To date, the Utility has tested more than 12,800 samples for arsenic.

• Arsenic Occurrence
• Meeting USEPA’s Arsenic Limit
• Arsenic Compliance Strategy
• USEPA Arsenic Health Effects Language

Arsenic Occurrence

Although all of the drinking water supplied to our customers meets the current 50 parts per billion standard, some of the water does not meet the 10 parts per billion standard that will be effective on December 31, 2008. Consumers need to be aware of USEPA's health effects language for arsenic.

Meeting USEPA’s Arsenic Limit

Microfiltration units at College Arsenic Treatment Facility

Arsenic occurs naturally in the earth’s crust. When rocks, minerals, and soil erode, they release arsenic into groundwater. Arsenic occurs naturally in varying amounts in groundwater in Albuquerque and throughout New Mexico. The average concentration of arsenic in Albuquerque’s drinking water is 13 parts per billion.

All of the water supplied to our customers in 2007 met the current 50 Parts Per Billion standard. After many years of debate on the health effects of arsenic in drinking water and the accuracy of estimates of costs and benefits, USEPA lowered the Maximum Contaminant Level to 10 Parts Per Billion.

The New Mexico Environment Department (NMED) has granted the Authority an exemption to the new arsenic standard. As a result, the MCL will remain at 50 PPB until December 31, 2008. The exemption will allow time to complete the Arsenic Compliance Strategy.

Water provided by the San Juan-Chama Drinking Water Project will meet the new arsenic standard and reduce the expected initial cost of arsenic treatment from $150 million to $30 to $40 million. Because we will return to the ground water supply in times of drought, the Water Utility must prepare to treat ground water to meet the new arsenic standard.

For information on voluntary arsenic monitoring at EPTDS and in your distribution zone, see the Arsenic Compliance Strategy below, your Water Quality by Distribution Zone, or call the Water Quality Information Line at 857-8260.

The Arsenic Compliance Strategy Includes:

1. Continued protection of public health during the time of the exemption by blending groundwater to keep quarterly arsenic concentrations at all EPTDS below the 35 PPB excess exposure level allowed by law.

Microfiltration units at College Arsenic Treatment Facility

To lower the arsenic concentration even more, water with low arsenic concentrations is pumped between storage tanks. Some water lines have been reconfigured and contruction of new pump stations is nearly complete to create more blending opportunities.. As a result of these changes, arsenic concentrations at EPTDS are being reduced.

The Water Utility analyzes samples for arsenic every three months to monitor arsenic concentrations at the EPTDS and in the distribution system. The map below demonstrates the 2003 compliance monitoring results and the effects of efforts to lower arsenic concentrations in 2007.

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. 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 2003.
5. The bottom (black) number is the quarterly average for 2007, in PPB.
6. 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.
7. Find the appropriate health effects language below for the amount of arsenic on your distribution zone.

2. Construction of an Arsenic Removal Demonstration Plant on the West Side.

The plant was completed and in operation in July 2007. The plant removes arsenic from water pumped from two West Side wells. The plant will be used in combination with the Drinking Water Project Transmission lines 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 new process works.

3. Completion of the Drinking Water Treatment Plant.

In the fall of 2008, San Juan-Chama water will be diverted from the Rio Grande, treated, and delivered to our water taps as drinking water.

Regulatory compliance monitoring requirements for drinking water from treated surface water sources are more stringent than for ground water alone. Drinking water produced by the Drinking Water Treatment Plant will meet all drinking water standards, including the new Arsenic standard, and will reduce the initial cost of Arsenic treatment.

The water will be treated with a combination of gravity settling, chemical treatment, and filtration technologies. As a final step in the process, the water will be disinfected with sodium hypochlorite and fluoride will be added.

Arsenic Concentrations are Falling

Operational changes, the arsenic removal plant on the West Side and the use of the San Juan-Chama pipelines to move water allow blending of water that results in falling arsenic concentrations. Before the end of December 2008, all arsenic concentrations in all distribution zones will meet the new arsenic standard.

You can learn more about the Drinking Water Treatment Plant and other project components by visiting the San Juan Chama Drinking Water Project.

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.

For water containing greater than 10 PPB of arsenic, but not greater than 50 PPB of arsenic: Some people who drink water containing arsenic in excess of the new MCL over many years could experience skin damage or problems with their circulatory system, and may have an increased risk of getting cancer.

The Water Utility selectively pumps wells to lower arsenic concentrations of water in storage tanks. While some wells have been turned off, others are used only in combination with low arsenic wells. To further decrease arsenic concentrations, low arsenic concentration water is pumped between storage tanks.