Updated Wednesday, May 18, 2016
To help inform how to best test and mitigate for the potential lead goosenecks in its system, Tacoma Water collected samples from 12 customers’ homes where we suspected lead goosenecks may be present.
The in-home sample results showed very safe lead levels, ranging from non-detectable levels to just over 4 parts per billion (ppb) – well below the regulatory action level for water of 15 ppb. (92% were less than 1 ppb)
For each home, three rounds of samples were collected from inside the home and one sample outside the home at the meter location near the street. Six of the 12 homes were discovered to actually have goosenecks when the service was dug up.
- Understand if lead is present at levels above the EPA action level
- Identify sources of any detected lead, if possible
- Verify recommended flushing procedures
- Help identify if a lead gooseneck is present
- Inform a broader plan for the remaining locations with potential lead goosenecks
Although Tacoma Water’s system fully complies with federal Lead and Copper Rule regulations, concerns about components installed in the early 1900s prompted special monitoring and testing beyond the regulation.
While Tacoma Water did not use service lines constructed entirely of lead, in the early 1900s they did use some lead materials in the water system. These were standard practices under prior regulations. (View a diagram
Over time, Tacoma Water has removed 30,000 lead goosenecks while replacing old service connections. However, there are still hundreds of old service connections from the early 1900s for which we do not have information.
We currently estimate that up to 1,200 service connections may still have lead goosenecks.
To help identify lead goosenecks in our system, we collected multiple water samples from the old service connection pipes at four customers’ homes. We collected the samples after disconnecting the pipes from the homes. As part of this testing, we intentionally created a worst-case scenario to improve our chance of detecting lead from a gooseneck if it was present.
We found elevated levels of lead in the water samples taken directly from the service lines leading to four homes. Some of the test results greatly exceeded the EPA’s accepted limit of lead in drinking water, which is 15 parts per billion for at least 90 percent of homes tested.
The samples and subsequent testing were not required by regulation. Rather, they were designed to create conditions where lead would be present in the water; the goal of that was to help identify and replace old lead parts.