Potable Water - Saraniecki Flashcards
Nitrates
Significant disease?
MCL?
Water treatment?
Sources?
relatively non-toxic except to infants under 6 months
higher pH in intestinal tract allows bacterial conversion of nitrates to nitrite
nitrite attacks heme, no oxygen carry in blood, baby turns blue, treated with methylene blue
MCL 10 ppm
Water treatment: distillation, reverse osmoses, ion exchange, boiling
Sources: ammonia fertilizers, animal feedlots, human wastes
How is benzene a risk in water?
VOC
chomosomal aberrations
increased risk of cancer
What does toluene cause?
VOC
pronounced nervous disorders, spasms, tremors
impaired speech, hearing, vision, memory
kidney and liver damage
Where is perchloroethylene from? How is it consumed and what does it cause?
MCL?
used in dry cleaning of fabrics and metal degreasing
inhalation risk or ingestion of contaminated food or water, skin absorption
PERC is stored in animal fatty tissues
Group 2A human carcinogen - reasonably anticipated to be a human carcinogen
damages CNS
MCL 0.005 mg/l
What does lead in water cause?
implicated in stroke and kidney disease
increased risk of cancer
childhood delayed mental development
What does cadmium in water lead to? Sources?
kidney damage
sources - galvanized pipe, cisterns, pesticides
What does fluoride in water do?
mottled teeth/bone disease
4.0 ppm action level
Where does arsenic come from to be found in water?
found in natural rock formations, industrial wastes, pesticides, fertilizers
10 ppm MCL
What is atrazine and what might it cause?
synethetic organic chemical
man made pesticide
may cause weight loss, cardiovascular damage, retinal damage, increase risk of cancer
What is alachlor and what might it cause?
synthetic organic chemical
man made pesticide
eye, liver, kidney, spleen problems, anemia, increased risk of cancer
What are radionuclides and are the MCLs?
naturally occurring particles, possible from nuclear fallout
emit alpha and beta radiation
alpha particles from Radon is the major preventable cancer concern - action level 300 pCi/l
uranium poisoning linked to kidney toxicity
MCL alpha - 15 pCi/l
MCL beta - 4 millirems/year
MCL gamma is zero
What contaminants would cause acute health effects?
pathogens and nitrates
What contaminants would cause chronic health effects?
VOCs
IOCs
SPCs
radionuclides
What is Crenothrix?
nuisance microorganism
iron bacteria that does not usually cause disease
causes severe fouling or plugging of pipes
reddish-orange slimy deposits
adds iron flavor to water
How must water and sewer lines be separated?
must be laid below frost level
must be kept 10’ horizontal separation, 18” vertical separation
Describe a dug well
shallow, 10-35 ft
watertight casing material
sealed in cement grout or bentonite clay
mounded ground for runoff
Describe a bored well
does not penetrate bedrock
relies on ground water that is filtered by local soil
large diameter, 20”-36”, 30’ to 100’ deep
Describe a driven well
30-50+ ft deep
pulls water from saturated zone
usually sand screen point
2” to 4” pipe
pump at top of well in an access pit below the frost line or in the house
Describe a drilled well
100-400ft into bedrock fractures
6” well casing extends into bedrock and 1-2’ above ground
sealed with cement or bentonite to avoid contamination
most sanitary type of system
What soil formations indicate good water sources?
sedementary- weathered or eroded rocks and decomposed organic material
sand, gravel, peat, shale, sandstone
basalt
What soil formations indicate poor water sources?
igneous - formed by cooling and hardening of molten rock, granite, diorite
metamorphic - heat and pressure treated, sedimentary and igneous rock
What are Karst areas?
fast moving underground water through very porous limestone that forms caves, sink holes, tunnels
usually contaminated
What does a positive fecal coliform test indicate in regards to polution?
fresh pollution
What does a positive Clostridium perfringens indicate in regards to pollution?
previous pollution
