be distributed to residents and commercial areas prior to field investigations. The door hanger will describe the upcoming smoke testing efforts and what should be done in advance to minimize smoke from entering buildings. Residents do not need to be home during the testing. Contact information will be provided on the door hanger in the event smoke does enter a building.

Neighborhoods to be tested will be published weekly in the Schedule/Map section.

Additionally, anticipated work areas for the upcoming work week will be published in the Sunday issue of the Suffolk News-Herald.

During testing, crews will seal off segments of the sanitary sewer system and push smoke into the gravity sewer pipes with smoke blowers. Materials used to generate the smoke are non-toxic, harmless, virtually odorless, and do not create a fire hazard. The City of Suffolk Department of Fire and Rescue will be onsite to assist condition assessment crews during smoke testing and help answer citizen's questions regarding smoke sightings that may occur in the area.

Should smoke enter your home or business, the room should be promptly ventilated through an open window or door.

Public Preparation for Smoke Testing

The smoke that you may notice rising from the vent stacks on house roofs or from the ground is: NON-TOXIC, HARMLESS, VIRTUALLY ODORLESS, AND CREATES NO FIRE HAZARD.

Smoke should not enter into buildings unless leaks or plumbing defects exist. Infrequently used drains, however, may permit smoke to enter. Please make sure that the elbow traps for seldom-used drains (such as basement floor drains), sink traps and other plumbing fixtures have water in them by pouring approximately 24 ounces of water into each drain. Drains can be prepared as soon as notification has been issued for smoke testing in the area. Preparation procedures only need to be performed once before smoke testing in the area begins. Residents do not need to be at home during smoke testing.

Note that it is also possible for smoke to enter your building around a faulty wax ring seal at the base of toilets.

Should smoke enter a building, the room should be ventilated through an open window or exterior door. There is also is a chance that the smoke could set off a smoke detector. Acute exposure can cause irritation of the respiratory system. Occupants are urged to leave the area and ventilate well to dissipate the smoke. Use the contact information included on the smoke testing door hanger to notify the condition assessment technicians who are conducting the smoke testing.


A sanitary sewer system is designed to transport wastewater to a treatment facility. In dry weather, it usually does so without an overflow. However, in wet weather, storm-related runoff may leak into the sewer system, resulting in an increased volume of flow the system wasn't designed to handle.

This may result in Sanitary Sewer Overflows (SSOs). SSOs are violations of several federal regulations, including Section 301 of the Clean Water Act and National Pollutant Discharge Elimination System permit requirements.

Although above ground problems, such as SSOs, indicate that a problem exists somewhere within the sewer pipe, locating that problem can be challenging. A smoke test is one of the best ways to locate defects in a sewer pipe, and a cost-effective method to assess the condition of the sanitary sewer system.

A smoke test is the process of injecting artificially produced smoke into a blocked off sewer pipe to see where the smoke emerges. If the sewer pipe is in good condition, then the smoke will emerge at the other end of the pipe. However, if the sewer pipe is in poor condition, the smoke escape through defects in the pipe. It is not unusual to see smoke coming up from cracks in the street or in residential yards during smoke testing.

A three or four person crew will conduct the tests. Each crew member will have proper identification and use well marked vehicles. The test is performed by injecting opaque-colored smoke into an isolated sewer pipe with specially designed blowers. Based upon the smoke testing location, temporary traffic control may be implemented to direct vehicular and pedestrian traffic.

While the smoke test is being conducted, crews walk around the smoke test area to observe and flag the places where smoke is escaping from a pipe defect. The defect locations are documented with digital photos and GPS so that the defect and necessary repairs can be evaluated.

The artifical smoke utilized during smoke testing is Lubspar 110, a petroleum distillate, and is commonly used in the industry.

While the smoke is not considered harmful, it is recommended to avoid prolonged periods of exposure. If smoke appears from a drain inside your residence or business, open windows/exterior doors and ventilate well to dissipate the smoke.

It is possible, although unlikely, that smoke could enter a residence through a drain trap which has dried out or some other plumbing defect such as an un-trapped washing machine drain.

That may indicate a break or other defect in the sewer pipe.

However, smoke doesn't always originate at the spot the smoke pipe emerges. Sometimes smoke will escape through a defect in the sewer pipe, then travel along the pipe until it finds a way to rise to the surface.

This may be good. If the sewer pipe is in good condition, the smoke will migrate along the isolated gravity sewer pipes and appear at nearby manholes or at sewer vent pipes on top of a residence.

Work Area and Schedule

Condition Assessment field technicians will be conducting smoke testing of gravity sewer pipes in the areas defined below. Door hanger notification of the areas to be tested will be distributed 1 week before testing begins in each area. Technicians will perform the tests between the hours of 8:00am to 5:00pm, as weather permits.

Testing is scheduled to begin:
September 19, 2018
and be complete by:
September 28, 2018

Please select the 'Work Area Map' below to view the smoke testing locations.

Condition Assessment Contacts

Jarrett Moran - City of Suffolk, Engineering Manager - Office: 757.514.7024 - Cell: 757.334.5929
Celeste Ostman - Jacobs, Project Engineer - 530.953.9748