Published: Mar 31, 2014 5:24 AM EDT

DARRINGTON, Wash. (AP) - The rains that have bedeviled rescuers working to find more victims in the debris field from the deadly Washington state mudslide are expected to ease this week, but searchers faced other challenges at the site like household chemicals and sewage.
    
The number of confirmed dead has increased from 18 to 21, Jason Biermann, program manager at the Snohomish County Department of Emergency Management, said Sunday evening.
    
Fifteen of the victims have been identified by the Snohomish County medical examiner, and six have yet to be identified, Biermann said. Another four bodies were found Sunday, but they won't be added to the official count until the medical examiner receives the bodies. Biermann said 30 people remain missing.
    
The March 22 landslide, one of the deadliest in U.S. history, struck a rural community about 55 miles northeast of Seattle.
    
Crews have completed a makeshift road that will link one side of the debris field to the other, significantly aiding the recovery operation. They have also been working to clear mud and debris from the highway, leaving piles of gooey muck, splintered wood and housing insulation on the sides of the road.
    
Searchers have had to contend with treacherous conditions, including septic tanks, gasoline and propane containers. When rescuers and dogs leave the site, they are hosed off by hazardous materials crews.
    
"We're worried about dysentery, we're worried about tetanus, we're worried about contamination," said Lt. Richard Burke of the Bellevue Fire Department, an on-site spokesman. "The last thing we want to do is take any of these contaminants out of here and take them into town."
    
The slide dammed up the North Fork of the Stillaguamish River, causing water to pool up on the east side. The river cut a new channel through the mud, but the rain has raised the water level nearly a foot, said Kris Rietmann, a spokeswoman for the team working on the eastern portion of the slide.
    
In at least one place, the water level got so high that it covered areas that have already been searched, said Tim Pierce, leader of Washington Task Force 1, a search-and-rescue team.
    
Searchers should get some relief soon. Conditions improved Sunday, and mainly dry weather is forecast Monday through Wednesday in western Washington.
    
"That's good news for our crews in the field, who have been working in extremely wet conditions," Biermann said.
    
The size of the debris field is also smaller than initially thought, officials said Sunday. After review and analysis, geologists have determined it is about 300 acres - just under half the size of an earlier projection of 1 square mile.
    
Away from the whirring chain saws and roaring bulldozers, many residents of nearby Darrington sought comfort in Sunday church services.
    
"I can only compare it to a hot, hearty meal after a very cold day," said Slava Botamanenko, who works at the hospital in Arlington. He said he spent two nights there to be sure he was available for work after the mudslide blocked the road.
    
All week, a steady stream of people has stopped in to pray at the Glad Tidings Assembly of God on the edge of town, said Lee Hagen, the senior pastor.
    
"At a time like this, everybody knows they've got to have God's help," he said.
    
At the St. John Mary Vianney Catholic church a few blocks away, the Rev. Tim Sauer said: "Bless our communities, bless our people, bless our valley."
    
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Baumann reported from Seattle.

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