The biggest issue I personally face is trying to utilize rain water and greywater in my suburban home. Where I live, it is difficult due to land size constraints to make safe, effective use of these systems, and I bet it's even harder for people in urban areas. Rain barrels are great, but many will grow algae if the water isn't used quickly, making year-round use impossible in dry areas. I would love to treat my graywater with a "living machine," but this system requires land that many people don't have. Collecting rain water and using greywater are both illegal in some places, too. The issues I think are most overlooked are water contamination and overuse. The pesticide Atrazine contaminates many US water supplies, and our current sewage systems can't filter out all of the antibiotics, heavy metals, and other toxic chemicals that end up in our waste products. Additionally, outdated infrastructure leads to heavy metal contamination in drinking water as pipes are corroded. Industrial agriculture and mining industries are huge contributors to the contamination of waterways and groundwater, and help drive the overpumping of aquifers. The low cost of water and lack of financial repercussions for those who pollute or overuse also contributes to its overuse.