Water Quality: Salinity, TDS, and Turbidity Measurements

Salinity

Concentration of salts in water, affects organisms.

Total Dissolved Solids (TDS)

Measure of all dissolved substances in water.

Hardness

Sum of divalent cations, mainly Ca2+ and Mg2+.

Soft Water

Low TDS and pH, more corrosive to metals.

Hard Water

High TDS and pH, less corrosive.

Practical Salinity Units (PSU)

Measurement of salinity in g/kg.

Turbidity

Clarity of water, affected by suspended solids.

Total Suspended Solids (TSS)

Particles suspended in water, affects clarity.

Titration

Method to measure salinity using AgNO3.

Ion Chromatography

Technique using ion exchange resin for salinity.

Optical Salinity Refractometer

Measures salinity

Nephelometric Turbidity Unit (NTU)

Unit for measuring turbidity in water.

Sources of TDS

Includes runoff, evaporation, and saline groundwater.

Measuring TDS methods

mass evaporation and conductivity.

Environmental Impact on TSS

Natural and human factors affecting sediment levels.

Bank Stabilization

Methods to reduce erosion and turbidity.

Geology

Type of material affecting stream turbidity.

Seasonal Weather

Spring runoff increases turbidity in streams.

Plant Root Systems

Help stabilize soil, reducing turbidity and erosion

Human Activities

Road building and development increase stream turbidity.

BMP for TSS

Best management practices to control sediment.

Conductivity Measurement

Reported as µS/cm, highly temperature dependent.

.64

Conversion factor for TDS from conductivity

Lake Okeechobee Example

Hard water lake with high Ca2+ and Mg2+.