Shandal SystemGeological Field Survey
العربية Get access
Shandal System
Platform Quarry & Earthworks SurveyStructural & Geotechnical SurveyStereonet LabRock Mass Classification LabStratigraphic Column DesignerGeological Unit FinderFossil Sites ExplorerGeo-Heritage & Archaeological TourismDEM & Contour Mapping Studio2D Contour Mapping LabGeomorphological & Contour SurveySentinel-2 Spectral IndicesRegional Magnetic LabThermal Maturity & Geothermal LabSeismic Evaluation & Building CodeSeismic Hazard ExplorerGlobal Soil PropertiesBearing Capacity of Shallow FoundationsMohr Circle & Failure EnvelopeAtterberg Limits & PlasticityGrain-Size AnalysisHydrochemistry Water LabHydrological Early WarningAir Quality MonitorEnvironmental Monitoring & ModellingNatural Hazards MonitorVolcanoes of the WorldKerogen Analysis LabPalynofacies Lab
Maps & Data Data hub Earth now Geo-heritage atlas
Learn Academy Library & journal Verify a report
About Shandal Pricing Contact
Switch light or dark theme
Get access Sign in
Water & rivers

Hydrochemistry Water Lab

Ionic balance, water type, drinking and irrigation quality for any number of samples.

Enter the major-ion analysis of surface or groundwater samples. The lab checks the ionic balance, classifies each sample on the Piper, Gibbs, Schoeller, Stiff and USSL diagrams, evaluates drinking quality against the Iraqi standard IQS 417 or the WHO guidelines with two water-quality indices, rates irrigation suitability with six indices and FAO classes, and writes the hydrochemical interpretation.

Subscribe to use this tool Already subscribed? Sign in
Hydrochemistry Water Lab
CationsAnions

Overview

Samples are typed into a table, imported from CSV or pasted from Excel, with optional coordinates. Every analysis is first checked by its charge-balance error; analyses outside ±5 % are flagged before they are interpreted, as reviewers expect.

The hydrochemical facies come from the dominant ions in meq/L and from the four fields of the Piper diamond. Gibbs diagrams separate precipitation, rock weathering and evaporation control. Drinking quality uses the weighted arithmetic index of Brown et al. (1972) per sample and the CCME index for the set, and irrigation uses SAR, %Na, RSC, Kelly ratio, magnesium ratio and permeability index with the USSL and FAO classes. Concrete sulfate exposure follows ACI 318.

What you enter · What you get

What you enter

  • Major ions in mg/L: Ca, Mg, Na, K, HCO₃, CO₃, Cl, SO₄, NO₃, F
  • pH, EC (µS/cm), TDS, turbidity
  • Optional coordinates for each sample
  • Drinking standard: IQS 417 or WHO

What you get

  • Ionic balance check and TDS/EC ratio
  • Piper, Gibbs, Schoeller, Stiff and USSL diagrams
  • Hydrochemical facies and total hardness
  • Drinking WQI per sample, CCME WQI for the set, exceedance table
  • SAR, %Na, RSC, KR, MAR, PI, USSL and FAO classes
  • Written interpretation, sample map, CSV and PDF

How it works in the field

Enter or import the samples
Check the ionic balance
Read the diagrams and indices
Export CSV and the report

Method and equations

Ionic balance

Concentrations are converted to meq/L with the equivalent weight of each ion; errors within ±5 % are accepted (APHA 2017).

CBE = (Σcations − Σanions) / (Σcations + Σanions) × 100

Weighted arithmetic WQI

Each parameter is rated against its limit and weighted inversely to it (Brown et al. 1972).

WQI = Σ qᵢWᵢ / ΣWᵢ, qᵢ = 100 (Vᵢ − V₀)/(Sᵢ − V₀), Wᵢ ∝ 1/Sᵢ

CCME WQI

Scope, frequency and amplitude of failures across all samples (CCME 2001).

CCME WQI = 100 − √(F₁² + F₂² + F₃²) / 1.732

Sodium adsorption ratio and USSL classes

Sodium classes on the USSL diagram have boundaries that fall with salinity (Richards 1954).

SAR = Na / √((Ca + Mg)/2); S1 < 18.87 − 4.44 log EC

Gibbs ratios

Plotted against TDS on a logarithmic axis (Gibbs 1970).

Na/(Na + Ca) · Cl/(Cl + HCO₃)

Who uses it

Hydrogeologists and groundwater engineersEnvironmental and water-quality laboratoriesAgricultural engineersGraduate students writing theses

Standards and references

  1. APHA (2017). Standard Methods for the Examination of Water and Wastewater, 23rd ed. American Public Health Association.
  2. Piper, A.M. (1944). A graphic procedure in the geochemical interpretation of water analyses. Transactions of the American Geophysical Union, 25, 914–923.
  3. Gibbs, R.J. (1970). Mechanisms controlling world water chemistry. Science, 170, 1088–1090.
  4. Schoeller, H. (1962). Les eaux souterraines. Masson, Paris.
  5. Stiff, H.A. (1951). The interpretation of chemical water analysis by means of patterns. Journal of Petroleum Technology, 3(10), 15–17.
  6. Brown, R.M., McClelland, N.I., Deininger, R.A. & O’Connor, M.F. (1972). A water quality index — crashing the psychological barrier. Indicators of Environmental Quality, 1, 173–182.
  7. CCME (2001). Canadian Water Quality Guidelines for the Protection of Aquatic Life: CCME Water Quality Index 1.0, Technical Report.
  8. Richards, L.A. (ed.) (1954). Diagnosis and improvement of saline and alkali soils. USDA Agriculture Handbook 60.
  9. Wilcox, L.V. (1955). Classification and use of irrigation waters. USDA Circular 969.
  10. Ayers, R.S. & Westcot, D.W. (1985). Water quality for agriculture. FAO Irrigation and Drainage Paper 29, Rev. 1.
  11. Eaton, F.M. (1950). Significance of carbonates in irrigation waters. Soil Science, 69, 123–133.
  12. Doneen, L.D. (1964). Notes on water quality in agriculture. University of California, Davis.
  13. World Health Organization (2022). Guidelines for drinking-water quality, 4th edition incorporating the first and second addenda.
  14. Central Organization for Standardization and Quality Control (2009). Iraqi Standard for Drinking Water No. 417, 2nd update.
  15. ACI 318-19. Building Code Requirements for Structural Concrete, Table 19.3.1.1.
Results support professional judgement. They do not replace a licensed engineer’s or geologist’s sign-off.

At a glance

Category
Water & rivers
Runs on
Phone, tablet and desktop browser
Export
CSV, PNG diagrams, PDF report
Access
Subscribers

Related tools

Hydrological Early WarningGlobal Soil Properties2D Contour Mapping Lab

Run this survey on your next site

All 29 tools, report export and the AI assistant come with one subscription.

See plansView all 29 tools