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Last Edited: 10/25/2011

New River, Imperial County - Public Health Activities

Starting in the early 1990s, The California Department of Public Health (CDPH) -- formerly the California Department of Health Services (CDHS) -- has conducted several investigations, as well as public awareness and education activities, related to the conditions of the New River.

The site

The New River flows north from the Colorado River in Baja California Norte, Mexico, across the International Border into the United States, through the Imperial Valley, and drains into the Salton Sea. On the Mexican side of the border, the New River passes through Mexicali, and on the U.S. side, through Calexico, Seeley, and Brawley.

                                                        Contamination of the New River  (Photos taken Dec. 9, 2008)                          


Map of the U.S./Mexico Border



CDPH's involvement at the New River

In 1993, the Imperial County Board of Supervisors petitioned the federal Agency for Toxic Substances and Disease Registry (ATSDR) to conduct an evaluation of the New River and its impact on the public health of the surrounding communities. In response, ATSDR prepared a health consultation evaluating environmental data collected for the New River from 1969 to 1994. However, when the petitioned health consultation was presented to the public, the relevance of some of the data dating back 20 years was a concern.

In an effort to explore the potential impacts from exposure to chemical contamination in the New River on surrounding communities, CDPH prepared three health consultations (see links below), under a cooperative agreement with ATSDR. Data collected in 1995 and 1996 as a part of a U.S./Mexico binational environmental monitoring program were used to evaluate potential health effects from exposure to the New River water, sediments, and fish.

Examination of contamination in fish of the New River at Westmorland  [2/18/00]

Examination of contamination in suspended and bottom sediment of the New River  [6/11/99]

Examination of contamination in the water column of the New River  [6/11/99]

Summary of CDPH's past findings 

CDPH found that several contaminants present in the New River water and sediment presented a public health risk, and recommended that the public avoid contact with and ingestion of New River water sediments.

In addition, CDPH found that the level of contamination in New River fish presented a potential health risk to children and/or frequent adult sport fishers; thus, CDPH recommended that consumption of fish captured in the New River be greatly limited.

CDPH's recent involvement at the New River

In 2008, CDPH was contacted again by Imperial County stakeholders who requested assistance in responding to the community’s continuing concern about potential health risks posed by the New River. Residents in the West Side Neighborhood (living closest to the New River) were concerned about the development of health symptoms when odors from the New River are strongest. On December 3, 2010, CDPH published a health consultation which evaluated the hydrogen sulfide (H2S) emissions from the New River and their potential health impact to Calexico residents.

Summary of CDPH’s evaluation of H2S findings 

CDPH conducted limited monitoring of H2S along the New River, the West Side Neighborhood, and other parts of Calexico. Although the monitoring was limited, the data obtained suggest that H2S levels are higher in Calexico than levels usually found in other urban environments.

The New River does not appear to be the source of H2S odors (rotten egg smell) in the West Side Neighborhood of Calexico as other parts of Calexico had higher readings of H2S than those taken along the river or in the West Side Neighborhood. The odors identified by the community are likely caused by multiple sources, both locally and in Mexicali, Baja California, Mexico.

Health Consultation (English Version) [12/3/10]

Consulta de Salud  (Spanish Version) [12/3/10]




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