Frank Houck, who has lived on the eastern side of Grand Lake for 20 years, remembers when he could walk the lake’s shores and see gravel at the bottom.

“You can’t see gravel anymore,” said Houck, who lives near Grove, in one of Oklahoma’s fastest growing regions. “It’s covered with algae because of the phosphates and nitrogen that are coming into the lake. The lake is deteriorating.”

Grand Lake’s quality suffers, in part, because of runoff from agricultural operations in Missouri and Kansas. Rainwater leaving farms and factories carries high levels of phosphates, nitrates and bacteria.

The lake, a drinking water source for the region, dilutes many of the pollutants.

But their effect is still apparent.

Such quality problems ?gure prominently into Oklahoma’s already complicated water equation. Environmental experts and planners must face this and similar issues, and propose solutions for them, as they rewrite the state’s water management program for 2011.

“You can have all the water in the world, but if the quality is not good, it’s like having no water at all,” said Derek Smithee, chief of water quality for the state Water Resources Board.

Skylar McElhaney, spokeswoman for the state Department of Environmental Quality, said many of the state’s water quality problems trace back to people.

“Just about everything we do threatens the quality of our water,” McElhaney said.

The department’s report on statewide water quality last year cited a host of threats to groundwater. They include animal feeding operations, brine plumes created by oil and gas industry practices and the lingering effects of old petroleum spills. Also, levels of naturally occurring arsenic spike in some overused aquifers after water levels drop.

Surface water in lakes, rivers and streams – which is ultimately connected to the groundwater supply – is also vulnerable. Government agencies monitor 4,117 bodies of water in the state. More than 530 fall short of quality standards.

The most signi?cant threats to surface waters like Grand Lake, environmental experts say, are pollutants washed in with rainwater runoff and snowmelt.

The problem is heightened near livestock operations. The nonpro?t group Food and Water Watch, which advocates against corporate control over food and water resources, shows in an online map how locations of animal feeding centers coincide with water drainage areas with abnormally high levels of nutrients.

Some cattle farms in far western Oklahoma have been blamed for poor water quality, just as pork farms get the blame in northwestern and central Oklahoma. Attorney General Drew Edmondson has sued some poultry operations for their role in fouling lakes and rivers in eastern Oklahoma.

For Grand Lake, the problem is not limited to what happens in Oklahoma. It starts with the water running away from livestock operations in neighboring states.

Missouri of?cials have raised concerns about E. coli levels for nearly every stream ?owing from their state into northeast Oklahoma. A group that regularly checks the quality of Grand Lake has not found the levels of bacteria to be high enough to be a problem so far.

That’s good news for a dozen or so entities that draw drinking water from the lake. But Bob Luckenbill, who lives near the lake’s Elk River Arm, said Oklahomans are still paying for the pollutants.

“They have to do more now to make it clean to use,” he said. “How much more is it costing us to clean the water?”

It doesn’t help that Grand Lake also gets hit with lead, cadmium and zinc seeping from abandoned mines near the Kansas border. Tar Creek runs next to a Superfund clean-up site once dedicated to heavy metal mining. It eventually ?ows into the Neosho River, then into Grand Lake.

Solutions to quality problems are usually not easy. One suggestion forces farmers to truck off livestock waste, so that extra nutrients and bacteria cannot be washed away from their farms in the rain.

Mark Harrison, a spokesman for the state Conservation Commission, said another approach that sets aside land is key to abating the nutrient-laden sediments that wash into streams and reservoirs.

The commission recently signed an agreement with the federal government to make available $20.6 million for landowners who join a conservation program. Farmers who set aside land for buffers for water runoff receive money in return.

Harrison said these buffers can play a dramatic role in ?ltering nitrogen and phosphorous from water runoff before it reaches streams and lakes. It was proven to work in New York, he said, where agricultural operations set aside land upriver from the sources of New York City’s drinking water supply.

The city must ?lter water for drinking, he said, but it does not specially treat it.

The question for Oklahoma is whether such a plan, or something else like it, can clear the waters of Grand Lake.

D.E. Smoot is a reporter for Muskogee Phoenix. Wallace Kennedy of The Joplin, Mo. Globe contributed to this report.