Burns & McDonnell, along with Garney Construction, is helping the Town of Cave Creek, Ariz., solve quality-of-life issues for the community while saving taxpayer dollars in building a new 0.66 million-gallon-per-day wastewater treatment plant. The American Public Works Association recognized this project as one of its Projects of the Year in the Environmental category.
PHOENIX — Since 1996, a wastewater treatment plant serving the Town of Cave Creek, Ariz., has drawn numerous complaints from residents and reached the end of its useful life. Located in the middle of an affluent neighborhood with minimal setbacks and minimal odor control, the plant was considered both an eyesore and a source of noxious odor, particularly to golfers playing on an exclusive course located nearby.
In 2009, Burns & McDonnell and Garney Construction were selected to help Cave Creek solve this problem by designing and building a new treatment plant with treatment capacity of 0.66 million gallons per day (MGD), a six-fold increase over the rated capacity of the old plant. Moreover, the $26.6 million price tag for the new plant was approximately 9 percent below the original project budget. Burns & McDonnell and Garney provided comprehensive planning, programming, architecture and engineering design and construction as the design/build project team. Staff from Burns & McDonnell's Denver and Phoenix offices served on the project team.
In April 2012, this successful project was named one of the American Public Works Association (APWA) Projects of the Year in the Environmental category. In addition to solving numerous community issues, the plant enables Cave Creek to meet all its treatment needs for the foreseeable future while using 100 percent of the reclaimed water for beneficial use in irrigation of the neighboring golf course. The new plant and expanded capacity can accommodate up to 5,000 new residential connections and has been instrumental in helping the Town attract new commercial establishments. The site can accommodate expanded treatment capacity of up to 2.25 MGD if needed in the future.
The project was executed under the design/build delivery method and achieved significant savings due to a number of engineering process design innovations, pipeline routing changes and scheduling efficiencies. The project achieved further savings for the community when it qualified for $2 million in American Recovery and Reinvestment Act (ARRA) funding, the first in the State of Arizona.
In addition to those savings realized during design and construction of the new plant, the Burns & McDonnell/Garney team was asked to install a new 16-inch water main in the same utility corridor that was used to accommodate new pipes for the treatment plant. The new water line was needed to provide added capacity and pressure to existing customers. The new water line also provided capacity for future development at the intersection and along Carefree Highway. Installing the line concurrent with construction of the wastewater lines saved the town considerable expense and time while reducing public inconvenience that could have been caused by a second round of road cuts.
The new Cave Creek water reclamation facility is located in a more secluded area of the community and has been designed to minimize noise, odor and visibility. Sewage is conveyed from the former treatment plant to the new facility site through three miles of new forcemain and a mile of gravity sewer. The new treatment facility includes an influent pump station to lift the raw wastewater into the plant where it is progressively treated in stages beginning with a rotary drum screen and vortex grit removal. From there, the water undergoes biological treatment with a sequencing batch reactor process, consisting of two treatment trains and a post-equalization basin. The final treatment stage incorporates cloth disc filtration followed by disinfection with hypochlorite in a chlorine contact basin, then dechlorination with sodium metabisulfite. The treated water is then pumped back to the golf course for discharge into ponds that are used for golf course irrigation via a 4-mile network of new forcemain.
Solids remaining from the treatment process are pumped from the sequencing batch reactor (SBR) process train basins to a sludge holding tank. From there the sludge is pumped to a belt filter press where it is dewatered for disposal at a local landfill. Odor control is provided for the entire facility through chemical wet scrubbers.
About Burns & McDonnell
Founded in 1898, Burns & McDonnell is a 100 percent employee-owned, full-service engineering, architecture, construction, environmental and consulting services firm. Burns & McDonnell is currently the 23rd largest AEC firm in the Engineering News-Record top 500 ranking. With the multi-disciplinary expertise of more than 3,400 professionals in more than 30 regional, national and international offices, Burns & McDonnell plans, designs, permits, constructs and manages facilities worldwide with one mission in mind — to make our clients successful.
About Garney Construction
Garney Construction is a 100 percent employee-owned construction company specializing in water and wastewater piping systems, concrete structures and water treatment facilities for the public, private and industrial sectors. Customers are served by a mobile, well-equipped, safety-conscious work force providing high quality, competitively priced, on-time performance through traditional or design/build procurement methods. Garney values the strong relationships developed with project owners, consultants, suppliers and subcontractors that have been built on integrity and a win/win philosophy.
About the Town of Cave Creek
Although Cave Creek was incorporated in 1986, the town was settled many years earlier in the 1870s. The town's main traffic route, Cave Creek Road, was built as a wagon route in the 1870s. The town is proud of its western heritage and is reflected in its current open space layout and its independent thinking citizens. Cave Creek celebrates its past annually with a horse parade, a rodeo, Country-Western music venues and a hoedown.