The specter of rain washing potentially toxic ash from thousands of burned homes into sensitive Sonoma County watersheds has injected a new sense of urgency to local fire cleanup efforts, with the immediate focus shifting to erosion control needed to safeguard water quality.
The risk comes at the outset of a historic government-funded debris removal program in the region, where the largest and most destructive wildfires that broke out Oct. 8 were finally brought under full containment Tuesday.
With rain in the forecast for Friday and next week, the health of the local watersheds, including 617 streams in fire-affected areas, has become a top priority, officials said.
“We consider it a very high threat,” said Mona Dougherty, a senior water resource control engineer with the North Coast Water Quality Control Board in Santa Rosa. “We are very concerned about the impacts to aquatic life and drinking water.”
The Tubbs and Nuns fires wiped out nearly 7,000 Sonoma County structures, including 2,900 homes in Santa Rosa alone.
Ash and debris from incinerated homes can contain numerous hazardous materials, including asbestos, heavy metals, by-products of burned plastics and other chemicals, according to the Sonoma County Department of Health Services.
While direct human contact with this material poses health risks to humans, the material also poses dangers to waterways, which feed local drinking water supplies and provide valuable habitat for a variety of species, including endangered salmon.
“Drinking water is safe and continually monitored, but because the county’s natural watersheds filter drinking water, it is critically important that ash, debris and other pollutants are prevented from entering stream systems to the maximum extent possible,” stated a joint press release from Sonoma County, the Sonoma County Water Agency and the city of Santa Rosa.
The Water Agency provides Russian River drinking water to 600,000 North Bay residents from Windsor to northern Marin County.
Local governments and other agencies have banded together in a taskforce to ensure measures are in place to prevent harmful runoff into creeks and rivers, said Rita Miller, deputy director of environmental service for Santa Rosa Water. The group’s first meeting was Monday.
To date, Santa Rosa city public works crews have placed 1,500 to 2,000 gravel bags around storm drains in Coffey Park, as well as straw bale weirs in the Fountaingrove area, Miller said.
While those gravel bags might not do much to remove or neutralize toxins and heavy metals, additional wattles with organic material designed to do just that will be added as soon as possible, she said.
The hope is that the upcoming rains will be modest, Miller said.
“We’re super grateful that this rain looks like is to going to be a light to moderate soaking that hopefully will not produce a lot of runoff,” Miller said.
About a quarter of an inch of rain is forecast for Friday evening, with more possible on Sunday, according to AccuWeather. Since Oct. 1, Santa Rosa has received a paltry 0.21 inches, compared to more than 7 inches last year at this time.
Doug Allard, owner of The Wattle Guys, said local water quality officials “have been having a hell of a time getting the wheels moving” but now they seem to have begun taking the threat seriously.
Allard said his manufacturing plant in Petaluma is running full-tilt to produce straw wattles. A one-of-a-kind truck will start making special weighted wattles embedded with organic material Wednesday.
The goal is to keep the material in place until the cleanup efforts can get underway in earnest. The immediate risk, Allard indicated, is damage to riparian habitat and sensitive fish species.
“If we kill off the spawning capacity for salmon, I don’t need to tell you what issues that is going to cause in the future,” Allard said.
The plan is to get Allard’s specialized wattles in place at the base of driveways in heavily impacted areas with lots of hardscape, such as Coffey Park, Dougherty said. Street sweepers also are going to be used to remove as much of the ash and other material from the streets, she said.
There is still concern, but somewhat less urgency, about more rural areas, she said. That’s because those home sites are more likely to be surrounded by soil, which, as long as the rain is light, would tend to hold back the ash, she said.
Heavier rains would be a bigger problem. A “preliminary hazard assessment” map released recently by the United States Geological Survey shows the probability of debris from burned areas washing into local creeks during a significant rain.
The map shows the Tubbs fire that roared into Santa Rosa with a less than 40 percent chance of a “debris flow” following a storm dropping an inch of rain in 15 minutes. But some smaller areas of Mark West Creek and Porter Creek, to the east, showed an 80 percent chance of a debris flow. More details about risks to streams are expected soon from an emergency response team studying the fires, Miller said.
The city public works crews began dropping the burlap sacks full of gravel at the edges of the storm drains in burned-out areas about a week ago, but they held off going onto people’s property, said Yarrow Bernhardt, the public works crew chief.
Residents had just been let back into the neighborhood, and crews wanted to respect their privacy and grieving process, Bernhardt said.
He said he was struck by how many people had brought new shovels to sift through the ashes but then upon seeing the devastation set the shovels aside.
“People just needed to see it,” Bernhardt said. “It was almost like a funeral.”
Crews on Tuesday were going onto the properties circling drains with straw wattles and staking them so cleanup crews don’t rip them up or bury them, he said.
Santa Rosa-based Stevenson Supply has already delivered several truckloads of wattles made from certified weed-free rice straw to projects in the Fountaingrove and Mark West Creek areas, said vice president Kent Stevenson.
They’ve also partnered with Selby’s Soil Erosion Control of Newcastle, a specialist in hydro-seeding and post-fire recovery work, he said. That work will involve spraying a mixture of mulch, binder and native seed onto hillsides to prevent erosion and encourage regrowth, he said.
There are so many sites, however, that the focus at the moment is on places where runoff might enter waterways, he said.
“They are not looking at the individual home sites,” Stevenson said. “They are looking at the creeks.”
Mark Newhouser, restoration program manager for the Sonoma Ecology Center, said he’s working with various groups on erosion control strategies but has been frustrated at the pace of the reaction to the threat.
“I, unfortunately, don’t think that people have embraced the need for triage and making rapid decisions and getting out information that is good enough for people to act on,” Newhouser said.
He said he’s confident that many of the various agencies working on the issue are well intentioned.
“What I’m not confident of is they are going to get to all the cleanups done before the heavy rains set in,” he said.
The forecast of rain is troubling some of the remaining residents of Coffey Park.
Kristen Ortlinghaus said she is “heartbroken” for her neighbors but can’t help but worry about the health impact on her family and the environment from living so close to hundreds of burned up homes.
She’s been taping doors and window shut and putting towels at the base of doors, but she is frustrated that she can’t get straight answers about air quality out of public officials.
“We don’t even use Round up. That’s that how much we don’t want to contaminate the environment. And now I know the rain is going to cause all kind of problems.”
You can reach Staff Writer Kevin McCallum at 521-5207 or firstname.lastname@example.org. On Twitter @srcitybeat.