Keeping region's 1.5 trillion gallon aquifer safe
Natural, man-made threats facing area’s drinking water supply.
The Dayton region is “water rich” — its aquifer has more water than residents and businesses can use for the foreseeable future, local experts say — but threats must be addressed to keep it safe.
The Buried Valley Aquifer has about 1.5 trillion gallons of water. It stretches underground from Logan to Hamilton counties, providing most communities in the region with drinking water.
The Dayton Daily News Path Forward project digs into solutions to the biggest issues facing our community, including the safety and sustainability of our drinking water. For this story, the newspaper examined the overall health of the aquifer and potential threats to it.
Natural and man-made threats — including some carcinogens — need to be addressed to ensure the
aquifer remains viable, said Mike Ekberg, water resource and monitoring manager at the Miami Conservancy District, and Abinash Agrawal, a ground water contamination expert at Wright State University.
Many of these c hallenges can be overcome with improved awareness and the use of technology, Ekberg said.
“Most of these water challenges are the direct or indirect result of how we live our lives — the neighborhoods we build, the services we demand, and the value we place on having clean water,” he said.
An abundance of clean and affordable water is also a significant economic asset for the Dayton region, for both new and existing companies, said Chris Kershner, executive vice president for the Dayton Area Chamber of Commerce.
“When you have access to a renewable resources under your feet, it gives us a significant advantage in terms of attracting companies to the region,” he said.
Usage
In parts of the country, such as the Great Plains, water is scarce. Much of that region’s water is extracted for agricultural uses faster than it’s replenished because it gets so little rain.
That’s not the case locally, Ekberg said. His team at the conservancy district works with state and federal agencies to monitor the Buried Valley Aquifer’s water supply long term. They measure the water level monthly via a network of about 100 observation wells.
“We’re in good shape,” Ekberg said.
The heavy rainfall here, including a record 26 inches during the first six months of 2019, replenishes the aquifer regularly.
At the same time, water consumption has declined steadily in the past decade, according to data from the Ohio Department of Natural Resources. From 2007 to 2017, total ground and surface water use in the region that stretches from Auglaize to Hamilton counties dipped from nearly 550 million gallons per day to nearly 280 million gallons per day, according to the latest state data.
That’s due in part to federal guidelines that require toilets, faucets and shower heads to use less water. Increased efficiencies in industrial water use, a regional decline in manufacturing, and the closure of the Dayton Power & Light Hutchings Station power plant also contributed, Ekberg said.
But that drop in usage also can make it difficult for some water utilities to generate enough money to deal with rising infrastructure costs, he said, and rates might need to be restructured in some areas.
PFAS
Polyfluoroalkyl substances, known as PFAS, are perhaps the aquifer’s biggest threat, Agrawal said.
Studies suggest that exposure to the chemical might affect a woman’s chance of getting pregnant, increase cholesterol levels a nd cause some forms of cancer, according to the Centers for Disease Control and Prevention. More research is needed to better understand the health effects of PFAS exposure, the CDC says.
PFAS includes various types of substances known as PFOA, PFOS, GenX and others. It can be found in firefighting foam, water-repellent fabrics, nonstick products, waxes, polishes a nd some food packaging, according to the U.S. Environmental Protection Agency.
Firefighters trained for decades with foam in at least two sites in this region for decades: Wright-Patterson Air Force Base and the Dayton Fire Training Center. Both of these locations are located above the aquifer.
The U.S. EPA has set a health advisory for chemi- cals, recommending drinking water not contain it above 70 parts per trillion.
Starting in 2016, the city
of Dayton proactively shut down drinking water wells when PFAS was detected at levels much lower than the federal advisory. It also has sued the chemical man- ufacturers.
The city of Dayton runs the region’s largest water system, serving about 400,000 people. Its water is delivered to homes in the city and several other Montgomery County communities via a county distribution system.
PFAS will eventually spread to other areas, he said, noting that wells near the contaminated areas are susceptible to future con- tamination.
It’s imperative that if city officials are working on a solution, they say so publicly, Agrawal said.
“There should be a con- certed effort (to clean up), not just ignore that part of the aquifer that is impacted,” he said. “Shutting down the
drinking water well is just trying to avoid the problem and not dealing with it.”
City leaders have said numerous times that they’re working on a plan to contain the contaminated water. But when asked last week for details on how they plan to do so, a city spokeswoman declined to discuss the ques- tions due to its pending lawsuit against PFAS manufac- turers.
Dayton has increased the number of monitoring wells and is routinely sampling its water sources for PFAS, said Dina Pierce, a spokes- woman for the Ohio EPA. Those sample results for the city’s drinking water wells and water leaving the Dayton drinking water plant are far below the federal health advisory limit, she said.
PFAS also was found in the ground water at Wright-Patterson Air Force Base, which has its own water system. In December researchers at the base did a two-week field demonstration of a plasma technology they say destroys PFAS. Testing is ongoing.
Around the time of the testing, Dayton City Manager Shelley Dickstein told the Dayton Daily News that city leaders were interested in seeing how the Air Force’s technology performs with larger water systems.
Agrawal insists that government has to be held accountable to address PFAS.
“That area of the aquifer is gone for the foreseeable future,” he said. “There’s no way we can recover it with the current technol- ogy. But at least we need to understand it and get a handle on it so it doesn’t become bigger, so (toxic) water doesn’t migrate to other wells nearby.”
Other chemicals
Volatile Organic Compounds — or VOCs — that have been found in landfills in the area also concern Agrawal.
VOCs are industrial chemicals used in manufacturing and a variety of products found in homes. They include nail polish remover, wall paper, furniture polish, paint and gasoline emissions. The main source is manufacturing, particularly rubber.
Some of the chemicals, such as gasoline, are not as toxic when spilled because they tend to evaporate quickly, Agrawal said, and are less likely to get into ground water. That’s not the case with chlorinated VOCs, which can cause cancer.
Dayton has had treatment in place at its well field for VOCs, Pierce said. In addition, Dayton has proactively used extraction wells to prevent the chemicals from migrating toward operating production wells.
Many VOCs have federal maximum contaminant levels, Pierce said, and Ohio’s public water systems must comply with those standards.
New developments
New developments can affect the aquifer in a couple of ways, Ekberg said.
That could include an increase in the storage and management of pollutants — such as gasoline tanks at a new convenience store — which can increase the risk of leaks and spills that could seep into the aquifer.
Land development also often creates more hard surfaces such as asphalt parking lots, roofs, and concrete streets and sidewalks. Those tend to prevent water from seeping into the ground and eventually into the aquifer, Eckberg said. That water can end up running off into streams instead, which can lead to eroding banks, floods and poor habitats for fish and other aquatic life.
“The challenge is trying to find a balance between the need to protect a community’s supply of drinking water and not being a burden to economic activity,” Eckberg said. “I think a community can serve both needs, but it requires some planning.”
Road salt and fertilizers
Road salt and nitrogen fertilizers are perhaps the two most prolific sources of man-made contaminants to aquifers, Eckberg said. Elevated levelsofchloride and nitrate, respectively, and failing septic systems have been detected in regional aquifers, according to groundwater data from the United States Geological Survey, the Ohio Environmental Protection Agency and Miami Conservancy District.
Nitrate can impact infants’ health, and excessive amounts of chloride can make groundwater more corrosive to water pipes, which can increase lead and copper levels in drinking water.
“The take-home message is better methods for applying road de-icing agents and agricultural fertilizers are needed in areas where regional aquifers are vulnerable to contaminants,” Eckberg said.
Micropollutants
Manufactured compounds known as micropollutants have been found in local streams, rivers and aquifers, Eckberg said. Some common micropollutants include pharmaceuticals, chemicals in personal care products and chemicals used in household products.
These compounds often get into the environment from sewage plants, he said, and experts don’t know much about the toxicity of many of them. Conventional drinking water and sewage plants don’t remove all of them.
Communities that recycle wastewater into drinking water are dealing with micropollutants, Eckberg said. In Orange County, California, the local water district uses advanced technology to remove micropollutants at the sewage plant. The treated wastewater is injected into an aquifer and reused as a source of drinking water. It’s expensive process, Eckberg said, but necessary for a region where there’s a water shortage.