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¶ Introduction
Survey of analysis results from Washington 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.
¶ Figure 1. Washington USDA-NASS Districts
Interpretation of survey results:
- Median = 50th percentile
- Typical range = 25th and 75th percentiles
- Low - High = 5th and 95th percentiles
¶ Table 1. Total dissolved solids, TDSc mg/L |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 575 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 330 | 215 – 475 | 100 – 640 |
| Southeast | ---- | ---- | ---- |
| Statewide | 335 | 215 – 485 | 100 – 640 |
("Acceptable" = 2000 - 4000 TDS mg/L)
¶ Table 2. Sulfate, SO4 mg/L |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 13 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 61 | 38 – 72 | 10 – 133 |
| Southeast | ---- | ---- | ---- |
| Statewide | 60 | 36 – 72 | 10 – 130 |
("Acceptable" = 200 - 500 SO4 mg/L)
¶ Table 3. Nitrate-nitrogen, NO3-N mg/L |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 0.2 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 1.2 | 0.2 – 9.2 | 0.2 – 39.2 |
| Southeast | ---- | ---- | ---- |
| Statewide | 1.1 | 0.2 – 8.1 | 0.2 – 39.2 |
("Acceptable" = 30 - 70 NO3-N mg/L)
¶ Table 4. Calcium, Ca mg/L |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 79 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 26 | 16 – 71 | 11 – 105 |
| Southeast | ---- | ---- | ---- |
| Statewide | 33 | 16 – 71 | 11 – 103 |
("Acceptable" = 80 - 120 Ca mg/L)
¶ Table 5. Magnesium, Mg mg/L |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 21 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 15 | 5 – 40 | 4 – 59 |
| Southeast | ---- | ---- | ---- |
| Statewide | 15 | 6 – 40 | 4 – 58 |
("Acceptable" = 50 - 120 Mg mg/L)
¶ Table 6. Potassium, K mg/L |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 103 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 6 | 4 – 11 | 1 – 22 |
| Southeast | ---- | ---- | ---- |
| Statewide | 6 | 4 – 12 | 1 – 42 |
("Acceptable" = 80 - 120 K mg/L)
¶ Table 7. Sodium, Na mg/L |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 27 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 25 | 18 – 51 | 4 – 104 |
| Southeast | ---- | ---- | ---- |
| Statewide | 25 | 18 – 51 | 4 – 101 |
("Acceptable" = Na plus Mg less than 50% of TDS)
¶ Table 8. Chloride, Cl mg/L |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 77 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 21 | 11 – 28 | 3 – 39 |
| Southeast | ---- | ---- | ---- |
| Statewide | 21 | 11 – 28 | 3 – 47 |
("Acceptable" = 125 - 250 Cl mg/L)
¶ Table 9. Electrical conductivity, EC μmho/cm |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 900 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 515 | 335 – 740 | 150 – 1005 |
| Southeast | ---- | ---- | ---- |
| Statewide | 520 | 335 – 755 | 150 – 1000 |
("Acceptable" = 1300 - 2600 μmho/cm)
¶ Table 10. Iron, Fe mg/L |
|||
| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 5.65 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 0.06 | 0.05 – 0.14 | 0.05 – 1.20 |
| Southeast | ---- | ---- | ---- |
| Statewide | 0.07 | 0.05 – 0.16 | 0.05 – 2.4 |
("Acceptable" = 0.20 - 0.40 Fe mg/L)
¶ Table 11. Manganese, Mn mg/L |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 1.230 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 0.005 | 0.005 – 0.010 | 0.005 – 0.195 |
| Southeast | ---- | ---- | ---- |
| Statewide | 0.005 | 0.005 – 0.011 | 0.005 – 0.272 |
("Acceptable" = 0.025 - 0.050 Mn mg/L)
¶ Table 12. Hardness, as CaCO3 grains/gallon |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 16.5 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 9.3 | 3.8 – 20.0 | 2.9 – 26.8 |
| Southeast | ---- | ---- | ---- |
| Statewide | 10.8 | 3.8 – 20.0 | 2.9 – 26.7 |
("Moderately hard" = 3.5 - 7.0 CaCO3 grains/gallon)
¶ Table 13. Hardness, as CaCO3 mg/L |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 285 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 155 | 65 – 340 | 49 – 458 |
| Southeast | ---- | ---- | ---- |
| Statewide | 180 | 65 – 340 | 49 – 457 |
("Moderately hard" = 60 to 120 CaCO3 mg/L)
¶ Table 14. Water pH |
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| Washington Districts | Median | Typical range | Low - High |
| Western | ---- | ---- | ---- |
| Central | 6.0 | ---- | ---- |
| Northeast | ---- | ---- | ---- |
| East Central | 8.1 | 7.9 – 8.3 | 7.9 – 8.3 |
| Southeast | ---- | ---- | ---- |
| Statewide | 8.1 | 7.9 – 8.3 | 7.9 – 8.3 |
("Neutral" pH = 6.5 - 7.5)
¶ Table 15. Conversion Factors |
| 1 mg/L ≈ 1 ppm |
| 1 mg/L = 1,000 µg/L |
| 1 mmho/cm = 1 dS/m |
| 1 mmho/cm = 1,000 µmho/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 |
¶ Table 16. Sample Count |
|
| Western | ---- |
| Central | 2 |
| Northeast | ---- |
| East Central | 105 |
| Southeast | ---- |
| Statewide | 107 |