Table 1.

Sample site descriptions

Site 1. Rio Grande at Sunland Park bridge near Texas/ New Mexico state line	A horse race track is located upstream and El Paso Electric is downstream [influenced by urban and agricultural runoff]
Site 2. Rio Grande at Courchesne Bridge in El Paso	This site is influenced by flows coming from Elephant Butte Dam. The use of water for irrigation upstream contributes large volumes of irrigation return flow and agricultural runoff. It also receives urban runoff and wastewater discharges from Anthony, Canutillo, and El Paso
Site 3. Rio Grande 2.4 Km upstream of Haskell street [WWTP]	Vehicle traffic is heavy and the area is also affected by urban runoff
Site 4. El Paso Haskell Street WWTP outfall	Wastewater is discharged to the concrete lined/ channel part of the river
Site 5. Rio Grande 1.3 Km downstream from Haskell WWTP	Vehicle traffic is heavy and the area is affected by urban runoff
Site 6. Rio Grande at Riverside Diversion Dam	Influenced by urban runoff, wastewater discharges from the Haskell Street WWTP and runoff from industrial facilities on both sides of the border
Site 7. Rio Grande at Alamo Grade Control structure 9.7 Km upstream of Fort Hancock Port of Entry	Receives large amounts of wastewater from domestic and industrial sources