Changes may be coming to the city of Wichita — changes that could affect residents in Harvey County — and so officials from the city's Public Works Department have been making the rounds to discuss a proposed shift in the operation of the Aquifer Storage and Recovery (ASR) project with potentially impacted communities.
Wichita officials' most recent stop was in Harvey County this week, speaking to the county commission about the history of the project itself, the changes being explored and the role of the ASR project moving forward.
The ASR project was established 25 years ago to divert water from the Little Arkansas River when it flows high, treat it to drinking water standards and inject the processed water into the Equus Beds aquifer (a primary water source for the region — and the sole source in Harvey County). Doing so allows the city of Wichita to accumulate recharge credits with the Kansas Department of Agriculture, allowing it to withdraw the additional water from the Equus Beds aquifer — which spans the west half of Harvey County, and further — when needed, like in drought conditions.
Currently, the aquifer sits at 98 percent full — a benefit to users and the aquifer, but a hindrance to the physical recharge capacity (as well as the creation of recharge credits). Instead of injecting water into the aquifer, it is pumped directly to the city in such conditions — which does not create recharge credits. Regulations also restrict the use of recharge credits to when aquifer groundwater levels are at or above a minimum standard (88 percent full, based on the lowest level in the aquifer's history). As the needs of the city are changing, Deputy Director of Public Works Joe Pajor noted city officials are looking to change how the ASR operates as well.
"Because of our needs today and forecasted for 50 years in the future, we're now looking at operating the ASR as a long-term banking of water, excess surface water out of the Little Arkansas River, to be able to be used to supplement our native water rights in the Equus Beds as well as our water rights from Cheney Reservoir," Pajor said.
Originally, the ASR project was established in phases to be adjusted based on customer demand, technological improvements and to provide better rate equity. Additionally, Pajor said it was initially believed to be an effective way to stop the Burrton salt plume from moving into the Wichita well field (which cuts across a large portion of southwest Harvey County) — threatening to increase the salinity of the water supply.
While remediation will be required to address the plume issue, the implementation of the ASR project has proved successful in addressing its other goals — raising saturation levels at the city's well fields to nearly 100 percent.
"That's a pretty significant change, and that's good news," Pajor said. "That's a result of natural recharge; it's a result of the city of Wichita changing our water sourcing strategy to emphasize Cheney Reservoir and the rest of the aquifer; it's a result of the ASR work that has occurred; and it's a result of improved efficiency on the part of other water rights holders in the areas. All of those forces have combined favorably."
Favorably as those practices have set up Wichita, the overall strategy regarding the ASR project remains unchanged — as the practice of using overflow water from the Little Arkansas River to maintain those high levels (and recharging as needed) is meant to prepare the region in the case of a 100-year drought event.
Seeing the current levels as high as they are, Pajor noted customer demands will be able to be met through the next 50 years — except in the case of a 100-year drought. To better prepare for that, the changes the city of Wichita is pursuing include the accrual of maintenance credits through diverting the Little Arkansas River water to supply Wichita directly, which would help build the credits needed during a drought. Also, Wichita is proposing a drop in the limit of when accrued credits can be used from the 88 percent threshold to 80 percent — to provide more of a cushion and extend the amount of time before the city would need to access credits, as the current arrangement could use up that resource too quickly and put the city in a difficult position.
"When you want to get your money out of the bank and the bank's closed, well, what good did it do to save your money in the bank if you can't get it out when you need it?" Pajor asked. "That's why we are requesting these two changes so that we can operate our project in a way that better serves the city's needs, the other area water rights producers' needs and the public interest."
Presumably, Pajor said, in the case of 100-year drought event the aquifer would still maintain a relatively healthy level (80 percent full) and then follow the pattern that has been established over the past 25 years — with water supplies being restored to capacity through recharge as precipitation and usage normalize.
Levels of the Little Arkansas River were concerns for Harvey County Commissioners in regards to these proposed changes, but Pajor stressed that water is only taken from that source in high flow events — with engineer Scott Macey noting that is the alternative water source of choice (compared with the Arkansas River) because of lesser salinity.
Questions were also raised about the threat of the Burrton salt plume. While remediation is proposed as the best solution, Pajor said the city does have a strategy — blending cleaner wells with higher saline wells to hold the average salinity down — in place, but Macey noted with that plume advancing an average of one foot per day (based on a United States Geological Survey) it is not expected to affect the Wichita well fields for another 40 years.
Maintaining drinkable, usable water is a key proponent of the changes being put forth by the Wichita city officials, but the idea of stretching that water source through multiple uses was also something brought up in addressing future water levels.
"I am a strong believer that tomorrow's households will use a gallon of water multiple times before its final discharge," said commission chair Randy Hague. "I think that technology's here and I think new homes are gonna be built where when you bring a gallon of water into that house it isn't used one time and discharged; it's going to be used multiple times and that's gonna be a tremendous impact on water usage."
Now, Wichita's application for change regarding the ASR project will have to go before the chief engineer of the Division of Water Resources in the Kansas Department of Agriculture, who will make a determination if those changes will be granted.
Playing into that final determination will be the recommendation from Groundwater Management District #2 (upon review), as well as information gathered through public forums, which county commissioners noted they would be happy to help facilitate in the next phase of the process.