Agriculture is the largest source of pollution to the Chesapeake Bay and its rivers and streams. As part of the Chesapeake Clean Water Blueprint, the regional plan to restore the bay, states in the bay’s watershed pledged to reduce agricultural pollution substantially.

As if that weren’t reason enough to accelerate cleanup efforts in agriculture, here’s another: It’s far cheaper to stop pollution from farms than any other major source, including sewage plants, cars and paved landscapes.

Despite this, the Maryland poultry industry is fighting a common-sense solution that would clean up the creeks and rivers of Maryland’s Eastern Shore. University of Maryland scientists proposed the solution after 10 years of study. It’s simple: If a farmer uses chicken manure as fertilizer, he or she must apply the right amount to his or her fields. In November, Gov. Martin O’Malley (D) proposed regulations to do just that.

The Maryland Department of Agriculture estimates that about 228,000 tons of excess chicken manure are being applied per year to the fields of the Eastern Shore. It’s not intentional. Farmers use an outdated scientific tool for determining the right amount of manure, and no state regulation mandates an update. So farmers clean out their chicken houses and apply the poultry litter on nearby fields as fertilizer — at legal but excessive levels. The result of the excess manure in Maryland is glaring.

Other agricultural states, including Pennsylvania and Virginia, have updated their phosphorus limits for manure application.

The list of polluted Eastern Shore waterways is long and includes the Chester, Choptank, Transquaking, Nanticoke, Sassafras, Manokin, Pocomoke and Wicomico rivers. About 80 percent of the phosphorus pollution fouling those rivers comes from agriculture, and much of it is from excess chicken manure applied to fields. When it rains, the phosphorus washes into nearby creeks or leaches out of the fields.

Phosphorus in the water stimulates massive outbreaks of algae, starting a chain reaction that results in dead zones of low oxygen and a crippled seafood industry. Excess manure also can make Eastern Shore swimming areas unsafe.

Many rivers around Maryland are getting cleaner, thanks to public investments to clean up sewage plants. Marylanders helped pay for these improvements through the so-called flush fees or other fees on sewer or water bills. But many creeks of the Eastern Shore are getting dirtier.

The manure solution would not only clean up Eastern Shore creeks and rivers but also would serve farmers. The soil would become healthier if it’s no longer receiving excessive levels of phosphorus. Farmers know healthy soil means increased productivity. And because phosphorus is a valuable commodity, innovative industries are waiting in the wings to pay farmers for their excess phosphorus.

New manure regulations would be phased in over years by the Maryland Department of Agriculture, and implementation would be subsidized by the state.

Farmers with excess manure may have to truck some to other areas where fields aren’t saturated or to private facilities that turn poultry manure into energy, fertilizer pellets or other products. Some farmers may have to buy commercial fertilizer to replace the nitrogen from the manure or use mixed-species cover crops to add nitrogen from the atmosphere to the soil. The state would help pay for these costs. Large poultry companies should have a role in helping the small chicken growers comply with this new regulation.

What’s not to like? Local creeks and rivers of the Eastern Shore would get cleaner. So would the Chesapeake Bay. Swimming areas that once were off-limits would be safe again. Crabs, fish and oysters would rebound. Watermen would go back to work. Farm fields would produce greater yields from healthier soil. Many farmers would sell excess phosphorus to the private market.

Unfortunately, Gov.-elect Larry Hogan (R) has been getting bad information on this issue. He has vowed to roll back progress. “The first fight [when I take office] will be against these politically motivated, midnight-hour phosphorus management tool regulations that the outgoing administration is trying to force upon you in these closing days,” Hogan told the Maryland Farm Bureau Convention in December.

Lobbyists for Maryland agriculture claim these regulations would harm the Eastern Shore. They also say the new rule was a last-minute effort, even though it was years in the making and frequently delayed by the same lobbyists. It’s the same old story. Industry fights science. Yet time and time again we have seen that reasonable regulations stimulate our economy. Smart companies see them as opportunities, not obstacles.

There’s too much manure on the shore. Those opposed to a reasonable solution need to stop shoveling it in Annapolis.

The writer is president of the Chesapeake Bay Foundation.