DEQ monitoring water levels
Published 12:57 pm Wednesday, October 19, 2016
Test wells will provide data on deep aquifer conditions
By Ryan Kushner
Staff writer
The Virginia Department of Environmental Quality is drilling down in Smithfield to test the waters.
Seven wells are scheduled to be installed in the yard next to the town manager’s Office on South Church Street within in the next two months. The wells will be used to monitor the water levels in the aquifers used by the town and by Smithfield Packing, both of which have permits issued by DEQ that restrict the amount of water they can withdraw.
The drilling of the wells is a condition of the permits held by both entities, which were issued by the DEQ in 2013. Smithfield Packing’s engineering department will be footing the bill for the construction of the wells, which the town will pay back, according to Town Manager Peter Stephenson.
Once installed, the wells will be monitored and maintained by DEQ. {mprestriction ids=”1,2,3,4,5,6″}
The information gathered by DEQ will also provide a better understanding of the geological model of the area, according to DEQ Ground Water Characterization Geologist Todd Beach.
“It’s not just for these folks (the town and Smithfield Foods),” Beach said. “This gives us information to kind of tie together other stuff in this area. We’re refining the geologic model that everything is based on.”
The VDEQ crew drilled 400 feet to acquire different samples of the core to help determine where the aquifers are located and where the monitoring wells should be placed.
“Core [samples] will go to Reston, Virginia to the United States Geologic Survey now and they have micropaleontologists and people who will subsample it, and again, you’re refining that geology,” Beach said. “We need to know about all of it.”
Restricting and monitoring the water levels of an aquifer is important, according to Beach, particularly for larger entities such as the town and Smithfield Foods, which are permitted 1.27 and 2.6 millions of gallons a day respectively.
“If you construct a well and you withdraw the water down below aquifer tops, you then start dewatering that aquifer,” said Beach.
Once an aquifer is dewatered, the space the water previously held seals up, according to Beach.
“You can never restore that capacity and instead of having water between the grains, you allow grain-on-grain collapse, so you can’t re-inflate it, essentially,” Beach said.
DEQ chose the location of the wells because they could access the water sources used by both the town’s and Smithfield Foods’ wells.
The ideal location, however, would have been down by the Pagan River crossing, according to Beach.
“But it was so low at the water level and they didn’t want us blocking access to fishing and that type of thing so this is as close as we could get on land that was available that still kind of satisfied everything everybody needed,” Beach said.
When completed, the “real-time wells” will broadcast to a satellite every hour, according to Beach, so one can look at the water level at the site and see the seven different aquifers at a 15-minute interval.
“So you’ll have a continuous plot of what the water levels are doing here,” Beach said.
DEQ will be splitting the responsibility of the wells with the United States Geologic Survey. USGS will run the system, which will feature a 10-foot antenna with a solar panel atop, while DEQ will be responsible for feeding the data into the system. {/mprestriction}