A rumbling blower, a cloud of white smoke and a grassy patch along East Third Street became the tools of an underground investigation in Apopka on Wednesday. The city is smoke testing its sanitary sewer system to find damaged pipes, leaking manholes and improper connections that let rainwater and groundwater into lines meant to carry only wastewater.
News 6 followed crews from contractor USSI as they worked in one of the city's older sewer service areas. A crew member showed the station a digital inspection map with more than 40 green markers, each noting a location workers said had been flagged for problems. The number of unique defects needing repair has not been independently confirmed, and the map covers suspected trouble spots in the inspected area, not the whole city.
The method starts with a powerful blower that pushes specially made, non-toxic smoke into sewer lines through access points. Crews then watch where it escapes. Smoke rising from rooftop plumbing vents is normal. "When you see smoke emitting from the roofs, that's healthy," said Tim McRoberts, a senior project manager on the operation. Smoke coming out of the ground, a street or a damaged pipe opening can point to a place where stormwater gets in. "Our job is to find those defects," he said.
McRoberts said the technique can reveal broken cleanouts, leaking manholes, residential gutters tied into sewer lines and stormwater pipes connected directly to the sanitary system. He also said crews sometimes find stormwater crossovers created by a previous contractor. He named cost as the main reason the city uses the approach, calling it one of the most affordable ways to assess a wastewater collection system.
The concern is known as inflow and infiltration. Inflow is water entering directly through openings such as gutters or damaged manhole covers, while infiltration is groundwater seeping in through cracks and joints. Both raise pumping and treatment demands, add to operating costs and cut available capacity in heavy rain. In serious cases they can contribute to backups or sanitary sewer overflows. Crew members estimated that about 800,000 gallons of unwanted water a day can enter the system in rainy conditions, a figure News 6 has not verified or tied to a specific service area.
Wednesday's work focused on the area served by Lift Station 17, part of one of the city's oldest basins. Gabby Lederer, Apopka's utility program supervisor, said the city started there "because there really hasn't been too much preventative work here." She said the city plans to proceed basin by basin. "We will do it citywide," she said, describing the effort as part of a maintenance strategy covering the next five to 10 years.
Finding a defect is only the first step. McRoberts said his team aims to locate all defects in a basin and fix those it can. Other repairs may fall to city staff, plumbers or other contractors. Lederer said she expects substantial inspection data from USSI within one to two weeks and hopes to address some manhole rehabilitation before the end of the year. Repair costs and the total number of confirmed defects have not been established. "We're going to strategically plan it based off of worst case scenario," she said.
The work fits a state requirement that took effect in June 2023. The Florida Department of Environmental Protection requires domestic wastewater facility permittees to develop collection-system action plans covering pipe assessments, repairs and replacements. The plans generally must aim to evaluate at least 25% of a utility's collection system over five years, subject to exceptions.
Residents may see smoke from manholes, yards, cleanouts or rooftop vents. The city and USSI say the smoke is non-toxic and designed not to harm pets or leave stains. If smoke enters a building, it may signal a dry plumbing trap or another opening, and USSI advises ventilating the space and notifying a uniformed crew member. Residents can reduce the chance by keeping traps filled in seldom-used drains. Homeowners need not be present, and testing typically takes about 15 minutes per area.
Testing runs weekdays from 8 a.m. to 5 p.m., weather permitting, through Friday, October 30, 2026. Residents in scheduled areas should receive a door hanger. People with heart or respiratory conditions who want advance notice can call USSI at 1-888-645-9570 or 941-926-2646 between 9 a.m. and 4 p.m.
