Issaquah invests nearly $1 million in water treatment

How much is a clean glass of water worth in Issaquah? As of this week, more than a cool million.

How much is a clean glass of water worth in Issaquah? As of this week, more than a cool million.

The Issaquah City Council voted unanimously Monday night to spend nearly $1 million from two city water funds to safeguard the city’s drinking water quality. The money will fund decontamination of one well in the short term, as well as fund monitoring and sentinel wells to better understand the extend of perfluorochemical contamination in the city’s water source.

“Issaquah is a city that chooses to make investments in outstanding multiple facets of municipal government,” Councilmember Tola Marts said, pointing to departments like police and emergency management. “… Water is every bit as critical an element as those others. I want other people saying, ‘How does Issaquah handle this?'”

Cleaning a well in the short term

Monday’s million-dollar vote continued business from the March 21 meeting, which saw Bret Heath, the director of emergency management and the Public Works Operations department, push the council to spend $150,000 to start a lease on a piece of rare and highly sought-after water cleansing equipment [“Council authorizes $150k to lease water cleaning plant,” Issaquah Reporter, March 25, 2016].

The system cleans organic chemical contaminants from water supply wells by filtering it through two tanks of granulated activated carbon.

The council authorized the system’s lease March 21 in order to scrub perfluoroctane sulfate — commonly abbreviated as PFOS — from city Well 4.

Well 4, housed with Well 5 in a pumphouse off Gilman Boulevard, is the smallest of Issaquah’s four operating water wells — to date, the city has drilled six such wells but has ceased use of Well 3 and never used Well 6.

Because it is known to have toxic affects and because it never degrades from the environment, the EPA banned PFOS from use in new manufacturing in most industries in the year 2000. But its presence in water is not regulated the federal or state government. However, it is recognized as having harmful effects to humans and other animals at high enough concentrations. In 2013 and 2014, the city participated in a voluntary Environmental Protection Agency program to monitor unregulated perfluorochemicals in its water.

Through that testing, Well 4 was found to contain PFOS at a level of 0.6 parts-per-billion — a concentration three times the advisory level recommended by the EPA.

The PFOS concentration went down to less than half the EPA’s advisory level when blended with water from the city’s other wells. However, Well 4’s PFOS levels raised residents’ eyebrows after the city was called out in an article in a January issue of The New York Times Magazine.

Well 4 was temporarily shut down in early March pending the results of a chemical composition analysis of its water. Presently, neither Well 4 nor Well 5 are being operated pending installation of the water cleaning plant.

By scrubbing Well 4’s water of PFOS, Public Works will also be able to get ahead of stricter EPA advisory levels for the chemical compound. EPA officials informally notified public works that agency decision-makers were thinking about lowering the advisory level at an unspecified point in the future, Heath said.

“[We] have not heard a hard number,” he said.

The cleaning plant will cost $658,000 to lease, install and operate in 2016. Subsequently, it is expected to cost $336,000 per year to operate through 2019, and $376,000 in 2020.

Filling in the picture

A recent concern of Issaquah officials has been whether the source of PFOS in Well 4 could contaminate Well 5.

Councilmembers have also wondered aloud in meetings whether there is credence to some residents’ theory that Well 4’s PFOS contamination came from a firefighting foam used to combat a gas tanker blaze on Issaquah’s portion of Interstate 90 in July 2002. Chemical company 3M stopped production of its firefighting foams that year because it was known to degrade into PFOS.

Bob Anderson, a hydrogeologist hired by the city to help examine the PFOS matter, said he believed the site of the tanker fire was “downstream” of Well 4 and likely not a source of contamination to its ground water. But there isn’t enough information available to determine whether that’s definitely the case, or if PFOS poses a threat beyond the Gilman pumphouse, Anderson said.

“What I’m faced with is, I can’t tell you where this stuff came from,” he said. “I can’t tell you how much is in there, I can’t tell you if it’s a skinny plume or a wide plume, I can’t tell you wif I think PFOS concentrations are going to go up, stay the same, go down. I’ve got one data point [the PFOS level of Well 4].”

But consultants and staff could develop answers to those questions with an expanded hydrogeologic monitoring network.

Basically, that network will consist of one deeply excavated “sentinel well” at the Gilman pumphouse to warn staff of contamination threats to Well 5, as well as five new shallowly excavated monitoring wells to track potential pathways of perfluorochemicals.

“So really, the whole focus of what we’re proposing here is so that I can answer those questions for you,” Anderson said.

Long-term solutions

With the cleaning plant and a monitoring network in place, the City Council will need to examine long-term solutions for maintaining the purity of its water supply.

Some of that work will have to remain further in the future.

The council unanimously removed $100,000 for long-term planning from the original $1,088,000 requested under the bill presented Monday, following an amendment by Deputy Council President Mary Lou Pauly, who called the expenditure inappropriate in an otherwise short-term package. Council President Stacy Goodman agreed.

“We’ve discovered over the past couple months — and past couple weeks — that the information is ever-changing,” Goodman said. “So I think we can slow down a bit.”

But the council examined four potential long-term solutions Monday night, presented by consultant Jeff Hansen.

The first solution would be to permanently shut down the wells in the Gilman pumphouse. That solution would require the city to obtain water by other means, such as purchasing it from Cascade Water Alliance.

The second solution would see the installation of permanent treatment at Well 4. That solution would continue the city’s standing plan to use the treatment plant.

The third solution would see the water rights of the Gilman wells transferred to the unused Well 6 site for full development.

None of those three options would fully account for the potential of PFOS migration or other “unforeseen water quality considerations,” Hansen said.

For that reason, Hansen recommended a fourth solution that would see the development of a centralized treatment plant between Issaquah’s wells and the tap.