Public-policy related to water quality is an enormously large issue. I assume that you mean water quality with regard to human sustainability and health. However, keep in mind that there are issues related to water quality other than human consumption. There are endangered species, aquatic and terrestrial ecosystems, recreational and commercial fisheries, etc. that rely on some level of adequate water quality. There is also the issue of water quantity, which is a beast of its own, and is sometimes considered in water quality policy discussions.
Defining water quality for human sustainability and health is always subject to political and economic forces in addition to scientific understanding. For example, there have been many contentious discussions related to "fracking." The production of natural gas and oil through this process produces large amounts of contaminated wastewater. But, this industry directly and indirectly supports many jobs and economies. How much water contamination is a society willing to tolerate to produce jobs and stimulate the economy? The answer is a political and economic one. Scientific studies can determine what level of various contaminants may be "safe" but only society can determine what the acceptable level of risk is.
Naturally occurring water quality issues also occur, among them naturally occurring arsenic concentration and blue-green algae blooms, both of which can be toxic to humans. Although there are scientifically established levels related to arsenic and blue-green algae concentrations, they are often exceeded under natural circumstances and must be monitored and dealt with by water utilities. However, blue-green algae blooms, while naturally occurring, increase their frequency and intensity in the presence of certain land use practices. Thus, the blue-green algae concentrations can be managed both at the water treatment plant and in the landscape in general.
An additional complexity is the issue of water rights, which differ substantially by state in the United States. Some waters are publicly held, while others are privately held. Maintaining water quality in areas where some waters are privately held is difficult and requires both regulation and voluntary compliance of the owners.
I hope this very brief touch on a couple of issues related to water quality provides some areas of further exploration for you.
The quality of water, especially in terms of potable water (water you can safely drink), is an important issue as the availability of water will become more scarce in future decades. Some things to think about include:
- Who owns this water?
- Whose job is it to make it safe enough to drink?
- Can I deny those who can't afford clean water access to it?
- How liable are companies that pollute the water?
- What right does a company have to take over the water supply when moving into a community with a water shortage already? See, for example, Coca Cola companies excessive use of water. Bloomberg: Farmer's Fight Coca Cola As India's Groundwater Dries Up.
- How realistic is it to use desalinization plants to consistently produce drinking water? Who will maintain the cost to run these plants? And who sets the price for access to this filtered water in coastal communities?
- Who is liable if something is introduced into a source of water that changes the quality of that water and/or ecosystem (i.e., chemicals, invasive species, animal waste)?
These are some starting points. Researching one of the above topics can lead to innumerable other questions. Hope your mind is crackling with ideas now!
1. What is society's obligation to provide such public services? How does it benefit society for communities to join together to provide services?
2. If society accepts this obligation, what is the extent of the obligation? Must society provide water for everybody, or just people who can afford it? How much water must society be willing to provide?
3. If society fails in delivering this service what are the repercussions? Failure can include not providing water, providing insufficient water, or providing water that is not safe.
4. If society decides to provide water, and we have answers to all of these other questions, how does society pay for this system?
5. If water is a scarce resource, should society control distribution?
6. If water is a scarce resource how does society control it and share it with other societies? How much should society be willing to defend its rights to water?
Main question: what are the issues surrounding water quality?
1. What the standard will be, and how you will be able to measure the water quality. Many people will disagree on how you measure water quality, and what the standards should be.
2. How much are we willing to pay for the standard we set? As water becomes more scarce the cost of preparing it and distributing it becomes higher. How much is society willing to pay for water?
3. How much are we willing to pay to build infrastructure and maintain it, for delivering the quality of water we desire? This includes the human resources cost.
4. How much should we control other factors that affect water quality? That would include geological practices such as fracking that may affect groundwater. That could include mining and other practices that may affect river water.
5. What other controls do we have in place to prevent pollution of our good water? For example, new construction usually requires prevention of water flowing backwards from building's outlets and returning to the main water supply.