hurwitz: the city bought up land around the reservoirs to prevent it from development. it provides assistance to local residents to see that there's no pollution of the reservoirs. it's much more cost effective to prevent pollution and to protect a source of water than to remove it at the drinking water treatment plant. lloyd: what epa said to us was, "you can have an exemption from filtration "if you keep this undeveloped, "and if you can manage the wastewater so that it does not pollute your water supply." and we feel that we've reached the point where we can really keep it clean enough to drink unfiltered for the indefinite future. and new york city is in a small club of cities that actually have that filtration avoidance waiver. narrator: while municipalities are responsible for maintaining systems and source supply, the standards that protect water are established at the federal level. there are two important pieces of federal legislation that were both enacted in the early to mid-1970s. the first was the clean water act, which acts to protect rivers and lakes, and

. >> reporter: diane hurwitz loved the sun until she got skin cancer. >> you have gorgeous color foru don't realize what it's doing to the rest of your skin. >> reporter: now she tries to protect her skin but is still confused when shopping for sunscreen. >> do they stay on all day? do they go away after ten minutes? if i swim do i have to put it on? i have no idea. i take what looks good but i really don't know what works. >> reporter: new fda regulations will affect how sunscreen bottles are labeled. sunscreen will no longer be called sunblock, waterproof or sweatproof. >> the first time that we as physicians as dermatologist will be able to tell our patients in an easy way how to select the right sunscreen to protect them the best. >> reporter: sunscreen has to protect equally against harmful uvb and uva rays to earn the label broad spectrum. brands have to say how long they are water resistant, 40 or 80 minutes per application and sunscreen with spf lower than 15 will have to include a warning that it does not prevent skin cancer or early aging. >> under the current labeling, unl