Most HDD contractors know the frustration of the paint filter test. Landfills, in order to accept drilling waste or spoils, put a sample of the material on a paint filter for five minutes. If any portion of the material passes through the filter in that test period, the material is deemed to have free liquids. Of course, landfills can then reject the whole truck or require premium disposal fees.
Our company advised horizontal directional drilling specialist Brotherton Pipeline Inc., a registered minority company out of Gold Hill, Oregon, on one solution for this issue. Brotherton has over 30 years of experience in natural gas transmission and distribution, plowing, trenching, vacuum excavation, auger boring, rock hammer boring and underground power installation. The company (like every HDD contractor) has always found drill spoils a challenge. Its crews work throughout the western and northwestern U.S. on a variety of projects, including crossings for highways, creeks, rivers, streets, wetlands, canals, railroads and lava fields, as well as beach approaches. We recommended and they have come to rely on our Slurrybond 2000 G, one of several spoils solidification products on the market.
“Finding an effective product that can be added to our spoils to achieve this level of dryness while staying on budget has proven to be challenging,” says Israel Brotherton, the company’s directional drill supervisor. “After researching possible solutions and networking with Carson Underground and CETCO, it was recommended that we try a different solution from CETCO to serve as a solidification/drying agent.”
Free liquids in drill spoils can stop a truck at the gates to the landfill, but free liquids that make it through can cause problems with a landfill’s leachate collection systems. Brotherton Pipeline doesn’t worry about either issue now, the company says.
“We have tried several different products from several different manufacturers,” Brotherton says. “Some products are effective yet very costly. Other are less expensive but also less effective. Another issue has been related to the application of the product: Windy conditions may impact proper application and result in product waste due to high winds, etc. … Slurrybond 2000 G … is far more granular than other products, reducing the likelihood of it becoming airborne. We started by trying half of a pallet to assess its effectiveness.”
The company says that, while the product costs slightly more than their previous solution, they use less of it, waste less and it is much more user friendly.
“On average, 7-10 bags of Slurrybond 2000 G are mixed per 10 yards of spoils, depending on the liquid content,” Brotherton says. “An excavator is used to mix the spoils, the spoils begin to clump and clumps break apart, making the spoils stackable. This allows the spoils to not only be hauled to a landfill at a reduced disposal cost, but they can be hauled with a dump truck. This reduced the cost of disposal significantly, by removing the need to rent lined bins, pay premium disposal fees for cuttings that do not stack, and pay the additional fees associated with using roll-off trucks to transport spoils.”
The company says minimizing dust production on the jobsite is another added benefit, cutting worker exposure — and the environmental impacts — associated with dust.
The disposal of drill spoils for horizontal directional drilling contractors is a big issue today. Fortunately, the options for solidification reagents are increasing, and specialty products are now available when dealing with waste slurry contaminated with salt, cement or even hydrocarbons.
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