Engine pumps were restarted Friday at a Manhattan wastewater treatment plant struck July 20th by a fire that caused millions of gallons of raw sewage to spill into the Hudson River, according to the Associated Press.

The four-alarm blaze began in the engine room of the North River Wastewater Treatment Plant at about 11:45 a.m., causing raw sewage to seep into the Hudson River at about 5:15 p.m., the New York City Department of Environmental Protection said in a statement. DEP said that staff and unspecified contractors are repairing equipment, assessing damage and performing clean up activities at the plant, which is located west of the West Side Highway from 137th Street to 145th Street.

Sewage from the plant, which treats on average 120-million gallons of wastewater per day, was still flowing into the river and the plant remained shuttered on Friday afternoon. Calls to Mayor Michael Bloomberg's office and NYC DEP were not returned by press time.

DEP says it is performing small "pump arounds," pumping wastewater flow out of an 84-in. sewer at West 117th Street that normally flows to the plant, and pumping into a 42-in. sewer at Frederick Douglass Blvd. and 117th, which flows to the Wards Island Wastewater Treatment Plant. To reduce bacteria, DEP is using chlorine to treat some sewer outfalls near the plant, the agency says.

Both New York and New Jersey authorities are monitoring water quality, and NYC officials issued advisories for several area beaches. In New Jersey, DEP officials said late Friday that their beaches had so far not been affected. The North River plant is located across from Bergen County, N.J.

The North River facility is built on a 28-acre reinforced concrete platform over the Hudson and rests on 2,300 caissons pinned into bedrock up to 230 feet beneath the river, according the DEP's Web site. Wastewater flows several stories underground from an 11-mile-long intercepting sewer that runs along Manhattan's west side. Five main sewage pumps lift the wastewater to surface-level primary settling tanks. The Riverbank State Park, a 28-acre multi-level landscaped recreational facility with several athletic fields and swimming pools, sits atop the facility.