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Nogales, Arizona, USA

Replacement of the International Outfall Interceptor,Upgrade and Expansion of the International Wastewater Treatment Plant, and Partial Replacement of the Wastewater Collection System in Nogales,Arizona.

Status: Completed Construction

Background

The city of Brawley owns and operates a water treatment plant and distribution system. Established more than 70 years ago, this system is operated as an enterprise fund in which the cost of providing water services is funded primarily through flat rate user fees. The old water treatment plant had a design capacity of 16 million gallons per day (mgd), but only produced a maximum of 12 mgd due to plant hydraulics and equipment limitations. The water treatment methods used by the old plant did not comply with the latest State of California health statutes and regulations. Thus, the State of California Department of Health Services issued an order requiring the city to update and/or replace its water treatment plant.

In addition, the city’s distribution system has problems due to the corrosion of its cast iron pipes. This has caused a significant decrease in pipe capacity, which creates excessive pressure losses and reduces the utility’s ability to deliver water in the city, thus interrupting water service.

Description

The proposed water distribution improvements involve the construction of a 12" water line to serve the surrounding area. This 12" line, totaling approximately 18,350 linear feet, will be constructed of AWWA C-900 polyvinyl chloride (PVC) pipe. A slight modification to the existing water pumping station to allow for the connection of this new line, the installation of a vertical high service pump, will be required. As part of these improvements, a 500,000-gallon elevated storage tank will be constructed. This tank will stabilize water system pressure in the project area. Proposed improvements to the wastewater system will be to the existing collection system. These improvements include construction of a new lift station, including structure pumps and electrical, 2,640 linear feet of 6" Class 160 PVC pressure main, 1,320 linear feet of 12" sanitary sewer gravity collection line, and modification of an existing lift station.

Project Financing

Total Project Cost US 11.1M
NADB Funding US M - NADB Loan
US 5.55M - NADB Grant: BEIF
US M - NADB Grant: CAP
US M - NADB Grant: SWEP
US M - NADB Grant: WCIF
Other Funding Partners City of Nogales