Panola County has plenty of winding, scenic backroads to enjoy. Anyone who has taken time to explore this section of the Sabine River valley has observed the wooded bottomlands, the wide open pastures and the piney hilltops. It’s actually pretty difficult to pick a favorite view around here. You’ve seen the many ponds and small lakes scattered around the countryside, and chances are you have also seen those large water hoses running for miles alongside the road. If so, you have witnessed an active water transfer operation, moving water to an active oil and gas drilling rig or frac well. In many cases, the water in those lines was recently pumped from the ground into a pond, and then delivered to a gas well to make the fluid mixture for hydraulic fracturing. It takes millions of gallons of water to supply a frac, and all of that groundwater removal has an effect on our local aquifer. This is where the Panola County Groundwater Conservation District’s monitoring and management programs come into play.
Over the last ten years, District staff members have actively checked water levels in monitor wells that are adjacent to where groundwater is pumped to supply frac ponds. This project, in addition to collecting groundwater production data from oil companies and water sales wells, has allowed the District to characterize the aquifer’s pumping response. In turn, this data has been useful in addressing public concerns about frac water usage. The largest frac ponds (by volume of groundwater used) in Panola County since 2011 have used around 200 million gallons per year, over a 1- or 2-year period, utilizing between 3 and 10 pumping wells. The drawdowns produced (drop in water level in a monitor well) from these highest pumping areas were on the order of 20 to 85 feet, and the monitor wells in these cases were within a quarter of a mile (1,320 feet) from the nearest frac pond pumping well. Most of the other frac ponds collected less than 120 million gallons of groundwater per year, and generally had smaller drawdowns in the surrounding areas. The largest drawdown ever recorded in a Panola County monitor well was 104 feet, which was in a well 1,000 feet away from the pumping wells (located in between two frac pumping areas), during a severe drought period in 2013.
There have been a few isolated cases where new frac supply water wells contributed to water supply issues in some adjacent water wells. In all of those cases where the District was involved, the oil company was required to cease pumping until the supply issues were resolved. Usually, the problems with the surrounding domestic or public supply wells were due to a combination of pump/equipment issues and added drawdowns. In all of the District’s monitored frac pond areas, water levels recover significantly in the 4 to 6 weeks after pumping stops. Complete recovery can take 6 months to a year or longer, depending on drought conditions and local pumping rates. The District has always checked their monitor wells until they are 100 percent recovered after the frac pumping stops.
Water quantity is often the biggest concern around heavily pumped areas, but another important factor for groundwater management is water quality. Every water well that has produced 150 gallons per minute (GPM) or more since 2012 has had a hydrogeological study conducted on it, according to District rules. This study includes pumping tests to measure drawdowns and water quality changes, and the reports provide 1 month and 1 year projections of anticipated changes in the aquifer. Additionally, every well that is approved to send water outside of Panola County also must complete a hydrogeological study beforehand, for review by District staff and the board of directors. After each hydro study, the high-producing wells also have samples collected quarterly for one year to demonstrate any changes in water quality. So far, all of these follow-up samples have shown minimal changes in water quality over time, which is great news.
People often have the concern that high pumping wells will degrade their own domestic/livestock water wells, and the data collected so far have shown that the aquifer quality remains fairly stable during these most active pumping times. The District also uses two other methods of monitoring frac ponds, involving two dedicated water well sensors and a portable water quality meter. The sensor is a small probe on the end of a cable, and it’s installed in a monitor well to record hourly measurements of the water level and selected water quality parameters. This gives the District high-resolution information to show the aquifer’s response to pumping wells. The portable meter, on the other hand, is used quarterly at all active frac pond water wells. Samples are gathered from the pumping wells and analyzed immediately for parameters including pH, total dissolved solids, chloride, temperature, and nitrate. Over time, this meter provides a profile of water quality in each pumping well, and the results have been similar to the hydro study follow-up samples. By and large, water quality is relatively stable in highly pumped areas, and there has been no degradation of aquifer quality over several years, numerous samples, and dozens of wells.
Oil and gas production is mercurial, as we all know. It brings booms and busts economically, and along with those swings come times of duress and relief for our local groundwater resources. Barring another historically severe drought, the Carrizo-Wilcox aquifer in Panola County should be just fine as long as we all keep conservation and good stewardship in mind.
Your local groundwater district will be staying on top of protecting this aquifer so we can all have a sustainable water supply for many years to come. To see more information, follow the District’s Facebook page and visit www.pcgcd.org. We are here to handle all of your groundwater management questions and concerns, so give us a call at (903) 690-0143, or stop by at 419 W. Sabine St. in Carthage.