At your disposal

When utility contractors describe their largest horizontal directional drilling (HDD) issues, disposing of the drilling mud, water, and various drilling fluids necessary for a drilling operation usually tops the list.

The problem lies in the fact that used drilling mud must be cleaned and disposed of properly. It can’t simply left on a public easement or private property. For many contractors, this process is as costly as it is time consuming.

Sonoma Underground Services understands the hassle of dealing with drilling mud. The company used over 15,000 litres (4,000 gallons) of mud daily on a recent HDD project involving a multi-duct pull through solid limestone under an interstate interchange. To collect and haul it away, a subcontractor charged at least $A3,100 ($US2,500) a day. On top of that cost, lack of available water inhibited drilling for three hours each day. Twice a day, crew members travelled an hour and a half to get more water to create more mud.

To reduce mud-related costs, Sonoma Underground Services switched to the new Ditch Witch MR90 mud recycling system. The self-contained system enabled the company to reuse drilling mud and handle spoils.

By recycling drilling mud, Sonoma Underground Services slashed the amount of water and mud needed on site and eliminated daily vacuuming. On the most water-consuming day, the crew began with a little over 7,500 litres (2,000 gallons) of mud and ended with 6,600 litres (1,750 gallons), gaining three hours of drilling-time by eliminating disposal runs.

Know your mud system

Mud recycling systems support contractors’ goals for a profitable operation and environmental compliance. When reviewing system options, consider the following:

• Size: Determine sizing on what the system will be tasked with doing. Many times a compact system meets the demands of standard-size directional drills. Ditch Witch engineers designed the MR90 – one of the most compact systems on the market – for contractors to use where other recyclers can’t fit, such as in congested easements and small backyards.
• Ease of setup: Equipment should be able to get to work quickly. Hydraulic leveling for screens and a hydraulic jack on tongue of the trailer are examples of timesaving features.
• Integrated controls: Automatic controls, such as those that prevent overflows, benefit contractors. For example, an automatic pit-pump control incorporates a float sensor on the MR90, so the pump automatically turns off, preventing overflows and subsequent time-consuming clean up.
• Full-fluid transporting: To increase jobsite productivity and reduce hauling expenses, seek a mud-recycling unit that can be transported full of fluid.
• Recycling technology and ease of service: Understand competing recycling technologies. For instance, the MR90 mud recycling system filters mud using an easy to change and service two-screen system along with six 6.35 cm (2.5 inch) hydrocyclones. A rear onboard hopper catches all screened spoils, which can then be mixed with drying additives and returned to the pit or disposed of off-site.

By recycling drilling mud, utility contractors can retain profits that others are literally throwing away.