ALLENTOWN, Pa. — Chemicals delivered to the Lehigh County Authority water plant in Allentown reacted Friday morning, sending five workers to the hospital to be checked and keeping people within a half-mile of the plant indoors until the evening.
Tap water was never affected, and people in Allentown and surrounding areas that rely on the plant can use their water as normal, Liesel Gross, LCA’s chief executive officer, said at an afternoon briefing the city streamed on Facebook.
“Water quality is exactly as it should be, and water quantity as well,” Gross said.
Operators caught the reaction almost at once and cut that part of the plant off from the treatment system, so nothing that shouldn’t be in the water got into it, she said.
Why a water plant uses chemicals
Much of Allentown’s drinking water comes from the Little Lehigh Creek, and creek water needs cleaning before it reaches taps, LCA explains on its website. Workers add a coagulant that makes dirt particles clump together and settle out, then chlorine, the same kind used in pools, to kill bacteria and viruses.
The chemicals were sodium hypochlorite, a liquid chlorine bleach, and polyaluminum chloride, a coagulant, The Morning Call reported. When the two mix, they can react and give off chlorine gas, the gas officials measured Friday.
What happened
At about 10:15 a.m., the plant on Martin Luther King Jr. Drive was taking a routine delivery of treatment chemicals when they “mixed together in a way that they were not supposed to and created a potential chemical reaction,” Gross said. The building was evacuated.
The five employees were nearby and were decontaminated before they were taken for evaluation, officials said. None had symptoms or complaints at last report, they said.
The city ordered everyone within a half-mile to shelter in place, an area reaching roughly from Linden Street to Lehigh Parkway and South St. Cloud Street to South Lumber Street, according to its boundary map. The city lifted the order Friday evening. By about 8:50 p.m., the Allentown Fire Department was wrapping up at the scene, roads around the plant were reopening and Rapid Response, a hazardous materials cleanup company, was taking command of the cleanup, officials said.
Chlorine readings
Earlier in the day, readings showed chlorine “slightly higher than acceptable for an eight-hour period” under federal workplace limits, Mayor Matt Tuerk said. Later fire department readings at four spots near the plant showed zero or close to zero parts per million, he said.
By the end of the briefing, officials said, readings outside the building were at zero and levels inside were still elevated. The order stayed in place while crews ventilated the building.
Tuerk said the situation posed no significant threat to health or life.
Cause and what’s next
The cause is under investigation, Gross said. Unloading is a shared job between the delivery driver and plant staff under a standard procedure, and LCA will look at whether that procedure broke down, she said.
“So it does not appear to have been a deliberate act, but we need to really work through all of the processes that occurred,” she said.
The plant is running on water from one of LCA’s springs, and the system holds a couple of days of water in storage, Gross said. That gives crews time to get back into the building and work out what happened; until then, LCA could not say whether a conservation notice might follow, she said.
LCA’s Allentown customer care office at the plant was closed after the incident; customers can call 610-437-7515 or email cityservice@lcawaterworks.org, according to an alert on LCA’s website.
