Portland officials have been tight-lipped about what immediate steps they'll take to reduce lead in drinking water. But some clues have emerged, courtesy of the U.S. Environmental Protection Agency.

Portland has the highest reported lead levels among the nation's largest water providers, and city officials must produce a plan by Dec. 2 with interim steps for reducing those concentrations. Portland's lead levels surpassed federal benchmarks in recent testing, and state regulators are now demanding action after coming under increased scrutiny from the EPA.

The Portland Water Bureau declined to offer any hints about its plan this week. State regulators deferred to the city about what's achievable. But the EPA has been speaking up, at least privately.

Among other things, federal regulators told Portland it should use its existing facilities to increase water pH levels from 8 to 8.2, according to public records obtained by The Oregonian/OregonLive. Increasing pH could help create a stronger protective buffer for in-home plumbing prone to releasing lead - and it's a process that could have been done years ago, had the city built a $3 million treatment plant that also would have increased alkalinity.

The EPA declined to answer questions about its guidance to Portland and the Oregon Health Authority. The agency has previously indicated it could intervene if the state's oversight of Portland is unsatisfactory.

"As we consider our regulatory options, EPA will review with particular interest" Portland's Dec. 2 plan "which we expect will reflect consideration of a full range of measures suitable" for the city's water system, spokeswoman Suzanne Skadowski said in a statement.

Federal regulators also have suggested flushing water inside the distribution and storage system, with an emphasis on problem areas. And the EPA proposed a temporary chemical feed at storage tanks and pump stations to stabilize pH and alkalinity, records show.

Those items are included in an email titled "EPA's recommendations" sent to state regulators. They're described as "minimum elements" that should be included in Portland's plan.

The Oregonian/OregonLive obtained the list through a public records request. State officials originally said they had no correspondence with the EPA but later turned over the document, dated Oct. 23.

That list also includes a "root cause analysis of high lead levels in schools" - something that has yet to happen nearly six months after lead problems at Portland's largest school district became public.

But the EPA didn't list that task in its correspondence with the city.

It's not clear what will happen if Portland's plan doesn't include items on the EPA list. Skadowski didn't answer questions about requirements or potential consequences.

Although state regulators demanded action from Portland on Nov. 4, they did not provide a specific list of actions. Instead, officials simply called for "immediate steps to reduce levels of lead in drinking water."

Kari Salis, a water manager for the state, said the EPA's list was provided on an "informal basis." State regulators don't want to be prescriptive with Portland.

"We chose to put the ball into Portland's court, in terms of telling us," she said. "Portland knows their system the best."

Salis declined to say when regulators expect to approve the city's plan.

In the long run, Portland is expected to build a new treatment facility to minimize lead levels. Officials have known for decades that lead levels could be minimized by increasing pH to 9 to 9.5 and raising alkalinity to at least 20. Other options may also be considered, such as adjusting calcium levels or adding phosphate or silicate-based corrosion inhibitors.

Portland avoided such aggressive treatment in 1997 by proposing minimal treatment and an alternative program focused on lead paint. But that one-of-a-kind deal has now pushed Portland into the crosshairs, with stubbornly high lead levels compared with other large jurisdictions.

State regulators now want a new treatment plant online by 2022. Construction could cost $15 million.

Salis declined to set any benchmarks about appropriate lead levels in the interim. Testing of Portland's high-risk homes typically finds lead at just below the federal guideline, of 15 parts per billion, although the latest round hit 17 parts per billion.

Salis reiterated that Portland is expected to lower lead levels - even if it's not clear by how much.

"We've told them they need to have a plan to do something, so there is something they can do," she said. "We'll see what Portland comes up with."

This post has been updated to clarify that Portland could have raised pH levels by building a treatment plan that also would have increased alkalinity. Increasing pH beyond 8, without increasing alkalinity, was not recommended.

-- Brad Schmidt

503-294-7628

@cityhallwatch