LISBON — The Lisbon Water Department, considered a large system by state standards, recently released its Lead Service Line Inventory that identified 630 service lines of concern due to lead exposure, most of them privately owned.

Of the 3,418 service lines identified, 2,788 do not contain lead and are not galvanized, according to the inventory report. Using assessing records, inspections  and other methods, department staff identified 630 lines of concern. Of those, 11 were lead and 157 were galvanized steel with a protective zinc coating to guard against corrosion and rust.

Galvanized lines can trap metal and material fragments in cervices, possibly pieces of lead and other minerals, from existing or previous lead lines directly upstream from it.

For 462 service lines, it is unknown what the their material is, according to the inventory.

Staff will continue to inspect lines until the materials of all of them can be accounted for, interim General Manager Shellie Reynolds said.

Most department service lines were non-lead copper, non-lead plastic or other materials that are not lead, according to the inventory. The department has replaced sections of its lines for several decades, most of them lead, Reynolds said. However some customers have not replaced lead lines at their properties.

Staff at the roughly 115-year-old water service identified one town line off Addison Street that is lead and four town lines off Farwell, Bauer, Addison and Davis streets that are galvanized.

Lead pipes may have been used from 1903-1925, according to the inventory. It is unknown if there are any lead goosenecks, pigtails or connectors in the system.

The service stopped installing lead pipes about 100 years ago but owners were still allowed to use whatever piping materials they wanted for their homes, Reynolds said. Property owners do not always contact the department when updating plumbing.

Almost four years ago the U.S. Environmental Protection Agency revised the Lead and Copper Rule, requiring essentially all public water services to create an inventory of all their lines and those privately owned. The purpose was to identify the materials in each system, specifically for lead lines.

Those inventories were due more than a month ago and now water services are required to make them viewable by the public. Those systems are now tasked with developing a plan to replace a certain rate of those pipes on a yearly basis. The new rule also required services to use better lead testing methods.

The Lisbon Water Department is still addressing concerns stemming from a malfunction at the water plant that led to an Aug. 29 Do Not Drink Order. An engineering report recently issued to the town identified a mechanical malfunction that resulted in sludge being released into the system.

Though the department has fixed the issue temporarily, it is still working to replace the malfunctioned equipment and improve operations at its plant.

A month after the order was lifted, more than 24 hours after it was issued, many residents did not feel completely safe consuming the water, some taking to Facebook to express their concern.

Reynolds expects there to be more information available for utilities and property owners alike about how to fund replacing pipes that are lead or of concern, she said.

“In the coming months, over the next three years more information will become available for owners and utilities about funding and the processes for that,” she said.