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OutlineWater Chemistry BackgroundChemistry in Urban StreamsMethods2019 ResultsComparison to 2019ConclusionsOutlineWater Chemistry BackgroundChemistry in Urban StreamsMethods2019 ResultsComparison to 2019ConclusionsTemperatureMost aquatic organisms are cold-blooded and have an ideal temperature range,specific to the organism:Diatoms 15-25 degrees CGreen algae 25-35 degrees CBlue greens 30-40 degrees CSalmonids cold water fishTemperature,continuedAffects development of invertebrates,metabolism of organismsAffects dissolved oxygen(warm water holds less oxygen)Warm water makes some substances more toxic(cyanide,phenol,xylene,zinc)and,if combined with low DO,they become even more toxicDissolved OxygenOxygen that is dissolved in waterDO increases with cooler water and mixing of water through riffles,storms,windNutrient loading can lead to algal blooms which result in decreased DO4-5 ppm DO is the minimum that will support large,diverse fish populations.Ideal DO is 9 ppm.Below 3 ppm,all fish die.Dissolved Oxygen,continuedDissolved oxygen can also be expressed as%saturation80-124%=excellent60-79%=ok 60%=poorConductivityMeasures the ability of water to carry an electric currentMeasures the ions such as Na+,Cl-in the waterDifferences in conductivity are usually due to the concentration of charged ions in solution(and ionic composition,temp.)Reported as microsiemens per cmpHpH measures the degree of acidity or alkalinity of the water(each number is a 10-fold difference)0-6=acid;7=neutral;8-14=baseIdeal for fish=6.5 8.2Ideal for algae=7.5 8.4Acid waters make toxic chemicals(Al,Pb,Hg)more toxic than normal,and alter trophic structure(few plants,algae)TurbidityMeasures the cloudiness of the waterTurbidity caused by plankton,chemicals,silt,etc.Most common causes of excess turbidity are plankton and soil erosion(due to logging,mining,farming,construction)Turbidity,continuedExcess Turbidity can be a problem:Light cant penetrate through the water photosynthesis may be reduced or even stop algae can dieTurbidity can clog gills of fish and shellfish can be fatalFish cannot see to find food,but can hide better from predatorsPhosphorus(Reactive)Is necessary for plant and animal growthNatural source=phosphate-containing rocksAnthropogenic source=fertilizer and pesticide runoff from farmingCan stimulate algal growth/bloomNitratesFormed by the process of nitrification(addition of O2 to NH3 by bacteria)Used by plants and algaeIs mildly toxic,fatal at high dosesLarge amounts(leaking sewer pipes,fertilizer runoff,etc.)can lead to algal blooms,which can alter community structure,trophic interactions and DO regimes)Below 90 mg/L seems to have no effect on warm water fish,but cold water fish are sensitiveAlkalinityA measure of the substances in water that can neutralize acid and resist changes in pHNatural source=rocksIdeal water for fish and aquatic organisms has a total alkalinity of 100-120 mg/LGroundwater has higher alkalinity than surface waterHardnessThe amount of Calcium and Magnesium in the water(the two minerals mostly responsible)Natural source=rocks Limestone=hard water,granite=not hard waterHardness,continuedSoft water can be a problem:in soft water,heavy metals are more poisonous,some chemicals are more toxic,drinking soft water over long periods can increase chance of heart attack0 60=soft water61-120=moderately hard water121-180=hard water181+=very hard waterHardness and alkalinity are relatedOutlineWater Chemistry BackgroundChemistry in Urban StreamsMethods2019 ResultsComparison to 2019ConclusionsPhysical Effects of Urbanization Related to Water ChemistryRiparian Vegetation RemovalDecreased Groundwater RechargeHeat Island EffectIncreased Surface Runoff/Impervious SurfacesLeaky Storm-water/Sewage PipesPoint Source PollutionTrends in Water ChemistryTemperature increasesNitrate increasesPhosphorus increasesConductivity increases(Increased ion concentration)O2 demand increasesOutlineWater Chemistry BackgroundChemistry in Urban StreamsMethods2019 ResultsComparison to 2019ConclusionsField MeasurementsDissolved OxygenTemperatureConductivitypHWater Collection For Laboratory AnalysisGrab SamplesThree replicates(from multiple samples)Measured within 24 hours(few exceptions)Picture Source:ci.gresham.or.us/departments/des/stormwater/water_quality.htmLaboratory AnalysisNitrateReactive PhosphorusAlkalinityHardnessTurbidityOutlineChemistry in Urban StreamsWater Chemistry Measurements and TheoryMethods2019 ResultsComparison to 2019ConclusionsField Measurements 2019 SAL PBTurbidityAll values for 2019 5 jtuFor 2019,all but one sampling date 5 was during a storm eventReactive Phosphorus 2019 PB SALNitrate 2019 PB SALAlkalinity 2019 PB SALHardness 2019 PB SALOutlineChemistry in Urban StreamsWater Chemistry Measurements and TheoryMethods2019 ResultsComparison to 2019ConclusionsField Measurement PB 2019 2019Field Measurement For SAL 2019 2019Paint Branch 2019 2019Stewart April Lane 2019 2019OutlineChemistry in Urban StreamsWater Chemistry Measurements and TheoryMethods2019 ResultsComparison to 2019ConclusionsBetween Site DifferencesLand use increased runoff cause increased input of particular constituentsNatural site variation Substrate typeBetween YearsIncreased snow caused more runoff increased use of road-saltDrought(temperature,DO)“.Rivers and the inhabitants of the watery element were made for wise men to contemplate,and fools to pass by without consideration,.for you may note,that the waters are Natures storehouse,in which she locks up her wonders.”Izaak Walton(from Ward,1992)END
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