Environmental protection agencies in Ohio and five other states are unable to inspect ''even a fraction'' of the 20,000 storm water permits that have been issued for industrial and construction sites, and, as a result, runoff pollution is posing a serious threat to Great Lakes water quality, according to a report released yesterday by several environmental groups.

The report by the Environmental Integrity Project and groups in Ohio, Illinois, Indiana, Michigan, Minnesota and Wisconsin details how heavy metals, bacteria, oil, debris and other pollution from construction sites, industrial lots and city streets pose a serious threat to the water quality of the Great Lakes watershed, including the Black River.

''States cannot realistically inspect even a fraction of 20,000 Midwest storm water permit holders, which may be only a fraction of those who should have such permits,'' said Ilan Levin, an attorney for the Environmental Integrity Project.

''We have to prevent erosion on construction sites and keep the sediment and mud out of streams to protect Ohio's wildlife,'' said Keith Dimoff, deputy director of the Ohio Environmental Council. ''Unfortunately, the Ohio EPA does not get enough funding to enforce the Clean Water Act across Ohio, so many industrial sites and other storm water problems go uninspected.''

Most storm water dischargers are regulated under the federal Clean Water Act and are required to obtain pollution permits from state oversight agencies. However, most sites are never inspected, according to the report.

The report claims that state water programs, already strapped for resources and staff, lack the ability to adequately monitor and inspect the sites they know about, let alone find those facilities that need to be brought into the regulatory fold.

Ted Conlin, who coordinates the Black River Remedial Action Plan for the Ohio EPA, said sediment and runoff pollution from all sources is the top threat facing Black River. Oil and antifreeze left in roadways, pesticides, farm runoff, and sediment washed into the river from construction sites can choke fish, destroy spawning beds and clog shipping lanes, he said.

Conlin couldn't say for certain if construction is contributing most to runoff pollution in the river, but he said sediment washed into waterways from parking lots, roads and construction sites is the biggest threat to the river.

''Sediment is huge,'' Conlin said. ''It's the reason why the U.S. Army Corps of Engineers has to go in every year and dredge 175,000 cubic yards of material.''

Conlin said sediment pollution is coming in equal loads from both the west and east branches of the river, which eventually dumps into Lake Erie. Satellite photos of the river mouth show huge plumes of dirt spewing out into the lake after heavy rainfalls.