Surface Water Sampling -...

Surface Water Sampling

Steve Howatt

Agricultural & Environmental Research

Who are we?

• CRO based out of Prince Edward Island, CANADA

• We have two research farms:

– New Glasgow, Prince Edward Island • serving Zone 1 (1A)

– St Marc-sur-Richelieu, Quebec• serving Zone 5 (5A, 5B)


What we do

• Pesticide Efficacy Studies:– Pesticide efficacy / crop tolerance– Trials to investigate label expansions– Setup, coordination and monitoring of research permit sites

• Pesticide Residue Studies:– Crop residue studies (OECD / EPA GLP)– Field dissipation studiesField dissipation studies

• Other Crop and Environment-related research


Surface Water Monitoring Experience

• Watershed monitoring programs– Monitor water quality– Determine water quality index– Correlate water quality with land use

• Effectiveness of constructed wetlands• Nitrate monitoring programs• Pesticide monitoring• Study of the impacts of agricultural practices on water quality• Study of the impacts of agricultural practices on water quality


Presentation Outline

• Sampling Methods

• Automated Sampling Equipment

• Selecting Sampling Locationsg p g

• Sampler Installation


Stream sampling considerations

• Understand the purpose of the sampling program• Be familiar with the stream to be sampled:

– Must sample downstream of the ‘discharge point’– Must sample downstream of the discharge point– Be aware of other possible contaminants– Know what is going on upstream (dams, effluent outlets, etc)


Stream sampling considerations

• Stream elements:– Riffles – shallow, fast moving water– Pools – deep, slow moving water– Runs – moderate depth and speed


Sampling Location

• Consider:– Access, weather, etc


Manual Sampling

• Involves filling a sample bottle by hand (grab sample)

• Considerations:– Should try to sample at the centre of the channel– Face the mouth of the bottle upstreamp– Avoid floating debris and avoid disrupting sediment– Always a good idea to label containers prior to sampling

• Good method when relatively few samples will be required, and when sampling can be conveniently scheduled.


Manual SamplingAdvantages DisadvantagesAdvantages• Simplicity• Low cost

Disadvantages• Requires site visits for every

sample

• Easy to monitor and observe• Easy to re-collect a sample

• Safety concerns • Labour costs can be high if

many samples are required


Equipment Required for Manual Sampling

B ttl• Bottles• Sampling pole• Coolers (when necessary)• Hip boots or chest waders

• Meters for DO etc if readingsMeters for DO, etc if readings taken on site


Automated Sampling

• Sampling and data collection are performed by a device (autosampler)

• The system records monitored conditions and sample collection data

• Samples are held in the sampler until they can be collected by the technician


Automated SamplingAdvantages DisadvantagesAdvantages• Lower labour cost (during

sampling) – can be extensive k i th l i d t

Disadvantages• Equipment cost• More technician training is

work in the planning and set-up phase

• Potentially safer working diti

required• Increased possibility of

equipment failureconditions

• Easier to plan and schedule site visits (as long as things are orking properl )

– Power failure – Programming problems– Vandalism or theftare working properly) Vandalism or theft – Flooding


Equipment for Automated Sampling

• Programmable Auto sampler• Flowmeters, rain gauges, probes to measure other parameters• Data logging capabilities ?• Communication options ?• Infrastructure – shelter, security, power, etc., y, p ,


Autosampler components

• Most samplers:– Use a pump to draw water through a strainer and flexible sample

t b d d it th l i t ll ti b ttltube and deposit the sample into a collection bottle– Use a computer processor to allow programming of sampler

functions:• Collection intervals• Sample volumes• Bottle positions in carousel


Auto sampler

• Many options available:

– Composite vs. discrete sampling

– Event based sampling ?p g• Flow based• Event based (rainfall, temperature, pH)• Water level based

– Refrigeration ?


Programmable controller

back

front


Refrigerated compartment


Sample compartment

Distribution arm and bottle carousel


Suction / Intake Line


Rain Gauge

• Key element for stormwater runoff monitoringM it i f ll d b• Measures on-site rainfall and can be used to trigger a sampling event– Sampler can remain idle until

diti i lconditions require a sample

• Must be installed properly, and away from any obstructions


Other parameter measurement devices

• Multi-parameter probes:– Dissolved oxygen– pH – Conductivity– Temperaturep– Turbidity

• Can be used to monitor and• Can be used to monitor and record data, or can be used to trigger sampling events


Flow / Level Monitoring

• For monitoring water level or to trigger sampling events


Data Collection


CommunicationsI t t f t it i / t l• Important for remote monitoring / control:– Re-programming or forcing a ‘grab

sample’– Monitoring system status & checking

on sampling events– Downloading data from logger

• Modem:– Can notify in the event of a problem:Can notify in the event of a problem:

• Low water level• Sample missed• Power failure


Power failure

Sampler Programming and Set-up

• Pre-use programming and system configuration


Sampler Programming and Set-up

• Shop testing:

– Verify accuracy of sensors and probes

– Calibrate suction line

Ensure operation of– Ensure operation of refrigeration unit, etc


Autosampler Site Selection• Accessibility• Accessibility• Identify flood line• Security / shelter• Power source• Vertical head


Site Planning


Shelter set-up


Sampler Installation


Routing of Cables and Hoses


Installation of Probes and Intake


Sample Intake Installation

• The sample intake MUST be properly positioned in the stream to collect representative samples

• Must be secured

• Tubing should also be secured


Sampler On-site Programming


On-site Calibration


Sample Collection


Thank you


Surface Water Sampling -...

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