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1、Analysis of Water Chemistry,Urban Stream Restoration Project,By:Bob Smith&Shelly Alicia,Outline,Water Chemistry BackgroundChemistry in Urban StreamsMethods2003 ResultsComparison to 2002Conclusions,Outline,Water Chemistry BackgroundChemistry in Urban StreamsMethods2003 ResultsComparison to 2002Conclu
2、sions,Temperature,Most 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 fish,Temperature,continued,Affects development of invertebrates,metabolism of organ
3、ismsAffects 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 toxic,Dissolved Oxygen,Oxygen that is dissolved in waterDO increases with cooler water and mixing of water through riffle
4、s,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,continued,Dissolved oxygen can also be expressed as%saturation80-124%=excellent60
5、-79%=ok 60%=poor,Conductivity,Measures 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 cm,pH,pH measures
6、 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),Turbidity,Measures the cloudin
7、ess 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,continued,Excess Turbidity can be a problem:Light cant penetrate through the water photosynthesis may be reduced
8、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 predators,Phosphorus(Reactive),Is necessary for plant and animal growthNatural source=phosphate-containing rocksAnthropogenic source=fertilizer and pesticide run
9、off from farmingCan stimulate algal growth/bloom,Nitrates,Formed 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 st
10、ructure,trophic interactions and DO regimes)Below 90 mg/L seems to have no effect on warm water fish,but cold water fish are sensitive,Alkalinity,A 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
11、 total alkalinity of 100-120 mg/LGroundwater has higher alkalinity than surface water,Hardness,The amount of Calcium and Magnesium in the water(the two minerals mostly responsible)Natural source=rocks Limestone=hard water,granite=not hard water,Hardness,continued,Soft water can be a problem:in soft
12、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 related,Outline,Water Chemistry BackgroundChemistr
13、y in Urban StreamsMethods2003 ResultsComparison to 2002Conclusions,Physical Effects of Urbanization Related to Water Chemistry,Riparian Vegetation RemovalDecreased Groundwater RechargeHeat Island EffectIncreased Surface Runoff/Impervious SurfacesLeaky Storm-water/Sewage PipesPoint Source Pollution,T
14、rends in Water Chemistry,Temperature increasesNitrate increasesPhosphorus increasesConductivity increases(Increased ion concentration)O2 demand increases,Outline,Water Chemistry BackgroundChemistry in Urban StreamsMethods2003 ResultsComparison to 2002Conclusions,Field Measurements,Dissolved OxygenTe
15、mperatureConductivitypH,Water Collection For Laboratory Analysis,Grab SamplesThree replicates(from multiple samples)Measured within 24 hours(few exceptions),Picture Source:stormwater/water_quality.htm,Laboratory Analysis,NitrateReactive PhosphorusAlkalinityHardnessTurbidity,Outline,Chemistry in Urba
16、n StreamsWater Chemistry Measurements and TheoryMethods2003 ResultsComparison to 2002Conclusions,Field Measurements 2003,Turbidity,All values for 2003 5 was during a storm event,Reactive Phosphorus 2003,Nitrate 2003,Alkalinity 2003,Hardness 2003,Outline,Chemistry in Urban StreamsWater Chemistry Meas
17、urements and TheoryMethods2003 ResultsComparison to 2002Conclusions,Field Measurement PB,Field Measurement For SAL,Paint Branch,Stewart April Lane,Outline,Chemistry in Urban StreamsWater Chemistry Measurements and TheoryMethods2003 ResultsComparison to 2002Conclusions,Between Site DifferencesLand us
18、e 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),
