Despite advances in technology, or in ever-more stringent federal clean-water regulations that place greater pressure on the contractor to eliminate erosion and prevent sediment loss (all under budget), no one is able to control Mother Nature. But knowing what’s coming, as well as preparing for the worst, helps contractors and their suppliers remain focused on avoiding or solving a problem rather than becoming part of the problem. One example involves a 2-mi. road-widening project in Charlotte, NC. This project involved a number of inlets that, by federal and state decree, had to remain free of any soil intrusion and prevent sediment loss. At a cost of more than $400 per inlet, a crew of four laborers and two equipment operators spent 45 minutes at each inlet excavating a small sediment basin and installing a 10- x 10- x 2-ft. wire and filter stone barrier to prevent sediment loss, yet they achieved only somewhat satisfactory results despite high-maintenance care.Silt-Saver Inc. in Conyers, GA, supplied the contractor with a sample of the Silt-Saver Frame and Filter Assembly. Again the workers excavated a small sediment basin around the inlet structure, but instead of using the time-consuming wire and gravel barrier, they simply installed the lightweight, reusable frame over the open inlet. They then placed the nonwoven fabric filter over the frame and filled the soil pockets at the bottom of the filter, and the inlet was protected in a scant five minutes. This reduction in installation time and subsequent maintenance minimized the overall cost, as well as fears about failures from rainfall events.Roger Singleton, owner of Silt-Saver, points out that National Pollutant Discharge Elimination System (NPDES) regulations require that all best management practices be designed, installed, and maintained to meet a 25-year, 24-hour rainfall event. New techniques such as the Silt-Saver Frame and Filter Assembly save time and meet clean-water regulations by reducing turbidity and sediment loss, but most can also add an element of safety by removing hazardous stakes and covering open holes. This additional safety precaution provides peace of mind to the contractor when the equipment shuts down for the night or weekend and children or other trespassers might be in areas with open inlets, Singleton says.Stabilizing the Soil
Ground-stabilization geotextiles separate soft soils from an aggregate layer.The increasing use of building sites in marginal or poor soil areas means contractors need to do more to stabilize the site to avoid getting stuck in the soil–and do it affordably. “This has led to the widespread use of ground stabilization fabrics,” says Dave Snyder, marketing manager for Webtec Inc. in Charlotte. Also known as ground-stabilization geotextiles, the fabrics provide valuable separation and stabilization functions. “They give quick protection at the time of need, whether in the staging area, road, or construction entrance. They help the contractor to proceed with his project rather than wait for the area to dry. Ground-stabilization fabrics can be very valuable tools when rain and spring thaw make construction sites especially soft.”Geotextiles keep the existing soil separate from the aggregate used to help stabilize the high-traffic spot. Snyder adds, “Laying the fabric takes about as much time as unrolling a roll of carpeting. It’s that simple.” He recommends that fabrics be overlapped 18-36 in., with 24 in. being typical.“These fabrics help contractors meet the new NPDES regs because they help keep the soil particles in the native soil from pumping up through the stone to be carried away by construction traffic or water,” adds Snyder.When choosing fabric, contractors need to know estimated soil strength, the load that will be placed atop the stone or aggregate, the aggregate thickness, and the final design. “For example, if you’re building a parking lot and you have to have a construction entrance to that lot that will become a permanent entrance, then you’ll be thinking not only short term but long term. That’s when you’ll go ahead and lay down 12 inches of aggregate instead of just 6 to 8 inches for construction. The extra thickness during construction ensures that the entrance will remain stable despite any foul weather.”Yard and Stockpile StabilizationA typical inlet protection device can be costly and ineffective and create hazardous job-site conditions when it fails under the forces of a normal rainfall event.Even as contractors work to stabilize work sites, there’s ever the need to ensure that the equipment yard doesn’t become part of the problem, no matter how strong the storm event. But not every contractor can afford to hardtop his yard. Tom Carpenter, owner of Carpenter Erosion Control in Ankeny, IA, notes that leaving equipment out in the weather is not a typical concern because his seeding and mulching work is focused within a 20-mi. radius of Des Moines. Equipment is driven to and from the site rather than left overnight. “We’ll have two to three tractors on-site for seeding and mulching, including one to pull the silt fence machine, and a skid loader for cleanup and other tasks, so most jobs are done in a single day. “At company headquarters we keep the equipment out of the mud because we laid down a geotextile material eight years ago on these 4 acres and topped it with 5 inches of limestone and gravel. Our trucks and machines have a firm, clean yard regardless of the weather.” As an erosion and sediment control contractor, Carpenter is often called to button up a site before a forecasted rain event. “Because erosion control is difficult or impossible to do during the earthmoving phase, sediment control with silt fencing is one of the best and most effective practices. We use the ‘tommy’ silt fence machine to properly install silt fencing around stockpiles and staging areas to prevent sediment loss. Mechanical installation means we get consistent, effective silt fences every time. Our customers don’t have to worry about the bottom blowing out and contamination to nearby streams.” The machine also allows Carpenter to button up many sites in a short time because of its high productivity. “We can install 100 to 150 linear feet per man-hour, so we can get in and out of most sites very quickly.”Fiber-Matrix SolutionThe ‘tommy’ silt fence machine installs silt fence around a staging before a storm event.While instant weather can be a problem, there’s still the challenge of dealing with the climate, especially as freezing weather encroaches. One of the challenges is getting the work accomplished more quickly so the contractor can wrap up the project rather than wait out the winter. EcoAegis Bonded Fiber Matrix, manufactured by Canadian Forest Products Ltd. in New Westminster, BC, is used on the site as well as around areas where the machines are temporarily parked. Joe Hargitt, product manager, comments, “This product makes a hydraulically applied blanket using conventional hydroseeding equipment. It can be applied where the terrain is too steep for labor crews or where surfaces are too rough to lay down blankets. It is also sprayed on as an insurance measure to stabilize soil where machines and related equipment are stored during the project.”Hargitt explains that a typical application is done in two passes, at a rate of 3,500 lb./ac., to make about a 1/8-in. mat that is water-porous but doesn’t break down or wash out. “A large hydromulching machine can cover an acre in less than 30 minutes.” An application of EcoAegis, combined with good vegetation, will ensure the equipment will be accessible when the contractor returns to the site. He reminds users to flush and blow out tanks nightly when overnight temperatures will be below freezing. This is to ensure that the machine is not iced up and unavailable for immediate use the next morning.“We recommend our excavation clients do something so the temporary base of operations doesn’t become a trouble spot,” reports Keith Porter, general manager of Mid-Canada Hydroseeding Inc. in Winnipeg, MB. He adds that his company takes on projects in Manitoba, Saskatchewan, and Ontario, doing some $500,000 a year in erosion control services, chiefly for those in heavy construction and grading and excavation.In Canada, the Department of Fisheries and Oceans oversees legislation that applies to sediment control. “And that includes our temporary parking lots,” Porter points out. “We strive to keep officials happy so the work can continue. Our weather challenges include a short period to work in, with about a six-month working season. There’s always the need to button up for the fall.”He reports that contractors utilize onsite generators to keep the coolant generating throughout the machine during off-hours. “The block heater is plugged into electricity to keep the coolant circulating so in the morning the engine isn’t frozen up. They still need warm-up time before operating, but block heaters shorten that time, plus initial startup is a lot easier.” Contractors also park on hard ground so machines don’t get frozen to the landscape.His Finn T170 and T60 HydroSeeders have heat tape on all the piping and the bottom of the tank. “Installing heat tapes may take five to six hours, but savings in broken parts alone can be phenomenal. In the fall, all water has to be drained out of the lines and antifreeze poured in to avoid crystallization of any remaining water. In one case we were on our last working day, but the pump had broken overnight, so we couldn’t finish the job until spring.” Here and NowBrubacher Excavating’s two full-time paving crews depend heavily on up-to-the-minute weather forecasting.While it’s not always easy to anticipate standard climate changes and prepare for them, an even more complex matter is determining whether an impending storm is reality or merely a threat. Fortunately, the technology is here (see the sidebar) to help keep the equipment moving as long as possible–yet not get caught in a storm. More and more companies of different sizes and in different locales, such as Brubacher Excavating in Bowmansville, PA, and Larkin Excavating of Lansing, KS, are using localized weather services to help plan the workweek and the workday.“Thunderstorms in summer and nor’easters in winter are two of our weather challenges,” reports Roger Sauder, dispatch manager for Brubacher. “We have 300 employees, work in a 100-mile radius in the southeast quadrant of Pennsylvania, and are able to work year-round, depending on the weather.”He comments that if there’s going to be a thundershower in the middle of the day, the need is to determine whether it’s better to wrap up and go home or find a way to wait it out for a half-hour or so and go to work again. “If it’s a large storm, we’ll usually tell them to come on in. With our weather service from Meteorlogix, we’re able to plan on which four days offer the best chance to keep on working so we can get the land cleared, do all the rough cutting, put the basins in for the ponds, and [do] other major earthwork, piping, and storm sewer installation. We rough-in those courses, and they do their own final landscaping.”Speaking from 17 years of experience with the company, Sauder adds that the other benefits to a localized weather service include notifying the concrete division of overnight temperatures if there’s a need to blanket its work to keep it from freezing. “The primary benefit to us is knowing whether the moisture will be at the level where we have to shut down. We need to know whether we’ll be getting one-tenth of an inch in a short shower or a major wetting.”It also helps to know when it’s going to remain dry. “The major things for us in excavating are the amount of rain and the speed of winds. We have four water trucks for dust control. If we know that site is going to have lots of winds and be hot and dry, we know we’re going to need more trucks on-site. As this country continues to get more and more built up, dust control will be more and more needed to keep the neighbors happy, to help us keep our reputation for quality construction.”After a storm, Brubacher uses its watering trucks to clean up any mud that has spilled out in the street. “We use silt fencing to control runoff and encroachment of areas adjacent to the site. Knowing the weather in greater detail helps us better care for the job site and make more efficient use of our equipment.”During winter, the contractor will have 30-35 machines handling snow-removal projects. “During a busy year, as much as 40% of winter activity is related to snow removal, and the weather service helps us know how many machines we’ll need in the morning.”Though a smaller operation, with some 40-50 employees, Larkin Excavating finds snow-removal contracts an important element to its winter activity. Keith Knickerbocker, assistant to operations, reports that their part of Kansas will get four to five snowfalls in a given winter. “The snow work is mainly in January and February, and it gives our equipment operators work during an otherwise slow time. They’re ready to plow anytime a storm drops more than 2 inches of snow. The weather service helps us decide when we need to get equipment ready to push snow, when we need to yard the equipment, and how to maximize production during the more active times of the year.”Cell-phone communication likewise helps Larkin’s field managers and equipment operators be more quickly aware of changing local conditions and know when there has been a change or a sudden need developed on the general contractor’s part. “We do a lot of one-to-one communication with the general contractor. Things which can’t be handled from the office can be taken care of quickly and efficiently on the site.”When Mother Nature Needs a PumpingAnother challenge facing many contractors is dealing with existing surface or underground water or with all the new water from the storm. “Contractors don’t want their site filling up too much with water, but they have to have somewhere to pump it to,” observes Brad Fine, director of marketing for Thompson Pump of Port Orange, FL. “One reason for pumping is to control unwanted water because of what gets washed around. With EPA, OSHA, and others watching the job site, you don’t want any hazardous material floating around.“Here in Florida, any road construction requires the entire site be dewatered. Then, if laying pipe is part of that roadwork, continuous pumping has to be done. Contractors need long-lived equipment to help keep their crews working and the site open for work.” Fine counsels operators to be sure their pump of choice meets the flow requirements and that it can handle any solids in the water being pumped. “If the pump isn’t large enough, solids, whether rocks, sticks, or sewage, can jam up in the suction line or in the pump itself and cause damage.“Another concern, especially in remote or continuous applications, is that the pump have adequate fuel capacity for a long run.” He also cautions, “Pump users don’t want to keep refueling, especially to hard-to-reach locations.” Fine adds that the learning curve with today’s pumps is short, thanks to the gauges and indicators that come with them. “Once the suction and discharge system is set up correctly, and all check valves are opened or closed as they should be, then the operation is mostly a matter of turning the key. Visual maintenance checks, done at refueling or on a weekly basis, take just a few minutes.”Fine points out that recently developed is a compressor-assisted dry priming system that is totally enclosed so there is no blow-by of any pumped material. “This makes the pump perfect in terms of keeping the environment and job site free of any hazardous material, including sewage. This will help make it easier to abide by the NPDES Phase II regulations coming next spring.”Getting Dry DitchesContractor pumps are designed to operate in severe weather conditions. These 6-in. pumps used for dewatering keep a job site dry for surface work.Thompson Pump user Dan Johnson, a salesman for Northern Dewatering Inc. in Rogers, MN, reports that his firm’s primary business is underground dewatering, with bypassing–as in sewer system renovation–a close second. “We’re certified in six states and do about $5 million a year in Texas, Minnesota, South Dakota, North Dakota, Iowa, and Wisconsin. Our goal is to provide the excavation contractor with a dry ditch so he can work below ground level.” Johnson has been in the business for 35 years and notes that winters are particularly challenging. “We recently participated in a $4 million project for the City of Minneapolis, which consisted of a number of sewer repairs in varying soil conditions, from dry, easy digging to swamps. Our job was to dewater as needed for the general contractor. We moved all over the place, drilling 40-foot wells and dewatering to 25 feet below surface level. This enabled the contractor to dig to 25 feet in midwinter with subzero temperatures and not let the job get stopped by an unexpected flow.”Northern Dewatering’s main winter objective is to keep the water moving. “At no time can we have water stop in a pipeline, else it freezes over. One of the ways we do that is with rapid response. If something goes wrong, we respond within a few minutes.” He recalls the time a well pump generator went down at 10 p.m., 20 mi. away in the northwest quadrant of the city. “We had someone there within an hour. He swapped generators and brought the failed one to the shop, where we had it ready for service the next day.”Onsite replacement is the fastest way to get the site running again. “Then the failed item can be turned over to any of the 10 full-time mechanics working in the relative comfort of the shop instead of enduring adverse conditions in an attempt to make a field repair.” As a rule, if the repair is greater than 50% of the replacement cost, the company selects replacement. “We have 400 Flygt, Prosser, Crown, and submersible pumps, with over 100 Thompson engine-driven pumps. We also have 50 generators of all brands and descriptions and all the associated materials to build a complete pumping system.”Chill Factors Affect EquipmentGround Heaters thaw ground and provide heat for curing concrete in cold weather.But what about cold weather? “Keeping the liquid moving becomes more important as it gets colder,” Johnson emphasizes. “We’ve had pumps working at 40-below, with wind chills 60- to 70-below. Contrary to scientific belief, wind chill does affect equipment. When it’s windy, the heat from the operating machine is dissipated more quickly. At times we’ll build a barricade of some kind. It’s more for the workers than for the machine, but both benefit.”Snow and blizzard conditions stop operations. When they have to shut down, Northern Dewatering immediately drains the equipment of all water. “This takes 10 to 15 minutes at shut down and another 10 to 15 minutes to get it back in operation. But without that care, startup delay could possibly be days because you’re usually talking about ruptured cast-iron parts, which take awhile to replace.”Bringing in BargesWaterway dredging, whether in Florida or Michigan, is a major excavation activity for some. And in case of a storm or freeze-up, the question is how fast can you get to shore. Ryan Horton, marketing manager for IMS Dredge of Olathe, KS, explains, “A contractor on Lake Michigan owned a competitor’s barge that used anchor spuds instead of our patented Starwheel Drive self-propulsion system. It takes a long time to get to the shore when using spuds, unless you have a boat to tug the dredge in. The contractor using the spud dredge almost lost it when he could not get it into shore. He now owns one of our Model 7012 Versi-Dredges. With our dredge you can easily disconnect the discharge hose and paddle into shore before the weather gets out of control.”Turning Up the HeatIf severe weather hits, the Versi-Dredge can propel itself to shore quickly and be removed with a single crane.Cold weather continues to be particularly frustrating for contractors in northern climes, but Jennifer Thompson, marketing manager for Ground Heaters Inc. in Spring Lake, MI, has a simple solution: heat the project. “Our Ground Heaters evenly deliver large amounts of BTUs over large areas, so the entire concrete slab cures at a uniform temperature. The equipment allows contractors to control the concrete curing process rather than the process controlling them. It saves them a lot of time and money.”She cites the example of Nova Scotia contractor B.D. Stevens, who won contracts to built two tilt-up concrete-wall schools. Working through the winter to meet the August deadline was a necessity. The firm rented two E3000 Ground Heaters, and each one was set up to handle about 5,000 ft.2 of slab. Don Grant, B.D. Stevens construction manager, recalls, “The first slab was a big success. We poured the 10,000—square foot slab in the middle of January with temperatures dropping down to -10º Celsius [15º Fahrenheit] that night, and it was no problem. It was a perfect slab. With the Ground Heaters, the slab was ready in 12 to 14 hours.” For the two schools, 200 concrete panels were poured and cured. Thompson adds, “The contractor maintained control of his project. He stayed on schedule and met his deadline.” The Canadian contractor stood up to the forces of nature and came away a winner. So although Mother Nature can’t be controlled, those who pay attention to possible weather problems, and make sure they prepare and care for their equipment, help minimize the effect of even her worst temper tantrums–and keep regulators happy.
