John R. Quarles Jr., 77, an environmental lawyer and former partner and chairman of the Morgan Lewis law firm in Washington, died Oct. 29 at the Fauquier Rehabilitation and Nursing Center in Warrenton.

He died of Alzheimer’s disease, his wife, Barbara Quarles, said.

For four years before joining Morgan Lewis in 1977, Mr. Quarles was deputy administrator of the Environmental Protection Agency. As a lawyer specializing in environmental matters at the Interior Department, he assisted in the founding of the EPA in 1970 and later served as the agency’s general counsel. He served two stints as acting administrator of the EPA.

In his time with the government, Mr. Quarles was instrumental in the creation of measures to curb water pollution and enforce environmental regulations.

In his private practice with Morgan Lewis, he advised clients on aspects of the developing landscape of environmental laws, including those governing clean air, Superfund cleanup and hazardous waste. He was the author of several publications on environmental law.

John Rhodes Quarles Jr., a Boston native, graduated from Yale University in 1957 and Harvard Law School in 1961. He practiced law in Boston before joining the Interior Department in 1969.

He stepped down as a Morgan Lewis partner in 2004 and became senior counsel. He retired in 2006.

In 2005, the Environmental Law Institute made him its honoree for that year.

Mr. Quarles was a resident of Gainesville, in Prince William County, and a member of Living Hope Evangelical Presbyterian Church of Haymarket.

Survivors include his wife of 51 years, Barbara Harris Quarles of Gainesville; four children, Laura Spillane of Nokesville, Va., Nancy MacGowan of Haymarket, John R. Quarles III of Chantilly and Benjamin H. Quarles of Salt Lake City; two sisters, Barbara Harper of Washington and Elizabeth Glennon of Arlington; and 10 grandchildren.

— Bart Barnes