Beyond the Loop in Bighorn Basin
A remote area in desperate need of efficient and reliable potable water and burdened with a variety challenging environmental issues picks fiberglass-reinforced pipe for its new pipeline.
In the arid, mountain-girt Bighorn Basin of Wyoming, a tricounty water authority—the Big Horn Regional Joint Powers Board—is pushing back the desert.
The board has launched its Water Supply Project (WSP) that will gather and treat water from widely scattered wells, then distribute it via pipeline to small-town and rural populations. John Joyce of Manderson, WY, is director of the seven-member board, founded in 2000. He’s one of many Wyoming farmers and ranchers who have taken on “outside jobs” with community responsibilities, and the task he has undertaken is to help make potable water available to his neighbors. Joyce’s family raises sheep and grows barley and hay. A 1979 graduate of the University of Wyoming–Laramie, he earned a degree in agricultural economics.
“Years ago I worked for Manderson, a community of a little over 100 people near our ranch that needed water,” Joyce says. “Along the way I came to recognize this need and educated myself on the water issues.”
In 1999, a steering committee that preceded the board’s formation hired Joyce. Since then, he has made numerous trips to Wyoming’s state capital, Cheyenne, seeking the means to acquire and distribute water.
The board’s service area consists of Big Horn, Hot Springs, and Washkie counties in north-central Wyoming, all in the Bighorn Basin—an intermountain plateau bounded on the east by the Bighorn Mountains, on the west by the Absaroka Range, and on the south by the Owl Creek and Bridger mountains.
“Billings, Montana, is about 150 miles north of Bighorn Basin, and Casper, Wyoming, is about the same distance to the south. Yellowstone National Park is about 120 miles west of us,” says Joyce. “Cash crops for Bighorn Basin farmers are alfalfa, sugar beets, and multiple varieties of barley for Anheuser-Busch Companies Inc., in St. Louis, Missouri, and Coors Brewing Company in Golden, Colorado. Local ranchers raise sheep and cattle.”
Eventually Joyce’s efforts helped to secure funds from the Wyoming Water Development Commission and the Wyoming State Loan and Investment Board in Cheyenne, as well as the Water and Environmental Programs of the US Department of Agriculture’s Rural Development/Rural Utility Service.
Combining Efforts
The Joint Powers Board’s WSP arose from the combined efforts of local communities, water boards, and other local facilities that include two small airports and the Wyoming Boys’ School in Worland.
“Prior to the Joint Powers Board, everyone in our basin had their own water-distribution system,” says Joyce. “Wells often were some distance from the towns. When a pipe or pump broke, the people it served were out of water. The Joint Powers Board is an effort to obtain reliable sources of potable water for everyone.”
 |
Photo: COP Construction LLC |
| The Joint Powers Board is responsible for a 3,200-square-mile area. |
The Bighorn Basin’s soils are alluvial, consisting of gravel, clay, sand, and silt with pebbles, cobbles, and boulders. The alluvial soils are underlain with limestone, dolomite, volcanic rocks of andesite and mafic, quartzite, granite, sandstone, and chert. The alluvial soil thickness sometimes reaches 35 feet in the older rivers, streams, and tributaries, and 15 to 50 feet at slightly higher elevations.
“The Joint Powers Board is responsible for a 3,200-square-mile area that extends about 80 miles north to south and 40 miles east to west,” says Joyce. “The elevation of the valley floor varies, but typically it is about 4,000 feet above sea level.”
Communities that are part of the WSP bring seven artesian water wells to the project. All draw from the Madison Aquifer. Together they produce about 6 million gallons of water a day, of which 5 million gallons come from the hotter wells. The City of Worland’s two wells discharge 85°F water from the ground. Husky Worland #1 is 4,210 feet deep, with a permitted yield of 5,000 gallons per minute (gpm). Husky Oil Co. drilled it as an oil well in 1979 and later turned it over to the city. Well #3 (there is no #2), drilled by the city, is 2,334 feet deep and has a permitted yield of 6,660 gpm. “Well # 3 has a lot of growth potential that is not currently adjudicated,” says Joyce. “We have applied to enlarge the adjudication.”
The City of Greybull has three wells about 2,000 feet deep, adjudicated collectively for 800 gpm to 900 gpm. Their water is the coolest, at 50°F to 60°F. The South Big Horn Rural Water District has two wells, Wild Horse 1 and Wild Horse 2. They are both 5,200 feet deep, adjudicated for a total of 600 gpm, and discharge the warmest water, at 93°F.
“We don’t try to collect and use the heat,” says Joyce. “Some personal well owners use the water heat as it comes out of the ground to warm their shops and homes.”
The wells are drilled into the Paleozoic Aquifer of the Bighorn Basin, says Keith E. Clarey, senior geohydrologist for the Wyoming State Geological Survey. “The deep Paleozoic Aquifer includes the Pennsylvanian-age Tensleep Sandstone, Mississippian-age Madison Limestone, and the Ordovician-age Bighorn Dolomite. In general, groundwater temperatures are warmer in deeper wells and the 80º-F-to-90ºF temperature of the water is typical for water from deeper aquifers. These older rock formations are similar to those found under the volcanic ones in Yellowstone National Park.”
The Joint Powers Board cities and communities vary in population from fewer than 100 to more than 5,500. “Finding ways to keep water bills affordable and to pay for the new distribution pipeline and its modern technology has been a huge challenge for our rural communities,” says Joyce. “Nearly everyone here depends for income on agriculture and related activities.”
The project costs $38.9 million, of which 80% comes from state and federal grants and 20% from loans. “That’s a big project for our small communities,” says Joyce. “The Big Horn Regional’s annual operating budget is about $530,000. To raise local funds to pay back loans, we are billing every water user a $7.40 monthly building fee. We have built anticipated growth into the project.”
Pipeline Design Considerations
Design of the pipeline took into account a number of complex considerations:
- The pipes used must perform with water that is warmer than usual. “Polyvinyl chloride [PVC] pipes become deaerated at higher water temperatures,” says Joyce, “so we selected fiberglass-reinforced pipe [FRP].”
- Artesian-well water comes out of the ground faster, with greater than normal pressure. The water flows with no assistance, and in fact the pressure has to be reduced. “PVC pipes are not designed to handle the pressure of our artesian wells,” says Joyce. “Their pressure goes as high as 250 pounds per square inch. Higher-rated pipes have thicker walls and are therefore more expensive.”
- The high mineral content of the local alluvial soils makes them very corrosive. Traditional steel and ductile iron pipes corrode easily; equipping them with cathodic protection is expensive. Careful investigation found that other communities using traditional ductile iron pipes have high maintenance costs because of corrosion. Local moisture is not an issue, as the Big Horn Basin gets only about 6 inches of rain a year. New pipelines typically don’t need maintenance, so the Joint Powers Board has yet to calculate the cost of long-term maintenance.
- The pipes must perform across a wide range of temperatures, from 107°F in summer to - 40°F in winter. Pipes must be buried below the frost level to keep them from freezing.
- To make different kinds of pipes fit together, they must be joined with special valves. New pipes connect the new and older facilities, including the existing well pipes that remain in the ground. The new pipeline supplements existing lines, which may stay in service for a while.
“Everyone benefits from the new water distribution system,” says Joyce. “Some of the towns have their own water distribution system construction crews, and the Joint Powers Board developed a good relationship with them. They live here, as my family does, and when the potable water system was broken we were all out of drinking water.”
The Winning Bids
The Joint Powers Board is required to obtain competitive bids, so it obtained bids from two companies, Amitech USA LLC (www.amitechusa.com) and Future Pipe Industries Inc.(www.futurepipe.com). “The biggest advantage we saw to using the Amitech product is it requires less material to manufacture,” Joyce says. “With the price of petroleum-based products and natural gas increasing, I think the FRP pipes will continue to be competitive.
“When we compared PVC and FRP pipes, we found that the FRP weighs 17.7 pounds per foot, while the corresponding PVC pipe weighs 52 pounds per foot. The WSP is in a very remote location a long way from where both pipes are manufactured, so freight delivery is always an issue for us. The FRP delivery truck was smaller and used less fuel than the PVC delivery truck.
“Since we started our organization we have constantly been in construction and have explored all the available potable water pipes—ductile iron and steel, FRP, high-density polyethylene [HDPE], and PVC—that could withstand corrosion, heat, and pressure. Any type of steel or ductile iron pipes corrodes badly here. To protect these kinds of pipes adds extra cost, making them expensive to use. We expect to purchase more FRP.”
In 2000, when the Joint Powers Board first looked at FRP, the product wasn’t manufactured in the US. Now it is, and FRP is rated by the American Water Works Association in Denver, CO, and NSF International (a private testing organization founded in 1944 as the National Sanitation Foundation) in Ann Arbor, MI. Through its bid process, the Joint Powers Board selected COP Construction Co. of Billings, MT, to construct the new water pipeline and buildings. Founded in 1947, COP is one of the region’s largest construction companies. “We were awarded this water distribution project in November of 2006,” says Joseph “Joe” Allen, project manager. “Our accepted bid of $10,156,000 was to lay 18.5 miles of pipe—equivalent to 97,680 linear feet—up and down hills, with very little level area and vast temperature changes.
“Construction began in January 2007. As of September, [we were] about 75% done. Pipes are in the ground and we’re doing electrical and final construction. We expect to finish by 2008.
“We’ve moved cautiously because FRP is new to our region. Our planning included a trip to Zachary, LA, just north of Baton Rouge, to tour Amitech’s manufacturing plant. Amitech engineers assured us their product was designed to handle our artesian wells’ 250 pounds per square inch, and they taught us how to install the pipe properly. A delivery schedule to our construction site was planned, but delivery issues delayed construction for over one month.
“We installed 80,000 feet of 18-inch FRP and specially designed pipe gaskets. An Amitech representative was onsite the first week. To lay pipe, we brought to the work site a PC 400 Komatsu excavator, two 950 Caterpillar loaders, and a 300 Komatsu trail hoe. When equipment breaks down, our own mechanics travel from Billings to our remote construction sites with a fully stocked service truck. There are no major suppliers, equipment dealers, or stores serving our construction site. In good weather, travel time was about four hours. We lost about eight days of installation.”
COP Construction planned for winter work in temperatures ranging from -20°F to 30°F. Most of the terrain where its crews laid pipe was dry, with little or no frost conditions. The workers wore proper winter work clothing and kept equipment engines warm at night by plugging them into a generator. “Typically we don’t lay pipe in below-zero temperatures,” Allen says, “so we knew going into this project that we would have some weather delays. FRP performed well in cold weather.
“We laid 15,600 linear feet of 20-inch PVC pipe, mostly in a trench across irrigated fields with about 2 feet of frozen ground. This was a challenge. We dug across the fields ahead of the pipe installation, to make the farmers’ deadlines. The field stage had to be completed by March 30, so the farmers could plant their spring crops.”
The pipes were buried with 5 feet of cover to prevent freezing and so that the fields could be plowed without damaging the pipes. Some of the lands the pipeline crosses belong to the US Bureau of Land Management, which leases land to ranchers for grazing.
“Erosion control is important,” says Allen. “Nothing is wasted. Larger rocks and boulders removed from our trench were used as riprap for erosion control near where the pipes are buried. The riprap protects the pipe during wet-season flash floods. We had a flash flood while we were working. It started with a light rain and ended with our stopping work and moving ourselves and our equipment to higher ground.”
Sand bedding for pipe installation—22,000 yards, or about 1,400 truckloads of sand—was hauled in 32 miles from Worland. Four trucks drove back and forth every day. Sand was laid under the pipe and halfway up the trench. Once the sand was 1 foot over the water pipe, the workers finished filling by covering the pipe with local soil that met required specifications.”
Pipe delivery slowed in June because of problems at the manufacturing plant. “We just about ran out of pipe,” Allen says. “We pulled one of our two crews and sent them to install HDPE pipe across the Norwood River. We had the HDPE pipe on hand and kept our crew working. When pipe was further delayed, we sent the crew off to another job, and finished installing pipe in the ground in the first week of September with just one crew. We laid 15,600 linear feet of 20-inch PVC pipe, mostly in a trench across farm fields.
“A third crew built and installed four underground valve and piping vaults. The two larger ones were poured in place; the two smaller ones were purchased precast and delivered to the job site. Support structures include several aboveground buildings: a chlorination building, a pump station, and a pressure-reducing and pressure-control valve building in Worland. We poured foundations and installed precast walls.
“At one time, we had as many as 38 construction workers on the project. To complement our crews, we hired farmers, oil-patch workers, and local construction workers. There is a lot of construction in this area, and the labor pool is shallow.”
Ductile iron pipes were used in the buildings. Pipe conversion to FRP usually occurs about 10 feet outside a building. The ductile iron pipes also were designed to handle local water pressure and temperatures. When ductile iron pipes are buried, they have to be wrapped and cathodically protected to reduce corrosion. Fiberglass, ductile iron, and high-density polyethylene (HDPE) pipes connect easily when they share an outside dimension of 18 inches. Water from the Worland wells requires pressure-reducing valves instead of pumps. There is about a 405-foot elevation drop from the Worland wells to where we connect the pipes at the Washakie County line. Another contractor installed a PVC pipeline into Worland.
Pipe Selection
Although FRP materials and products are new to many, the concept and products are over 40 years old. FRP is known by several names, including larger-diameter glass-reinforced plastic (GRP) and Flowtite Technologies. Such pipes are corrosion-resistant, light in weight, and come in many sizes, from 4 inches to 144 inches. Depending on size, they operate under pressures up to 450 psi.
In the mid-1960s, Jotun A/S of Sandefjord, Norway, a manufacturer of raw polyester, decided to use basic Anticorrosion Protective Systems (APS) materials to make some of the earliest GRP pipes and tanks. Polyester is a basic ingredient in these systems. In 1968 and 1969 a Jotun subsidiary, Vera Fabrikker in Sandejord, delivered the first GRP pipes and tanks. In 1977 Vera Fabrikker created a joint venture with Owens Corning of Toledo, OH, to manufacture, market, and sell GRP products worldwide. Owens Corning bought out its partner in 1993 and then sold its international GRP interest in 2001 to Saudi Arabian Amiantit Group (SAAG).
“Our pipes are immune to galvanic and electrolytic corrosion, which bother traditional steel and ductile iron pipes. The inner layer of our pipes is independent of the transported fluid,” says Ulrich Schott, a
corporate communications representative at SAAG’s European headquarters in Düsseldorf, Germany. “Depending on the substance transported, different resins are used. The core of the pipe is made of silica, sand, glass, and a resin—usually polyester. Our flexible technology allows for the design of individual fittings and attachments to enable our customers to connect other types of pipe to our pipes.
“Our lightweight pipes are easy to install and are maintenance-free. The smooth surface created by our resins does not require regular cleaning. Occasionally, when our pipes are in heavily used sewers, municipalities will jet-clean them. The life cycle of our pipes is longer than 50 years.”
The Big Horn WSP design was over seen by Susan Holmes, senior project manager at HKM Engineering Inc., in Sheridan, WY, about two hours away over the Bighorn Mountains. The firm has seven regional offices in Montana and Wyoming. Holmes recently learned about Amitech’s FRP pipes and recommended the product to her clients. “We published our design report in October 2003,” she says. “The Big Horn WSP’s Element 1, east of Manderson, uses FRP 12 inches to 20 inches in diameter to carry water between the South Big Horn Rural Water District/Wild Horse wells and the main water transmission lines. As necessary, other pipe materials are used.
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“Using FRP did cause some design modifications that required a little coordination with COP Construction Co.,” says Holmes. “The pipe bedding specifications changed slightly. We also had to design a restraint system to keep the pipes stable.”
Everyone involved intends to watch how the Amitech pipe holds up over time. “We hope this product will perform to industry standards,” Allen says. “There should be minimal maintenance for the first 10 to 15 years.”
January-February 2008
Beyond the Loop in Bighorn Basin
A remote area in desperate need of efficient and reliable potable water and burdened with a variety challenging environmental issues picks fiberglass-reinforced pipe for its new pipeline.
In the arid, mountain-girt Bighorn Basin of Wyoming, a tricounty water authority—the Big Horn Regional Joint Powers Board—is pushing back the desert.
The board has launched its Water Supply Project (WSP) that will gather and treat water from widely scattered wells, then distribute it via pipeline to small-town and rural populations. John Joyce of Manderson, WY, is director of the seven-member board, founded in 2000. He’s one of many Wyoming farmers and ranchers who have taken on “outside jobs” with community responsibilities, and the task he has undertaken is to help make potable water available to his neighbors. Joyce’s family raises sheep and grows barley and hay. A 1979 graduate of the University of Wyoming–Laramie, he earned a degree in agricultural economics.
“Years ago I worked for Manderson, a community of a little over 100 people near our ranch that needed water,” Joyce says. “Along the way I came to recognize this need and educated myself on the water issues.”
In 1999, a steering committee that preceded the board’s formation hired Joyce. Since then, he has made numerous trips to Wyoming’s state capital, Cheyenne, seeking the means to acquire and distribute water.
The board’s service area consists of Big Horn, Hot Springs, and Washkie counties in north-central Wyoming, all in the Bighorn Basin—an intermountain plateau bounded on the east by the Bighorn Mountains, on the west by the Absaroka Range, and on the south by the Owl Creek and Bridger mountains.
“Billings, Montana, is about 150 miles north of Bighorn Basin, and Casper, Wyoming, is about the same distance to the south. Yellowstone National Park is about 120 miles west of us,” says Joyce. “Cash crops for Bighorn Basin farmers are alfalfa, sugar beets, and multiple varieties of barley for Anheuser-Busch Companies Inc., in St. Louis, Missouri, and Coors Brewing Company in Golden, Colorado. Local ranchers raise sheep and cattle.”
Eventually Joyce’s efforts helped to secure funds from the Wyoming Water Development Commission and the Wyoming State Loan and Investment Board in Cheyenne, as well as the Water and Environmental Programs of the US Department of Agriculture’s Rural Development/Rural Utility Service.
Combining Efforts
The Joint Powers Board’s WSP arose from the combined efforts of local communities, water boards, and other local facilities that include two small airports and the Wyoming Boys’ School in Worland.
“Prior to the Joint Powers Board, everyone in our basin had their own water-distribution system,” says Joyce. “Wells often were some distance from the towns. When a pipe or pump broke, the people it served were out of water. The Joint Powers Board is an effort to obtain reliable sources of potable water for everyone.”
|
Photo: COP Construction LLC |
| The Joint Powers Board is responsible for a 3,200-square-mile area. |
The Bighorn Basin’s soils are alluvial, consisting of gravel, clay, sand, and silt with pebbles, cobbles, and boulders. The alluvial soils are underlain with limestone, dolomite, volcanic rocks of andesite and mafic, quartzite, granite, sandstone, and chert. The alluvial soil thickness sometimes reaches 35 feet in the older rivers, streams, and tributaries, and 15 to 50 feet at slightly higher elevations.
“The Joint Powers Board is responsible for a 3,200-square-mile area that extends about 80 miles north to south and 40 miles east to west,” says Joyce. “The elevation of the valley floor varies, but typically it is about 4,000 feet above sea level.”
Communities that are part of the WSP bring seven artesian water wells to the project. All draw from the Madison Aquifer. Together they produce about 6 million gallons of water a day, of which 5 million gallons come from the hotter wells. The City of Worland’s two wells discharge 85°F water from the ground. Husky Worland #1 is 4,210 feet deep, with a permitted yield of 5,000 gallons per minute (gpm). Husky Oil Co. drilled it as an oil well in 1979 and later turned it over to the city. Well #3 (there is no #2), drilled by the city, is 2,334 feet deep and has a permitted yield of 6,660 gpm. “Well # 3 has a lot of growth potential that is not currently adjudicated,” says Joyce. “We have applied to enlarge the adjudication.”
The City of Greybull has three wells about 2,000 feet deep, adjudicated collectively for 800 gpm to 900 gpm. Their water is the coolest, at 50°F to 60°F. The South Big Horn Rural Water District has two wells, Wild Horse 1 and Wild Horse 2. They are both 5,200 feet deep, adjudicated for a total of 600 gpm, and discharge the warmest water, at 93°F.
“We don’t try to collect and use the heat,” says Joyce. “Some personal well owners use the water heat as it comes out of the ground to warm their shops and homes.”
The wells are drilled into the Paleozoic Aquifer of the Bighorn Basin, says Keith E. Clarey, senior geohydrologist for the Wyoming State Geological Survey. “The deep Paleozoic Aquifer includes the Pennsylvanian-age Tensleep Sandstone, Mississippian-age Madison Limestone, and the Ordovician-age Bighorn Dolomite. In general, groundwater temperatures are warmer in deeper wells and the 80º-F-to-90ºF temperature of the water is typical for water from deeper aquifers. These older rock formations are similar to those found under the volcanic ones in Yellowstone National Park.”
The Joint Powers Board cities and communities vary in population from fewer than 100 to more than 5,500. “Finding ways to keep water bills affordable and to pay for the new distribution pipeline and its modern technology has been a huge challenge for our rural communities,” says Joyce. “Nearly everyone here depends for income on agriculture and related activities.”
The project costs $38.9 million, of which 80% comes from state and federal grants and 20% from loans. “That’s a big project for our small communities,” says Joyce. “The Big Horn Regional’s annual operating budget is about $530,000. To raise local funds to pay back loans, we are billing every water user a $7.40 monthly building fee. We have built anticipated growth into the project.”
Pipeline Design Considerations
Design of the pipeline took into account a number of complex considerations:
- The pipes used must perform with water that is warmer than usual. “Polyvinyl chloride [PVC] pipes become deaerated at higher water temperatures,” says Joyce, “so we selected fiberglass-reinforced pipe [FRP].”
- Artesian-well water comes out of the ground faster, with greater than normal pressure. The water flows with no assistance, and in fact the pressure has to be reduced. “PVC pipes are not designed to handle the pressure of our artesian wells,” says Joyce. “Their pressure goes as high as 250 pounds per square inch. Higher-rated pipes have thicker walls and are therefore more expensive.”
- The high mineral content of the local alluvial soils makes them very corrosive. Traditional steel and ductile iron pipes corrode easily; equipping them with cathodic protection is expensive. Careful investigation found that other communities using traditional ductile iron pipes have high maintenance costs because of corrosion. Local moisture is not an issue, as the Big Horn Basin gets only about 6 inches of rain a year. New pipelines typically don’t need maintenance, so the Joint Powers Board has yet to calculate the cost of long-term maintenance.
- The pipes must perform across a wide range of temperatures, from 107°F in summer to - 40°F in winter. Pipes must be buried below the frost level to keep them from freezing.
- To make different kinds of pipes fit together, they must be joined with special valves. New pipes connect the new and older facilities, including the existing well pipes that remain in the ground. The new pipeline supplements existing lines, which may stay in service for a while.
“Everyone benefits from the new water distribution system,” says Joyce. “Some of the towns have their own water distribution system construction crews, and the Joint Powers Board developed a good relationship with them. They live here, as my family does, and when the potable water system was broken we were all out of drinking water.”
The Winning Bids
The Joint Powers Board is required to obtain competitive bids, so it obtained bids from two companies, Amitech USA LLC (www.amitechusa.com) and Future Pipe Industries Inc.(www.futurepipe.com). “The biggest advantage we saw to using the Amitech product is it requires less material to manufacture,” Joyce says. “With the price of petroleum-based products and natural gas increasing, I think the FRP pipes will continue to be competitive.
“When we compared PVC and FRP pipes, we found that the FRP weighs 17.7 pounds per foot, while the corresponding PVC pipe weighs 52 pounds per foot. The WSP is in a very remote location a long way from where both pipes are manufactured, so freight delivery is always an issue for us. The FRP delivery truck was smaller and used less fuel than the PVC delivery truck.
“Since we started our organization we have constantly been in construction and have explored all the available potable water pipes—ductile iron and steel, FRP, high-density polyethylene [HDPE], and PVC—that could withstand corrosion, heat, and pressure. Any type of steel or ductile iron pipes corrodes badly here. To protect these kinds of pipes adds extra cost, making them expensive to use. We expect to purchase more FRP.”
In 2000, when the Joint Powers Board first looked at FRP, the product wasn’t manufactured in the US. Now it is, and FRP is rated by the American Water Works Association in Denver, CO, and NSF International (a private testing organization founded in 1944 as the National Sanitation Foundation) in Ann Arbor, MI. Through its bid process, the Joint Powers Board selected COP Construction Co. of Billings, MT, to construct the new water pipeline and buildings. Founded in 1947, COP is one of the region’s largest construction companies. “We were awarded this water distribution project in November of 2006,” says Joseph “Joe” Allen, project manager. “Our accepted bid of $10,156,000 was to lay 18.5 miles of pipe—equivalent to 97,680 linear feet—up and down hills, with very little level area and vast temperature changes.
“Construction began in January 2007. As of September, [we were] about 75% done. Pipes are in the ground and we’re doing electrical and final construction. We expect to finish by 2008.
“We’ve moved cautiously because FRP is new to our region. Our planning included a trip to Zachary, LA, just north of Baton Rouge, to tour Amitech’s manufacturing plant. Amitech engineers assured us their product was designed to handle our artesian wells’ 250 pounds per square inch, and they taught us how to install the pipe properly. A delivery schedule to our construction site was planned, but delivery issues delayed construction for over one month.
“We installed 80,000 feet of 18-inch FRP and specially designed pipe gaskets. An Amitech representative was onsite the first week. To lay pipe, we brought to the work site a PC 400 Komatsu excavator, two 950 Caterpillar loaders, and a 300 Komatsu trail hoe. When equipment breaks down, our own mechanics travel from Billings to our remote construction sites with a fully stocked service truck. There are no major suppliers, equipment dealers, or stores serving our construction site. In good weather, travel time was about four hours. We lost about eight days of installation.”
COP Construction planned for winter work in temperatures ranging from -20°F to 30°F. Most of the terrain where its crews laid pipe was dry, with little or no frost conditions. The workers wore proper winter work clothing and kept equipment engines warm at night by plugging them into a generator. “Typically we don’t lay pipe in below-zero temperatures,” Allen says, “so we knew going into this project that we would have some weather delays. FRP performed well in cold weather.
“We laid 15,600 linear feet of 20-inch PVC pipe, mostly in a trench across irrigated fields with about 2 feet of frozen ground. This was a challenge. We dug across the fields ahead of the pipe installation, to make the farmers’ deadlines. The field stage had to be completed by March 30, so the farmers could plant their spring crops.”
The pipes were buried with 5 feet of cover to prevent freezing and so that the fields could be plowed without damaging the pipes. Some of the lands the pipeline crosses belong to the US Bureau of Land Management, which leases land to ranchers for grazing.
“Erosion control is important,” says Allen. “Nothing is wasted. Larger rocks and boulders removed from our trench were used as riprap for erosion control near where the pipes are buried. The riprap protects the pipe during wet-season flash floods. We had a flash flood while we were working. It started with a light rain and ended with our stopping work and moving ourselves and our equipment to higher ground.”
Sand bedding for pipe installation—22,000 yards, or about 1,400 truckloads of sand—was hauled in 32 miles from Worland. Four trucks drove back and forth every day. Sand was laid under the pipe and halfway up the trench. Once the sand was 1 foot over the water pipe, the workers finished filling by covering the pipe with local soil that met required specifications.”
Pipe delivery slowed in June because of problems at the manufacturing plant. “We just about ran out of pipe,” Allen says. “We pulled one of our two crews and sent them to install HDPE pipe across the Norwood River. We had the HDPE pipe on hand and kept our crew working. When pipe was further delayed, we sent the crew off to another job, and finished installing pipe in the ground in the first week of September with just one crew. We laid 15,600 linear feet of 20-inch PVC pipe, mostly in a trench across farm fields.
“A third crew built and installed four underground valve and piping vaults. The two larger ones were poured in place; the two smaller ones were purchased precast and delivered to the job site. Support structures include several aboveground buildings: a chlorination building, a pump station, and a pressure-reducing and pressure-control valve building in Worland. We poured foundations and installed precast walls.
“At one time, we had as many as 38 construction workers on the project. To complement our crews, we hired farmers, oil-patch workers, and local construction workers. There is a lot of construction in this area, and the labor pool is shallow.”
Ductile iron pipes were used in the buildings. Pipe conversion to FRP usually occurs about 10 feet outside a building. The ductile iron pipes also were designed to handle local water pressure and temperatures. When ductile iron pipes are buried, they have to be wrapped and cathodically protected to reduce corrosion. Fiberglass, ductile iron, and high-density polyethylene (HDPE) pipes connect easily when they share an outside dimension of 18 inches. Water from the Worland wells requires pressure-reducing valves instead of pumps. There is about a 405-foot elevation drop from the Worland wells to where we connect the pipes at the Washakie County line. Another contractor installed a PVC pipeline into Worland.
Pipe Selection
Although FRP materials and products are new to many, the concept and products are over 40 years old. FRP is known by several names, including larger-diameter glass-reinforced plastic (GRP) and Flowtite Technologies. Such pipes are corrosion-resistant, light in weight, and come in many sizes, from 4 inches to 144 inches. Depending on size, they operate under pressures up to 450 psi.
In the mid-1960s, Jotun A/S of Sandefjord, Norway, a manufacturer of raw polyester, decided to use basic Anticorrosion Protective Systems (APS) materials to make some of the earliest GRP pipes and tanks. Polyester is a basic ingredient in these systems. In 1968 and 1969 a Jotun subsidiary, Vera Fabrikker in Sandejord, delivered the first GRP pipes and tanks. In 1977 Vera Fabrikker created a joint venture with Owens Corning of Toledo, OH, to manufacture, market, and sell GRP products worldwide. Owens Corning bought out its partner in 1993 and then sold its international GRP interest in 2001 to Saudi Arabian Amiantit Group (SAAG).
“Our pipes are immune to galvanic and electrolytic corrosion, which bother traditional steel and ductile iron pipes. The inner layer of our pipes is independent of the transported fluid,” says Ulrich Schott, a
corporate communications representative at SAAG’s European headquarters in Düsseldorf, Germany. “Depending on the substance transported, different resins are used. The core of the pipe is made of silica, sand, glass, and a resin—usually polyester. Our flexible technology allows for the design of individual fittings and attachments to enable our customers to connect other types of pipe to our pipes.
“Our lightweight pipes are easy to install and are maintenance-free. The smooth surface created by our resins does not require regular cleaning. Occasionally, when our pipes are in heavily used sewers, municipalities will jet-clean them. The life cycle of our pipes is longer than 50 years.”
The Big Horn WSP design was over seen by Susan Holmes, senior project manager at HKM Engineering Inc., in Sheridan, WY, about two hours away over the Bighorn Mountains. The firm has seven regional offices in Montana and Wyoming. Holmes recently learned about Amitech’s FRP pipes and recommended the product to her clients. “We published our design report in October 2003,” she says. “The Big Horn WSP’s Element 1, east of Manderson, uses FRP 12 inches to 20 inches in diameter to carry water between the South Big Horn Rural Water District/Wild Horse wells and the main water transmission lines. As necessary, other pipe materials are used.
“Using FRP did cause some design modifications that required a little coordination with COP Construction Co.,” says Holmes. “The pipe bedding specifications changed slightly. We also had to design a restraint system to keep the pipes stable.”
Everyone involved intends to watch how the Amitech pipe holds up over time. “We hope this product will perform to industry standards,” Allen says. “There should be minimal maintenance for the first 10 to 15 years.”