Approaches to Resolving Overdraft of the Sparta Aquifer

[Primary reference for this section: ['Sparta Aquifer: Status and Trends,' Ben McGee, USGS, http://www.spartaaquifer.com orUSGS Sparta Slide Show]

The Sparta Aquifer is located in south-central Arkansas and north-central Louisiana. The aquifer supplies all or the major part of the drinking water for fifteen Louisiana parishes.

In 2000, ground-water withdrawals from the Louisiana region of the Sparta aquifer totaled 77 Mgal/d (million gallons per day).

In 2000, the major users of Sparta-Louisiana water were public supply (37.62 Mgal/d) and industry (37.32 Mgal/d). The remaining 3 percent (2.26 Mgal/d) of Sparta-Louisiana water was used by agriculture, rural domestic, and power generation withdrawals.

Thus, a little less than half of Sparta-Louisiana water is used by industry. A poultry processing plant might use as much water as a town and a paper mill as much as a small city. These industries provide jobs and are important to the regional economy.

Public use of Sparta-Louisiana water has increased dramatically since the 1960s. In 2000, public use overtook industrial use, and it continues to pull ahead with a steadily widening gap.

Eighty-seven percent of Sparta-Louisiana's consumption takes place in Ouchita, Bienville, Lincoln, Webster, Union, and Claiborne parishes, in that order. Consumption ranges from 23.5 Mgd for Ouchita Parish to 3 Mgd for Claiborne Parish.

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Overpumping

According to the Sparta Aquifer Study for Sparta Groundwater Conservation District by Meyer, Meyer, LaCroix and Hixson, Inc., 2001 (full study: http://www.spartaaquifer.com/ and follow links), the sustainable yield of the Sparta Aquifer in Louisiana is approximately 52 Million gallons of water per day. Slightly more than this amount was pumped in 1985. According to USGS (see hydrologist Ben Magee's slideshow by following links from www.spartaaquifer.com or USGS Sparta Slide Show), since 1985, pumping has increased by 37 percent. This has caused water level declines averaging almost two feet per year.

Authors, in 'The Sparta Aquifer: A Sustainable Water Resource,' (water.usgs.gov/pubs/fs/fs-111-02/fs-111-02.pdf) reported that an aquifer test near El Dorado resulted in a 6 ft water-level decline at a distance of 2,400 ft from the pumping well after three days of pumping at a rate of approximately a half Million gallon a day. Industries and even small communities pump many times more than this amount.

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The Sparta is Stressed

Meyer, Meyer, LaCroix and Hixson list the following factors that place the Louisiana part of the Sparta Aquifer in a stressed condition:

• continuing annual declines in water level in areas of significant pumpage;
• water levels below the top of the aquifer in significant portions of seven parishes; and
• indications that saltwater, on the eastern side of the Sparta formation is moving westward.

Overdrawing an aquifer's water seriously impairs water quality and can eventually compact sands, permanently reducing the aquifer's storage capacity. USGS hydrologist Ben Magee (slideshow reached through www.spartaaquifer.com or USGS Sparta Slide Show) reported that Ground Water Models show that a 50 percent increase in pumping over 1985 amounts could have resulted in dewatering conditions in Southern Arkansas by the year 2005.

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Requirements for Recovery and Maintenance of Sustainable Withdrawal Rate

Meyer, Meyer, LaCroix and Hixson recommended that Sparta-Louisiana pumpage must be no more than 52 Mgd by the year 2025, with a 17 Mgd reduction in pumpage by 2005.  They warned that the aquifer region should prepare for an increase in its water consumption from the current 70 Mgd to 82 Mgd by 2025. With these figures in mind, and assuming that diversion of current aquifer use to surface water use would be the only approach to correcting the deficit, they recommended that provision be made now for consumption of surface water to increase by30 Million gallons per day. That goal might be reduced somewhat if current aquifer water use is decreased through conservation and/or if measures are taken to increase aquifer recharge.

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Approaches to Aquifer Recovery

Overview

Authors, in 'The Sparta Aquifer: A Sustainable Water Resource,' (water.usgs.gov/pubs/fs/fs-111-02/fs-111-02.pdf) observed, "Volumes of water pumped from a ground-water system must come from some change in the water budget. This change occurs in one or more of the following: (1) more water entering the aquifer system (increased recharge), (2) less water leaving the system (decreased discharge), and (3) removal of water stored in the system (water-level declines)."

Aquifer Overdraw -- too little in, too much out

Aquifer Sustained -- more in and/or less out until inflow equals withdrawal

To prevent declines, approaches must be found to increase recharge and/or decrease discharge.

To decrease discharge, new plants may be built to provide treated surface water to current aquifer users. West Monroe is considering treating up to 10 million gallons daily of wastewater and/or river water to standards required by a packaging plant. Savings from taking this plant off the aquifer would be approximately one third the amount needed to return the Sparta in Louisiana to sustainable withdrawal rates. (West Monroe-Graphic Packaging Well Water Reduction Initiative, started 2001, remains in planning stage. http://www.dnr.state.la.us/CONS/gwater/cgwa_app/02-0001/monroehearing.pdf) In 1991, Arkansans passed legislation designated critical groundwater areas, established authority for withdrawals, set fees and provided a mechanism for locally based groundwater management. Since that time, five counties in southern Arkansas have been designated as "critical groundwater areas." Voters in Union County passed a 1 cent sales tax increase in 2002 to help pay for a $45 million pipeline from the Ouachita River to the county's four largest industrial users of the Sparta (http://argis.ualr.edu/website/unioncograph/spartaHistory.asp). Several above-ground reservoirs were built in Columbia County to store drinking water.

Meyer, Meyer, LeCroix and Hixson, Inc. calculated that, if constructing plants that treat surface water to drinking water standards is the sole approach used to address the Sparta-Louisiana overdraft, capital costs would be almost $200 million. Operating and financing would each cost almost as much. The firm suggested that revenue to pay capital costs might be generated by a 1/4 cent sales tax in an 11 parish taxing district, surface water contract sales at $1 per thousand gallons, and groundwater extraction fees at 23 cents per thousand gallons.

Another way to decrease discharge is to institute water conservation measures, such as education and incentives to use water-sparing technology. A Sparta Source Water Education Project was initiated by Louisiana and Arkansas Extension Services in 2000. Also, for the past two years, the LSU Ag Center Extension Service and Watershed District have sponsored Waterfest, which takes all Claiborne Parish sixth graders to the State Park for lessons in water conservation.

Increasing-recharge approaches are becoming more prevalent where quality water is needed. One such approach, 'Water Resources and Scenic Attractions for Retirees in North Louisiana's Sparta Area,' that has been considered for the Sparta area is the construction of lakes in the recharge area. These lakes would enhance aquifer recharge and provide new surface water sources, while, at the same time, attracting a retirement industry. The project should eliminate the need for one or more water treatment plants and pipelines.  Savings will be partially offset by construction and maintenance of impoundments on the Sparta outcrop; however, lakes will attract retirees, who will add to the local and state tax base. The lowered total cost of this aquifer sparing approach would increase chances for public support. Webster and Claiborne Police Juries have endorsed the development of this design by a team led by Dr. James Robert Michael.

Need for the most cost efficient approach

The more cost efficient that Sparta sparing projects are, the less the true cost of water will be for the public. The Congressional Budget Office projects that, nationwide, within 15 years, the cost of water, not counting operation and maintenance costs, could either double or hold steady depending on the water supply solutions that are adopted ('Future Investment in Drinking Water and Wastewater Infrastructure,' Congressional Budget Office, Nov., 2002).

The Environmental Protection Agency advises, "We can no longer take our drinking water for granted. Public participation is vital to protecting our water resources, building adequate treatment plants, improving water delivery, analyzing costs versus risks, and enacting appropriate legislation."

Residents may obtain Sparta information from the Claiborne Parish Watershed District Commissioners. The Ag Center and parish library also have educational material.

Author: Alice Stewart, Claiborne Parish Watershed District Commissioner, Feb. 2005

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