Seasonal Effects on Ground Water Chemistry of the Ouachita Mountains Data Interpretation: Drew Lonigro

Signatures CaHCO 3 : J,K,N,M (TDS~ mg/L) NaHCO 3 : F (low pH, low TDS~60mg/L) NaCl: O (low pH, low TDS~30mg/L)

Site K: Spring flows from a cement basin. This is calcium-bicarbonate water with calcium averaging 37.84% and bicarbonate averaging 91.93%. Calcium has a low percentage due to a relative abundance of other Alkaline Earth Elements; Na, 17.98%, Mg, 33.25% and Sr at about 2ppm. Ammonium levels are also relatively high averaging.32meq/L.

Site J: Spring flows from forest floor and rock. This is the strongest calcium- bicarbonate water with calcium averaging 91.54% and bicarbonate averaging 90.72%. This site also gives the highest Uranium and Iron concentrations. Uranium ranges from 5.4x10-6 to 6.4x10-6 meq/L, and Iron ranging from 3.71x10-3 to 8.64x10-3 meq/L.

Site M: Warm spring flows from a large cement basin; Contains algae. This is calcium-bicarbonate water with calcium averaging 85.36% and bicarbonate averaging 85.71%.

Site F: Spring flowing from a covered culvert. This is barely a sodium-chloride concentrated water with sodium being the dominant cation with an average of 37.62%. Chloride is the dominant anion with an average of 22.53%. Other major ions include: Ca, 24.75%; Mg, 22.48%. This water has a relatively low concentration of TDS; to mg/L. Also low are the pH levels, 4.0 to 4.5, which yields relatively lower levels of bicarbonate and relatively higher levels of carbonate. Nevertheless, total alkalinity levels are low at <5 mg/L CaCO3.

Site N: Hot spring flows from rock. This is calcium-bicarbonate water with calcium averaging 77.79% and bicarbonate averaging 85.27%. This site gives the highest levels for measured specific conductance with an average of 417µS/cm, but interestingly only gives an average of µS/cm for calculated SC. Other ions of considerable concentration which were not taken into consideration when calculating SC include: Mn with an average of ppb and Sr with an average of 116ppb. This site also gives the highest concentration of SiO2 with an average of 49.13ppm.

Site O: Spring flows from display fountain. This is sodium-bicarbonate water with sodium averaging 41.87% and bicarbonate averaging 20.25%. Other major ions include: Ca, 29.46%; Mg, 13.44%; Cl, 17.79%; and SO4, 6.94%. Levels of pH are low at this site ranging from 4.6 to 5.3, which yields relatively lower levels of bicarbonate and relatively higher levels of carbonate. Nevertheless, total alkalinity levels are low at 5 mg/L CaCO3. This water also has a relatively low concentration of TDS with an average of 30.08mg/L.

Cation Exchange

Daily Samples: SO4 vs. (Ca+Mg)-HCO3 (Ca+Mg)-HCO 3 (meq/L)

Excess Calcium, Little Bicarbonate Identify excess Ca by subtracting HCO 3 from Ca+Mg. Correlate with SO 4 to see what contribution is from CaSO 4 + H 2 O(gypsum) F: HCO 3 data are <5 ppm, CO 3 increases only a little due to low pH.

Site F: Spring flowing from a covered culvert. This is barely a sodium-chloride concentrated water with sodium being the dominant cation with an average of 37.62%. Chloride is the dominant anion with an average of 22.53%. Other major ions include: Ca, 24.75%; Mg, 22.48%. This water has a relatively low concentration of TDS; to mg/L. Also low are the pH levels, 4.0 to 4.5, which yields relatively lower levels of bicarbonate and relatively higher levels of carbonate. Nevertheless, total alkalinity levels are low at <5 mg/L CaCO3.

Oxidizing vs. Reducing Oxidizing Reducing

Uranium K J M F N O

Oxidizing U vs. NO 3