The National Ground Water Assn. (NGWA) announced that ...
A California contractor recently won the bid to develop a residential development with more than 300 homes on a hillside north of Lake Elsinore, Southern California’s largest natural lake. Before construction could begin, the contractor needed to create a 1.3-million-gal reservoir at the top of a 450-ft elevated peak to maintain dust control and ground compaction during the grading process. Pumps were an important part of the process, helping to maintain a dust-free environment for workers, neighbors and job quality alike.
A Thompson Pump distributor supplied a turnkey package including design, pumping equipment, piping, a portable power generator, auxiliary fuel bulk storage, onsite fueling capability and installation. The team also provided 24-hour maintenance service to alleviate any jobsite problems.
Pumps can help control dust from vehicle traffic on unpaved roads.
Pumping the Water
To complete this project, the distributor integrated a system to pump water from the reservoir into two 10,000-gal water towers used to rapidly fill 4,000-gal water trucks. The system utilized two pumps, a generator and approximately 4,600 ft of Victaulic pipe. They chose a 50-hp electric motor-driven pump supplied with a quiet pack to provide reduced noise for the residential community located at the base of the hill.
Approximately two-thirds of the way up the hill, a diesel-driven 6-in. jet pump was used to propel water the remaining 1,500 ft to the jobsite reservoir where there was another 200 ft of elevation change. Overall, the water traveled a total elevation of 450 ft, incorporating more than 4,600 ft of 8-in. Victaulic pipe along with various pipe fittings, assorted valves and control measures.
Many challenges were overcome on this project, including working with the steep elevation, loose hillside conditions, the canal crossing and the overall distance. The pumps ran efficiently 24 hours a day, seven days a week, allowing the project to be completed on schedule.
Watering is a very effective dust suppressant. When applied regularly, water provides temporary stabilization to disturbed surface areas. Dust-control measures should also be applied to any industrial activity that generates large quantities of dust, particularly if this dust could be transported to a nearby body of water.
Dust from highway projects can temporarily blind motorists. Dirt particles on building sites can clog the insides of construction equipment, wearing out machines and forcing expensive repair jobs on their owners. Exposure to large amounts of airborne dust can aggravate respiratory illnesses. With all of these potential problems, developers, engineers and state officials can hardly be surprised that municipalities, federal agencies and other regulatory bodies are putting more pressure on them to limit the amount of airborne dust generated on their construction sites.
Pumps can be used to control dust under numerous circumstances including: construction vehicle traffic on unpaved roads; drilling and blasting activities; sediment tracking onto paved roads; soil and debris storage piles; batch drop from front-end loaders; areas with unstabilized soil; and final grading and site stabilization.
Using Water to Settle the Dust
To wet the surface of construction areas, pumps should be used prior to any activity on the worksite. The area should be wet to a depth of cuts or equipment penetration. After clearing an area, water should be applied every two hours or sooner to prevent visible emissions.
During active operations, water should be applied 15 to 30 minutes before starting operations. A water truck should be used while grading and a fine spray or mist should be used when trenching. When screening, mist material after it drops from the screen.
Water should be applied in front of equipment. Do not water too much because muddy conditions increase the amount of trackout on the jobsite. Surfactants added to water increase penetration.
Water should be applied at the end of the day in order to allow the next day’s work area to soak overnight.