Background

JMAS-Juarez provides wastewater collection and treatment services to approximately 98% of homes in its service area, which is segmented into five main wastewater service zones: Anapra, North, South, Valle de Juarez, and Laguna de Patos.

In the Northwest zone, a large segment of the wastewater system has exceeded its useful life and is showing signs of deterioration.  Due to topographic conditions in the area, a significant amount of sediment, trash, and debris enters the sewer system, while infiltration and inflow from rain events at rapid velocities often clog and break the pipelines within the system. These conditions have resulted in sewage overflows onto the streets, which form streams that flow into the Rio Grande. The sedimentation problem is even worse where manhole covers have been stolen and sold as scrap metal, allowing sand and particulate matter from erosion to fill the pipelines. Debris and trash are also caught in the open manholes, becoming a traffic hazard. Additionally, the wastewater system does not have a grit collection or screening system, which allows sediment to be deposited in the pipelines, further clogging the system and reducing capacity.

To help remedy this situation the project sponsor plans to rehabilitate four large sewer mains: Las Viboras, El Mimbre, Nadadores, and Norzagaray. These sewer mains were constructed of reinforced concrete pipe and have been in service for approximately 40 years, which is beyond their expected useful lives.

Description

The Project consists of improvements to the existing wastewater collection infrastructure in the northwest area, including the total replacement of approximately 18,540 meters (60,827 feet) of wastewater collection lines and the installation of new sedimentation boxes. The main components are:

• Norzagaray Sewer Main: Replacement of 5,420 meters (17,782 feet) of polyvinyl chloride (PVC) and high-density polyethylene (HDPE) pipeline with diameters ranging from 18 to 60 inches and the construction of two sedimentation boxes.
• Las Viboras Sewer Main: Replacement of 3,840 meters (12,598 feet) of PVC and HDPE pipeline with diameters ranging from 8" to 48" and the construction of two sedimentation boxes.
• El Mimbre Sewer Main: Replacement of 4,800 meters (15,748 feet) of PVC and HDPE pipeline with diameters ranging from 8" to 42" and the construction of two sedimentation boxes.
• Nadadores Sewer Main: Replacement of 4,480 meters (14,698 feet) of PVC pipeline with diameters ranging from 8" to 30" and construction of two sedimentation boxes.

Background

The project will reduce the human health risks associated with waterborne diseases caused by exposure to untreated wastewater and eliminate potential surface and groundwater contamination by replacing deteriorated wastewater infrastructure prone to leaks and failure. Specifically, the project will prevent the potential discharge of up to 1,000 liters per second (lps) or 22.8 million gallons per day (mgd) of untreated wastewater that could impact the Rio Grande River, a binational water source.