Nogales, Sonora Pretreatment Program
Within the cross-border neighboring cities of Nogales, Arizona, and Nogales, Sonora, or Ambos Nogales, wastewater from both countries is treated at the Nogales International Wastewater Treatment Plant (NIWWTP). Located in Rio Rico, Arizona, the NIWWTP discharges treated effluent to the Santa Cruz River. The Office of Border Environmental Protection (OBEP) currently provides material and technical support to the wastewater utility in Nogales, Sonora (OOMAPAS-NS) for the purpose of improving the quality of wastewater discharges originating in Mexico. This helps protect investments in infrastructure and water resources in both countries.

Through a memorandum of understanding with Sonora, ADEQ provides financial support for analyses of wastewater samples collected from industrial discharge points in Nogales, Sonora. Samples are analyzed in laboratories certified by the state of Arizona and the results are incorporated into a database for generation of an annual pretreatment report by Nogales, Sonora.

Through the partial assistance of an EPA Border 2012 grant, Nogales, Sonora, has constructed a water quality laboratory for analyses of wastewater samples collected in Sonora. The laboratory is undergoing Mexican certification for metals analyses. Once certified, results generated by the lab will be legally defensible and may be used for compliance purposes. This laboratory will be the first of its kind along the entire Arizona-Sonora border region, and may serve the analytical needs of other border communities in Sonora.

In December 2007, OBEP acted as a liaison between the City of Phoenix Pretreatment Program and the Nogales wastewater utility in facilitating the donation of two autosamplers, flow meters, and flumes for the purpose of characterizing water quality in the broader Nogales wastewater collection system. OBEP's bilingual staff regularly provides training in the use of this kind of equipment. During the last three years, the legitimacy of the Nogales, Sonora, Pretreatment Program has steadily improved in the eyes of the Sonoran regulated community made up of maquiladoras and commercial enterises. As such, it is beginning to realize its environmental significance. In response, Nogales is currently modifying state laws to improve the sustainability and effectiveness of this program.

Nogales Wash Coordination Committee Meetings
Nogales Wash is the main drainage conveyance for the Ambos Nogales watershed. During periods of heavy rain, surface runoff may introduce sand, oil and grease, and/or garbage may be introduced into the wastewater infrastructure of Nogales, Sonora. The obstructions cause sanitary-sewer overflows (SSOs) which may create sewage problems in Nogales Wash. Nogales Wash flows northward into Arizona.

OBEP has taken the leadership role in coordinating binational meetings between local, state, and federal stakeholders impacted by sanitary sewer overflows within the wash. Outcomes of these meetings include generation of historical metrics related to water quality in Nogales Wash and formalized communication protocols for responding to abnormal flows within the wash.

OBEP also supports the EPA Border 2012 Water Task Force in identifying and developing projects which may help diminish the flooding impacting the watershed. Through a 2012 Water Task Force grant, Arizona State University is developing strategies for offsetting flood peaks within the watershed. OBEP will support this effort as needed. Respective strategies may be funded by future money available through the Border 2012 program.

Friends of the Santa Cruz River - River Watch Volunteer Monitoring Support
ADEQ regularly monitors the quality of surface waters in Arizona. This is done in order to meet federal Clean Water Act requirements to develop a Water Quality Inventory Report for Congress every two years. Given funding shortages, ADEQ frequently relies on data collection activities of volunteer monitoring organizations. One such organization is the Friends of the Santa Cruz River (FOSCR) river watch monitoring group based in Rio Rico, Arizona. This group regularly monitors six sites located along the Santa Cruz River and Nogales Wash near Arizona's border with Sonora.

Given Tucson's proximity to Rio Rico, OBEP works closely with FOSCR volunteers on data collection activities for integration into the ADEQ water quality database. Most recently, OBEP assisted FOSCR in revising its sampling protocols to ensure that the data it collects reflects the needs of ADEQ with respect to its water quality assessment. The ADEQ Water Quality Division currently provides financial assistance for quarterly monitoring of metals, nutrients, and microbiological content in samples collected by FOSCR volunteers.

Technical Assistance to Sonoran Wastewater Utilities
The border region is unique in that binational watersheds share binational wastewater infrastructure. OBEP provides technical assistance on an as needed basis to Sonora wastewater utilities to ensure that wastewater is of an adequate quality to protect investments in shared wastewater infrastructure.

Border Infrastructure Review
In response to many transboundary infrastructure needs, border communities are the recipient of Border Environment Infrastructure Funding (BEIF) provided by the U.S. Environmental Protection Agency. The funding assists with rehabilitation and replacement of deteriorating infrastructure within border communities in the United States and Mexico. For projects in Mexico, the Mexican Federal Department of Water Resources (CONAGUA) provides a matching grant. Improvements in border infrastructure contribute to the sustainability of the growing industrial sector This benefits U.S. companies operating in Mexico as well as citizens living on both sides of the border. In order to ensure Arizona's priorities and concerns are addressed, OBEP staff reviews and comment on projects facilitated by the BEIF. More information on ADEQ participation is available.

Upcoming
ADEQ recently renewed a memorandum of understanding (MOU) with the City of Nogales, Sonora. The MOU facilitiates continued support of the Nogales, Sonora Pretreatment Program by formalizing protocols for data sharing and technology transfer. By supporting the Nogales, Sonora Pretreatment Program, OBEP can help protect U.S. Federal investments in the Nogales International Wasetwater Treatment Plant in Rio Rico, Arizona.

The Nogales, Sonora Wastewater Utility (OOMAPAS-NS) is currently considering a monitoring program for the broader wastewater collection system in order to identify sources of contamination not captured during its oversight monitoring of specific industrial discharges. OBEP will assist as needed.

OBEP will continue biannual monitoring of groundwater wells associated with Nogales Wash. Recent monitoring of binational wells just north of the Arizona-Sonora border demonstrates the presence of perchloroethylene in groundwater, but at levels below EPA's maximum contaminant levels - the highest level of a contaminant allowable in drinking water. Continued monitoring of wells near the border will ensure that no new contamination is entering Arizona from upstream sources in Sonora.

OBEP is considering development of a Web page to facilitate submission of water quality data collected by volunteer water quality monitoring organizations. Facilitating data submissions will ensure that volunteer data is reflected in water quality assessment reports to Congress. A pilot site will be developed for Friends of the Santa Cruz River. If successful, the model can be extended to other volunteer monitoring organizations in Arizona.

OBEP will continue to coordinate and support binational meetings related to Nogales Wash and the EPA Border 2012 Water Task Force. These meetings will ensure that binational stakeholders are engaged in the unique environmental challenges faced on the border and that resources are made available for mitigation.