Presentation on theme: "Water Quality & Testing"— Presentation transcript:
1 Water Quality & Testing Water quality is the physical, chemical and biological characteristics of waterThe vast majority of surface water on the planet is neither potable (fit for drinking) nor toxic (poisonous) – essentially, not good or badApproximately ___% of the world’s population has no access to potable water25
2 Water QualityNo single property can tell whether water is polluted or notReview: What are some sources of water pollution?
3 Sources of Water Pollution Industrial discharge of chemical wastes and byproductsDischarge of poorly-treated or untreated sewageSurface runoff containing pesticides or fertilizersSlash and burn farming practice, which is often an element within shifting cultivation agricultural systemsSurface runoff containing spilled petroleum productsSurface runoff from construction sites, farms, or paved and other impervious surfacesDischarge of contaminated and/or heated water used for industrial processesAcid rain caused by industrial discharge of sulfur dioxide (by burning high-sulfur fossil fuels)Eutrophication by runoff containing detergents or fertilizersUnderground storage tank leakage, leading to soil contamination, and hence aquifer contaminationInappropriate disposal of various solid wastes and, on a localized scale, litteringOil spills
4 Water RegulationsThe Environmental Protection Agency (EPA) regulates limits on the amount of certain contaminants in the waterThe Food and Drug Administration (FDA) limits contaminants in bottled waterDrinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of these contaminants does not necessarily indicate that the water poses a health risk.
5 Categories of Water Tests BiologicalMicroorganisms such as fecal coliform bacteria (Escherichia coli), Cryptosporidium, and Giardia lambliaDissolved organics: Colored Dissolved Organic Matter (CDOM), Dissolved Organic Carbon (DOC)Bethic Macroinvertebrates:Mollusca (Snails)Ephemeropteroidea (Mayfly)Plecoptera (Stonefly)Trichoptera (Caddisfly)ChemicalDissolved Oxygen(DO)pHBiochemical oxygen demand (BOD)Chemical oxygen demand (COD)Nutrients, such as nitrogen and phosphorusDissolved metals and metalloids (lead, Mercury (element),arsenic, etc.)PesticidesHeavy MetalsPharmaceuticalsHormone analogsPhysicalElectrical Conductivity (salinity)Color, Taste and OdorTurbidity (clarity)Total suspended solids (TSS)Nutrients, such as nitrogen and phosphorusDissolved salts and elements (sodium, chloride, potassium, calcium, manganese, magnesium)Temperature
6 Temperature Determine types of organisms that can live in water Affects how much oxygen water can holdWarm water holds less oxygenThermal Pollution (increased water temperature)decreasing oxygen supplykilling fish juveniles which are vulnerable to small increases in temperatureaffecting ecosystem composition.
7 Dissolved Oxygen Measurement for outdoor bodies of water Measure of the amount of oxygen dissolved in waterMeasurement for outdoor bodies of waterMore DO generally relates to “healthier” water (oxygen necessary for most aquatic species to breath)Related to Biochemical Oxygen Demand (BOD)how fast biological organisms use up oxygen in a body of water
8 Representative pH values SubstancepHHydrochloric Acid, 10M-1.0Lead-acid battery0.5Gastric acid1.5 – 2.0Lemon juice2.4Cola2.5Vinegar2.9Orange or apple juice3.5Tomato Juice4.0Beer4.5Acid Rain<5.0Coffee5.0Tea or healthy skin5.5Urine6.0Milk6.5Pure Water7.0Healthy human saliva6.5 – 7.4Blood7.34 – 7.45Seawater7.7 – 8.3Hand soap9.0 – 10.0Household ammonia11.5Bleach12.5Household lye13.5pHPotential of Hydrogen – measures hydrogen concentration in water7.0 is neutral on scale of 0 – 14Can affect how chemicals dissolve in water
9 NutrientsEutrophication, strictly speaking, means an increase in chemical nutrients (typically nitrogen and phosphorus)Resultant increase in primary productivityexcessive plant growth and decayFurther impacts, including lack of oxygen and severe reductions in water quality and in fish and other animal populations.
10 Turbidity / Total Suspended Solids Amount of particulate matter in waterRelated to sediment, phytoplankton and nutrients in waterTurbidity reflects matter visible to naked eye (measured with secchi disk)TSS collects dissolved material (filtered) measured as weight
11 Salinity Dissolved salt content in water Influences organisms that can live in that areaOceans are about 35 ppt or soWater salinityFresh waterBrackish waterSaline waterBrine< 0.05 % %3 - 5 %> 5 %< 500 ppmppmppm> ppm
12 Heavy MetalsLiving organisms require trace amounts of some heavy metals, including iron, cobalt, copper, manganese, molybdenum, vanadium, strontium, and zincexcessive levels can be detrimental to the organism.Other heavy metals such as mercury, lead and cadmium are toxic metalsthey have no known vital or beneficial effect on organismstheir accumulation over time in the bodies of mammals can cause serious illness
13 MicroorganismsE. coli (fecal coliform bacteria) can generally cause several intestinal and extra-intestinal infectionsCryptosporidium is a protozoan pathogen and causes a diarrheal illness called cryptosporidiosisGiardia lamblia is a flagellated protozoan parasite that colonises and reproduces in the small intestine, causing giardiasis. Symptoms of include diarrhea, malaise, excessive gas, etc