Lave Havasu City, AZ, recently entered year four of an 11-year program that will eliminate more than 28,000 residential septic tanks by connecting residents to a new sewer system.
The Wastewater System Expansion Program, estimated at $500 million, included the design and construction of sewer collection systems, wastewater pump stations and transmission mains, the upgrade and expansion of the city’s two existing wastewater treatment plants, construction of a new wastewater treatment plant, and reuse and disposal facilities.
“In each program year, three independent collection projects are constructed, eliminating an average of 2,500 septic systems each year and connecting an equal number of residences to the new sewer system,” said AMEC Spokeswoman Jeannine Martin, of the projects that will average $9 million to $13 million each.
This year’s Wallapai project was awarded to Western Municipal Construction, while S2 Contractors Inc. successfully bid on the Caribbean and Pima projects.
S2, an Aurora, OR-based company, also was awarded two other projects in previous program years.
President Jeff Shunn said the company purchased three excavators from Portland, OR-based Feenaughty Machinery Company to add to the 12 already available.
It also leased five backhoes from RDO Equipment in Flagstaff, bought a reclaimer at an auction in Phoenix, and will use up to six loaders for the job.
S2’s subcontractors include Little Septic Pumping, ARQ Surveying and Combs Construction.
Lake Havasu City Project Manager Greg Froslie said contractors typically divide their crews between mainline, lateral and yard restoration work.
“It’s like a parade as they come through the project,” he said.
In addition to milling up the asphalt and installing manholes and mainline sewer, the first crew also connects a portion of the 4-in. (10 cm) lateral pipe to the mainline.
As the mainline crew moves up the street, the lateral crew begins trenching toward each residence.
It’s their job to disconnect the septic tank and connect the house to the sewer main.
Workers clean and disinfect the tanks before crushing in the tops and backfilling the hole.
Next, the yard restoration crew begins landscaping, followed by a paving crew responsible for restoring the asphalt.
“The inconvenience to the residents is pretty significant when you think about it because the first thing we do is tear up all of the pavement on the streets in front of their houses,” Froslie said. “It’s like that for up to two months while we get all the work done and then we pave it back. During that time we’ve got large machines and a lot of men and equipment in the front yards where the septic tanks are, which is very intrusive for our residents.
“Fortunately the sewer expansion program was widely accepted by our community. People understand that this is what it takes to get an underground sewer in.”
AMEC, an engineering firm, and the city use newsletters, open houses, surveys, a toll free project line and the Web to communicate with the approximately 50,000 residents in the Mohave County city located near the California border.
Other challenges include traffic impacts, underground utilities, yard restoration and the excessive heat.
“We have to put everything back the way it was,” Shunn explained. “It’s a lot of fancy landscaping. There are a lot of tight areas, under carports and through carports. That’s our toughest challenge.”
K.R. Swerdfeger will finish up the North Regional 18-in. (46 cm) Reuse Project this month while Alder Construction continues upgrades to the Island Wastewater Treatment Plant.
The Aztec, Saddleback and Bluegrass collection projects are currently in design.
The Wastewater System Expansion Program is a Community Investment Program and the result of a bond election held in 2001 authorizing the city to borrow the funds necessary to make the improvements.
“In the mid 1990s, high levels of fecal coliform were detected in the waters of Lake Havasu, causing beach closures and significant economic consequences that lasted for years,” Martin said.
She added that the Arizona Department of Environmental Quality (ADEQ) conducted investigations in Lake Havasu City and the lake itself from 1994 to 1996 to find the cause of the contamination.
In 1996, through the use of monitoring wells along the shoreline and throughout the city, the agency found elevated levels of nitrates above federal standards.
In addition, elevated nitrate levels were found later in the year in a privately installed monitoring well in the city.
As a result ADEQ prohibited the installation of conventional septic systems within a 1-mi. radius of the wells.
“In response to rising concerns over the need to preserve the quality of the groundwater and Lake Havasu, a comprehensive wastewater master plan was authorized by the city,” Martin said.
The program will result in 28,564 connections, 390 mi. (624 km) of 8-in. PVC mainline, 400 mi. (640 km) of 4-in. PVC laterals, 9,700 concrete manholes, and 10 pump stations.
Items completed through year three included 4,576 connections, 63 mi. (100.8 km) of mainline, 66 mi. (105.6 km) of laterals, 1,165 manholes, and four pump stations. CEG