Melanie Hartwig-Davis, who in December had urged state lawmakers to give suburban water commissioners a pay raise, is stepping down from the Washington Suburban Sanitary Commission.

Hartwig-Davis and her husband Lance Davis, who were living in Cheverly in Prince George’s County, bought a home in Edgewater in Anne Arundel County late last year, according to land records. But Hartwig-Davis decided to keep her primary residence in Cheverly, and hoped to stay on the commission as one of three representatives of Prince George’s.

Hartwig-Davis heads an architectural firm based out of her Cheverly residence.

State law requires the WSSC commissioners to live in the counties they represent and be registered to vote there.

However, aides to Prince George’s County Executive Rushern L. Baker III (D) questioned the arrangement, according to a letter Hartwig-Davis sent to Baker, and she has decided to step down once a replacement is confirmed. Baker is searching for a replacement, a spokesman said.

The part-time commissioners are paid $13,000 annually to oversee the $1. 4 billion water authority. Three commission members each are appointed from Montgomery and Prince George’s counties.

Baker has come under fire recently from the Prince George’s County Council for naming non-residents to some boards and commissions even though many do not require that members be residents of the county. Last year the council passed a law that would require residency in the county for certain appointments, mostly boards whose members are uncompensated volunteers.

Hartwig-Davis said in an interview that she hopedher successor would pursue efforts to make the water authority more attuned to environmental issues and green development. She testified in December — a few weeks before closing on the house in Anne Arundel — at a hearing of the Prince George’s House delegation and urged the General Assembly to give water authority commissioners a pay raise. She would not have benefitted from the raise, unless she were reappointed to a second term. The bill has stalled in the county delegation.

Jennifer Jenkins contributed to this report