Sewer System Smoke Testing at the Greenbrae Boardwalk

As part of our continuous effort to improve the sanitary sewer infrastructure, Sanitary District No. 2 (SD2) will be smoke testing the sanitary sewer lines within the District. These tests require blowing smoke into the sewer system in order to locate possible pipe damage, illegal connections, and any other defects and breaks in our sewer system. As a result, white smoke may be seen coming from roof vents, building foundations, the ground, catch basins, clean-outs, down spouts, sewer laterals or manhole covers. The smoke from the test should not enter your home unless you have plumbing that is defective or you have drain traps that are dried up.

Greenbrae Boardwalk

Greenbrae Boardwalk walkway

 








   


When will the smoke test be conducted?

Please be advised that SD2 will be conducting smoke tests in the sanitary sewer lines at the Greenbrae Boardwalk area at the end of November, 2022. Work will be taking place Monday through Thursday. NO WORK WILL OCCUR ON A HOLIDAY. The tentative duration for this work is Wednesday Nov. 30, 2022 to Thurs. Dec. 1. 2022, between the hours of 8:00am to 3:30pm.  If necessary work will continue beginning on Monday Dec. 5, 2022 thru Wednesday Dec. 7, 2022 from 11:00am to 5:00pm. 

It is anticipated that the work can be completed within the 2 week period noted above. Notices will be provided to individual residences approximately 24 to 48 hours prior to the actual testing. Your presence is not required during the test. If you have any questions or concerns please call. (628) 253-1158. 

Recommendation for Residents: If you have any plumbing fixtures that are not used or are rarely used, traps should be filled by running a gallon of water in the fixtures (typically sinks) the day before the scheduled smoke testing.

*** Please note that the smoke used is a non-toxic substance that is harmless to humans, pets, plants, food, and household items.  If smoke does enter your residence, proper ventilation will clear it within a few minutes. Please make sure to contact SD2 at (628) 253-1158 or notify SD2 crews in the area regarding smoke inside your residence.

***** Public Meeting at the Boardwalk*****

Sanitary District No. 2 will hold a meeting to discuss the work and answer questions from property owners on November 16th at 4pm at the entry of the Greenbrae Boardwalk. All residents are encouraged to attend.


Questions You May Have About Smoke Testing

1. What is the reason for smoke testing?

Smoke testing is a process to find leaks in the sewer system before small leaks and tidal become larger problems. It’s one of the several investigative methods used to locate storm water inflow sources in a community’s sanitary sewer collection system.

Typically, direct sources of surface water or groundwater can enter a collection system during rainfall events – including catch basins, area drains, house roof downspouts, sump pump discharge and/or foundation drains directly connected to the sanitary system or storm sewer.

In addition, properties that are close to the bay can be influenced by high tides that inflow into the system through pipe deficiencies that can compromise the pump stations (causing alarms) and unnecessarily inundate the water treatment facilities.

Local municipalities test sewers by putting non-toxic smoke into the sewers to find leaks and faulty connections. This method of field investigation is helpful in detecting direct connection points of groundwater or surface water intrusion into the sewer. The process is cost effective and highly efficient.

sanitary systemstrom

2. What is smoke testing and how does it work?

A smoke test is a sewer inspection method in which a non-toxic smoke (similar to products used at concerts and theater venues during live performances) is pushed through a community’s sanitary sewer collecting system, and then the locations where the smoke exits are observed and documented. The smoke makes its way through all the connected pipes in the sanitary sewer system, helping to locate pipe leaks, broken manholes, cracks, uncapped lines, and more. The test may also locate unknown sections of pipe (or sections professionals may not have realized were connected to the sewer), such as cleanouts, roof downspouts, and sump pumps. Certain types of discovered connections are actually illegal and will need to be disconnected.

Homeowners are requested to pour water down all drains of plumbing fixtures that are not used or are rarely used in order to fill the P-traps, which will help prevent smoke from entering the house. 

During the smoke test, you may see smoke coming out of grass, utility boxes, cracked pavement, and more. Each test typically lasts about 15 to 30 minutes. Homeowners do not need to be home during that time, although it can be helpful to ensure the home is well-ventilated if smoke enters the home. You should also alert the testing crew if this happens.

smoke sewer line image

The image above, shows a field technician using a blower over a neighborhood manhole and pumping non-toxic smoke through the sewer line to identify problems.

3. Is the smoke from this type of test hazardous?

Not in the slightest! The odorless, colorless simulated smoke will not cause a fire or explosion and isn’t hazardous or flammable. As noted previously, this “smoke” is similar to what you see at concerts and other live events.

Simulated smoke should disappear quickly. However, it’s encouraged to avoid unnecessary exposure to the smoke; extended exposure may cause some skin irritation.

double image smoke

Smoke testing is an efficient process, often taking just minutes. However, it requires careful planning and coordination, and sometimes unknown issues are revealed which may slow the process.

4. How long does the testing process take?

For a single town block, smoke testing can last as short as approximately 30 minutes or may be in several 30 minute increments. Residents may see the simulated smoke emerging from manhole covers, storm drains, roof vents or building foundations.

5. How can we (residents) prepare for smoke testing?

On November 16th, two weeks before the testing, a public meeting will be held to provide residents with the opportunity to ask questions and voice concerns. 

Another option is to access the District website and find additional information about the smoke testing process and what is involved.

Also, in the days leading up to testing, field crews will walk the neighborhood and place flyers or door hangers to remind residents of the upcoming work. These flyers provide information about the tests, tips to prepare and numbers residents can call with any questions. Residents should expect to see these crews around the neighborhood.

Residents should also follow the instructions given by the District in any notices. In question number 2 above, “What is a smoke test and how does a it work?", the paragraph instructs you to pour water down all drains of plumbing fixtures that are not regularly used in order to fill the P-traps, which will help prevent smoke from entering the house.

After your home is tested, you will receive communication regarding deficiencies in your line. (Since most homes in the Bay Area have relatively old sewer systems, most homes will have some sort of deficiency to fix.) The most important thing to do is follow the directions given and ensure you have fixed any issues by the given deadline.

On our website you can find a list of pre-qualified sewer contractors that will be happy to help translate and make sense of any issues reported in the notification you have received.

6. What happens after a smoke test? 

All deficiencies that are noticed are documented in a written report that should also include photos of the observed smoke. Smoke sources observed on private property will result in a letter from the District explaining the issues noted, with an included deadline for correcting the issues, as these issues are the responsibility of the homeowner to fix.

In general crews will smoke test a group of parcels on a given day and then send notices to homeowners after they have tested the lines. In some cases, the time lapse between the smoke test and the actual notice going out is large enough that homeowners are able to diagnose and address their problems by the time the notice arrives.

The challenges resulting from smoke test results will vary depending on the issues present in the system. There are some fixes that are relatively simple to fix, including:

  • Disconnecting downspouts from sanitary lateral
  • Replacing a missing or broken lateral cleanout cap

However, more difficult corrections may also result. Issues that will usually require professional assistance include:

  • Cracked sewer laterals
  • Tree root issues
  • Re-routing damage from separating storm lines

If the source of the issue is not readily apparent, a sewer camera inspection is the next step whenever there is a more serious problem. The closed circuit TV (CCTV) will allow inspectors to discover/verify the true extent of the damage, helping to ensure a solution that truly solves your sewer problems once and for all. This is also important for the environment in our communities, as fixing these issues helps keep the Bay clean and preserves our overall local ecosystems. 

7. Will smoke enter my house? What should we do if it does?

The smoke from smoke testing should not enter homes or buildings. However, do not be alarmed if it does. As noted previously, the smoke is not toxic. Property owners are encouraged to simply open their doors and windows to ventilate the area. Simulated smoke should clear out quickly and will not stain walls or furniture or leave residue. The smoke is safe, but long exposure may cause irritation. Please make sure to contact SD2 at (628) 253-1158 or notify SD2 crews in the area regarding smoke inside your residence.

double smoke 2

Highlighting smoke escaping from two manholes during smoke testing. Both photos reveal high likelihood of problems with the sewer system.

8. Will the District enter my home?

Neither the District nor the crew that performs smoke testing will enter your home during the testing process. However, if smoke is found in your home, you can request they enter to determine where the smoke is entering from.

District Personnel on-site can have helpful, educational conversations with residents regarding smoke arising from within homes, but the homeowner will need to connect with an approved licensed plumber to fix any issues.

9. Will first responders be on standby in case of emergency?

Smoke testing teams and/or District/Town staff will inform local fire and police departments of planned testing, so that they can be on notice and educate residents if calls related to smoke testing arrive. Smoke testing will not create an emergency situation, but first responders can provide additional education, assurance and guidance.


Capital Improvement Program

This project is part of the District’s Capital Improvement Program, which includes projects that will help prevent storm water from entering the sewer system and over loading the pump stations and the local sewage treatment plant. Smoke testing is just the first part of the larger projects. 

Sewer Lateral Inspections

Be advised that Sanitary District No. 2 requires that a sewer lateral inspection be conducted, which could lead to sewer lateral repairs or replacement, under the following circumstances:

21.22.020 CMMC - Mandatory inspections. 

 (a)  Health and safety basis for requiring a private sewer lateral inspection. An owner of any private sewer lateral serving owner's residential property, fixed and floating property, commercial property, publicly owned building, common interest development, apartment building and any other structure which has a private sewer lateral shall have the sewer lateral inspected in accordance with the requirements of this chapter (as directed and within the time period indicated by the district Manager) upon the occurrence of any of the following events:

  1. Overflow or malfunction. Whenever District staff determines that the private sewer lateral has recently overflowed or has recently malfunctioned;
  2. Lateral failure or lack of maintenance. Whenever District staff finds that there is sufficient evidence to conclude that the private sewer lateral has failed, is likely to fail, or has not been properly maintained.
  3. Public health threat. Upon any other reasonable cause to believe that there is a threat to the public health, safety, or welfare due to the condition of a private sewer lateral.
  4. Age of pipes and/or extent flora causing higher flow within the service area. Whenever the District Manager determines that the age of pipes (clay, plastic or other material) in combination with observed flora (tree roots near the sewer lateral suggesting root intrusion causing infiltration) or the age of the pipes independently are causing excessive flow in a neighborhood or area, the District Manager may direct an inspection of the private sewer lateral to determine the need for repair.

(b)  Events requiring a sewer service lateral inspection.

All properties- An owner shall have the private sewer lateral serving his or her property inspected and all defects repaired in accordance with the requirements of this chapter and the district standard specifications upon the occurrence of any of the following events:

  • When a property owner submits a building permit application for improvements valued at $50,000 or more over a cumulative three-year period, or when the permit improvements involve legalizing or constructing ADU, size change of a water meter or install of fire sprinklers, fixture count change, or District manager request.
  • When a property is sold or has any transfer of property title. Note: There are 2 start times for the 180 days compliance division; 1) Is notice of repair, 2) Is the date of close of escrow which whatever comes first will trigger the 180 days compliance.
  • When a sewage overflow, malfunction or other public health threat occurs at a property as determined by the SD2 staff. 
  • When the sewer main is being improved or the road above a resident’s sewer lateral is being paved as part of a Capital Improvement Project led by the Town of Corte Madera, Sanitary District No. 2 or other government agency. 

The District will waive sewer fees for property owners who are proactive in testing or replacing their sewer lateral by December 2022.

Useful Links for Sewer Lateral Work

List of Pre-Qualified Sewer Contractors: 
https://www.townofcortemadera.org/DocumentCenter/View/3807/Pre-Qualified-Contractor-List-For-Public

2018 Private Sewer Lateral Ordinance Information:
https://townofcortemadera.org/745/Private-Sewer-Lateral-Ordinance

Available Grant Programs for Private Sewer Laterals:
https://townofcortemadera.org/774/Grant-Programs-for-Private-Sewer-Lateral 

Frequently Asked PSL Questions:
https://townofcortemadera.org/761/Frequently-Asked-Questions


Have more questions? Contact Us. 

If you have further questions regarding this project, please contact Sanitary District No. 2 at (628)253-1158 or Project Manager Fernanda Stefanick at (415)927-5792 or fstefanick@tcmmail.org.