Water quality

Question 1

water quality definition

Answer 1

basic chemical & physical characteristics of water that determines its suitability for life or human uses

Question 2

3 water quality parameters

Answer 2

biological
chemical
physical

Question 3

list all physical water quality parameters

Answer 3

-water temperature
-electrical conductivity
-salinity
-alkalinity
-pH
-dissolved oxygen
-turbidity (Total Suspended Solids)
-total dissolved solids

Question 4

water temperature use and trends with development of watershed

Answer 4

-use: determines suitability for various forms of aquatic life, generally follows mean daily air temperature without as much diurnal differences
-development of watershed:
-pavement heated by sun warms water flowing on it -> increased lake surface inflow temperature
-riparian vegetation removal increases temperature as the sun heats water surfaces directly

Question 5

electrical conductivity definition

Answer 5

measures ability of water to conduct an electrical current, which is proportional to the number of ions in water

Question 6

EC of different water types & impact of development

Answer 6

freshwater: low conductivity given in microSiemens per cm (uS/cm)
marine: very high conductivity given in milliSiemens (ms)
GW: higher conductivity than surface water
development of watershed: increase conductivity with increase in chemical washing into waterbodies

Question 7

Total dissolved solids definition

Answer 7

total amount of dissolved substance in water -> measure of dissolved matter remaining behind after water evaporates
-1 TDS is 0.66 x EC

Question 8

salinity and how it is reported

Answer 8

it is the amount of salts dissolved in water
-reported as ratio of EC to a standard :
-old : Copenhagen seawater
-now: KCI standard

Question 9

using TDS to classify water

Answer 9

-freshwater: potable, generally <1000mg/L TDS
-brackish: non-potable, less saline than seawater
-seawater

Question 10

how to assess water chemistry analysis

Answer 10

• commonly expressed as mass in liter of solution (mg/L, ng/L, etc.)
  -closely related to parts per million or mg/kg (mass of solute in mass of solution)
  -because density of natural water is near 1kg/L -> mg/L = ppm

Question 11

Dissolved oxygen (DO) use and impact

Answer 11

oxygen is required for most living thing and scarcer in water because dissolved. Solubility depends on temperature and pressure -> 10 ppm at temp of 20 degrees C AND most aquatic organisms need >5mg/L
-decrease in DO = excess respiration because decomposition of OM inputs
-most natural stream close to saturation -> water discharge/velocity helps deliver O2-rich water

Question 12

pH use and optimal range

Answer 12

measure of acidic or basic characteristics of water using -log[H+]
-organism prefer pH 5 to 9

Question 13

alkalinity use, cause, potential and development impact

Answer 13

-use: ability of water body to resist acidification
-cause: amount of carbonate & bicarbonate ions in water because of rock & soils, salts, plant activities and industrial wastewaters
-potential: moderate-high alkalinity water is not subject to acidification (can buffer acid rain)
-development impact: increase alkalinity from mobilization & washing of carbonates & bicarbonates

Question 14

turbidity definition, problems when high and cause

Answer 14

-definition: how clear the water is, relating to the amount of total suspended solids in water (TSS)
-problems of high turbidity: limit light penetration (less photosynthesis), covers aquatic plants & animals (affect biodiversity), brings insoluble toxins into waterways and threat to human infrastructure (hydroelectric turbines)
-cause: erosion of agri land, overgrazed grassland, strip mines, etc.

Question 15

Biological factors list:

Answer 15

BOD
disease-causing agents

Question 15

Biological factors list:

Answer 15

BOD
disease-causing agents

Question 16

disease causing agents definition and examples

Answer 16

-definition: infectious organisms causing disease originating from waste of infected individuals
-examples: typhoid, cholera, polio

Question 17

Biological Oxygen Demand (BOD) definition and factors influencing it

Answer 17

-definition: amount of DO consumed by aquatic organisms while degrading OM -> higher BOD = higher chance of depleting DO
-factors influencing OM degradation: temperature, flow and volume

Question 18

oxygen sag definition

Answer 18

region where oxygen level sharply decline downstream of pollution sources as decomposers metabolize waste materials
-after oxygen sag = recovery zone -> clean zone

Question 19

chemical factors list:

Answer 19

heavy metals
nutrients

Question 20

nutrients: 2 main ones and sources

Answer 20

-nutrients are usually limited in aquatic envr (excess is detrimental)
-P and N are very important because building blocks of biological molecules and stimulate growth of plants and algea
-sources: human & animal waste, plant residues, atmosphere deposition, fertilizer runoff

Question 21

pollution definition

Answer 21

presence of a substance in the environment that, because of its chemical composition or quantity, prevents the functioning of natural processes AND produces undesirable environmental and health effects

Question 22

environmental consequences of water pollution

Answer 22

-health hazards
-loss of biodiversity
-loss of aesthetic
-impact and leisure & sporting activities

Question 23

point source pollution definition and examples

Answer 23

-water pollution that can be traced to a specific origin (single point of entry) and is easy to regulate and monitor
-examples: landfills, drainpipes, factories

Question 24

non-point source definition and examples

Answer 24

-pollutants entering the water body over large area as scattered or diffuse but having a large cumulative effect. Difficult to trace & regulate -examples: runoff from agricultural fields, urban runoff, golf course

Question 25

atmospheric deposition definition

Answer 25

contaminant carried by air current and precipitated into watershed or directly onto surface water as rain, snow or dry particles. -non-point source pollutant

Question 26

sewage treatment steps and actions

Answer 26

-primary treatment: physical separation of large solids from waste stream -secondary treatment: biological degradation of dissolved organic compound in trickling bed or aeration -> usually disinfected before release into waterway -tertiary treatment: removal of plant nutrients using chemical which bind OR natural wetlands

Question 27

sewage treatment issue

Answer 27

sanitary sewers connect to storm sewers -> heavy storm can overload the system and cause raw sewage to runoff directly into waterways.

Question 28

polluted agricultural runoff: products, causes and effects

Answer 28

-products: nutrients, sediments, pathogens -causes: agricultural activities like grazing, plowing, fertilizing, planting and Animal Feeding Operation (farms with high concentration of livestock generating lots of waste) -effects: leading source of water quality problems in lakes & rivers

Question 29

polluted urban runoff: products, causes and effects

Answer 29

-products: sediment, oil & greases, heavy metals, debris, road salts, fertilizers, pesticides & herbicides -cause: impervious surfaces causing water to accumulate and runoff in large amount while carrying large amount of waste from urban envr -effect: large source of water quality impairments to river

Question 30

eutrophication process and consequences

Answer 30

-process: increasing biological productivity of algea in water body via the addition of nutrients by runoff -> leading to algal bloom and depletion of oxygen as they decompose -consequences: depletion of DO, significant changes in ecological dynamics, human health consequences

Question 31

Oligotrophic VS eutrophic and cultural eutrophication

Answer 31

oligotrophic: waterbodies with clear water & low productivity eutrophic: waterbodies rich in organisms and OM cultural eutrophication: increase in bio prod & ecosystem succession caused by human activities

Question 32

watershed export definition, units and calculation

Answer 32

def: amount of a substance exported from a watershed unit: kg/ha/yr calculation: (flow x pollutant concentration) / watershed area

Question 33

watershed load def and units

Answer 33

def: amount of a substance delivered to a waterbody unit: mg/m2/yr OR kg/m2/yr

Question 34

3 basics pollution management strategies

Answer 34

-reduce/remove pollutant -treat/purify tainted water -monitor downstream waterbodies

Question 35

water quality classification

Answer 35

good: sufficient to meet all designated uses impaired: insufficient to meet AT LEAST ONE designated water use

Question 36

How to regulate water quality and types of water uses

Answer 36

different jurisdictions designating different water uses: -food supply -water supply -recreation -ecosystem health

Question 37

heavy metals problem and source

Answer 37

problem: highly toxic and persistence metals that can bioaccumulate in the food chain source: mine drainage and leaching