Meanwhile, about 173,000 properties still have unknown water service pipe materials, said Paul Sayan, acting bureau chief of water and wastewater for the Baltimore City Department of Public Works.
Under a mandate from the federal Environmental Protection Agency, the city has 10 years to identify and replace any lead pipes that deliver water to customers, with its first benchmark in October. To get to the finish line, the city now has enlisted the help of a new technology called Swordfish.
In June, Baltimore's spending board approved a $7.6 million contract with a California-based company called Electro Scan, which will dispatch its crews around the city to check for lead pipes — using its unique technology that can test for lead without the need to excavate the pipe.
It functions like a plumbing snake used to unclog drains, Electro Scan CEO Chuck Hansen said. From the water meter outside of someone's home, a technician can feed in a probe that uses low voltage electricity to determine a pipe's material.
"Every material has its own electrical resistivity. So every pipe material has a different resistance. We measure the pipe resistance," Hansen said.
Afterwards, crews swab the probe to test it for lead to confirm their result, Hansen said.
It's an attractive option for cities, saving them the significant cost of tearing up pavement and soil to reach pipes and visually inspect them.
"It's just a great way for us to identify the pipe material with really no disruption to private property," Sayan said.
Initially, Electro Scan used the technology to test for leaks in pipes, Hansen said. But soon the company discovered it could be used to determine a pipe's material.
"It was about 2015. We were evaluating a pipe in the southwest United States," Hansen said. "And we just saw these strange readings when we hit the joints. And it wasn't a leak — but it wasn't good."
The team exhumed the pipe, and opened it up, Hansen said. It was lead.
Then came the directive from President Joe Biden's administration: For the first time, utilities would be responsible for reporting whether any of their drinking water pipes contained harmful lead, as well as the service lines connecting individual homes and businesses to larger water mains — traditionally considered a property owner's responsibility.
It was a sea change for the industry, Hansen said, but his company began working to modify its technology so it could be used to meet the EPA's requirements.
"When we saw this coming up, what we had to do was make our probes go into smaller diameter pipes," Hansen said. "Our technology is applied up to 96 inch, 100 inch-diameter pipes. So what we had to do was make our probe small enough that they could go into a half inch pipe — half inch to about three inches in diameter."
In the city, the Swordfish will be used for two purposes, Sayan said. At the 32 properties where residents have identified lead in their line, the Swordfish will be used to confirm or deny the presence of lead, Sayan said.
On top of that, the city — with the help of a contractor using computer modeling — is developing a list of a few thousand properties to be tested by the Swordfish that would provide predictive results about other similar lines, Sayan said.
"Properties with unknown pipe material are grouped into categories based off of geography, age, what is the pipe material around their neighbors — things like that," Sayan said. "And then you have these groupings throughout the city and you're able to take sample size inspections at each one of those groups, instead of doing inspections at all of the properties."
Properties that are identified for the testing will receive a door hanger notice 30 days prior to technicians' arrival, and then again two days prior, Sayan said. If someone were to complete the self survey prior to the testing day, they would be removed from the list, Sayan said. If city officials determine the property is abandoned, they would select another representative property, he added.
During the Board of Estimates hearing for the contract, Comptroller Bill Henry wondered if it might present a cost savings for the city to incentivize homeowners with discounts on their water bills to complete the survey themselves, saving the city the cost of sending a crew to their home with the Swordfish.
"What's the expression? You catch more flies with honey than with vinegar?" Henry said. "You also catch more flies with honey than with just asking them to do it because it's the right thing.'"
In response, DPW Deputy Director Richard Luna said the Swordfish would be necessary even with an incentive program in place encouraging water customers to test their own pipes.
"We're still going to need this type of technology," Luna said. "You're still going to see those gaps within the public inventory."
The test isn't easy for residents of all abilities to complete. It requires gently scratching the pipe with a key or a coin, observing the color left behind, and listening to the pipe's sound when lightly tapped.
In October, the city will be required to produce its first inventory for the EPA, but that inventory can include any quantity of "unknown" pipes. Technically, the city has 10 years to both find and replace any lead service lines in its territory, but city officials want to move quickly, Sayan told The Sun.
"Theoretically, if you had no lead you can go 10 more years before submitting your inventory. That's certainly not our plan at all," Sayan said. "We are pushing hard to get the inventory done as quickly as possible and then replace whatever pipe we need to as quickly as possible. We don't want to be taking another decade for this."
In an email sent to the Maryland Rural Water Association, provided by Hansen, a Maryland Department of the Environment official confirmed that the agency will accept survey results from the Swordfish units, given that it correctly identified pipe materials during a demonstration in late July. But the official, Christina Ardito-Sterner, a regulatory compliance engineer with the agency's water supply program, cautioned that there are potential side effects.
When inserted into a pipe, the technology could scrape the pipe's interior coating. And if it contains lead, the contact could cause more lead to be released into the water traveling through the pipe. The technology also could cause leaks for galvanized steel or iron pipes, Arditor-Sterner wrote.
"Water systems should have a plan in place to mitigate and address any disturbances that may arise from using the technology during field investigations," Ardito-Sterner wrote. "It is important for water systems to communicate with customers during the investigation process and maintain appropriate water quality throughout the process which may include flushing."
As a result of MDE's directive, Electro Scan will flush out a homeowner's water line after it completes each test on pipes in Baltimore, Hansen said. Homeowners undergoing testing likely will be without water for about 30 minutes, Hansen said.
The company is also careful to avoid continuing to push the probe if an obstruction blocks the way, Hansen said, with the goal of avoiding causing any damage. The probe can go 80 feet into a pipe, Hansen said, and at minimum, the probe will check 10 feet of pipe before its work is considered complete.
"That has been our caveat to the city: We will go the greatest distance that we can, unless we encounter any sort of obstruction. And if we can get it past 10 feet, then we'll call it done," Hansen said.
© 2024 the Catonsville Times (Ellicott City, Md.). Distributed by Tribune Content Agency, LLC.
