EVERETT — The state plans to dig up the lawns and topsoil from 21 homes in north Everett starting today to clean arsenic contamination left from the former Asarco smelter that closed 100 years ago.

It’s part of the ongoing effort to rid as many as 500 homes and three parks of the decades-old pollution. The work on this round of homes around East Marine View Drive and 8th and 9th streets is expected to take three to five months.

Each yard will be restored with fresh topsoil, grass and landscaping. “We’re working in areas closest to the smelter (where the contamination is the highest) and working our way out,” said Meg Bommarito, a manager in the state’s toxics cleanup program.

The Department of Ecology, the city of Everett and the Everett Housing Authority also are gearing up to clean the three parks in north Everett: American Legion Memorial, Wiggums Hollow and Viola Oursler Overlook.

They hope to start on American Legion next year and finish in 2015, Bommarito said. The work on the other two parks is scheduled to begin in 2015 and finish in 2016.

They’ve moved up the timeline for cleaning the parks after the Legislature set aside $4.75 million this year for the effort. It was originally scheduled to occur after all the homes were cleaned. “That was a huge piece of funding to be able to start that sooner than we originally planned,” Bommarito said.

Asarco, a mining and smelting company, operated the Everett smelter from 1894 to 1912 at what is now the intersection of E. Marine View Drive and Highway 529. The smelter’s smokestacks rained arsenic onto a square-mile area of north Everett.

But the contaminaton wasn’t discovered until decades later in 1990. Arsenic is not absorbed through the skin but there is a long-term risk of developing cancer for people who swallow contaminated soil over a period of years, such as if children play in the dirt and put their hands in their mouths.

The state, the city and the Housing Authority have cleaned up around 200 properties. Much of the work has been done as money has become available over the years.

In 2009, the state received $34 million in a settlement from Grupo Mexico, a mining company based in Mexico City that acquired Asarco, and that money is being used for the cleanup. It is part of a larger $188 million settlement to repair environmental damage here and in other parts of the state, including Tacoma.

But that will not cover all of the costs for the clean up. The state has used about $15 million of the settlement so far including the work contracted for this year, Bommarito said.

The state agency is also investigating industrial properties along the waterfront and areas east of East Marine View Drive for contamination.

Bommarito said the state is hopeful that fewer properties will need to be cleaned up. She said they have found less contamination and it’s in shallower ground as they’ve tested soil further away from the smelter.

The contamination at the parks was discovered in 2011. The state recommends that anyone who visits the parks wash their hands and toys with soap and water after playing in the dirt, wash their hands before eating and take off their shoes when they get home.

Bommarito said the state will work with the city’s parks staff before the work on the three parks begins.

“We have not started talking to (the park’s staff) about which areas will be handled and how it will be handled,” Bommarito said. “I know they’re anxious to get as much contamination out of the parks as possible.”

People who have questions or concerns about the efforts to clean arsenic out of soil in north Everett can meet with state Department of Ecology workers from 10 a.m. to 1 p.m. at Liberty Hall, Everett Community College, on the corner of 10th Street and Broadway. A consultant will also be available from 7 a.m. to 5 p.m. Monday through Friday at the work sites.

People can also get more information by calling a state hotline at 425-446-1024.