Water Quality Test 2
Sources of Hardness
1. dissolution of limestone
Reduction
a process involving gain of electrons
Identify Information Inputs
identify data and information needed to answer study questions
Laboratory Analysis
selection of an analytical laboratory (accreditation organizations: EPA, ISO, NELAP, ELAP); selection of analytical methods
Photosynthesis
solar energy + 6CO2 + 6H2O -> C6H12O6 + 6O2 C6H12O6=biomass
Define the Boundaries of the Study
specify the target population and characteristics of interest, define spatial and temporal limits, scale of inference
Identify the Goal of the Study
state how environmental data will be used in meeting objectives and solving the problem, identify study questions, define alternative outcomes
Quality System
structured and documented system describing the policies, objectives, principles, organizational authority, responsibilities, accountability, and implementation plan of an organization for ensuring the quality in its work processes, products, items, and services
Total Hardness
sum of calcium amd magnesium expressed in equivalent of CaCO3 at mg/L water; carbonate hardness (temporary) + non-carbonate harness (permanent)
Total Hardness Measurement
sum of metal cations in water 1. complete cation analysis 2. calculation of the hardness causes by each ion; hardness = [divalent cation]i * 50 / EW of divalent cation i; titration A*N*50000/mL of sample A: mL EDTA titrant N: normality of EDTA titrant
Sensitivity
the capability of a method or instrument to discriminate between measurement responses representing different levels of variable of interest
Arsenic
"king of poisons;" "poison of kings;" short term: vomiting, throat and stomach pain, bloody darrhea long term: circulatory problems, high blood pressure, cancer *MCL=10 ppb* natural sources: volcanic activity, weathering of rocks and forest fires anthropogenic sources: certain fertilizers, chromated copper arsenate pressure treated wood, animal feeding operations, industry practices such as copper smelting, mining and coal burning As(III): toxic; oxidation to get to As(V)
TSS
((A'-B')*1000)/(C) [=] mg/L A: weight of dried residue + filter paper B': weight of filter paper C: volume of sample used in mL
DOM
((A-D)*1000)/(C) [=] mg/L A: weight of dried residue + dish in mg D: weight of dried residue + dish after 550 C evaporation C: volume of sample used in mL
Percent Saturation
(([O2]unequilibrated,Ti,Pi)/([O2]saturated,Ti,Pi))*100 [O2]unequilibrated,Ti,Pi: @ non-equilibrium; [O2]saturated,Ti,Pi: @ equilibrium
Empirical Factor
(0.55-0.9 usually 0.65) range because not all salts have higher conductivity when dissolved in water; depends on soluble components of the water and on the temperature of measurement
Sources of Acidity
1. CO2 2. acid rain 3. sulfide-bearing soils and bedrocks (FeS2: pyrite)
Environmental Impacts of TDS
1. affect water balance in cell of organisms 2. serve as carriers or source of contaminants which readily cling to suspended particles 3. affect water pH 4. make drinking water unpalatable 5. clog pipes of water system 6. decrease water clarity 7. decrease the passage of light through water 8. heat up water more rapidly and hold more heat
Sources of Odor
1. algal blooms (ex. geosmin: musty reservior water chemical->absorbs catfish) 2. industrial wastes 3. domestic sewage 4. disinfection byproducts 5. dissolved minerals (iron/manganese)
Biotic Factors Affecting DO Concentrations
1. aquatic organisms aquatic plants and phytoplankton (single cell floating plants that are the base of that aquatic food web and provide most of the aquatic oxygen) release oxygen into the water as a product of photosynthesis
Inorganic Pollutants
1. arsenic 2. cadmium 3. chromium 4. lead 5. mercury 6. selenium 7. nitrate 8. nitrite 9. fluoride
Affects of Water Temperature
1. color of water 2. suspended solid content 3. depth of water 4. shade of shoreline vegetation 5. latitude of the waterway (weather) 6. time 7. volume of water 8. temperature of water supplying waterways
Negative Impact of Increasing Atmospheric CO2 on Calcifying Organisms
1. depletion of ocean CaCO3, building block for the shells of many marine organisms 2. disappearing coral reefs 3. reduction of phytoplankton and zooplankton
What makes up a Water Quality Standard?
1. designated uses 2. water quality criteria 3. anti-degradation policies 4. general policies
Sources of Total Dissolved Solids
1. hard-water ions (Ca 2+, Mg 2+, HCO3 -) 2. fertilizer in agricultural runoff (NH4 +, NO3 -, PO4 3-, SO4 2-) 3. urban runoff (Na +, Cl -) 4. salinity from tidal mixing, minerals, or returned irrigation water (Na +, K +, Cl -) 5. acidic rainfall (H +, NO3 -, SO3 2- and SO4 2-)
Environmental Impacts of Suspended Solids
1. increases water temperatures 2. reduces dissolved oxygen in water 3. reduces light penetration in the water 4. clog fish gills 5. affecting egg and larval development 6. smother fish eggs and benthic macroinvertebrates
Chemicals that Cause Odor
1. iron: rusty or metallic taste 2. manganese: rusty or metallic taste 3. hydrogen sulfide: rotten egg smell 4. methane gas: garlic taste 5. aldehydes: fruity
Eutrophication Changes Water Chemistry
1. pH 2. dissolved O2 3. CO2 4. ammonia 5. nitrates/nitrites 6. phosphates 7. bad taste/odor/toxins
Thermal Pollution Sources
1. power plants 2. urban runoff 3. urban construction 4. agriculture activities 5. impoundments (dams: water stays still and then is released downstream from bottom of dam-water temperature is not the same as temperature of water in contact with the atmosphere)
TDS/TSS/DOM Measurements
1. pre-treat filter 2. filter water 3. evaporate filtrate, dry, cool and weigh until constant or <0.5 mg (TDS) 4. evaporate filter (TSS) 5. dry dried evaporated sample at 550 C for 1 hr (DOM)
Rejection Criteria
1. presence of insect(s) 2. presence of vegetation particulates 3. presence of unusually large amount of sediment 4. presence of potential contaminant was observed but values < MDL 5. H2So4 preserved nutrient sample pH < 1.3 of > 2 6. nutrient preserved with HNO3
Contaminant Groupings
1. produce no health effects until a threshold concentration exceeded 2. no threshold 3. essential to diets-absence causes problems, but too much also causes problems
What Can Be Done?
1. reduce use of P in fertilizer/detergents 2. reduce P in sewage effluent 3. balance fertilizer/feed P supply with requirements (transport excess P to P-deficit areas) 4. manage runoff (no till, contour tillage, terracing, buffer strips)
Still Water
1. select one or more vertical section(s) 2. lower sensors to the depth appropriate to meet study needs 3. monitor field-measurement readings *report median of values measured after readings stabilized
Sources of Suspended and Settleable Solids
1. soil erosion 2. waste discharge 3. urban runoff 4. eroding stream banks 5. large numbers of bottom feeders 6. excessive algal growth
EPA DQOs Formulation Process
1. state the problem 2. identify the goal of the study 3. identify information inputs 4. define the boundaries of the study 5. develop the analytical approach 6. specify performance or acceptance criteria 7. develop the plan for obtaining data (1-5: qualitative criteria; 6: quantitative criteria)
Desirable Hardness Range for Aquatic Organisms
61-121 (moderately hard water) and 121-180 (hard water)
Dissolved Solids
< 2 µm; consists of calcium, chlorides, nitrate, phosphorus, iron, sulfur, other ion particles, minerals, and organic matter
Suspended Solids and Settleable Solids
> 2 µm; include soil particles (clay, silt, sand), plankton, algae, fine organic debris, and other substances; typically 4 µm - 1000 µm
Settleable Solids
> 2 µm; particles settling out of a water sample within a one hour period
National Field Manual for Collection of Water-Quality Data
A1: preparations for water sampling A2: selection of equipment for water sampling A3: cleaning of equipment for water sampling A4: collection of water samples A5: processing (preservation) of water samples A6: field measurements A7: biological indicators A8: bottom-material samples A9: safety in field activities
Respiration/Decomposition
C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy (in form of ATP) C6H12O6=biomass
Cw=Pi/H'RT
Cw=concentration of a compound in water (M) Pi=partial pressure of a compound in air (atm) H'=Henry's law constant (dimensionless) R=gas constant (0.082057 L*atm/mol*K) T=temperature (K)
Anoxic
DO concentration 0-0.2 mg/L no life really
Normoxic
DO concentration >2 mg/L low
Hypoxic
Do concentration 0.2-2 mg/L deadly
Nernst Equation
E=Eo-(RT/nF)*ln(([C]^c*[D]^d)/([A]^a*[B]^b)) R=gas constant F=Faraday constant (F=96,490 coulombs/mole) T=298 K n=number of electrons being transferred
Flowing Water
EWI: divide cross section into minimum of 10 equal-width increments; at each increment 1. locate the mid-point 2. lower sensors to middepth of the vertical 3. monitor field-measurement readings *record median measurement at each vertical; report mean value of the medians of verticals to get a discharge-weighted value* EDI: divide cross section into minimum of 4 equal-discharge increments (unless conditions are appropriate for 1 equal-discharge vertical at centroid of flow); at each increment 1. locate the centroid 2. lower sensors to middepth of the vertical 3. monitor field-measurement readings *record median measurement at each vertical; report mean (or median), if appropriate, of the medians of verticals (can be used in area-weighted calculations)*
Cause of Acid Rain
SO2 and NO2
Quality Assurance
a management function that document and establishes quality control protocols and evaluates and summarizes their outcomes
Conductivity
a measure of the ability of water to pass an electrical current [=] µmhos/cm or µs/cm ; affected by the presence of anions and cations (mostly organic); higher temperature = higher conductivity *conductivity is always reported at 25 C*
Turbidity
a measure of the amount of light that is scattered by suspended particles; high suspended solids = high turbidity; high turbidity = low water clarity
Completeness
a measure of the amount of valid data needed to be obtained from a measurement system
Accuracy
a measure of the overall agreement of a measurement to a known value; includes a combination of random error (precision) and systematic error (bias) components of both sampling and analytical operations
Biological Oxygen Demand
a measure of the potential for DO within a water body to become depleted and possibly become anaerobic due to the decomposition of organic matter by microbial organisms (nutrient depletion->massive algae die off->BOD because of decomposition of algae biomass->permanently decreases [DO]->decrease population of other aquatic organisms
Oxidation
a process involving loss of electrons
Representativeness
a qualitative term that expresses "the degree to which data accurately and precisely represent a characteristic of a population, parameter variations at a sampling point, a process condition, or an environmental condition"
Comparability
a qualitative term that expresses the measure of confidence that one data set can be compared to another and can e combined for the decision to be made
Oxidant (oxidizing agent)
a species that accepts electrons
Reductant (Reducing Agent)
a species that gives electrons
Quality Control
a system of technical activities that measure and control the quality of field sampling and lab analysis to ensure the results meet the requirements for the project and under certain standards
Eutrophication
accumulation of nutrients (usually phosphorus, sometimes nitrate) in aquatic ecosystems; alters dynamics of a number of plant, animal and bacterial populations; form of pollution
Alkalinity of Water
amount of strong acid added to 1 L of solution to bring the pH to 4.5 or 5.2; capacity of species in water to produce OH- ions or accept H+ ions; due primarily to CO3 2- and HCO3 - or OH- [=] mg CaCO3/L
Acidity of Water
amount of strong base added to 1 L of solution to bring the pH to 7 or 8.4; capacity of species in water to produce H+ ions or accept OH- ions; due primarily to CO2 or pollutants, metal ions, and minerals [=] mg CaCO3/L
pH
an intensity factor (indicates [H+]) *preferred range 6.5-8.0* 1.0-6.5: increased [cations] 8.0-14.0: increases [NH4+]
pH Measurement
approved pH meter; titration method; alkalinity = A*N*50000/mL of sample A: mL standard acid N: normality standard acid; acidity= [(A*B) - (C*D)]*50000/mL of sample A: volume of standard sodium hydroxide used in titration B: normality of standard sodium hydroxide C: volume of standard sulfuric acid used to reduce pH to 4 or less D: normality of standard sulfuric acid
Quality Control Checks
blanks (validates sample); spikes (amount of contaminant added stays at that value-correct method); calibration check samples; replicates, splits, etc.
Acidity and Alkalinity
capacity factors indicates capacity to generate H+ or OH- through various processes
Total Hardness
capacity of water to precipitate soap; soap wasting property of water; cations such as Ca 2+, Mg 2+, Sr 2+ or Fe 3+ in the water to replace the Na + or K + in soaps and form sparingly soluble products; issues: 1. scaling 2. clogging of pipes 3. cleaning 4. public health
Temperature Increases
cause decreased dissolved oxygen; cause increases solubility of some contaminants (pesticides)
Conductivity Measurement
conductivity meter; analysis may need to be in field or lab; may need to filter before storing (protocols vary); calculations depend on temperature < 25 C: add 2% of reading per degree, > 25 C: subtract 2% of reading per degree
CRDL
contract required detection limit; minimum level of detection acceptable under the contract statement of work
Specify Performance of Acceptance Criteria (decision making; estimation and other analytical approaches)
decision making: specify probability limits for false rejection and false acceptance decision errors; estimation and other analytical approaches: develop performance criteria for new data being collected or acceptable criteria for existing data being considered for use
Develop the Analytical Approach
define the parameter of interest, specify the type of inference, and develop the logic for drawing conclusions from findings
State the Problem
define the problem that necessitates the study; identify the planning team, examine budget, schedule
Physical Characteristics of Water Impacted by Temperature
density
Threshold Odor Test
determining the "concentration" of odor found in water; 1. dilute the tested water with odor-free water to 200 mL (smelled from odor-free water highest dilution to lowest dilution 2. dilutions continue until no odor can be discerned 3. geometric mean of TON numbers from several people (>10); subjective because it depends on human perception of the taste and odor in the water
Osmosis
diffusion of water across membrane *osmotic effect: salt draws water out of cells*
Threshold Odor Number (TON)
dilution ratio for the last dilution at which odor is detected; G=(X1*X2*...Xn)^(1/n)
Abiotic Factors Affecting DO Concentration
direct impacts: 1. temperature 2. salinity 3. atmospheric pressure 4. current velocity (flow) 5. wind indirect impacts that affect the biological activity of aquatic organisms: 1. total dissolved and suspended solids 2. water clarity (turbidity) 3. cloud cover
Chemical Characteristics of Water Impacted by Temperature
dissolved oxygen level; pollutant solubility
Total Solids
dissolved solids + suspended and settleable solids
Biological Characteristics of Water Impacted by Temperature
enzymatic catalysis rate; photosynthesis; metabolic rates,; sensitivity of organisms to pollution (toxicity), parasites and disease
EW
equivalent weight of divalent cation i; = formula weight of a cation/ 2
TDS Estimation
estimated TDS [=] mg/L = conductivity (µmhos/cm) * empirical factor ; 15% typical error with 0.65 empirical factor *conductivity is always reported at 25 C*
Settleable Solids Measurement
fill Imhoff cone with 1 L of well-stirred test water->allow settling for 45 minutes->gently stir sample with glass rod to release suspended matter clinging to sides->let sample settle for 15 minutes-> record volume of setteable solids directly from cone graduations; [=] mL/L/hr
TDS
filterable residue ((A-B)*1000)/(C) [=] mg/L A: weight of dried residue + dish in mg B: weight of dish in mg C: volume of sample used in mL
Odor Measurement
human nose or gas chromatography-olfactometry
Growth Rate
increased temperatures effect enzyme catalysis of fish and lowering dissolved oxygen levels->bigger fish cannot survive *by 2050, warming will shrink the average maximum body weight of fish by 14-24% globally*
Thermal Stratification
layering of a body of water based on its water temperature change with depth; During late fall, surface water temperatures decline and the density gradient between the layers weakens. The cooler, denser water on the top of the lake becomes heavier than the layers underneath and begins to sink, displacing the water below. This happens when the water reaches a temperature of 39 F/4 C. Lake turnover results the entire lake rolls over and what was once the deeper layer of the lake becomes the top layer. Lake turnover occurs again in the spring when the weather becomes warmer. Roughly one to two weeks after the ice of the top of the lake is gone, the cool water will sink to the bottom, displacing the warmer water underneath. Again, this takes place when the water warms to a temperature of roughly 39 F/4 C. The lake will completely flip, and the cycle starts over, slowly stratifying until the process of fall turnover takes place; During the fall, as the lake turns over and the denser, oxygen and nutrients rich top layer sinks to the bottom, oxygen and nutrients can be replenished in the bottom layers of the lake. As the winter months approach, fish will dwell at the warmer bottom layer; the enriched oxygen and nutrients in the lower layer of the lake is crucial for fish survival during these months, as fish need dissolved oxygen for respiration. During the Spring lake turn over, the nutrients rich bottom layer water moves to the top layers of the lake to provide nutrients for summer fish and other organisms.
Redox Potential
measure of the tendency of a chemical species to acquire electron and thereby be reduced [=] V; Eo > 0: reaction proceed goes to the right; Eo < 0: reaction goes to the left; Eo = 0: reaction is at equilibrium
Diurnal Oxygen Cycle
midnight-sunrise: R>P (moonshine) DO decreases; sunrise-sunset: P>R (sunshine) DO increases; sunset-midnight: R>P (moonshine) DO decreases
Temperature Effect on Solubility of Solid Compounds
most increase with increasing temperatures; some exhibit fairly independent properties; some becomes less soluble with increasing temperature; solubility enhancement with increasing temperature only when dissolution of a solid in water is exothermic (extra heat from temperature increase will cause the equilibrium for an exothermic process to shift toward the reactants)
Enzymatic Catalysis Rate
optimum temperature for catalysis; too hot: denaturation of enzymes
Highest Limit of Potential
oxidation of water to form O2
Dissolved Oxygen
oxygen gas dissolved in water [=] mg O2/L H2O; temperature increases=DO decreases; Pressure increases= DO increases; salinity increases=DO decreases; surface area of water in contact with atm is increases by wind-driven waves and ripples=increased DO (faster flowing water=more atm oxygen mixing=increased DO; muddy water/cloudy sky=less light reaching plants=decreases DO
Water Quality Monitoring Project Life Cycle
planning->project implementation->data validation and assessment->product or decision
Natural Eutrophication
proces that occurs as a lake or river ages over a period of hundred or thousands of years; oligotrophic->mesotrophic->eutrophic->senescent
Cultural Eutrophication
process that occurs when humans release excessive amounts of nutrients; shortens the rate of aging to decades; algae grow fast, using up lots of O2 during respiration and producing lost of O2 during photosynthesis and blocking sunlight->aquatic plants and algae begin to die->dead matter provides food for microbes->further depletion of O2->deoxygenated water (fish die)
Project Planning and Quality System Implementation
project life cycle projection, implementation of a quality system, formulation of data quality objectives, preparation and implementation of a project plan, preparation and implementation of standard operating procedures
Data Quality Objectives
qualitative and quantitative statements of the overall level of uncertainty that a decision-marker will accept in results or decisions based on environmental data; a series of logical steps that guides managers or staff to a plan for the resource-effective acquisition of environmental data; flexible and iterative; applies to both decision-making and estimation
Water Quality Monitoring
quality monitoring and data collection->quality data->reliable, cost-effective defensible environmental decisions; project planning and quality system implementation, field sampling, laboratory analysis, data interpretation, decision
Lowest Limit of Potential
reduction of water to form H2
RPD
relative percent difference; RPD=100%*(|duplicate1 - duplicate2|)/((duplicate1 + duplicate2)/(2))
Develop the Plan for Obtaining Data
select the resource-effective sampling and analysis plan that meets the performance criteria
Precision
the measure of agreement among repeated measurements of the same property under identical, or substantially similar conditions; calculated as either the range or as the standard deviation; may also be expresses as a percentage of the mean of the measurements, such as relative range or relative standard deviation
Equal Discharge Increment
the stream cross section is divided into increments (>4) of equal discharge; field measurements can be made in situ at the centroid of each increment or by collecting an isokinetic depth-integrated sample at the centroid of each increment and determining the value either of each sample or of a composite of samples; result in data that are discharge weighted; knowledge of streamflows distributions in the cross section is required to select verticals at which measurements will be made or subsamples collected; streamflow distribution can be based on the long-term discharge record for the site or on a discharge measurement made just prior to sample collection
Equal-Width Increments
the stream cross section is divided into increments of equal width; knowledge of the streamflow distribution in the cross section is not required; in situ field measurements are made at the midpoints of each increment; area-weighted concentrations or temperature can be computed from these measurements; subsample field measurements are made in discrete samples that usually are withdrawn from a composite sample collected using an isokinetic sample and isokinetic depth-integrating method; the volume of the isokinetic sample must be proportional to the amount of discharge in each increment and measurement in subsamples taken from the compositing device result in discharge-weighted values
Bias
the systematic or persistent distortion of a measurement process that causes errors in one direction
DO Measurement
titration; probe (reduces oxidation); Winkler method-collect sample using BOD incubation bottle (narrow to prevent O2 diffusion) Samplers: ~ 5 ft: ALPHA > 5 ft: Kemmerer *record temperature with every DO measurement*
Turbidity Measurements
turbidimeter; have to dilute sample if above 40 NTU (nephelometric turbidity unit)
Measuring Temperature
use liquid thermometer or thermistor thermometer (NIST certified/calibrated); test, calibrate, and check field instruments->allow sensors to equilibrate with ambient water->select sampling method->still water vs. flowing water->report stabilized value of the median of the last 5 or more values and the time of the measurement
Reducing Waters (anoxic)
waters that contain both dissolved iron and sulfide
Oxic Waters
waters that contain measurable dissolved oxygen
Suboxic Waters
waters that lack measurable oxygen or sulfide, but do contain significant dissolved iron (> ~0.1 ml/L)
Standard Operating Procedures
written instructions that document routine or repetitive activities to guide an activity or a set of activities to maintain consistency and integrity in the data collection process (technical; administrative)