Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Potable Water
Chapter 4 REHS
| Question | Answer |
|---|---|
| "potable" | look good, free from turbidity, color, odor, taste and disease |
| "potable water management" | the science and practice of protecting surface and ground water |
| "public water system" | piped water with 15 service connections and serves 25 individuals at least 60 days of the year |
| microbiological quality of water expressed in these terms | concentration, frequency or +/_ of bacteria |
| who is in charge of water standards | The EPA under the SWDA |
| 3 additional water tests (critter type) | crypto, giardia, legionella |
| Interim Standards | 1975, specify's MCL |
| Maximum contaminant level | maximum allowable concentration of contaminant |
| surface water | open to the atmosphere |
| zone of saturation | all the openings or voids are filled with water |
| ground water | water in the zone of saturation |
| percent of disease related to inadequate water and sanitation | 80% |
| snow in 1845 | london water pump cholera |
| gambierdiscus toxicus | tropical marine dinoflagellate that synthesis ciguatoxin |
| 2 waterborne protozoa | giardia and cryptosporidium |
| asiatic cholera outbreaks | london in 1849 and 1853 investigated by john snow |
| vibrio cholerae in 1892 | koch isolated from polluted Elbe river |
| multiple barriers for safe water (6) | 1) source water protection 2) treatment plant processes 3) disinfectin 4) distribution 5 ) security 6) education |
| one of the first biological warfare weapons | smallpox given to N.A. Indians on blankets 3 points of entry for anthrax |
| plague | gram-, non motile Yersinia pestis zoonotic |
| 3 forms of plague | bubonic, septicemic and pneumonic |
| Halogenated Hydrocarbons (examples) | PCB's, DDT, PBB's, chloroform, vinyl chloride |
| 4 groups of chemicals in drinking water | 1. halogenated hyrocarbons and organics 2. heavy metals 3. nonmetallic inorganics 4. biological contaminants, drugs and additives |
| public water system | 15 connections, 25 individuals daily at least 60 days of the year |
| community water system | 15 connections for year-round or serves 25 year round residents] |
| noncommunity system | public sysem that is not a community system and can be transient noncommunity or (TWS or NTNCWS) parks, rest stops, 25 people but not the same 25 people |
| main drinking water contaminant | sewage |
| most widely used bacterial indicator | coliform |
| examples of disinfectants for water | fre and combined chlorien, chlorine dioxide, ozone, UV irradiation. Chlorine is the most common |
| disinfectant byproduct | Trihalomethant (THM) is most common |
| THM examples | chloroform, bromoform, dibromochloromethane |
| Ozone | the most pwerful disinfectant but is unstable in water |
| minimum requirement of free chlorine | o.2ppm as set by National Interim Primary Drinking Water Regulations |
| factors that influence the movement of groundwater | geological formation and permeability, rainfall and infiltration and hydraulic gradient |
| geomagnetics | magnetic field used to find buried metals |
| electromagnetics | measures difference in conductivity (finds boundaries of contaminated plumes around landfills with leachate |
| electrical resistivity | resistance with probes- identifies porosity and ground water limits |
| ground-probing radar | uses radar to measure reflection from water table |
| photoionization meters | finds specific volatile compounds like gasoline, methane |
| microbes travle a shourt distance though (soil) | sandy loam or clay |
| acidic soil | increases movement of pollutants in soil |
| petroleum products tend to ____ | float |
| halogenated solvents tend to migrate___ | downward |
| removing bacteria from liquid in soil is | inversely proportional to particle size of the soil |
| soil for removing viruses | fine loamy sand over course sand |
| igneous rocks | formed by cooling and hardening of molton rock. Not good source of water granite, dioxite, basalt (some water) |
| sedimentary | eroded rocks like sand, gravel, clay, silt, loess usually a lot of water especially sandstones, shales and limestones |
| metamorphic | heat and pressure on igneous and sedimentary (small amount of water) |
| karst areas | caves, channels, rapid groundwater movement easily polluted |
| glacial drift | sediment that is moved by glacier ice |
| porosity | amount of water that can be held by rock or soil |
| effective porosity or specific yeild | percentage of total volume or mass of water that drains freely our by gravity |
| specific retention | volume of water retained |
| permeability or hydraulic conductivity | rate of flow of water at 60F in gallons per day through cross section of 1ft2 |
| transmissivity | hydraulic conductivity times saturated thickness of aquifer |
| Darcy's Law | Q=KIA (Quantity of flow per time, gpd=(hyd. Conductivity)(hydraulic gradient)(cross sectinalarea) |
| Groundwater Class 1 | special groundwater-irreplaceable and ecologically vital |
| Groundwater Class 2 | current and potential sources of drinking water |
| Groundwater Class 3 | not considered potential sources of drinking water salt water |
| standard plate count | total colonies of bac developing from measured portions (two 1ml and two .1ml) 48 hrs at 95F |
| guinea-worm | most comon dracontiasisnhelminth |
| odor | less than 3 on threshold odor number |
| taste | not objectionalble |
| turbidity | 0.5 Nephelometric turbidity units and occasionaly not more than 1NTU |
| color | less than 15 true color units |
| temperature | less than 60F |
| dug well | 15-30 ft deep, not dependable |
| bored well | uses an auger to go 25-60 feet, small yields, easily pollulted |
| driven and jetted wells | pounded in and 50-100 feet deep |
| drilled well | in general, they are better, less contaminated |
| chlorine dioxide | more bowerful biocide than free cholorine but doesn't persist as long |
| ozone | most powerful disinfectant but highly unstable in water and lacks persistent redisual so usually add a secondary like chlorine |
| uv radiation | good biocide but no persistend residual |
| coagulation-flocculation | combine small particles into aggregates as part of a process (coagulation, sedimentation, flitration) |
| coagulant formation (add what?) | add chemical like alum |
| The first 3 steps of Coagulation in Coagulation-Flocculation | Coagulant formation (alum), particle destabliization, interparticle collision |
| flocculation | small particles transformed into larger pieces or floes |
| seidmentation and flotation | solid-liquid gravity separation |
| flotation | introduce gas bubbles into water that attach to solids to float to top |
| filtration | suspended matter is removed (clay, silt, organic matter, |
| mandated by the EPA surface water treatment rule | filtration- enterovirus, giardia, legionella, reduces crytosporidium resistent to disinfection |
| most common type of filter | granular media filter |
| slow sand filter | very effective, grain size .25-.35mm |
| rapid filtration | treated water through granular media bed larger sand (.5-.7mm) PRE-TREATMENT is essential |
| Pressure filters | sometimes used in rapid filtration. Water enters filters under pressure |
| standard for lead | 15ppb flush for several minutes a day to reduce problem |
| standard for copper | 1500 ppb may be naturally occuring causes of copper in water |
| what and where are radionuclides | raduim, uranium, polonium, can test radon in ari. Shallow wells more likely to have these |
| human caused contamination of water | nitrates, pesticides, VOC's, hazardous materials spills |
| VOC's examples | solvents, cleaners, degreasers, benzene, toluene, fuel suppliers, dry cleaners, paint shops |
| VOC's healh effects | CNS impairment, liver and kidney, skin, cancer |
| definition of coliform bacteria | rod shaped, gram negative, non-spore forming, lactose fermenting with production of acid and gas at 35C |
| E. coli | ferments lactose at 44F. Metallic green colonies on dark purple plate |
| membrane filtration | sample vacuumed through a special filter that is sealed off in growing medium 44F |
| ONPG-MUG | colilert and colisure 35C for 24 hours |
| dissolved oxygen | the amount of oxygen available in fresh water |
| BOD | amount of oxygen in water for microorganisms to decompose organic material - a measure of pollution |
| BOD Test and cause | 5 days- canneries, dairy plants |
| when bod is high, DO is | when DO is low (less pollution), BOD is |
| COD (Chemical Oxygen Demand) | oxygen equivelant of what is susceptible to oxidation by strong chemical oxidant |
| standard for arsenic | 10ppb |
| dissolved oxygen | the amount of oxygen available in fresh water |
| BOD | amount of oxygen in water for microorganisms to decompose organic material - a measure of pollution |
| BOD Test and cause | 5 days- canneries, dairy plants |
| when bod is high, DO is | when DO is low (less pollution) |
| COD (Chemical Oxygen Demand) | oxygen equivelant of what is susceptible to oxidation by strong chemical oxidant |
| soil conditions for removal of virus and bacteria | fine loamy sand over course sand and gravel |
| this water organism dies off quickly outside of host | streptococcus |
| very resistant to unfavorable conditions and indicate past or present pollution | C. perfringens (intestines of humans and anumals) more resistant than escherichia and streptococci |
| most dependable water well | drilled well |
| best method for back flow preventor | air gap |
| what causes water hardness | dissolved calcium, magnesium bicarbonates, sulfates and chlorides |
| problems with hard water | pipes clog and heaters become coated with lime scale |
| what fixes hard water | water softener like |
| common disinfection of water | chlorine, chlorine-ammonia compounds and ozone |
| hydropneumatic tank or pressure systems are commonly used for | small communities, housing developments, private homes, camps, hotels |
| hydropneumatic tanks typically contain what percent of its volume as water? | 10-20% |
| nitrate levels | MCLG for nitrate is 10 mg/L or 10 ppm |
| nitrate presence | indicates previous pollution |
| can diatomaceous earth filters stand alone? | no, they need to be augmented wit chlorine |
| epilimnion | top mixed zone of reservoir- high in o2 and algae |
| metalimnion or thermocline | transition zone of reservoir, ox decreases, best source of water |
| hypolimnion | zone of stagnation, cold, deficient in oxygen |
| hydrogen sulfide in water | rotten egg smell, makes water corrozive, death at 300 ppm |
| best way to remove nitrates | ion exchange is most practical. Reverse osmosis and electrodialysis are effective but expensive. |
| removal of cadmium | can be removed more than 90% through iron coagulation. Reverse osmosis in not practical. |
| prevent backsiphonage by (3) | vacuum breaker, air gap, backpressure units |
| backpressure | pressure from nonpotable exceeds pressure from potable |
| backsiphonage | pressure in public water system is less than that in non-potable due to a vacuum or reduced presure in potable |
| Q=AIR | watershed runoff and reservoir design |
| how should a drilled well be sealed? | cement grouting |
| sodium chloride | used in water softeners |
| plain sedimentation | quiescient (still) water settling using gravity to collect solids |
| centrifugal pump design depends on | impeller |
| sodium hypochlorite | (NaCl) can be used full strength for disinfection of water |
| pressure filter and DE earty filter commonly used for | filtration of industrial water supplies an swimming pools, generally not drinking water |
| "fresh polllution" indicator | free ammonia |
| effectiveness of chlorine depends on | pH, temp, contact time, clarity |
| copper sulfate used to | control growth of algae and protozoa |
| gases found in water that encourage corrosion | carbon dioxide and h2o |
| Nephelometric turbidity units | mesures amount of light scattered |
| testing for residual chlorine | DPD-colormetric |
| granulated activated carbon filters used for | treating water for drinks, removing taste and odor and removing organic chemicals (suspected carcinogens) |
| ozone treatement levels | 1.0-1.5 mg/l |
| ozone treatment goals | remove color taste and odors, viruses, cysts and bacteria |
| control of inorganic chemicals in drinking water | sanitary survey, source ID, determination of amount of pollutants |
| trihalomethanes are created during: | prechlorination with long contact periods and sunlight langelier saturation index |
| hydraulic ram is powered by | water- water flowing in pipe is used to elevate a smaller quantity of water |
| centrifugal pump max water lift | 15 feet |
| jet pump lifts water up to | 120 feet but efficient at 50 feet or less |
| GAC removes tastes and odors by | adsorption |
| sewage travelled over ___ feet in sandy soil | 200 feet |
| ideal water hardness level | 50-80 mg/l |
| alkalinity levels (desirable) | 30-100 mh/l |
Created by:
sanitarianpankey
Popular Standardized Tests sets