BY LISA STAYTON
MOUNTAIN CITIZEN

INEZ — For weeks in July 2025, brown water ran from taps across Martin County, leaving residents upset, frightened and distrustful of a system meant to sustain life. Faucets ran rust-colored. Laundry was ruined. Families questioned whether their water was safe even to bathe in.

What they did not have then—what they have now—is a science-based explanation that the issue is the chemistry of the water that comes from the Tug Fork River.

At a Jan. 27 meeting of the Martin County Water District board, engineers with Prime AE delivered the findings of a professional investigation into the brown water event. Their conclusion: the discoloration did not originate at the water treatment plant. Instead, it was the result of corrosive, low-alkalinity water interacting with decades-old infrastructure throughout the county’s distribution system.

“This is not brown water leaving the plant,” said engineer Jonathan McCracken, who explained that the water becomes discolored only after traveling miles through water pipes. “It’s what happens between the plant and the tap.”

Corrosive, not acidic

One of the most striking findings, and one that initially defied public intuition, is that the water’s pH is neutral. The corrosion responsible for the brown water is not acid-driven.

“The ‘corrosive’ we’re talking about here is not pH-driven,” said Timothy Thoma, chair of the water board. “It is mineral-driven, which is alkalinity.”

Alkalinity, engineers explained, is the water’s buffering capacity—its ability to maintain chemical stability and protect pipes by keeping minerals like calcium carbonate in balance. In Martin County that balance is badly off.

During the summer months, alkalinity levels measured just 20 to 30 milligrams per liter, according to engineer Michael Galavotti. The ideal range for system stability is 80 to 120 milligrams per liter.

“When that water gets out into the distribution system, it’s a corrosive type of water,” Galavotti said. “It releases your manganese and your iron. That’s what the brown water is all about.”

Inside the pipes

Over time, iron and manganese accumulate on the interior walls of water pipes as scales and biofilm. Under stable chemical conditions, those materials remain adhered to the pipe. But low-alkalinity water is chemically undersaturated and cannot maintain calcium carbonate stability. As it moves through the system, it dissolves minerals wherever it can find them—including from pipe walls themselves.

“With the alkalinity being what it is, the insides of the pipe wall have biofilm, basically scales that include iron and manganese,” McCracken explained. “When water that is corrosive goes through your distribution system … that corrosion is going to leach out into the water.”

Because pipe age, material and condition vary across the county, residents experience different degrees of discoloration.

“Not every single person is going to experience the same water at their tap,” McCracken said. “The older the pipe is, the more scaling and sediment that a newer pipe may not have.”

Langelier Saturation Index and a system out of balance

Thoma pointed to the Langelier Saturation Index (LSI) as the key diagnostic tool. The index evaluates whether water will form a protective scale or dissolve it, based on six factors: pH, temperature, calcium hardness, total alkalinity, total dissolved solids and cyanuric acid.

Balanced water typically falls between –0.3 and +0.3. According to Thoma, Martin County’s water has been in the –1.5 to –2.0 range, a zone considered strongly corrosive.

“pH has very little influence on the LSI,” Thoma said. “Temperature has a little bit more influence than pH. Alkalinity has a huge influence; it’s highly weighted … To attack an LSI problem, you go after what gives you the biggest impact.”

Calcium, Thoma added, is also low—another factor preventing the formation of a protective mineral layer inside pipes.

Source water complications

“The issue has more to do with the quality of the water coming from the Tug Fork River, but the water that’s in the reservoir also has characteristics that are low in alkalinity and causing the problem,” Galvotti told board members. “It’s multifaceted.”

The river carries water that is low in alkalinity. It flows through a watershed dominated by sandstone, shale and coal-bearing rock, rather than limestone. High rainfall and steep terrain move water quickly across the landscape, limiting contact with rock that could add buffering minerals, while organic acids from forested headwaters further consume the little alkalinity that remains.

Martin County pumps water from the Tug and pipes it to the Curtis Crum Reservoir on Turkey Creek Road, which introduces additional complications: thermal stratification, longer residence time and, in recent summers, higher water temperatures due to low reservoir levels.

Treatment options

Prime AE evaluated two potential treatment strategies, both designed to raise alkalinity and stabilize the water before it enters the distribution system.

One option would be to add sodium carbonate (soda ash), requiring an estimated $700,000 in capital investment and an additional $176,000 in operating costs per year.

The second option would use calcium carbonate. That approach carries a much higher upfront cost—approximately $4 million—but a lower annual operating increase of about $60,000.

“These two options are a little bit different,” Galavotti said.

Both would treat the water as it leaves the plant, not before it enters.

System aging under corrosive water

As the discussion unfolded, Thoma revealed that the corrosive water is damaging the treatment plant itself. Recent reports, he said, showed concrete degradation and steel corrosion in the plant’s filters.

Galavotti confirmed the concern.

“You’re running this corrosive water through your treatment system; you’re corroding that concrete and that steel,” said Galavotti.

Treating water upstream of the plant would be ideal, but much more expensive, the engineer noted.

That reality led Thoma to question whether investing millions into a 54-year-old treatment plant is the right long-term path.

“That’s where my head’s at,” said Thoma. “When the water master plan gets done, you’re going to hear a lot about how bad a shape the water treatment plant is in. It’s going to come to light.”

Board members pressed engineers with questions about temperature, reservoir dynamics and whether adjusting alkalinity is possible without drastically changing pH. Galavotti offered a metaphor that resonated.

“pH is like the temperature in the room,” he said. “Alkalinity is the insulation. It’s the buffer that keeps that temperature stable.”

Following the discussion, board members voted in favor of the calcium carbonate option.