• Compliance with Arsenic Maximum Contaminant Level
• Arsenic Compliance Map
• USEPA Arsenic Health Effects Language
• Arsenic Removal Demonstration Plant

Compliance with Arsenic Maximum Contaminant Level

To date, the Water Authority has tested more than 13,000 samples for arsenic.

The Water Authority maintains compliance with the 10 Parts Per Billion (PPB) MCL for arsenic by:

• Selectively pumping wells.
• Using new pipelines and pump stations to move low arsenic well water to other parts of the system.
• Treating higher arsenic well water at the Arsenic Removal Demonstration Plant on the West Side.
• Distributing very low arsenic drinking water from the San Juan-Chama Drinking Water Project.

Arsenic Compliance Map

When rocks, minerals, and soil erode, they release naturally occurring arsenic into ground water. Arsenic occurs in varying amounts in ground water in Albuquerque and throughout New Mexico. Arsenic concentrations in Water Authority wells range from No Detection to 81 PPB.

USEPA defines where and how often compliance samples must be collected for analysis.  For arsenic, samples must be collected at each Entry Point to the Distribution System (EPTDS) once every three years. The citywide results of compliance monitoring completed in 2009 are shown in the map below.

Although all of the results met the 10 PPB standard, some of the water contained arsenic concentrations between 5 PPB and 10 PPB. Consumers need to be aware of USEPA's health effects language for arsenic.

To use the map below:

1. Find your location on the map.
2. Determine your distribution zone. The distribution zones are outlined by a dark blue line and the distribution zone number is the large number printed in that zone. Drinking water supplied within a distribution zone is of the same water quality.
3. Look for the water drop in your distribution zone. The top (dark blue) number in the water drop is your distribution zone.
4. The middle (light blue) number in the water drop is the amount of arsenic in the compliance sample(s) collected at the EPTDS for your distribution zone in 2009.
5. A single number for arsenic in a water drop indicates there is a single EPTDS for that distribution zone. If a range of numbers is given for a distribution zone, there are multiple EPTDS to that distribution zone.
6. Find the appropriate health effects language below for the amount of arsenic on your distribution zone.

USEPA Arsenic Health Effects Language Applies As Follows:

For water containing greater than 5 PPB of arsenic and up to and including 10 PPB of arsenic: While your drinking water meets USEPA’s standard for arsenic, it does contain low levels of arsenic. USEPA’s standard balances the current understanding of arsenic’s possible health effects against the costs of removing arsenic from drinking water. USEPA continues to research the health effects of low levels of arsenic, which is a mineral known to cause cancer in humans at high concentrations and is linked to other health effects such as skin damage and circulatory problems.

Arsenic Removal Demonstration Plant

Microfiltration Units at the Arsenic Removal Demonstration Plant

The plant was completed and in operation in July 2007. The plant removes arsenic from water pumped from two West Side wells. The plant is used in combination with the San Juan-Chama Drinking Water Project distribution pipelines to carry the low arsenic water to other storage tanks across the West Side. The plant, which can treat 5.2 million gallons per day, is the largest facility of its kind in the world. The $6.3 million plant was built with financial assistance from the Federal government. Water customers, students, regulators and officials from other water utilities may visit the demonstration plant to see firsthand how the process works.