Hot Springs — Federal and state officials are jointly conducting tests to ensure development won’t negatively impact the city’s eponymous hot springs.
The newly opened King Expressway extension provided an opportunity to check the health of the thermal water recharge zone that feeds springs on the southwest slope of Hot Springs Mountain.
The Arkansas Department of Transportation, National Park Service, and U.S. Geological Survey jointly conducted tests on 13 wells throughout the recharge zone to gain knowledge and collect data on the impacts of such a large project. I am.
Eight monitoring wells were drilled by the organization for research purposes in conjunction with five existing wells in the country. Monitoring, which began in 2020, was divided into three phases: pre-construction, construction, and post-construction.
“All the development is going on in recharge zones, but no one is studying the long-term effects,” said John Fleming, ArDOT’s environmental director. “Each one has a different effect depending on which rock it’s in.”
Fleming said ARB4, a well on the eastern slopes of Indian Mountain, has seen the largest decline since the project began. This well, located in a shale layer above the road cover, has significantly reduced volume and is nearly depleted. Because of this and another benefit, the USGS and NPS have proposed extending the monitoring period.
Currently, ArDOT has agreed to monitor it until September of next year, and could continue into December 2024. The USGS and NPS are discussing extending the study for 10 years, focusing on five likely new wells.
“As part of the National Environmental Policy Act (NEPA) reassessment process, ArDOT and the USGS entered into an agreement to characterize and evaluate potential changes to shallow groundwater systems and NP spring recharge areas. during and after the freeway bypass construction activity east of Hot Springs,” Fleming said in a follow-up email.
“ArDOT and [Federal Highway Administration] FHWA is funding the study and USGS is conducting the study. A portion of the highway construction project is located within a hot springs recharge area within Hot Springs National Park. NPS is evaluating concerns regarding potential anthropogenic impacts on NP’s hot springs. ”
Sixty acres of land along the highest elevation of the five-mile stretch of the King Expressway are protected from development. This is a protective measure taken by the state to protect the hot springs that give the city its name.
A 2005 environmental assessment that preceded the original plan for the highway expansion was shelved after hot spring water was discovered in a private well in the Bratton Drive area, 5 miles east of the park. A USGS study released in 2009 stated that the well is unrelated to the park’s thermal water system.
All data from the study will be made public, along with a report interpreting the data, said Laura Rule Whittle, chief of the USGS Hydrogeology Research Section.
He said the process takes time, as several quality assurance checks are done before the data is published to various sites and databases.
USGS provides data to NPS and ArDOT and meets regularly to discuss findings. This allows government agencies to make informed decisions about projects that take water and aquifer health into account.
“At this point, the impact on charging zones is pretty minimal,” Fleming said.
Two of the 13 wells showed significant declines, and both were on the eastern edge of the zone, he said.