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Measuring Water Pollution. A Quick Overview. How do you measure the quality of a moving, ever changing fluid medium?. TECHNOLOGY-BASED LIMITS: Use a certain treatment technology (BPT, BAT, MACT, BPJ) to achieve a given quality of effluent (work backward from effluent chemistry).
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Measuring Water Pollution A Quick Overview
How do you measure the quality of a moving, ever changing fluid medium?
TECHNOLOGY-BASED LIMITS: Use a certain treatment technology (BPT, BAT, MACT, BPJ) to achieve a given quality of effluent (work backward from effluent chemistry) WATER QUALITY-BASED LIMITS: Quantitative relationship between inputs and quality (LD50, NOEL)--dose/response risk assessment, hydrology, mass balance Two Basic Approaches:
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
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 Oxidizing (Oxygen-Using)Reactions
“Assimilative capacity”: ability of a waterbody to convert a pollutant into something harmless (to whom or what?)
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)
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 clearing/impervious cover, storm events, seasonal variations, channel structure, etc.
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
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
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
Impacts of toxics • Acute mortality (instant death) • Chronic illnesses (e.g., cancer) • Toxicity at low doses (e.g., dioxin) • 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)
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)
Automated Measurements:Sondes (Hydrolab or YSI) • Automated sampling of basic conventional parameters • Fine-grained (e.g., every 15 minutes) • Download to laptop for analysis
Indices Bring diverse measurements together into a single-number value
Ecosystem approaches • Look at interactions of living and nonliving parts of the ecosystem (what’s an ecosystem?) • Try to identify stresses and responses • Holistically integrate physical, biological, and social aspects of the area in question
Institutional Context: Remedial Action Plan • Great Lakes Water Quality Agreements • “Areas of Concern” • Plan to restore “beneficial uses”
Restrictions on Fish Consumption Restrictions on Dredging Added costs to agriculture or industry Tainting of fish flavor Restrictions on drinking water consumption Degraded fish or wildlife populations Degraded benthos Eutrophication or undesirable algae Loss of fish or wildlife habitat Fish tumors or deformities Beneficial Uses