Post-Fire Remediation Workshop in Paradise
Last November the Camp Fire destroyed the entire town of Paradise burning nearly 20,000 buildings and taking 85 civilian lives. Once fire crews slowed fire progression and civilians were pulled to safety, the next emergency began. Slope stability and water quality was immediately at risk. Lucky for firefighters (and bad news to Erosion Control and Stormwater Managers), a large storm brought inches of rain to the newly burned surfaces.
While this storm helped to extinguish the fire it also caused massive amounts of chemicals and sediment to contaminate the watershed before crews had time to clean and implement protective measures. The reduction in vegetation for erosion control management also raised concern for flash flooding and mudslides (https://www.cnbc.com/2018/11/22/first-rain-in-months-douses-california-wildfire-raises-risk-of-mudslides.html ).
Hazardous materials from burned structures gets picked up by storm water and moved into nearby creeks and water bodies. As a result, dangerously high levels of heavy metals, detectable pH, and high turbidity were found in the watershed. Metals found include Antimony, Lead, Cadmium, and Selenium. High sediments were also present in the water which kills fish and wildlife if too high, and can be a threat of safety for both humans and surrounding ecosystems.
One of the affected creeks, Butte County Creek, flows into the Sacramento River. This creek has migratory, spawning, and cold beneficial uses. These three criteria help us dictate if a water body is considered at high risk. This creek is only one of seven that still has a Salmon run.
Preserving Salmon population is crucial to Pacific coast habitats. "In short, salmon are the key to protecting a way of life rooted in the North Pacific environment: protect salmon and you protect forests, food, water, communities, and economies," explains the World Salmon Center (https://www.wildsalmoncenter.org/work/why-protect-salmon/). With the introduction of harmful chemicals that were released by the fire and moved downstream by storm water, there is a huge concern that Salmon populations will be impacted.
Butte Creek has COLD, MIGR, and SPWN beneficial uses (Source: CalTrans Water Quality Planning Tool)
It's unknown how exactly the materials released from this fire will interact with water and other elements, and to what extent the impact they will have on human health and ecosystem preservation. But, from what we do know in regards to human health, we understand that heavy metal consumption can cause cancer, developmental problems, and sometimes death (https://www.freedrinkingwater.com/water-education/quality-water-heavymeatal.htm). Because of this and the level of pollutants found in the water post-fire it was assumed that the water was unsafe for human and animals.
Side Note: It's questioned whether or not this water is safe to swim in (for those who swim in the creeks in the area), and it's recommended this summer to avoid swimming in and downstream of Paradise.
With the likelihood of water quality and erosion control being threatened, a team of multi-agency Biologists, Engineers, and laborers began collaborating an effort. Post-Fire Remediation is still in it's initial stages of development since fires like these do not typically occur often. But, large fires have become more prevalent in California. Unfortunately a system needs to be integrated. This team that worked with the Camp Fire has implemented a system that will change the way erosion control and stormwater management is performed, and will influence how we protect our waterways post fire.
Due to the novel situation that is predicted to become more common, the local engineers and erosion control experts decided to host a workshop in Paradise to discuss their findings. As Stormwater Managers who have helped with smaller post-fire operations, we wanted to participate and learn from this experience.
As we drove up through Highway 191 to the workshop in Parade, we were shocked by the empty foundations, standing fireplaces, and burned cars. Workers in Hazmat suits and dump trucks lined the streets. It was surreal to drive by a supermarket and see the metal structures melted and falling in on itself.
Todd Thalhamer, from the Office of Emergency Operations, opened up the workshop. He described this experience as one that will change the way we do things here on out. Such changes will be to require Erosion Control installers to attend Hazmat Training. Thalhamer explained the current operations, stating that about 1,000 homes are being cleaned per week, with an aircraft carrier removing waste off of the hill every three days.
Due to the circumstances presented with property lines and the need to rebuild immediately, the philosophy behind Best Management Practices (BMP) installation was different. Erosion Control installers typically stuck with the triage of Hydromulch (no seed, as to avoid growth removal before rebuilding), Fiber Rolls (as sediment control), and Compost Socks (which filter out water - and heavy metals - as it leaves your site).
A demonstration performed by Grass Roots Erosion Control showing a typical BMP installation used for areas affected by the Camp Fire. The BMPs used were 1) Fiber Rolls 2) Compost Socks and 3) Hydro Mulch.
Implementing BMPs in the burn area was difficult for several reasons, including:
Property Rights (can't protect without permission)
Lots of Soil Contamination
No tactical operations
Robert Horowitz from CalRecycle then talked about the utilization of Organics and Compost in Stormwater Management. Compost can filter out water as it leaves your site, and can be reused as a soil amendment when no longer needed. The beneficial bacteria in the compost can help the soil become healthier and support vegetation. Compost is a much safer alternative to wood chips and plastic, as it is clean and doesn't kill wildlife. As a bonus, he explained that Compost is taking a material that would otherwise fill landfills, and giving it a new life that could have enormous beneficial impacts for Stormwater Management.
To use as a BMP compost is stuffed into a sock and tied at the ends. The sock is made of permeable material, so that water can flow through the fabric and get cleaned as it passes through the compost chunks. These socks are easy to install and maintain. Compost socks were used throughout the Post-Fire Remediation in Paradise, and research is being collected to see what their potential impact was on reducing water body contamination.
Fun Fact: Compost socks can be used to treat water as it leaves your site, and is scientifically proven to remove heavy metals. What's better than combining erosion control with water filtration and easy installation? Sounds like something we want to play around with more. They're even integrating the technology with inlet protection.
Next, Michael Parker from the Central Valley Regional Water Board spoke along with NorthStar Biologist, Carol Wallen. Both have been involved with Post-Fire stormwater management. Carol explained that some of the worst offenders of stormwater quality were Trailer Parks that contained high amounts of metals, and were oddly placed very close to many streams and creeks. She also said that ash will typically bind with soil and be stabilized onsite; however, with it being the wettest winter on record there were high amounts of ash that got picked up and moved into streams.
One of the techniques they used to minimize storm water pollution was to direct water away from the worst offenders. There were lots of burned cars in the area that contained high levels of metals and pollutants. They used gravel bags to divert water away from burned cars, and directed the water through a compost sock so that it could filter before entering the creek. Upon many other issues talked about, she also mentioned the importance of keeping the water clean to protect Butte County Creek's salmon run.
Parker then described how resources were stretched thin after the Car and Mendocino Complex fires. It was a tough situation to work with. A part of the goal with this fire was to research if the implemented BMPs were working for future emergency use. They sampled during five of the six rain events (they didn't catch the first rain event), and documented the flux of pollutants throughout the course of the winter. He said that they are not too sure how the fire affected shallow groundwater. This issue will need to be addressed soon.
An affected mobile home park that we visited during the workshop. Crews in hazmat gear were present earlier in the day cleaning up materials. Each site needs to be tested for contamination as many toxic substances have been found.
After the classroom portion of the workshop we went outside to visit burn areas and watch a BMP installation demonstration. Dealing with Post-Fire Remediation is sticky business. It's a very complicated multi-level issue that involves several agencies and property owners. We really hope that this is not something that we will have to deal with as a community on an on-going basis. We are happy to see many bright minds working together to come up with solutions, and carve a path for better clean up.
Thank you to all who helped put on the free workshop. And many condolences to all impacted by the fire. We hope for speedy construction and protection of your homes for years to come. To all of the clean up crews, please stay safe and wear appropriate protective gear.
For Wildfire donations please visit http://time.com/5451804/california-wildfires-how-help-donate/