1. Air, Water and Land Pollution
Chapter 4:
Environmental Sampling Techniques
Copyright © 2010 by DBS

2. Contents General Guidelines of Environmental Sampling Techniques
Techniques for Sampling Various Media: Practical Approaches and Tips

3. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Sequence of Sampling Matrices and Analytes
Project deals with multimedia and/or multiple parameters use following sequence:
Collect from least to most contaminated sampling locations
If sediment and water is being collected, collect water first to minimize effects from suspended bed materials
For shallow streams, start downstream and work upstream to minimize sediment effects due to sampling disturbances
If sampling at different depths, collect surface samples first and then proceed deeper
Always collect VOCs first, followed by SVOCs (e.g. pesticides, PCBs, oil, etc.), then total metals, dissolved metals, microbiological samples, and inorganic nonmetals

4. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Sample Amount
Minimum sample required depends on the concentration of the analytes present
Should take enough for all analyses and additional for any QA/QC work required
Heterogeneous samples generally require larger amounts to be representative of sample variations
Taking too much sample can lead to problems with storage and transportation

5. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Sample Amount - Water
5 mL for total petroleum hydrocarbons (TPHs), 100 mL for metals, 1 L for trace organics (pesticides)
As a general rule the minimum volume collected should be 3-4 times the amount required for analysis (EPA, 1995)

6. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Sample Amount – Soil/Sediment/Solid Waste
For physiochemical properties (particle size, texture etc.) requires a minimum of 200 g soil
For contaminant analysis g is sufficient
More samples are required if the goal is to detect low solubility (hydrophobic) organic contaminants
Sample volume of waste samples should be kept small to reduce disposal costs

7. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Sample Amount – Air Samples
Volume of air required depends on the minimum chemical concentration that can be detected and the sensitivity of the measurement
Concentration range may be unknown – sample size determined by trial and error

8. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Sample Amount – Water/Sediment Samples for Toxicity Testing
20-40 L Water for an effluent toxicity test
15 L sediment for bioaccumulation tests
8-16 L sediment for benthic macroinvertebrate assessments (EPA, 2001)

9. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Sample Preservation and Storage
Purpose – minimize physical, chemical and biological changes
3 approaches:
Refrigeration
Use of proper sample container
Addition of preserving chemicals

10. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Sample Preservation and Storage
Refrigeration is a universally accepted method to slow down loss processes
Container choice (material type and headspace) is critical to reduce
Volatilization
Adsorption
Absorption
Diffusion
Photodegradation
Addition of preservatives is critical to reduce losses due to chemical reactions and bacterial degradation

11. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Sample Preservation and Storage

12. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Sample Preservation and Storage
Maximum Holding Time (MHT) is the length of time a sample can be stored after collection and prior to analysis
MHTs vary by agency

13. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Sample Preservation and Storage
American Public Health Association (APHA) MHTs:

14. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Sample Preservation and Storage
Immediate: pH, temperature, salinity, DO
Within 1-2 days: careful pre-planning is required to avoid sampling on Friday, Saturday or near holidays

15. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sample Containers
Water
Glass vs. Plastics:
Glass may leach boron and silica, metals may stick to walls
Glass is generally used for organics and plastic for metals, inorganics and physical properties
For trace organics cap and liner should be made of inert materials (teflon)
Headspace vs. no Headspace:
No headspace is allowed for VOC samples
40 mL vial with a teflon-lined septum
Oil and grease should only be half-filled in wide mouthed glass bottles
Special containers:
e.g. BOD/DO bottles and VOC vials

16. 1-33
Standard Methods (1998)

17. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sample Containers
Soil
Low temperature storage
No preservatives except ethanol or sodium bisulfite for VOC analysis (Popek, 2003)
Biological
Aluminum foil (shiny side out) and closed glass containers with inert seals or cap liners

18. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sample Containers
Air
Various collection media:
Filter cassettes
Adsorbent tubes
Bags
Canisters
Reeve, R.N. (2002) Introduction to environmental analysis. Wiley.
Reeve, 2002

19. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sampling Equipment
Surface Water and Wastewater Sampling
Grab sampler, weighted bottle sampler, Kemmerer bottle

20. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sampling Equipment
Groundwater Sampling
Collected from wells using a bailer or by pumps (peristaltic and bladder)
Samples do not come into contact with mechanical components of the pump

21. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sampling Equipment
Soil Sampling
Soil depth and whether or not each soil horizon is necessary to sample are main considerations
Scoops and trowels, tube sampler, augers, split spoon sampler (drilling)

22. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sampling Equipment
Sediment Sampling
Dredges (Ekman dredge, Peterson dredge, Ponar dredge)
Core samplers (Livingstone, Kullenberg, and Mackereth)

23. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sampling Equipment
Sediment Sampling
Dredges (Ekman dredge, Peterson dredge, Ponar dredge)
Core samplers (Livingstone, Kullenberg, and Mackereth)
Glew, J., Smol, J.P. and Last, W.M. (2001) Sediment core collection and extrusion. In Last, W.M. and Smol, J.P. (eds.), Tracking Environmental Change using Lake Sediments, Volume 1, Basin Analysis, Coring, and Chronological Techniques. Kluwer Academic Publishers, Dordrecht, pp
Glew et al, 2001

24. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sampling Equipment
Hazardous Waste
Sludges: Dredges, scoops, trowels, buckets
Composite liquid waste: coliwasa, Thief and Trier samplers

25. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sampling Equipment
Biological Sampling
Very unique and diverse range of equipment
Mammals - Trapping(live and kill)
Fish - Electrofishing, gill nets, trawl nets, sein nets, minnow traps
Benthic macroinvertebrates - Petersen and Ekman dredges

26. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sampling Equipment
Air Sampling
Many direct-reading instruments for monitoring (real-time) levels
Sampling still needed for trace level analysis (expensive and complex)
e.g. High volume total suspended particulate samplers (TSP), PM-10 samplers, PM-2.5 samplers, personal sampling pumps, canister samplers

27. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sampling Equipment
Air Sampling
TSP/PM-10

28. Question
Calculate the PM-10 concentration for the following conditions:
Filter mass gain = mg
Sample time = 1446 min
Initial sampler flow rate = cm3 min-1
Final sampler flow rate = cm3 min-1
Average flow rate = cm/min
Volume of air = cm3/min x 1446 min = 2662 cm3 = x10-3 m3
PM concentration = 6.70 x 10-1 μg / x 10-3 m3 = μg m-3

29. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sampling Equipment
Air Sampling
Summa canister, filter cassettes (particulates), impingers, diffusion tubes, sorbent tubes, polyurethane foam (PUF)

30. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sampling Equipment
Air Sampling
SUMMA canister
Electroplated with Ni and Cr oxides to prevent adsorption of VOCs
Low-ultra low ppt-ppb range concentrations

31. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Air Sampling
Palmes diffusion tubes (PDTs)

32. Environmental Sampling Techniques General Guidelines of Environmental Sampling Techniques
Selection of Sampling Equipment
Air Sampling
Polyurethane Foam Sampler (PUF)
For organics need both solid and vapor phases
Vapor cartridge is placed in-line with quartz fiber filter for semi-volatile organics
PUF plug
Adsorbent resin (XAD-2)
Source:
- Pesticides
- PCB’s
- Dioxins
- PAH’s

34. Environmental Sampling Techniques Techniques for Sampling
Surface Water and Wastewater Sampling
Fresh surface waters: flowing waters, static waters and estuaries
Wastewaters: mine drainage, landfill leachate, industrial effluents etc.
Differ in their characteristics, samples collection is specific for each

35. Environmental Sampling Techniques Techniques for Sampling
Surface Water and Wastewater Sampling
Streams and rivers – size and amount of turbulence impact representativeness of samples
Small streams (<20 ft wide) possible to select a location where a grab sample represents the entire cross-section
Larger streams and rivers multiple samples across the channel width are required
(Also at least one vertical composite (surface, middle, bottom))
Fast moving rivers and streams difficult to collect mid-channel sample
Ponds and impoundments use a single vertical composite at deepest point
Estuaries inland fresh water mixes with oceanic saline water have specific sampling routines

36. Environmental Sampling Techniques Techniques for Sampling
Groundwater Sampling
Requires installation of a sampling well
Well must not change integrity of surrounding waters
Routine groundwater sampling tasks:
Characterize flow
Purge and stabilize groundwater prior to sampling
Minimize cross-contamination due to well materials and sampling devices

37. Environmental Sampling Techniques Techniques for Sampling
Groundwater Sampling
Groundwater Flow Direction
Hydraulic gradient – slope of water table measured from high point to low point across a site
Flow is proportional to gradient, in direction of gradient
Hydraulic head is a vertical measurement from sea level to the water table
Hydraulic gradient = Difference in Hydraulic Head/Distance between two wells

38. Environmental Sampling Techniques Techniques for Sampling
Groundwater Sampling
Well Purging
Used to remove stagnant water in the well borehole and sandpack for representative sample
USGS stabilization parameters:
DO ± 0.3 mg/L
Turbidity ± 10 % (for samples > 10 NTUs)
Specific conductivity ± 3%
ORP ± 10 mV
pH ± 0.1 unit
Temp. ± 0.1 oC

39. Environmental Sampling Techniques Techniques for Sampling
Groundwater Sampling
Cross Contamination

40. Environmental Sampling Techniques Techniques for Sampling
Soil and Sediment Sampling
Soil sampling at shallow depths relatively easy
Sediments are treated similarly with regard to post-sampling pretreatment (homogenizing, splitting, drying and sieving)
Horizontal (grab) or vertical (core) sampling
Composite sampling is common (except for VOCs)
Nonsoil/sediment or nonsieved materials should be noted and not discarded
Sediments from lakes, ponds and reservoirs should be collected at the deepest point (contaminants tend to concentrate in fine grained material in depositional zones)

41. Environmental Sampling Techniques Techniques for Sampling
Hazardous Waste Sampling
Sources: drums, storage tanks, lab packs, impoundments, waste piles, debris
Sampling approach varies considerably
Requires HAZWOPER training
Drums etc.
Research documentation (labels etc.) for health and safety precautions
Use proper protective equipment
Unknown wastes should be opened remotely
Should not be moved since some chemicals are shock-sensitive, explosive or reactive
Sample each phase separately

42. Environmental Sampling Techniques Techniques for Sampling
Hazardous Waste Sampling
Waste Impoundments
Contaminants will be stratified by depth, also horizontally from point of entry
Surface Sampling
Wipe, chip and dust sampling

43. Environmental Sampling Techniques Techniques for Sampling
Biological Sampling
Biological samples difficult to collect
Species availability - Insufficient sample size may result in invalid statistical inference
Sampling protocol needs to account for size differences between species, tissue differentiations, growth stage, and habitat
Susceptible to decomposition of organic analytes

44. Environmental Sampling Techniques Techniques for Sampling
Air and Stack Emission Sampling
Ambient air, indoor workplace air and stack/emission exhausts
Concentrations for most atmospheric pollutants are very low
Analysis of organic compounds requires huge volumes
Large variation in analyte concentration due to changes in meteorlogy
Meteorological parameters must be noted

45. Environmental Sampling Techniques Techniques for Sampling
Air and Stack Emission Sampling
Indoor Air
Ventilation systems can alter air flow and add pollutants
Sampler location will influence the results obtained
Household chemicals can add compounds to the air

46. Environmental Sampling Techniques Techniques for Sampling
Example 4.1: Two wells are drilled 300 m apart along an east-west direction. The east well and west well have hydraulic heads of 20.4 m and 20.0 m, respectively. The third well is located 200 m due south of the east well and has a head of 20.2 m. Schematically determine groundwater flow and direction and estimate hydraulic gradient.
Hydraulic Gradient = Head of well C – Head of well B/Distance from B to the equipotential line CD
= (20.2 – 20.0) / 120 =

48. References
Bodger, K. (2003) Fundamentals of Environmental Sampling, Government Institutes, Rockville, MD.
Cowgillum (1988) Sampling Waters: The Impact of sample variability on planning and confidence Levels, In: Keith, L.H. (1988) Principles of Environmental Sampling. American Chemical Society, Washington, DC.
US EPA (1995) Superfund Program Representative Sampling Guidance: Volume 2, Air (Short-Term Monitoring), Interim Final, EPA 540-R , OSWER Directive , PB , December 1995.
US EPA (2001) Methods for Collection, Storage and Manipulation of Sediments for Chemical and Toxicological Analyses: Technical Manual. EPA-823-B , October 2001.
Keith, L.H. (1988) Principles of Environmental Sampling. American Chemical Society, Washington, DC.
Keith, L.H. (1991) Environmental Sampling and Analysis: A Practical Guide. Lewis Publishers, Boca Raton, Fl.
Reeve, R.N. (2002) Introduction to Environmental Analysis. Wiley.
Popek, E.P. (2003) Sampling and Analysis of Environmental Chemical Pollutants: A Complete Guide. Academic Press, San Diego, CA.

49. Questions
2. Which of the following should be monitored in the field: (a) acidity, (b) DO, (c) pesticide, or (d) hardness.
5. Explain why: (a) HNO3 rather than other acids is used for metal preservation; (b) amber bottles are preferred for PAHs; (c) zero-head space container for groundwater samples collected for tetrachloromethylene analysis.
8. Explain why glass containers are generally used for organic compounds whereas PVC-type containers are used for inorganic compounds.
11. The maximum holding time for metal analysis (excluding Cr6+ and dissolved Hg) after acidification to pH < 2 is most likely: (a) 6 h, (b) 6 days, (c) 6 weeks, (d) 6 months.
18. Suppose you were recently hired as an entry level Environmental Field specialist in a new firm dealing with groundwater remediation where a sampling and analysis plan (SAP) has not been developed. You are assigned as an assistant to a Project Manager for groundwater sampling, and are asked to do the office preparation for this sampling event. Make a list of items you may need in the field. Exclude containers and sampling tools in the list.