Smoke is rising from the sewer vent pipes and manholes around the village — but it’s no cause for alarm.
Smoke testing of the District I sewer system has begun this week.
Residents will be notified, neighborhood by neighborhood, but Fire Chief Heather Burford said her department is still bracing for a surge of calls and false alarms as smoke is pushed through sewer lines in village neighborhoods full of businesses, condominiums, and homes.
“There’s no doubt about it, this is going to generate some calls,” she said.
An illustration of what a smoke testing operation is doing. Here is detects a leak.
In fact, on Tuesday, the fire alarm at East Ridge Middle School was apparently triggered by the smoke testing.
She recommended that people who see smoke should go ahead and call the fire department, unless they’re sure it’s from the sewer testing.
The eventual goal is to find leaks that allow excess storm and ground water into the system, overburdening the treatment plant — before the town begins a state-required plant upgrade that is sure to be costly.
“Our plant averages less than 700,000 gallons a day, average. However, during high rain events, our average flow can be well over one million, close to two million, if not more, gallons per day,” First Selectman Rudy Marconi said.
“So, when it rains, we know that more water’s getting into the system. The questions are: Where and why? And how do we reduce that?”
The smoke testing is expected to begin this coming Monday, Sept. 9, and will proceed from 8 a.m. to 5 p.m. Monday through Friday in Ridgefield center and village neighborhoods served by the District I sewer system.
Notices will placed on the doors of properties in areas to be smoke tested approximately 24 to 72 hours before the tests are done.
The town’s consulting sewer engineers, AECOM, offered this description and advice:
“During this testing, gray or white smoke is introduced into the sewer system and will exit from vent pipes on rooftops and breaks in the sewer lines. The smoke used is not harmful to people or furnishings. It is almost odorless and leaves no residue.
“The smoke should not enter buildings unless there is a defect in the plumbing or a dry trap in a seldom-used sink or drain.
“If you have seldom-used drains, please pour water in the drain to fill the drain trap. This procedure will help prevent smoke from entering your living areas through seldom-used drains.
“Caution must be used if smoke does enter your home. Should smoke enter your home, please do not call the Fire Department, and notify a member of the crew performing the smoke testing and the crew will investigate the source…
“The Police and Fire departments will be notified of smoke-test locations. More information about the smoke-testing program can be found on the Town’s website at www.ridgefieldct.org. If you have any questions, please contact Alberto Angles of AECOM at 781-224-6505.”
Fire Chief Heather Burford was reluctant to say people shouldn’t call fire department, taking a better-safe-than-sorry attitude.
The area of town affected by sewer line smoke testing.
“Unless you’re absolutely sure it’s smoke from the testing, we would suggest still calling the Fire Department to have it investigated,” Chief Burford said.
She said the department expects the tests will bring numerous extra calls.
“It’s going to generate some ‘smoke in the area’ calls from people who are unaware of the program who may be driving through, or walking the area, or are home and missed the notice.
“The second category is, this smoke, should it seep into your home through a dry sewer trap somewhere in your home, or dry sump pump holes in your basement — if those are dry, then the smoke may come back through the pipe and get into your home. That may set off smoke detectors and monitored fire alarm systems inside your homes or businesses. Remember, this is all in the downtown area, with all the commercial buildings.
“It’s likely that we’re going to see these systems activated should smoke get into the homes, or businesses,” Chief Burford said. “So, we do anticipate additional calls.”
She said the department will have a daily list of the streets where tests are being done, and will monitor the call volume.
“We’re going to continue to respond to calls that come in, even if we know that these smoke tests are taking place in that area,” she said.
“But if the calls become excessive, we may make some modifications to the response — meaning, instead of sending two engines, we might just send one.”
She said the Fire Department, which also provides ambulance service, had another concern.
“That’s an issue with our EMS patients,” she said. “Although this smoke, should it get into a home, is listed as a non-toxic product, it may still be an irritant to people with respiratory illnesses. And, in that case, we’d encourage people to call us and we will respond and do an evaluation.”
The smoke testing is being done by Stacey DePasquale Engineering Inc. (SDE), a subcontractor to AECOM.
The engineers describe the tests as designed to located leaks that allow excess water into the system.
“The leakage, termed infiltration/inflow (I/I), can enter the system during periods of wet weather through many sources, including catch basins, damaged manholes, roof leaders, sump pumps, and basement drains,” a release from the engineers said. “I/I reduces the capacity of the system to convey sanitary flow which can contribute to sewer system overflows (SSOs). I/I also increases the overall cost of treating the flow at the wastewater treatment facility.”
Mr. Marconi said the testing — and line repairs that will follow — are needed.
“Water penetrates the lines through various means — through the top of unsealed manholes through an area that’s prone to flooding. Is it the line itself that’s cracked and allowing ground water in?’ he said. “That entire system needs to be assessed to see if that can be tightened up, and what that cost is.”
The smoke testing is a first step a process that will include other investigations, such as sending video cameras down lines, repairs to the lines such as inserting sleeves where leaks are found in pipes, and — eventually — a renovation of the wastewater treatment plant.
The renovation is expected to include state and federally required improvements to the treatment process, to reduce pollutants not now treated for, such as phosphorus and zinc.
The costs for the state-required program will be covered mostly by a combination of grants and charges to sewer system users. The costs are expected to be substantial.
“Yeah, it’ll be tens of millions,” Mr. Marconi said.
The “phase one” study — just the study — is expected to cost $600,000.
Eventually, before the design of the plant upgrade, the town will have to figure out how much capacity the system has — in part, by eliminating the leaked-in storm and ground water.
The town will then be able to compare that with the projected demand that would come with a “build-out” of undeveloped land within the sewer district.
“That will tell us how much true capacity we have, with the plant today,” Mr. Marconi said. “And, do we: (A) need to increase the capacity at all, and (B) to what extent does that capacity get increased?”
The decision-making process will involve the Water Pollution Control Authority, the Planning and Zoning Commission, and the Board of Selectmen.
“That’s where you need input from all three boards in town,’ Mr. Marconi said.
Then the town will face a decision on how much unused capacity it wants the renovated plant to have.
Most of the town is not sewered and houses that have septic systems won’t be affected by the tests.