Why California’s Nitrate Problem Will Take Decades To Fix

When folks talk about “black gold” in California’s Central Valley, it’s usually a reference to oil – unless you’re in the dairy business. No state in the country produces more milk than California, thanks to its 1.7 million cows. Those cows also produce a lot of manure – 120 pounds per cow per day. But manure isn’t a problem; it’s an opportunity, says Ryan Flaherty, director of business partnerships at the San Francisco-based Sustainable Conservation, a nonprofit that works with diverse stakeholders to help clean water, air and land.