Sampling & Monitoring for Water Pollutants

Question 1

Why do sampling or monitoring of aquatic environments? (4)

Answer 1

Determination of:
- overall status/condition
- changes in status/condition
- specific influences
- fitness for use

Question 2

Example of specific influences?

Answer 2

Point sources such as combined sewer overflows

Question 3

Which parameters can be monitored to determine quality? (7)

Answer 3

Water temperature, dissolved oxygen, pH, turbidity, fecal coliform, nitrate, phosphorus

Question 4

Which parameters are assessed using different guidelines?

Answer 4

Nutrients [nitrate/phosphate]

Question 5

Hypoxia?

Answer 5

Low levels of oxygen

Question 6

Anoxia?

Answer 6

No oxygen levels

Question 7

Cause of hypoxia or anoxia?

Answer 7

Excess organic materials - e.g. algal blooms - decomposed by microorganisms

Question 8

DO levels of concern?

Answer 8

< 3 mg/L

Question 9

DO levels considered hypoxic?

Answer 9

< 1mg/L

Question 10

Dissolved oxygen?

Answer 10

how much oxygen dissolved in water & available to living aquatic organisms

Question 11

2 considerations for sampling & monitoring?

Answer 11

• scale
• specificity, general or impacts of discrete sources

Question 12

Representative sampling?

Answer 12

General monitoring of quality reflecting a large spatial scale

Question 13

Random stratified sampling?

Answer 13

Randomly - selected bodies of water from categories/types

Question 14

Example of different categorizations for random stratification?

Answer 14

Position in catchment, altitude, size, permanent/temporary, underlying geology, urban/rural

Question 15

Repeated measures?

Answer 15

Used in combination with random stratification or representativeness

Question 16

Upstream-downstream?

Answer 16

What changes at different points within the river as a result of a specific influencing factor?

Question 17

Before-after-control-impact?

Answer 17

What happens if we do something to effect positive change? Is change really due to what we did?

Question 18

Factors sampling may need to take into account?

Answer 18

• when
• where [within catchment]
• where [within river]
• midstream
• margins
• still or flowing waters

Question 19

Practical limitations of sampling?

Answer 19

Which resources available to carry out work - time/people/equipment

Question 20

Which factors does representative sampling need to consider? (3)

Answer 20

• flow conditions
• events & extremes
• time [season? day?]

Question 21

Primary choices for sampling? (4)

Answer 21

Collect samples, return to lab, process, analyse?
Collect samples automatically, preserve, return to lab, process, analyse?
Measure directly, manually?
Measure directly, instrumented?
EXPENSE

Question 22

How can you add value to sampling? (3)

Answer 22

• opportunistic deployment: co-location at sites used by others & sharing data
• experimental design to align with modelling?
• experimental design to align with stats?

Question 23

Phosphorus in Chalk Streams [Test & Itchen] (4)

Answer 23

• combination of autosamplers & EA gauging stations used
• autosamplers on private land, limited visibility, difficult to get to, only Itchen
• if not next to gauging station, pressure sensor used alongside auto
• bucket for sites next to bridges/roads