final Flashcards
Define point of entry household water treatment. What issues does it address?
Whole home filtration system installed where the water enters the house
Addresses issues of hard water from calcium and magnesium and taste and odor due to chlorine
Define point of use filters.
Treats a portion of water in the home that would not be used for bathing or cleaning
Most systems are used for drinking water and cooking use through a separate tap rather than the faucet
Installed under sink or at the beginning of the fridge water
Most common are carbon filtration systems that improve taste and odor
Define reverse osmosis
The processes of osmosis and reverse
A reverse osmosis membrane is a semi permanent membrane that allows the passage of water molecules but not the majority of dissolved salts, organics, and microorganisms
water is pushed through the reverse osmosis membrane by applying pressue that is greater than the naturally occuring osmotic pressure in order to desalinate water in the process
This allows pure water through while holding back a majority of the contaminants
Reverse osmosis membrance rejects contaminants based on their size and charge
Define the clean water act
The clean water act addresses water pollution and discharges
Enacted in 1948 and amended in 1972
Established a structure for regulating pollutant discharges into the waters of the US
Gave EPA authority to establish pollution control programs
Define the Safe Drinking Water Act
Protects public drinking water supplies throughout the US
EPA set standards for drinking water quality and implements various programs to ensure drinking water safety
Define the drinking water contaminant candidate list (CCL)
A list of contaminants that are currently not subject to any proposed or promulgated national primary drinking water regulations but are known or anticipated to occur in public water systems
Define watewater-based epidemiology
a method to understand the distribution and determinants of health-related states and events using wastewater samples from the sewershed
non-invasice, unbiased, population-level, near real time status
How did the Greeks have a history in wastewater?
Beginning of plumbing and drainage in Greece began in 1500 BC
Prior to the 19th century, Greece had the most developed waste managment of any division
Describe the steps of wastewater treatment
- Transportation to WWTP through WW system
- Preliminary treatment: SEDIMENTATION - removes grit, rags, and solids that float and may harm other operations at the WWTP(bar racks, mechanical screens, grit chamber)
- Primary treatment: sewage flows slowly to frit tanks where particles of sand and grit settle out - fine particles remain suspended in sewage so it is passed to large primary sedimentation tanks where most of the remaining particles settle out to form sludge
- Secondary treatment: biological process that involves the oxidization of dissolved organis material by microogranisms to decompose the organic compounds (filter beds and activated sludge), increases oxygen availibility
- Tertiary treatment: only used if necessary to reduce plant nutrients or toxic compounds beyond acceptable levels (nutrient stripping, UV disinfection, filter membrance)
How is advanced purified watre treatment proposing to be used?
A portion of treated WW will go directly to an advanced water purification facility where the purified water becomes a new source of drinking water to increase drinking supply
What are the two methods used in secondary ww treatment?
- Filter beds: liquid is sprayed slowly over beds of broken stone or gravel which provide a large surface area for oxidization microbes living eithin filter beds to break down organic matter - liquid that collected at the base of the filter bed contains some waste products that are then separated from effulent and sent to sedimentation tanks producing more sludge
- Activated sludge: a sludge containing bacteria and other organisms is mixed with the liquid and the whole mixture is agitated by paddles or has compressed are bubbles through it to keep it well oxygenated - process lasts ten hours then mixture flows to sedimentation tanks where sludge settles out from effluent
What gas can be produced by the digestion of sewage sludge?
Methane
Why implement drinking water treatment?
- Remove the things that can cause disease
- Remove the things that can create nucances
Overall goal of protecting public health
Name some health-related contamiants
Pathogens
Inorganic agents (arsenic, lead, nitrate, nitrite)
Disinfection byproducts formed during cholrination
Name some aesthetic contaminants (affect appearance, odor, and taste)
Iron, magnesium, and calcium (taste and hardness)
Chlorine and Chloromine (taste and hardness)
Organic Colloidal particales (color)
hydrogen sulfide has (bacterial anaerobic decay causing odor)
turbidity (suspended solids)
Name the steps of water treatment
- Assessing intake water: cornerstone of water treatment, when groundwater is involved first concern is to design an intake that draws in the least possible amount of soil and sand; surface water intake must be adapted to various elements that water sources may contain
- Chemical action: Prechlorination is when chlorine is applied to water immediately after entering treatment facility - eliminated algea and other forms of aquatic life so they won’t cause issues later; aluminum sulfate added as a coagulant to bind fine particles; CaOH added to adjust pH
- Sedimentation Basins: water moves slowly causing heavy particles to settle to the bottom; flock/sludge sinks to bottom of basin
- Filtration: water flows through filter designed to remove particles; filters made of layers of sand and gravel or crushed anthricite; filtration collects the suspended impurities which enhances the effectiveness of disinfection
- Disinfection: ensures that any pathograns are destoyed, usually using chlorine; provides residual disinfectant
What system is used for treatment of water with a surface water intake?
Filtration system to control microorganisms, turbidity, color, taste, and odor
What system is used to treat water from a groundwater intake?
Removal of manganese, arsenic, iron, CO2, and HSO common in groundwater
Define hardness
Results from presence of magnesium and calcium ions in water; associated with groundwater
Define flouridation
Fluoride added to drinking water supply
How do you mitigate taste and odor control
oxidation using chlorine, ozone, potassium permanganate or granular activated carbon
How do you mitigate corrosion control in pipes
Lyme and soda ash increases pH to reduce corrosion
Sinz orthophosphate lines the inside of pipes as protection
Where is the best location for WW sampling for analyzing infection trends of a community?
Primary tanks
Where is the best location for WW sampling for analyzing the infection status of a university campus?
Building level sampling
Where is the best location for WW sampling for analyzing if the virus was removed during treatment?
Effluent
What are the components of wastewater?
99.9% water
0.1% - organic and inorganic compounds and microorganisms:
Ca, Cl, Mg, Na
Heavy metals,
pesticides, fats, oils, grease
fungi, viruses, bacteria, protazoa
What are the three main application of WW epi?
- Antimicrobial resistance: caused by misuse and overuse of antibiotics; AMR in wastewater mirrors clinical antibiotic resistance prevalnce
- Virus Detection: i.e. covid, enterovirus, polio
- Illicit drugs: tracks drug consumption in populations (why WBE was proposed)
What was the first effort for WW based epi?
Polio in NY and Newhaven
Describe the pros and cons for WBE
Pros:
Longitudinal trends
can indicate local clusters
high per sample cost but low per capita
non invasive, non intrustive and unbiased
Cons:
requires normalization and knowlegde of catchement
prone to inibition
no clear guidelines available
What is the issue with water crises in mass media?
sensationalism and blame, political undertones
What are talking points for presentations?
What do you want people to learn?
Statements that are specific to a topic (opinions and may elicit discussion)
help keep presentation focused and on message with the most important points that need to be addressed
What are the common characteristics of news stories regarding water and health?
Acute event, emphasized negative aspects, misuse of terms, presents as a conflict, may be politically driven, political undertones
Invloves experts and may provide call to action
What is water conservation and sustainability? Why is it important?
The development, control, and protection of water resources
Important for maintaining quality water in the amounts needed for basic needs
T/F: Water quantity influences water quality
True
What are the primary driver of water conservation in Texas?
- Efficient use of water
- Economical cost savings
Name some water conservation efforts to be done at home.
- Identifying and stopping leaks
- Reduce water use outdoors (climate appropriate landscaping, watering lawns efficiently)
- Use water-efficient equipment (low flow toilets, efficient shower heads and washing machines)
- Change behaviors (turning off water while brushing teeth, fuller loads of laundry and dishes)
Name some water conservations effort from cities.
Conservation efforts are focused on water efficient landscaping and irrigation and the management of nutrients and possible pollutants
i.e. Stormwater management, rainwater harvesting, urban stream and reservoir protection from erosion and sedimentation
What is the top priority of water sustainability in cities? Why?
Stormwater management
Stormwater is a primary source of water pollution in cities that carries both microbial and chemical hazards that can come into , impacts sediment and contributes to erosion, negatively impacts water quality, and increases run off
Creates public hazard by accumulating and causes flooding that creates an increase in the concentration of pollutants that present a public health hazard
What is storm water? Why does this occur?
Precipitation that does not soak into the ground
Can be caused by impermeable surfaces (streets, parking lots, sidewalks) prevent the precipitation from soaking naturally into the ground.
Name some structures that manage storm water erosion and flooding.
- sediment traps and basins
- earth dykes
- detention ponds
- vegetation
What are the nine key steps to the EPA’s watershed protection plan?
- Causes/Source of pollution identified
- Expected load reductions for solutions identified (nutrient and sediment loads)
- Nonpoint source management measures identified (best management practices that address issues in first element)
- Technical and Financial Assistance needed
- Education and outreach (identifying and engaging relevant stakeholders)
- Implementation schedule (timeline)
- Milestones identifies
- Load reduction evaluation criteria (review process to ensure goals are met)
- Monitoring
What does addressing water conservation and sustainability look like globally?
Promotes sustainable agriculture
Empowers farmers and women
Informs communities
How much of the world’s population is projected to face water scarity by 2025?
2/3
Agriculture is responsible for ____% of water withdrawls but _____% of the water consumption
70, 90
Globally, the agricultureal sector uses about ____% of the planet’s accessible freshwater. More than twice that of the industry _____% and much greater than what is used for municipal purposes _______%
70, 23, 8
The average American uses ____ gallons of water per day
100
A swimming pool can lose about _____ gallons of water a month to evaporation
1000
A small bag of peanut candy neds how many gallons of water to be made?
300
Each person needs approximately _____ gallons of water per day for basic necessities
5 - 13
There are approximately _____ water main breaks each day in the US
700
T/F: Approximately 1/2 of pipes in water systems that deliver water to more than 100,000 people are at least 40 years old
False, it is 1/3
The average home in the US uses ______ gallons of water outdoors every year mostly for irrigation
58000
What is the water related issue with population growth?
Has the greatest influence on water by effecting water usage
Urbanization impacts sanitation infrastructure and water quality
Leads to greater demand for food that increases agricultural use
The global water consumption rate doubles every 20 years, double the rate of population growth
If trend continues, water demand will surpass water availability
What is the issue with water rights?
Many water conflicts throughout world
Ex. India-China Brahmpautra river, China wants to use for hydroelectric power but will deplete for India
Ex. Nile has conflicts over water usage
Ex. Georgia and Tennesse near a river but increasing population of Atlanta has led to increase in water demand and georgia wants to redraw state line to have access to Tennesse river
What is the issue with climate change?
Increases water demand while decreasing water supply
Can cause severe weather events
Result in sea level rising, increased flooding and runoff
What is the issue with storm water?
One of the biggest issues city planners face today, very challenging because it is one of the top contributors to pollution and mitigation strategies are needed
An increase in extreme weather events has led to city streets filled with flood waters that may harbor pathogens and toxic chemicals
What are emerging contaminants? What is the issue?
New waterborne contaminats have been detected and characterized - speculated that their presence is not new but the technology has advanced enough to detect it
i.e. personal care products, pesticides, disinfectants and byproducts, and drugs
What is direct potable reuse? What is the issue?
Invloves the planned use of recycled water either directly into a public water system or into a raw water supply upstream of a water treatment plant to increase drinking water supplies
It’s treated wastewater
What is the issue with aging water distribution systems?
Majority of physical infrastructure for water supplies, when the systems age they pose persistent health risks
Deterioration can occur due to corrosion or external pressures leading to main breaks, breaches in pipes and storage facilities, and intrusion due to water pressure fluctuation
What is the issue with premise plumbing?
Includes the portion of a potable water distribution system associated with public and private housing, hospitals, schools, and other buildings; series of service lines connected to the main distribution system
Recently there have been water quality challenges
Ex. outbreaks in hospitals due to opportunistic pathogens that originated in premise plumbing (i.e. legionella, pseudomonas originosa)
Particularly neonatal outbreaks of pseudomonas originosa due to pp
What are opportunitic pathogens?
Disease causing organisms that take advantage of vulnerable situations and people who are immunocompromised.
