β¦ Back to Water Resource Management Home
ΒΆ Introduction
Survey of analysis results from Oklahoma surface and groundwater samples submitted to ServiTech Laboratories during 2013 to 2022, inclusive, for analysis of Livestock Suitability. The results are grouped by National Agricultural Statistics Service (USDA-NASS) reporting districts.
ΒΆ Figure 1. Oklahoma USDA-NASS Districts
Interpretation of survey results:
- Median = 50th percentile
- Typical range = 25th and 75th percentiles
- Low - High = 5th and 95th percentiles
ΒΆ Table 1. Total dissolved solids, TDSc mg/L |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 630 | 460 β 1730 | 280 β 3030 |
| West & North Central | 1270 | 445 β 1670 | 230 β 13560 |
| Southwest | 1560 | 510 β 2330 | 235 β 8530 |
| Central & East Central | 455 | 145 β 1195 | 90 β 15455 |
| Statewide | 695 | 425 β 1735 | 170 β 4280 |
("Acceptable" = 2000 - 4000 TDS mg/L)
ΒΆ Table 2. Sulfate, SO4 mg/L |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 130 | 65 β 1200 | 20 β 2000 |
| West & North Central | 660 | 40 β 1400 | 5 β 4140 |
| Southwest | 360 | 85 β 1700 | 5 β 4940 |
| Central & East Central | 40 | 5 β 770 | 0 β 3830 |
| Statewide | 135 | 45 β 1400 | 5 β 2300 |
("Acceptable" = 200 - 500 SO4 mg/L)
ΒΆ Table 3. Nitrate-nitrogen, NO3-N mg/L |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 3.5 | 2.1 β 5.9 | 0.1 β 22 |
| West & North Central | 2.8 | 1.1 β 5.3 | 0.1 β 68 |
| Southwest | 1.5 | 0.2 β 5.6 | 0.1 β 13 |
| Central & East Central | 1.2 | 0.1 β 5.6 | 0.1 β 45 |
| Statewide | 2.7 | 0.9 β 5.7 | 0.1 β 22 |
("Acceptable" = 30 - 70 NO3-N mg/L)
ΒΆ Table 4. Chloride, Cl mg/L |
|||
| Oklahoma | Median | Typical range | Low - High |
| Panhandle | 52 | 33 β 160 | 15 β 550 |
| West & North Central | 69 | 26 β 160 | 19 β 4200 |
| Southwest | 110 | 43 β 220 | 6 β 2820 |
| Central & East Central | 20 | 6 β 62 | 4 β 8225 |
| Statewide | 58 | 25 β 160 | 6 β 1465 |
("Acceptable" = 125 - 250 Cl mg/L)
ΒΆ Table 5. Calcium, Ca mg/L |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 85 | 60 β 437 | 36 β 610 |
| West & North Central | 255 | 68 β 520 | 22 β 620 |
| Southwest | 109 | 57 β 612 | 31 β 894 |
| Central & East Central | 40 | 15 β 99 | 7 β 524 |
| Statewide | 86 | 55 β 465 | 18 β 660 |
("Acceptable" = 80 - 120 Ca mg/L)
ΒΆ Table 6. Magnesium. Mg mg/L |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 43 | 33 β 110 | 20 β 208 |
| West & North Central | 53 | 16 β 112 | 8 β 268 |
| Southwest | 67 | 25 β 134 | 8 β 806 |
| Central & East Central | 18 | 6 β 44 | 4 β 238 |
| Statewide | 42 | 26 β 110 | 7 β 253 |
("Acceptable" = 50 - 120 Mg mg/L)
ΒΆ Table 7. Potassium, K mg/L |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 5 | 4 β 7 | 2 β 39 |
| West & North Central | 3 | 2 β 5 | 1 β 23 |
| Southwest | 7 | 5 β 10 | 1 β 89 |
| Central & East Central | 5 | 2 β 13 | 1 β 140 |
| Statewide | 5 | 3 β 9 | 1 β 45 |
("Acceptable" = 80 - 120 K mg/L)
ΒΆ Table 8. Sodium, Na mg/L |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 42 | 35 β 110 | 19 β 360 |
| West & North Central | 70 | 40 β 120 | 24 β 3480 |
| Southwest | 97 | 32 β 195 | 9 β 2104 |
| Central & East Central | 31 | 14 β 98 | 3 β 6434 |
| Statewide | 48 | 34 β 137 | 10 β 674 |
("Acceptable" = Na plus Mg less than 50% of TDS)
ΒΆ Table 9. Iron, Fe mg/L |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 0.05 | 0.05 β 0.20 | 0.05 β 3.2 |
| West & North Central | 0.17 | 0.05 β 0.50 | 0.05 β 9.0 |
| Southwest | 0.23 | 0.07 β 0.73 | 0.05 β 5.1 |
| Central & East Central | 0.30 | 0.06 β 1.77 | 0.05 β 10.8 |
| Statewide | 0.09 | 0.05 β 0.50 | 0.05 β 4.5 |
("Acceptable" = 0.20 - 0.40 Fe mg/L)
ΒΆ Table 10. Manganese, Mn mg/L |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 0.005 | 0.005 β 0.026 | 0.005 β 2.19 |
| West & North Central | 0.013 | 0.005 β 0.086 | 0.005 β 1.62 |
| Southwest | 0.011 | 0.005 β 0.116 | 0.005 β 1.64 |
| Central & East Central | 0.014 | 0.005 β 0.382 | 0.005 β 1.16 |
| Statewide | 0.006 | 0.005 β 0.045 | 0.005 β 1.64 |
("Acceptable" = 0.025 - 0.050 Mn mg/L)
ΒΆ Table 11. Hardness, as CaCO3 grains/gallon |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 22 | 17 β 99 | 12 β 135 |
| West & North Central | 50 | 15 β 100 | 5.0 β 134 |
| Southwest | 41 | 15 β 120 | 8.3 β 320 |
| Central & East Central | 12 | 3.7 β 26 | 2.1 β 120 |
| Statewide | 22 | 15 β 100 | 4 β 150 |
("Moderately hard" = 3.5 - 7.0 CaCO3 grains/gallon)
ΒΆ Table 12. Hardness, as CaCO3 mg/L |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 380 | 280 β 1700 | 200 β 2300 |
| West & North Central | 860 | 260 β 1800 | 85 β 2300 |
| Southwest | 710 | 250 β 2100 | 140 β 5440 |
| Central & East Central | 195 | 65 β 430 | 35 β 2100 |
| Statewide | 380 | 250 β 1800 | 75 β 2565 |
("Moderately hard" = 60 to 120 CaCO3 mg/L)
ΒΆ Table 13. Electrical conductivity, EC ΞΌmho/cm |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 985 | 720 β 2700 | 435 β 4730 |
| West & North Central | 1980 | 695 β 2610 | 355 β 21190 |
| Southwest | 2430 | 795 β 3640 | 365 β 13360 |
| Central & East Central | 710 | 225 β 1870 | 135 β 24145 |
| Statewide | 1085 | 665 β 2710 | 270 β 6695 |
("Acceptable" = 1300 - 2600 ΞΌmho/cm)
ΒΆ Table 14. Water pH |
|||
| Oklahoma Districts | Median | Typical range | Low - High |
| Panhandle | 7.6 | 7.4 β 7.8 | 7.1 β 8.2 |
| West & North Central | 7.6 | 7.4 β 7.9 | 7.1 β 8.4 |
| Southwest | 8.1 | 8.0 β 8.2 | 6.9 β 8.7 |
| Central & East Central | 8.0 | 7.6 β 8.3 | 6.7 β 9.1 |
| Statewide | 7.7 | 7.5 β 8.1 | 7.1 β 8.5 |
("Neutral" pH = 6.5 - 7.5)
ΒΆ Table 15. Conversion Factors |
| 1 mg/L β 1 ppm |
| 1 mg/L = 1,000 Β΅g/L |
| 1 mmho/cm = 1 dS/m |
| 1 mmho/cm = 1,000 Β΅mho/cm lb/ac-in = mg/L x 0.2267 lb/ac-ft = mg/L x 2.7204 |
| lime equivalent, lb/ac-ft = HCO3 mg/L x 2.2304 |
| 1 acre-inch = 27,154 gallons |
| 1 acre-foot = 325,848 gallons |
ΒΆ Table 16. Sample Count |
|
| Panhandle | 89 |
| West Central | 17 |
| Southwest | 51 |
| North Central | 14 |
| Central | 23 |
| South Central | 2 |
| Northeast | 1 |
| East Central | 9 |
| Southeast | 0 |
| Statewide | 206 |