Computer models showing the movement of saltwater in two important layers of the aquifer that supplies Baton Rouge’s drinking water should be delivered to the state Department of Natural Resources’ Office of Conservation by early 2013.
The models are being developed by the U.S. Geological Survey to help inform decisions on the future of the Southern Hills Aquifer.
Although concerns about saltwater intrusion into Baton Rouge drinking water aquifer layers have been around since the 1970s, the efforts of a community group formed by Hays Town, a retired contractor and engineer, have brought a greater sense of urgency to the problem.
Office of Conservation Commissioner James Welsh has said a decision on what needs to be done to protect the Southern Hills Aquifer from saltwater intrusion should wait until the USGS study is completed.
Patrick Courreges, policy analyst with the state Department of Natural Resources, said that study should be available in early 2013.
“That’s where you start working with modeling to see if you change withdrawals in this area, what happens,” Courreges said.
The cause of the saltwater intrusion is salt domes south of the Baton Rouge geological fault line. As more water is drawn from the ground north of the fault, the difference in pressure pulls the saltier water across the fault and closer to groundwater wells serving Baton Rouge and surrounding areas.
Although the Baton Rouge Water Co., a private company, takes drinking water from 10 different layers of sand in the Southern Hills Aquifer, the largest percentage come from the 1,500-foot sand, which is one layer experiencing the saltwater intrusion problem.
One issue that Town has raised is that about half of the water withdrawal in the aquifer is for industrial purposes that could come from the Mississippi River instead. Some industries have been credited with making an effort to reduce groundwater use, and others have pointed out that the other half of the groundwater use goes to residential and other uses.
The modeling being done by USGS is looking at what effect changing the amount of water withdrawn by certain users would have on the aquifer.
A May 23 order from the Office of Conservation asked for additional information from users of groundwater in an area around Baton Rouge to include current and projected use of the groundwater supply.
One large groundwater user is Georgia Pacific’s plant, but it is far north of the order’s boundaries because Courreges said it was believed to have little impact on the saltwater intrusion issue.
However, USGS modeling is including the Georgia Pacific plant and it will be brought within the order’s boundaries if it’s determined that the facility is having an impact, Courreges said.
In the meantime, other portions of the May order from the Office of Conservation are moving forward.
In July, state Department of Natural Resources officials announced a three-year, $2.7 million program to beef up the state’s ground water monitoring.
There were about 200 groundwater monitoring wells around the state and the program was going to add about 200 more, bringing it back to 1980 levels before budget cuts forced a reduction.
More recently, Welsh announced the formation of a public awareness campaign to focus initially on the Southern Hills Aquifer and its importance.
Although the “Water-Wise in BR” campaign is in the early stages, there are plans to have a free teacher workshop Feb. 1 in Baton Rouge to work with middle and high school teachers on a curriculum to teach students about the aquifer, said Matthew Reonas, education and public outreach director for the Office of Conservation.
The program fulfills part of the May order that said the “Baton Rouge area is generally lacking an aggressive groundwater conservation and water resource sustainability public education, awareness and outreach effort.”
Reonas said studies from California and Texas show that consumer awareness and conservation efforts on the individual level can make a difference.
“They’ve been much more aggressive in programming and public awareness and they’ve seen dramatic reductions (in water use),” he said.