joining us live now to talk about this is darren polhemus, deputy director of the division of drinking water at the state water board. darren, thank you for joining us. >> oh my pleasure. >> i gave a couple of numbers there, but explain the key findings of this recent report and how many water systems we're talking about. >> yeah. on average generally we're talking about, 350 to 370 water systems throughout the state that are, failing to meet our water quality standards as we measure them with the human right to water tool that we use, there's also approximately another 600 that we consider at risk of failing at any time. so you can see there's quite a load these are all really small water systems, a couple hundred connections up to maybe a thousand connections that tend to be in this category. >> what are the most common contaminants, contaminants found and what kind of a health risk do they pose? >> yeah, our most common contaminants in california would be, nitrates, being usually the number one, nitrates are usually from, ag fertilizer use, they can also be from septic tanks and oth