Environmental Health Pt. 3 Flashcards
2 sources of water for community water systems
surface water
ground water
91% of public water systems are supplied by
groundwater
(however, more total people are supplied by surface water since metro areas tend to rely on surface water)
what percent of U.S. population relies on private groundwater wells?
15%
After ice, groundwater is the second largest source of freshwater
T. It provides 40% of the water used in agriculture and domestic use in the US
How climate change will affect the water cycle
-will alter the amount, distribution, timing and quality of available water
-warmer temps cause more water to evaporate from land and water
-a warmer atmosphere can hold more water —> increased precipitation, flooding
-SW can expect less precipitation as storm tracks shift northward leaving arid areas increasingly dry
-NE and Midwest can expect increased flooding in winter and spring
-overall wet areas expected to become wetter and dry areas drier
climate change effect on water quality
water quality will decline as water temps rise which lowers levels of dissolved oxygen which stresses aquatic organisms.
-there will be increased runoff in certain regions
-increase in algae/bacterial blooms
climate change effect on tide
anticipated rise in sea level worldwide due to expansion of the ocean as it warms, and increased ice melt
-results in salt water being driven into freshwater estuaries and coastal communities.
5 major reasons for water monitoring
1) characterize waters and identify changes or trends in water quality over time
2) identify specific existing or emerging water quality problems
3) gather info to design specific pollution prevention or remediation programs
4) determine whether program goals (ie.compliance with pollution regulations) are being met
5) respond to emergencies
where does water monitoring take place?
-fixed stations on a continuous basis
-selected sites on as-needed basis
-temporary or seasonal basis
-random sites throughout area
-emergency basis
which agencies are responsible for water monitoring?
-State pollution control agencies
-Indian tribes (which are funded by EPA grants)
-interstate commissions
-local city and county governments
-EPA gives out grants for monitoring, and also conducts some monitoring of its own
-US Geological Survey conducts extensive chemical monitoring through its National Stream Quality Accounting Network (NASQAN)
-private entities
How does the EPA store water monitoring data?
In the STORET: STOrage and RETrieval system
-data collected by state, local and federal agencies and some private entities is also entered into STORET
How does the EPA store water monitoring data?
In the STORET: STOrage and RETrieval system
-data collected by state, local and federal agencies and some private entities is also entered into STORET
Safe Water Drinking Act
-enacted in 1974
-main federal law that ensures the quality of Americans’ drinking water
-authorizes EPA to set national standards for drinking water to protect against health effects from exposure to naturally-occurring and man-made contaminants
-requires public water systems to monitor their water supplies to ensure compliance with drinking water standards and to report monitoring results to the states
-requires public water systems to notify customers of violations of drinking water standards or other requirements such as monitoring or reporting requirements
Surface Water Treatment Rule (1989)
-establishes tx techniques for Giardia, viruses, legionella, and turbidity in surface water (ie. disinfection, filtration)
-establishes monitoring requirements for turbidity and disinfectant residual
Total Coliform Rule (1989)
-requires system to sample for coliform
-no more than 5% samples can be positive per month, zero positive E. coli
-applies to all public water system
