You Asked, We Answered: Can you examine the water quality of drinking water from Jordan Lake?


Feeling Curious?

This week, Our Chatham dives into a topic with big impact: Jordan Lake. We look at Jordan Lake’s water quality and the factors that impact the water.

We answer the important questions hanging in your mind:

  • How do people measure water quality?
  • How safe is Jordan Lake?
  • What do experts have to say about it?

Plus, found out if Jordan Lake is actually a lake (Hint: It’s not!) Join Our Chatham’s Chloe Arrojado and learn something new about the water around you.

Jordan Lake Water Quality

Out of the hundreds of thousands of people who use Jordan Lake, few people probably question it. But Michael Hobbs is one of those few. For this week’s Curious Chatham, he asked, “Can you examine the water quality of drinking water from Jordan Lake? And, go beyond the assurances provided by the agencies that supply it.”

If you’re also one of those who wonder about Jordan Lake, keep reading.

History of Water Quality in Jordan Lake

I’ll let you in on a little-known fact: Jordan Lake isn’t a lake. Technically, it’s a reservoir. Reservoirs differ from lakes because reservoirs are man-made waters that usually form through river dams. In Jordan Lake’s case, it was created through a dam on the Haw River.

This difference is important. Reservoirs essentially hold a lot of nutrients and sediments that come from the river, worsening water quality. Jordan Lake is no different. Since Jordan Lake’s impoundment in 1983, the government saw the problems of Jordan Lake’s waters. Jordan Lake was declared a “Nutrient Sensitive Water” because of its extremely high amount of nutrients— namely phosphorus and nitrogen.

Water Measurement

But how do you know if your water is impaired?

Water Quality is measured according to different criteria adopted by the North Carolina government. The criteria is federally regulated by the Clean Water Act, which requires the state to review its water-quality standards every three years.

Water-quality standards change depending on their classification. Jordan Lake is a surface water classified as Water Supply IV, Primary Recreation Fresh Water, Nutrient Sensitive Water, and a Critical Area. You can read more about what those classifications mean here.

Water quality is measured using a variety of different measurements. I spoke with hydrologist Dani Johnson, who helped me decode some key terms in water-quality jargon. You can follow along using the latest 2017 Jordan Lake report posted on the Department of Environmental Quality website:

  • n refers to the number of samples taken at a specific test site. According to the 2017 report, 12 samples were taken at each site.
  • TP means total phosphorus. Phosphorus is a nutrient commonly found in nutrient-rich water.
  • TN stands for total nitrogen. You can also find nitrogen in nutrient-rich water.
  • Chla refers to the amount of chlorophyll a in the water. Chlorophyll a is a pigment that gives organisms like plants its green color.
  • Turbidity is the clarity of the water. Many substances, including algae and clay, contribute to murky water. And murkier water means higher turbidity.
  • DO is an abbreviation for dissolved oxygen. Dissolved oxygen is essential to aquatic life. In the 2017 report, the dissolved oxygen level must be above four micrograms per liter.
  • pH measures the acidity of the water. Jordan Lake’s water should be in between 6pH and 9pH.
  • Exceedance shows us what percent of samples did not meet North Carolina Water Quality standards.

Chlorophyll a shows high exceedance compared to the other measures from the 2017 Jordan Lake report. This is no coincidence. Chlorophyll in abundance indicates a big concern of Jordan Lake: algae. Algae, like all organisms that photosynthesize, has chlorophyll a in its system. When large amounts of nutrients like phosphorus and nitrogen are in the water, algae can spread monstrous proportions. Too much algae can ruin ecosystems and can possibly be toxic.

Present Efforts

In 2013, the North Carolina government tried to improve the quality of Jordan Lake. They budgeted over $1 million to deploy machines called SolarBees into the reservoir to mix the water. The legislature hoped that the mixed water would help solve problems like algae. Instead, the project made no substantial difference to the water quality of Jordan Lake.

In 2016, the North Carolina General Assembly budgeted $500,000 a year for six years to the University of North Carolina at Chapel Hill. The budget instructs UNC-Chapel Hill to supervise water quality research in Jordan Lake and Falls Lake. This past Wednesday, scientists were able to present their findings at the 2019 Jordan Lake Nutrient Management Study Research Symposium.

So… How Safe is the Water?

Pretty safe— if it’s treated.

During the symposium, Professor Astrid Schnetzer said that toxins from algae were way below drinking water concerns, especially since the water is treated at a facility. She said that a little bit of consumption during recreation shouldn’t be an issue either.

“Levels are generally low,” Schnetzer said. “So, it’s not a reason to alarm, but I think there’s several questions to follow up on.”

Retired UNC-Chapel Hill professor Bob Rubin has worked with water quality and waste management in North Carolina for over 30 years. He said that without water treatment, he wouldn’t take the risk.

“Would I go to Jordan Lake right now and stick a straw in the lake and drink the water? Nope, wouldn’t do it,” Rubin said.

Some people, like hydrologist Dani Johnson, prefer alternatives to water treatment facilities. Even though Johnson lives five minutes away from Jordan Lake, she gets her water from a well. She said she doesn’t drink water from Jordan Lake because she doesn’t like treatment process. However, Johnson said that as a resident of the area, she is concerned about the water.

“I think it’s definitely an issue,” Johnson said. “And if people aren’t aware of it, they need to become aware of it.”

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