Questions and Answers about Perchlorate

What is perchlorate?
Perchlorate is an inorganic chemical that is used in solid rocket propellants, fireworks, and a variety of industrial uses.

What is the concern about perchlorate in drinking water?
Perchlorate is known to interfere with the uptake of iodine in the thyroid gland. This can effect the production of thyroid hormones needed for healthy growth and development of unborn and newborn children, as well as normal body metabolism in adults.

What is the regulatory status of perchlorate in drinking water?
Perchlorate is a regulated drinking water contaminant in California, with a maximum contaminant level (MCL) of 6 parts per billion (ppb), effective October 18, 2007.

Does Redlands’ drinking water comply with all regulatory standards for perchlorate?
YES! In fact, the average level of perchlorate detected in Redlands’ water in 2004 was well below the DPH MCL of 6 ppb. Note: 6 ppb is about the equivalent of 3 drops of water in an Olympic size swimming pool.

Is the City of Redlands actively working to remove perchlorate from drinking water?
YES! Since discovering perchlorate in some of its water wells in 1997, the City of Redlands Municipal Utilities Department has been hard at work developing its water facilities to reduce and eliminate the need to deliver water with any detectable perchlorate.

Efforts in recent years have included shutting down contaminated wells, or treating the water from these wells to remove all detectable amounts of perchlorate. Water from less contaminated wells is also blended with uncontaminated sources to reduce perchlorate to below detectable levels.

In 2003 the City of Redlands drilled two new high volume, perchlorate-free water wells to replace water supply capacity lost due to perchlorate contamination, and increased production capacity from its surface water treatment facility to optimize the use of perchlorate-free water sources.

And, under a cooperative agreement with Lockheed-Martin Corporation in 2004, Lockheed installed a new state-of-the-art ion exchange water purification system to remove perchlorate from a City well. Additionally, the City of Redlands has been working closely with scientists from Penn State University who are looking to find alternative methods to treat water contaminated with perchlorate.

Additional information on perchlorate and DHS notification levels are available online at: www.dph.ca.gov