Vadose ZoneVadose Zone&&

AutosamplersAutosamplers

AutosamplersAutosamplers An autosampler is a programmable liquid sampler that is capable An autosampler is a programmable liquid sampler that is capable

of operating in hostile environments such as sanitary sewers and of operating in hostile environments such as sanitary sewers and heavy storms without additional protection. heavy storms without additional protection.

The unit uses a peristaltic pump that pulls in the samples and The unit uses a peristaltic pump that pulls in the samples and purges the sample line. The sample is fed from the pump down to purges the sample line. The sample is fed from the pump down to a filling arm beneath the control case. The filling arm rotates a filling arm beneath the control case. The filling arm rotates above the bottle case and fills each bottle, up to 24, as the above the bottle case and fills each bottle, up to 24, as the according to the program the user has entered. A variety of bottle according to the program the user has entered. A variety of bottle sizes varying from twenty four 350 mL bottles to one 4 gallon sizes varying from twenty four 350 mL bottles to one 4 gallon bottle can be used in the bottle case. Samples that are heat bottle can be used in the bottle case. Samples that are heat sensitive can be kept cold by addition of ice to the water proof and sensitive can be kept cold by addition of ice to the water proof and insulated (R-14) bottle case. insulated (R-14) bottle case.

With an autosampler you can program the machine to sample on With an autosampler you can program the machine to sample on a daily basis or when the stream flow reaches a certain level thus a daily basis or when the stream flow reaches a certain level thus saving you a great deal of time and risk.saving you a great deal of time and risk.

Two or more autosamplers can be coordinated to record data at Two or more autosamplers can be coordinated to record data at identical times upstream and downstream of a sewer discharge. identical times upstream and downstream of a sewer discharge.

Vadose ZoneVadose Zone

The region of the The region of the shallow subsurface shallow subsurface bounded on top by the bounded on top by the earth’s surface and earth’s surface and the bottom by the the bottom by the water table.water table. Unsaturated zoneUnsaturated zone Tension dominated Tension dominated

zonezone Soil moisture zoneSoil moisture zone Zone of aerationZone of aeration

Vadose Zone PhasesVadose Zone Phases Solid phaseSolid phase

Skeletal structure, through which the fluid Skeletal structure, through which the fluid phases may pass or be retainedphases may pass or be retained

Fractured rock, cobbles, gravel, sand, silt and clayFractured rock, cobbles, gravel, sand, silt and clay Organic matter-roots, leaves and waste productsOrganic matter-roots, leaves and waste products

Non-solid phasesNon-solid phases WaterWater

Gas/vapor Gas/vapor

Immiscible fluidsImmiscible fluids

Vadose Zone PhasesVadose Zone Phases

Vadose Zone Monitoring MethodsVadose Zone Monitoring Methods

Tensiometer – measure soil Tensiometer – measure soil matrix potential (pressure)matrix potential (pressure) Easily available Easily available InexpensiveInexpensive Can be custom madeCan be custom made

Cannot measure Cannot measure hydraulic gradienthydraulic gradientpositive pressurepositive pressure

Other MethodsOther Methods Electrical Resistance BlocksElectrical Resistance Blocks

Measure soil moisture or soil-water pressureMeasure soil moisture or soil-water pressure Thermocouple PsychrometersThermocouple Psychrometers

Measure in-situ woild=water pressure under very dry Measure in-situ woild=water pressure under very dry conditionsconditions

Gamma-Ray AttenuationGamma-Ray Attenuation Indirectly measure moisture content be nondestructively Indirectly measure moisture content be nondestructively

determining soil density determining soil density Nuclear Moisture Logging-neutron sourceNuclear Moisture Logging-neutron source

Soil-Gas monitoringSoil-Gas monitoring

Soil Sampling and Water Soil Sampling and Water QualityQuality

Soil Sampling and Water Soil Sampling and Water QualityQuality

Pore water extractionPore water extraction Core samples – not most desirable Core samples – not most desirable

methodmethod Suction LysimetersSuction Lysimeters

In-situ soil water collectionIn-situ soil water collection