The Arizona Department of Environmental Quality (ADEQ) and local officials confirmed an intermittent sanitary sewer overflow (SSO) in a tunnel under the international border, which transports stormwater from Nogales, Sonora to Nogales, Arizona. A SSO is a release of untreated wastewater and contains raw sewage.
When flowing, the SSO originates from Nogales, Sonora and is exiting the tunnel into the Nogales Wash about one mile north of the international border. Depending on volume of flow and frequency, the SSO could reach the Santa Cruz River.
Over the last two weeks, the number of Zika cases spreading in Sonora, Mexico has increased significantly, prompting officials from Maricopa County Department of Public Health to remind women who are pregnant or trying to get pregnant to avoid travel to Zika-affected areas.