March- Arsenic in Groundwater on the Tohono O’odham Nation

The Tohono O’odham Nation is located in Southern Arizona and borders the US-Mexico border covering 2.8 million acres. The Tohono O’odham Nation is a federally recognized tribe and includes approximately 30,000 members making it the second largest reservation in the state. Selso Villegas is the Director of the Tohono O’odham Nation Water Resources Department and has the responsibilities that include: to locating clean water, collecting weather data to document climate, and implementing the Nations water code. This also involves permitting, the implementations of the 1982 Southern Arizona Waters Right Settlement Act to receive Central Arizona Project water, and keeping the department functioning on a daily basis. During an interview Villegas had this to say about his work:

“When the first discussions of the water code began this question kept coming up because it is true, how to you ‘permit’ the sacredness of water? It got to the point where we were going to pass it anyway but in that discussion I told the lawyers and writers, there had to be a clause in the water code that stated: ‘The Water Resource Department and the Director will administer the water code respecting all traditional O’odham culture and traditions’.”

Arsenic is a carcinogen and a precursor to cancer. In 2001, the US EPA set the arsenic standard in drinking water to 10 parts per billion (ppb). All public water suppliers are required to meet this standard. 19 of the 35 public water systems on the Nation were out of compliance. The arsenic in these systems ranged from 11 to 33 ppb. Although these levels are low, many scientists have argued that drinking water with low levels of arsenic, consumed over many years, can adversely affect the body and increase the risk of cancer. Seven water systems now have arsenic treatment plants and all the public water systems on the Tohono O’odham Nation are in compliance. This was made possible through the efforts and funding provided by the Environmental Protection Agency, Indian Health Service, and the Tohono O’odham Utility Authority.

The long-term goal of Villegas is to group nearby water systems together and connect them to a common well or wells that have arsenic levels less than 10 ppb, eliminating the need for the arsenic treatment plants. The estimated cost for this regionalization project will be about $11 million. Although this cost is high, in the long run, it will be more cost effective than operating and maintaining the arsenic treatment plants.



Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s