ARVADA, Colo. (KDVR) — A fourth public library in Colorado has closed for methamphetamine contamination. This time, it was the Arvada Library in Jefferson County.

The library closed to the public Saturday and will be closed until further testing can determine the extent of the contamination, officials said.

Health risks from casual secondary exposure to meth in public are low, Jeffco officials said.

The first library in Colorado to close for meth contamination was the main library in Boulder in late December.

This was followed by the Englewood Public Library on Jan. 11 and the Bemis Library in Littleton a week later.

The Boulder Regional Transportation District also closed the downtown station bathroom after meth residue was found there.

As for the City and County of Denver, it said it has always been adamant about cleaning protocol and is working to put a policy in place to eliminate unknown toxic substances.