Seattle's mayor, police chief, fire chief, and homelessness response director are among city leaders expressing serious concerns about legislation to stop "sweeps" in Seattle.

A memo, dated Wednesday, was sent to Seattle City Council in advance of a public meeting about the topic and measure sponsored by Councilmembers Kshama Sawant, Mike O'Brien and Kirsten Harris-Talley. That proviso, as it is called, would restrict city spending on the removal of unauthorized homeless encampments.

However, the 10-page memo addresses several concerns from the department heads, including public health and safety risks and opening up the city to legal liability. The memo also includes a note from the State Recreation and Conservation Office, which indicates the city could lose state grants.

The package of documents also includes a stern letter from Seattle Mayor Tim Burgess, who says there are 400 unauthorized encampments inside the city, which pose health and safety risks "to the residents of these encampments and adjacent neighbors."

He also notes that 6,000,000 pounds of trash and human waste from authorized encampments were cleaned over the course of the year, and the "public health risks posed by this trash should not be minimized."

The memo from the department heads highlights the work of the city-funded Navigation team, and a failed attempt at allowing an unauthorized encampment.

The memo notes the case of "The Field," which "attempted to serve-in-place approach similar to that suggested by or what will result from the proposed proviso. Regularly serviced porta-potties and dumpsters were not utilized by campers, and at the time of the cleanup, the City removed 1,263 tons (2.5 million pounds) of garbage and debris from the site, including four inches of topsoil contaminated with human and rodent waste. It has been our experiences that when the City serves residents in unsanctioned encampments, many campers naturally infer services as an endorsement of their site."

Sawant is hosting a rally and public meeting on the issue Wednesday at 4 p.m. She has also encouraged people to set up tents outside Seattle City Hall.