Using aerial photos, satellite images and state permit figures, two environmental groups say more than half of the manure in the Maumee River watershed comes from unpermitted farms with livestock.

The Environmental Working Group and Environmental Law & Policy Center took about a year to collect and analyze the data, which showed a 40 percent increase in hog, cattle, dairy and poultry operations in the Maumee River watershed in Ohio, Indiana and Michigan from 2005 to 2018, for a total of 775 livestock farms.

The Maumee River watershed is about 6,500 square miles — the vast majority in Ohio — and has been identified by university researchers as the main source of phosphorus entering Lake Erie from farm runoff. The phosphorus leads to algae blooms that can turn the water a murky green color, contaminating the drinking water supply and harming aquatic life in what is a prime area for walleye and other fishing. Since the 1990s, the algae blooms have appeared each year beginning in May and can last through October.

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If a farm is not considered large enough to have a permit through the Ohio Department of Agriculture, then the state agency does not track its activities. For example, the state requires a farm with at least 700 mature dairy cows to get a permit. However, the department won't track a farm with 699 cows. Only 14 percent of the farms in Ohio have permits.

"Farms below the permit threshold do not have records with the department unless they’ve had an enforcement action," said Brett Gates, a spokesman for the Ohio Department of Agriculture. Enforcement action would take place only if there's a complaint because, without a permit, there are no routine inspections, he confirmed.

“To me, this really spotlights how much more Ohio should be doing to track and oversee these big sources that are effectively industrial agriculture operations when you get to this scale,” said Madeline Fleisher, a senior attorney with the Environmental Law & Policy Center, a Midwestern environmental legal advocacy organization.

The groups’ analysis found that at least half the manure generated along the Ohio portion of the Maumee River comes from operations that lack state permits.

“You can’t fix what you’re not paying attention to," Fleisher said. "There just needs to be a lot more oversight.”

Joe Cornely, a spokesman for the Ohio Farm Bureau, questioned the method of the analysis and its accuracy.

"If everything is based on simply aerial imaging, I’m not sure what that tells us. Does an aerial image tell us what animals are in a barn or if animals are even in that barn?" he said. "It’s kind of iffy data. If you want to make policy recommendations, I think you need more than a picture from 5,000 feet."

Sarah Porter, a lead GIS analyst and project manager for the Environmental Working Group, a nonprofit, nonpartisan organization dedicated to protecting the environment, said the analysis used images from the National Agriculture Imagery Program, Google images and permit data. In some cases, staff drove out to sites to learn more.

"There was a significant data gap in understanding how much of a contributor animal operations are to the issues we're seeing in Lake Erie," she said. "And without knowledge of where these operations are, how many animals are there, how much manure and phosphorous they are generating — there's not going to be much progress made."

bburger@dispatch.com

@ByBethBurger