Introduction to Environmental Sampling

1. A J A Y S H A R M A
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Environmental Sampling

2. Three major areas
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Water sampling
Air sampling
Soil sampling

3. Important criteria's for environmental
sampling are
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Location
Interferences with surrounding
Instruments/ apparatus /tools
Integrity & composure of individual

4. Water sampling
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To understand water sampling first understand
water cycle (hydrologic cycle) in nature, soil
characteristics (permeability & porosity) and basic
characteristics of water such as temperature,
dissolved oxygen and turbidity.

5. Hydrologic cycle
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Transfer of water between land, sea and atmosphere
(air).
Water precipitates onto land, may transpired by
vegetation, runoff, sink into land and some part
evaporate.
Circulation of water in earth’s hydrosphere.

6. Permeability of soil
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Due to the existence of the inter-connected
voids, soils are permeable. The permeable
soils will allow water flow from points of high
energy to points of low energy.
Permeability is the parameter to characterize
the ability of soil to transport water.

7. Water table
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Below a certain depth, all the interstices are filled
with water. The upper surface of this water
saturated zone is called the water table.

8. Ground & surface water
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Ground water: Water below the water table is
ground water
In area of higher water table, GW interacts
with earth’s surface in form of seepage, streams
and spring.
Surface water: water in contact with atmosphere
and earth surface is surface water.

9. Before sampling
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Make health and safety plan (be safe)
Extra sample kits (how many duplicates)
Sampling plan & strategy (what ,where & how)
Turnaround time (communication with lab or
project manager)
Legal issues (access permit)

10. Site observations
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Color ,odour & turbidity (cloudiness)
Algal bloom (consumes oxygen & give off toxins)
Full description of weather activity on sampling time
Any indication of interference or unusual activity

11. On site tests
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Those parameters that may change on way to
laboratory should be tested immediately on site
Chlorine can be measured with test kit
Oxygen & temperature can be measured with meter

12. Sampling location
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One has to survey the site to determine the sampling
locations.
To conclude that there was a discharge from a
particular facility, samples will have to be taken
before discharge point, at discharge point, and below
the discharge point.
Flow estimates should be made (use basic
mathematics skills)
Sampler has to judge or predict how far downstream
to sample so that a possible slug of pollutant might
be found.

13. Sampling Locations
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14. Flow rate calculations
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Amount of fluid flowing in given time is flow rate.
Flow rate= Area(m2) × Velocity (m/s)
Daily Flow= (m3/s) × 60 s/min. × 1440 min/d

15. Detention time
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Length of time a drop of water or sediment remains
in chamber.
It is amount of time in which any tank fill up o
overflow.
Detection time= Volume of tank/ Flow rate