PEORIA, Ill. (AP) _ State laws have failed to keep up with the threat to drinking water posed by manure runoff from giant livestock farms, says a report released today by two national environmental groups.

The report prepared by the Natural Resources Defense Council and the Clean Water Network cites examples of pollution by manure runoff from cattle, poultry and hog farms.

``Today's large livestock operations look more like animal factories than animal farms,'' the report says. ``This trend toward industrial-scale farming has created an enormous increase in the concentration and quantity of manure that is generated at a single site.''

According to the report, many states don't have a system in place to inspect large-scale livestock farms, have only weak penalties for those who violate the law and allow manure lagoons to be placed near critical water supplies.

``It's time we recognized this as an industry and not traditional farming,'' said Bill Emmett, a McLean County farmer. ``Many of the legislators have forgotten what farmers are.''

Andy Baumert, environmental services director for the National Pork Producers Council, disputed the argument that state and federal regulations were inadequate.

``In the last 24 months, all the states with the most hog farming or the most growth in hog farming have seen new legislation or regulation,'' Baumert said. ``Will they ever make these activist groups 100 percent happy? Of course not. They're never going to make producer groups entirely happy, either.''

According to the report, the number of hog farms has fallen from 600,000 to 157,000 during the last 15 years, while the number of hogs produced has stayed about the same.

As the number of hogs raised on a single farm has gone up, so has the amount of manure contained in one site. In some instances, manure has contaminated groundwater either by a leak from a storage tank or lagoon, or when rainfall has swept the manure off farm fields where it was spread as fertilizer.

Some of the information was gathered by environmental activists, like the Illinois Stewardship Alliance and the Iowa Environmental Council. Other details were culled from newspapers and investigations by state and federal agencies.

For example, the report cites a study by the Centers for Disease Control and Prevention of three women in LaGrange County, Ind., who had six miscarriages from 1991 to 1993. The miscarriages were traced to the nitrates in the water from manure produced at a nearby hog farm.

In all, 30 states are listed in the report as having contaminated drinking water because of large livestock farming: Alabama, Arkansas, California, Colorado, Illinois, Indiana, Iowa, Kansas, Kentucky, Maryland, Minnesota, Mississippi, Missouri, Montana, Nebraska, North Carolina, North Dakota, Ohio, Oklahoma, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin and Wyoming.