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Built in 1831, London Bridge was falling down by 1962. To make way for a new and bigger bridge, London sold its famous bridge to Robert McCulloch of chain saw fame, who had it disassembled stone by stone and rebuilt in his newly created desert oasis: Lake Havasu City, Ariz. Today, the resort town is halfway through its 11-year, $450 million conversion from septic tanks to a citywide wastewater treatment system. Photo: William D. Palmer Jr.
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Bullhead City relies on the Colorado River, seen here in the distance, for water and recreation. Photo: City of Bullhead City

How'd you like your town to have a completely new wastewater system, including collection sewers and treatment plants? Sounds great.

Now think about all the havoc building that system will create. Not so great.

Two neighboring Arizona towns on the banks of the Colorado River, Bullhead City and Lake Havasu City, faced this prospect when they signed a consent decree with the Arizona Department of Environmental Quality mandating that residents abandon septic tanks.

Neither town had any significant sewer system. High nitrate levels in the ground-water from all the septic tanks had the potential to degrade the quality of the river, which supplies water to millions of people in Arizona and Southern California.

While both towns made strong commitments to this difficult project, each is implementing it differently. In the end, though, the result is the same: Residents get a completely new, technologically advanced sewer system within a very short time frame.

Different Approaches

When you think about what a desert looks like, the Mojave Desert is it: bleak, otherworldly, rock blackened by desert varnish, vicious stabbing cactus, dust devils swirling in the distance.

But as you drop down out of the mountains, suddenly there's the Colorado River, impossibly blue and wet in the midst of the brown landscape. Strung out next to the river is Bullhead City. Although it had a few sewers and a couple of small, privately owned treatment plants, the town had relied primarily on septic tanks to treat wastewater.

Beginning in 1999, the city created three sewer improvement districts (SID). SID1, the first of three major portions of the city's septic-removal project, connected 5000 homes to 40 miles of sewers and included construction of a new treatment plant. SID2 tied in 2500 homes with 25 miles of pipe. Scheduled for completion by the end of the year, SID3 is pulling in the rest of the town: about 3600 homes and another 40 miles of sewer.

Engineering and construction management firm AMEC, headquartered in London, was project designer for SID2 and SID3, but is providing limited construction management.

“This is not an affluent community,” says Bullhead City public works director Pawan Agrawal. “Our citizens are paying the cost directly and consultants are not inexpensive. So we hired 16 temporary inspectors who work directly for the city.”

Fifty miles downstream, Lake Havasu City, on the eastern bank of Lake Havasu, was wrestling with the impact its growth was having on the Colorado River.

Initially, the city retained Kansas City, Mo.-based Burns & McDonnell to convert its 25,000 septic tanks to a sewer system, but brought in AMEC in the fall of 2005. The firm has 34 employees in Lake Havasu City who are doing all of the design, construction management, and program management. AMEC broke the project into 11 drainage areas, each connecting 2000 to 4000 homes.