The head of Flint's water pipe replacement program says the city in Michigan hopes to finish the project in 2019.

Retired National Guard Brig. Gen. Michael McDaniel coordinates the FAST Start initiative to replace lines that leached lead into homes and businesses. He made his comments during the first day of a three-day water infrastructure conference in Flint.

He says they hope to replace pipes to 6,000 homes this year. The city has said at least 30,000 homes may have service lines that need replacement. Residents still are being urged to use water filters.

Flint was under state control when it switched from Detroit's water system to the Flint River in 2014 to save money. The river water was not properly treated to prevent pipe corrosion.

Elevated levels of lead later were found in some children.

WJRT in Flint is also reporting that a preliminary hearing is set for four men facing charges tied to the crisis.

The attorneys for the men, former emergency managers Darnell Earley and Jerry Ambrose, and city employees Howard Croft and Daughtery Johnson, were in court Tuesday morning. 13 people have been criminally charged since the Attorney General launched his investigation. Earley and Ambrose face three felony charges and a misdemeanor. Croft and Johnson are facing two felonies.