“The challenging thing was that the site had its own internal drain system that took water from all around the project that put it into a channel in the back of the project,” explains Jay Selby, president and owner of Selby’s Soil and Erosion Control Company based in Newcastle, CA. “Drainage eventually flowed to a creek.”
Nothing had been done at the site, he says, when a massive storm struck in December 2014, dropping 5 inches of rain.
“At this time there was no roof or walls on the concrete building. We had not been contracted at this point. There was equipment stuck everywhere. It was a little unexpected,” notes Selby. “The sediment and dirt that came off the site filled the channel with three feet of sediment. Dirty water drained into the neighboring creek. It was a big, big problem.”
At that point the owner was given two weeks by the water-quality control board to apply erosion control on the entire site or face massive fines.
Wattles were used to filter the water and slow it down as it left the site, and erosion control blankets and silt fencing were also added.
“In the channel we installed rock check dams as water dissipated,” says Selby. “The entire site was hydroseeded with [Fiber Marketing International’s] Rainiers Bonded Fiber Matrix Supreme. Depending on slope variation and how much water was going to be travelling through the site, we varied the application from 2,500 pounds to 3,500 pounds of bonded fiber matrix over the 30-acre site. One of the challenges we faced is that the site never really dried up. It was still a muddy mess when we were out there. It was just the nastiest mud I’ve ever seen, and the tractors that had been driving though it during the rain event just made it a very undulating surface. It was still very, very muddy.”
Sediment control was not the only problem workers faced. “When you build such a large concrete building, it creates a high pH level. As water drains off the site, the high pH levels could kill fish,” says Selby. “On top of this, the site also used a lime treatment.”
Filtration would be needed to curb this threat and to lower pH levels in the water before runoff left the site. The company worked with a $150,000 erosion control budget for the 10-day project. Selby says the company chose the Rainier BFM because of its “outstanding performance” on a site with challenges like this.
“In conjunction with BFM, we used polyacrylamides. Our goal was to trap soil particles and lower the pH level in the soil before it left the site. We used a compost wattle then put a riprap check dam over the top of compost wattle,” explains Selby. “The riprap held the wattle in place. As the water filters through the compost wattle, it helps reduce the amount of pH leaving the site.”
Solutions like this are examples of how challenges continue to be met in the modern hydroseeding industry.
“We have chosen products out of a process of elimination over the years,” says Selby, who notes that sometimes you have to wait to see what is working and what is not in rain events like the one that occurred in Vacaville. “You really never know until you try. This whole industry was built on innovation.”