Sparta Groundwater Study –Approach Scenarios
Meyer, Meyer, LeCroix, and Hixson selected several scenarios of Sparta use, using the ground-flow model described in the section above (5.f.3.a.). For all scenarios, they assumed that Sparta pumpage would be reduced by 8 mgd by El Dorado industries converting from Sparta to surface water. For all scenarios except the ‘No Change in Use’ scenario they projected demographic changes in the base case Scenario 2.
For the No Change in Use scenario, the model calculates for well water levels, by the Year 2025: (Ref. 2, p.6-2)
Meyer, Meyer, LeCroix, and Hixson reported in the Sparta Groundwater Study (2) results of the application of their model to Ouachita Parish, which is at particular risk of salt water intrusion because of heavy pumping in the area and close proximity to the freshwater/saltwater interface. The optimized solutions maintained hydraulic heads at or above the top of the Sparta Sand by the end of the simulation period (2025).
Sparta Groundwater Study –Recommended Approaches to Reduce Sparta Pumpage
Meyer, Meyer, LeCroix, and Hixson reported that the Sparta aquifer can be significantly restored within 25 years with an 18 million gallon per day (mgd) reduction of its current 70 mgd withdrawal rate, and another 12 mgd would provide for population and industrial growth. (2) The recommendation they put forth in greatest detail was to build new surface water treatment plants and pipe the water to current aquifer users. They calculated that, if this is the sole approach used, capital costs in 2001 dollars would be approximately $190 million, operating costs would add to those costs, and financing costs would add more. They suggested that revenue to pay capital and financing costs might be generated by a 1/4 cent sales tax in an eleven parish taxing district, surface water contract sales at $1 per thousand gallons, and groundwater extraction fees at 23 cents per thousand gallons.
Based on criteria that included area of greatest stress, demographic projections, and evidence of salt water intrusion, Meyer, Meyer, LeCroix, and Hixson recommended, as first priority, a 10 mgd project using river water from the Ouachita River at West Monroe to replace Sparta water use. The estimated cost of the project, in 2001, was $55.7 million ($82.8 million in 2009, adjusted for inflation-Ref.22d).