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It’s Not Just Water Supply: Drought Harms Water Quality, Too

July 12, 2021, 10:00 AM

A June heat wave sparked an earlier-than-expected algae bloom in the drought-ravaged drinking water reservoir in Price, Utah—a sign of climate change-related water quality challenges to come in the tinder-dry West.

Extreme heat and wildfires are engulfing the region amid a historic drought that scientists think may be the region’s worst in at least 1,200 years. In response, some drinking water systems are beginning to grapple with maintaining both water supplies and water quality as they deal with potential legal and regulatory concerns.

Climate change-driven heat and drought are exacerbating long-standing water shortages in the West, said Anne Castle, a senior fellow at the University of Colorado Law School and a former water lawyer at Holland & Hart LLP.

“The drought and dry conditions in the West are lowering water tables, making existing wells more unreliable, and reducing the dilution of contaminants in both surface and ground water,” she said.

The problem will only build upon water systems’ challenges upgrading infrastructure and securing supplies as they shrink in the West, said Tim Davis, director of Utah’s Division of Drinking Water.

“It’s the tip of the iceberg as to how many systems will really struggle,” he said.

Intense Pumping, Aquifer Stress

In a sense, Price—a city of 8,265 southeast of Salt Lake City—is lucky because water managers will be able to switch water sources before treatment costs increase and the algae bloom affects water quality severely, said Miles Nelson, the city’s public works director.

Harmful algae are common, but usually bloom later in the summer when water temperatures heat up.

But experts warn that other communities won’t be as lucky. Though uncertainty remains about how the drought will affect drinking water quality, some water lawyers fear it could create a situation similar to the 2014 lead contamination crisis in Flint, Mich. that triggered a public health state of emergency.

The next Flint is “probably not going to be lead. It could be something else no one is thinking about,” said Andre Monette, the Washington, D.C. office managing partner at Best Best & Krieger LLP

Some of the most drought-stricken regions are just beginning to assess how drought will affect their water quality.

“Droughts trigger more intense groundwater pumping and that can put stress on shallow aquifers and pull contamination down into deeper” aquifers, said Scott Seyfried, chief of the groundwater monitoring unit of the California State Water Resources Control Board.

In times of drought, agricultural users rely more on groundwater, which could affect wells or potentially shift contamination plumes. Water pumping amid the drought can also cause saltwater intrusion into some drinking water aquifers, but the effects vary from place to place, he said.

Studying Links

California contracted with the U.S. Geological Survey to study the link between drought and water quality, Seyfried said. Some systems saw increases in nitrates, arsenic, and uranium during the last drought and this study could answer whether those were related to scarcity or other issues.

The study is looking at groundwater levels and nitrates in wells over 30 years in the Central Valley of California to try to understand water quality trends during drought, research geologist Zeno Levy said.

“There is a big gap in the knowledge about what happens to groundwater in droughts,” he said.

Nitrates can cause blue baby syndrome, when infants’ blood can no longer carry sufficient oxygen. They often occur alongside fumigants, uranium, and other compounds relating to agriculture.

“We kind of use it as a general proxy to just look at how drought affects different water sources moving to the wells,” Levy said.

The report should be published within the next month.

“What we see in these drought conditions is compounding events,” said Ben Stanford, associate vice president of Hazen and Sawyer, a water treatment engineering firm.

Stanford co-authored a 2014 study showing that drought affects sediment, taste, odor, pathogens, and disinfection byproducts in drinking water. Heat leads to algae blooms in reservoirs and possible cyanotoxins in water supplies, it said. Cyanotoxins can cause a range of health problems, from skin rashes to death.

Effects From Wildfires

Heat and drought also contribute to the wildfire threat. Wildfires scorch watersheds, sending soot and other organic material downstream, possibly contributing to algae blooms and making water more difficult and costly to treat, Stanford said.

The municipal watershed for the cities of Greeley, Colo., and Fort Collins, Colo., was incinerated by two of Colorado’s largest-ever wildfires in 2020 that burned in extreme drought conditions. The scale and severity of the infernos will severely harm the cities’ raw water quality for many years, according to the Fort Collins website.

The city of Fort Collins estimates that erosion control and slope stabilization in its scorched watershed could cost more than $45 million to protect its water infrastructure. The state of Colorado this year invested $30 million in restoring watersheds burned in 2020’s wildfires, which burned in federally-managed forests.

Even small amounts of rain on wildfire burn scars can send soot and other organic material coursing into cities’ water system intakes, Stanford said.

“Utilities typically end up using more chemicals, more activated carbon to treat the water,” Stanford said. “In the short term there’s an immediate operational impact.”

Long term, he said, some utilities will begin to rethink the design of their water systems.

Regulatory, Legal Challenges Ahead

As the problem gets worse, regulatory and legal battles loom as water treatment becomes more costly and complicated.

Colorado public health officials expect drought to contribute to increased water pollution, but it’s up to local water systems to ensure they’re meeting federal drinking water standards, said Erin Garcia, spokeswoman for the Colorado Department of Public Health and Environment.

“Public drinking water systems in Colorado are subject to the same safety requirements regardless of drought. If drinking water safety is compromised, they must inform the public and take steps to correct the problem,” Garcia said.

In June, California sent notices to public water systems telling them to evaluate their water supplies, start planning for drought conditions, and encourage customers to conserve, said Darrin Polhemus, California’s Division of Drinking Water deputy director. An estimated 1,200 systems in the state rely on only one well, putting them at risk.

“We don’t want someone to just sit around hoping they can make it through and then finding themselves in a bad situation,” Polhemus said of water system staff.

EPA spokesman Tim Carroll said the agency expects water systems to meet drinking water standards and is pointing to infrastructure financing programs, such as Water Infrastructure Finance and Innovation Act loans, as ways for drinking water systems to overcome challenges posed by climate extremes.

The EPA is “prioritizing projects that protect water infrastructure against the impacts of climate change in the $6.5 billion notice of funding availability under WIFIA,” Carroll said.

But it’s unclear if Western water managers are prepared for the water scarcity to come as climate change contributes to spiraling extreme conditions.

“The story, I think, is about the gradual increase in average temperatures which has a multiplier effect on decreased water availability,” Castle said.

To contact the reporters on this story: Bobby Magill at bmagill@bloombergindustry.com; Emily C. Dooley at edooley@bloombergindustry.com

To contact the editor responsible for this story: Chuck McCutcheon at cmccutcheon@bloombergindustry.com

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