Measuring Water Pollution

1
Measuring Water Pollution

• A Quick Overview

2
How do you measure the quality of a moving, ever
changing fluid medium?
3
Two Basic Approaches

• TECHNOLOGY-BASED LIMITS Use a certain treatment
  technology (BPT, BAT, MACT, BPJ) to achieve a
  given quality of effluent

• WATER QUALITY-BASED LIMITS Quantitative
  relationship between inputs and quality (LD50,
  NOEL)--dose/response risk assessment, hydrology,
  mass balance

4
The Conventional Pollutant Measures

• Oxygen (BOD, COD, DO)
• Solids content (TSS, Conductivity, Secchi disk,
  settleable solids)
• Nutrients (phosphorus, nitrogen)
  /Algae/Eutrophication
• Acidity (pH)
• Bacteria (e.g., fecal coliform)
• Temperature

5
Oxidizing (Oxygen-Using)Reactions

• Fire
• Metabolism of humans and animals
• Fate of pollutants in water

• C in fuel combines with atmospheric O2
• carbon-bearing organic compounds oxidized to
  CO2,water, energy
• pollutants are oxidized, depleting O2 in water

6
Measures of oxygen in water

• Dissolved oxygen (DO)--time and space variables,
  dilution
• Biological oxygen demand, five days (BOD5)
• Chemical oxygen demand (COD)
• Sediment oxygen demand (SOD)

7
Oxygen and other pollutants may vary according to

• Fluctuations in inputs (lagged)
• Time of day (day-night)
• Time of year (summer-winter)
• Water temperature (thermal stratification)
• Stream flow
• Which in turn varies with land clearance/imperviou
  s cover, storm events, seasonal variations,
  channel structure, etc.

8
Effects of sediment loading

• Destruction of spawning beds
• Adsorption and transport of other pollutants
• Reduced light penetration, aquatic vegetation
• Greater nutrients loadings, oxygen demand
• Interference with navigation, flood control,
  recreation, industry

9
Effects of nutrient loadings (N, P measured by
Chlorophyll a, Secchi, algal species)

• Algae blooms
• DO changes, fish kills
• Shift of trophic status toward eutrophic
• Drinking water impairment (direct and indirect)
• Aesthetics (color, clarity, smell)
• Uptake and release of toxics

10
Effects of acidification(measured in pH--log
scale)

• Direct kill of living things
• Shift toward acid-tolerant species
• Mobilization (dilution, desorption) of metals and
  other toxics

11
What about toxics?
12
Impacts of toxics

• Acute mortality (instant death)
• Chronic illnesses (e.g., cancer)
• Reproductive and developmental toxicity (hormone
  mimics)
• Persistence over space (toxaphene) and time
  (PCBs) or transformation (DDT to DDE, PCB
  dechlorination, methyl mercury)
• Storage in reservoirs (sediment sinks)

13
Some approaches to toxics parameters

• Chemical levels (water, sediment)
• Ability to support designated uses
• Ability to support beneficial uses
• Fish advisories
• Historical baselines
• Background levels
• Narrative criteria (no toxics in toxic amounts)

14
Indices

• Bring diverse measurements together into a
  single-number value

15
Ecosystem approaches

• Look at interactions of living and nonliving
  parts of the ecosystem (whats an ecosystem?)
• Try to identify stresses and responses
• Holistically integrate physical, biological, and
  social aspects of the area in question

16
Social Indicators

• Stewardship
• Sustainability
• Stakeholder Involvement
• Etc., etc. (what is the good society?)

17
(No Transcript)