The Washington State legislature has given local air pollution control agencies and the Washington Department of Ecology the authority to prohibit the use of uncertified wood burning devices in an area that is designated as a "nonattainment area" as of January 1, 2015, or if required by the United States Environmental Protection Agency (EPA).
This state law referenced above gives the Puget Sound Clean Air Agency the legal authority to prohibit uncertified wood-burning devices in the Tacoma-Pierce County Wood Smoke Reduction Zone.
You can see this law in its entirety here:
RCW 70.94.47 - LIMITATIONS ON USE OF SOLID FUEL BURNING DEVICES
(Scroll down to Section 7 of this page for specific language describing the prohibition of uncertified wood burning devices)
You can find the Puget Sound Clean Air Agency's specific regulations pertaining to the Tacoma-Pierce County Smoke Reduction Zone within the Solid Fuel Burning Device Standards.
(Scroll down to Section 13.07 to see language specific to Tacoma-Pierce County Smoke Reduction Zone)