Last June, the Longview City Council voted to switch the municipal water supply from the Cowlitz River to a deep aquifer that would be tapped through a series of wells drilled at the Mint Farm Industrial Park.

The decision sparked outrage and disbelief among some community members, who were shocked that city leaders would choose to draw water from beneath an industrial area contaminated with hazardous waste sites.

The yet-to-be-built $34 million water treatment plant at the Mint Farm should begin operating in December 2011. It will replace the Fisher’s Lane Regional Water Treatment Plant, which is quickly deteriorating because the Cowlitz River contains high levels of abrasive volcanic silt. Upgrading the 60-year-old plant would cost an estimated $46 million.

Despite science-backed assurances by hydrogeologists, consultants and city officials that the aquifer is fairly safe from contamination, misperceptions about the project persist, if the comments Daily News readers post on stories about the Mint Farm wells project are any indicator.

Last week, The Daily News sat down with Longview Public Works Director Jeff Cameron for some clarity.

Q: Why do you suppose some people can’t be convinced that treated aquifer water from below the Mint Farm would be safe to drink?

A: “A lot of them don’t trust the government, and I just don’t think there’s anything we can say or do to alleviate their concerns,” Cameron said.

“Our responsibility is to reach out to as many people as we can and provide them with the facts and information, and they’re going to draw their own conclusions. … It is frustrating when people continually bring up information that’s anecdotal and not supported by facts, and we address it and then it gets brought up again.

“But we don’t ever think we’ll get 100 percent support. That doesn’t happen on any project that we do.”

Q: Where does water in the aquifer come from?

A: The aquifer is fed by waters rolling off surrounding hills and sources up the Columbia River canyon. Hydrogeologists believe the predominant volume’s coming from the Columbia River’s underground channel, which was scoured out in the Glacial Age (more than 10,000 years ago) and eventually filled in with rock and gravel. The aquifer’s water trickles through the spaces between the rocks.

Q: Is there any chance the aquifer could run dry?

A: Not at the 20-million-gallons-per-day maximum pumping capacity Longview would require. The average city use is 6 million gallons a day, though that can spike to 17 million on a hot summer day.

One hydrologist working for the city explained the aquifer is fed horizontally by rivers sourced in Canada, and that it would never run dry unless there were another Ice Age.

Q: Why has the city chosen to drill wells at the Mint Farm Industrial Park rather than somewhere else in the city that has less of a stigma than an industrial area?

A: The Mint Farm is the only area engineers have found where the aquifer has both high water quality and high production, Cameron said.

As you move east and west, the aquifer’s productivity and quality decreases. Concentrations of iron and manganese go up dramatically, requiring more treatment.

Q: Can toxic wastes from industrial sites above the aquifer seep into the water supply?

A: There are three hazardous waste cleanup sites near the proposed well: the former Reynolds Metals Co. plant (now Chinook Ventures), the Weyerhaeuser Co. mill and the Flexible Foam plant (formerly Prudential Steel). Chinook Ventures and Weyerhaeuser are cleaning up the hazardous waste under supervision of the state Department of Ecology. The contamination at Flexible Foam is considered minor and state officials are not ordering any clean up.

Water testing results indicate the hazardous waste has not penetrated the deep aquifer, Cameron said.

The aquifer is in a layer of gravel lying 150 to 200 feet below the city’s surface and reaches down to bedrock about 400 feet down. The risk of contamination is low because it’s isolated and protected from surface water contamination by relatively impermeable layer of sand and clay-laden silt that lies over it, according to consultants’ reports. Some solvents could penetrate the layer — if they are not cleaned up.

Years ago, Reynolds Metals bored eight wells that tap into the aquifer, three of which are still working. Chinook Ventures still uses the wells for its operations, and the water is tested weekly to ensure it meets state drinking water standards. Although the Chinook site is contaminated with FLUORIDE and cyanide from Reynolds’ aluminum production days, “that stuff has not shown up in their drinking water samples in spite of all the pumping they’ve done,” Cameron said. “So that to me reinforces the impermeable layer separating the shallow water from the deeper water.”

Also, water in the aquifer is under pressure and wants to escape — like air in a balloon — instead of seeping in. In fact, when the city drilled test wells at the Mint Farm, the water gushed out on its own without pumping. That indicates surface water isn’t leaking into the aquifer, he said.

Q: If the water from Chinook Ventures’ wells is safe for drinking, why does it look and smell bad?

A: It’s not treated to remove iron and manganese, as the city will at its wells. Those metals affect the water’s color and smell but don’t pose a health risk, according to the state.

Q: Why can’t the city just use the wells already drilled at Chinook Ventures?

A: Only three of the eight wells are working, and the water isn’t treated to the same level as the city’s drinking water, Cameron said.

The city’s biggest concern is over ownership and control of the wells and water system, he said.

Chinook’s wells are connected to internal piping systems that run through and around Chinook’s industrial manufacturing facilities. How would the city separate its raw water from the water Chinook’s processes use? What if there were a backflow of contaminated industrial water into the municipal system? he asks.

The city decided it would be simpler to drill its own wells, Cameron said.

Q: One reader posed this question: If the water at the Mint Farm is safe to drink, why are there dead crawdads, bullfrogs and turtles in the nearby drainage ditches?

A: Cameron said that’s the first he’s heard of dead wildlife in the drainage ditches. However, if it’s true, it could be because the water in the ditches doesn’t meet state water quality standards. The ditches can contain fecal coliform, a waste product from mammals, or have high turbidity or a low level of dissolved oxygen. All of those factors could kill fish and crawdads, he said.

Q: What contaminants are in the untreated aquifer water?

A: The water would need to be treated to reduce levels of manganese, arsenic and iron, but that may not even be necessary once the city started drawing large amounts of water, creating a flushing effect, Cameron said.

Also, raw water from the aquifer is clear when it comes from the ground, so a well system would need no settling basins like those at the Fisher’s Lane plant, said Amy Blain, the city’s manager on the Mint Farm water project. The system wouldn’t be subject to the volcanic grit that plagues the Cowlitz River plant.

Q: What safeguards will be in place to ensure water pumped by the production wells isn’t contaminated?

A: The city would establish eight monitoring wells around the production wells to detect whether any contamination gets into the groundwater supply before it’s pumped for municipal use.

Each “sentry” well site will have a 2-inch well of up to 100 feet deep, and a 6-inch well of up to 400 feet deep.

Water moves so slowly through the aquifer, which is full of gravel, sand and rock, that it would take an estimated three to five years for contaminants detected by the sentry wells to reach the city’s production wells, Cameron said. That would give the city time to design and construct a treatment technology at the new water plant to eliminate that contamination.

“The technology exists to treat just about any kind of contamination,” Cameron said.

Q: How does Mint Farm water taste?

A: Results from a blind taste test at a City Council workshop last year were inconclusive. Well water didn’t score any differently than water from the river.

Q: Which would you rather drink, untreated Cowlitz River water or untreated well water from the Mint Farm?

A: “I would prefer the ground water,” Cameron said. “There’s more likelihood in terms of getting sick in drinking raw Cowlitz water.”

When water moves through the ground, it’s naturally filtered, and most contaminants are removed, he explains. Untreated river water, however, contains microorganisms, such as Giardia and Cryptosporidium, that cause gastro-intestinal illnesses.

River water is exposed to more contaminants than water in the aquifer below the Mint Farm, Cameron said.

Runoff from Interstate 5 and farm pastures washes oil, gasoline, fertilizer and animal waste into the Toutle and Cowlitz rivers. Also, roughly 60 trains run next to the river each day, and many carry hazardous chemicals which could spill into the water if a train derailed.

Upstream of Longview, there are nine sewage treatment plants with outfalls into the Cowlitz River, according to Kim Adamson, general manager of the Beacon Hill Sewer District. The treated sewage isn’t hazardous because it’s disinfected first to remove bacteria. Even if there were a sewage plant failure and raw sewage were discharged into the river, most plants are far enough upstream that the sewage is fairly diluted by the time it reaches Longview’s Fishers Lane water treatment plant, Cameron said.

But in recent years, water testing has revealed high levels of pharmaceutical medications and antibiotics in the state’s surface waters that scientists haven’t figured out how to eliminate.

Q: If the rising riverbed is threatening to block the Fisher’s Lane water plant’s intake, why doesn’t the city just run its intake pipe into a deeper part of the river?

A: “That was our obvious first choice,” Cameron said. “But the challenge we have is that the conditions in the river area changing daily. … We cannot count on having a particular channel or swimming hole, deep pool, to pull water from.”

The city considered upgrading the intake structure to screen out sediment better so it wouldn’t tear up the plant’s filtering equipment. But the screens used today already tend to clog, and a finer screen would make the problem worse. Also, techniques used to keep the screens clear of debris release suspended solids in the water, which harms fish. In addition, the state Department of Fish and Wildlife prohibits unnatural sources of turbidity (cloudy water).

To keep sediment from building up against the water plant’s intake structure would require regular dredging of the river bed, and getting environmental clearance for dredging is difficult, Cameron said.

Q: Does the city care about the public’s concerns and fears about drinking well water drawn from below an industrial site?

A: Yes, because the city wants to make sure it’s not overlooking anything, Cameron said. That’s partly why the city did so many quality assurance reviews of its engineers’ first studies, he said.

“But we do need to follow the science,” Cameron continued, “and if the science says we need to go to the Mint Farm to avoid uncertainty in quality and the uncertainty in cost by staying in the river, then we just need to weigh where the science is telling us to go, versus the perception of risk at the Mint Farm. It certainly is not risk-free, but all of our hydrogeologists have said it’s a risk that can be managed, and it’s less of a risk to the overall municipal water supply than staying in the Cowlitz River.”

Q: Is the decision to switch the city’s water supply to the Mint Farm wells irreversible?

A: No, Cameron said. The city is hiring a design firm that will re-evaluate all the information about the project gathered so far. The firm will examine all treatment technology to see if anything’s missing. The project also must go through state and federal environmental reviews.

“I don’t think we’ll get anything that says, ‘Go back and plan to stay in the Cowlitz River,’ but we haven’t yet ruled it out entirely,” Cameron said.

The design process will go over the project’s risks and evaluate at least three alternatives. This will be a public process in which people will have another chance to voice their concerns.