New Arsenic MCL: The Dealerâ€™s Perspective
The new arsenic rule takes effect on Jan. 23, 2006. The U.S. Environmental Protection Agency (EPA) has set the new arsenic limit to 10 parts per billion (ppb), down from the previous limit of 50 ppb. Municipal water utilities are the major water treatment facilities that are faced with these changes. All purveyors of drinking water are affected, including public and private systems.
WQP: What potential market does this create for POU/POE dealers?
Frank DeSilva: Thousands of water supplies will be impacted by the new arsenic regulation. The western states, including California, Nevada, Arizona, New Mexico and Oregon, each have hundreds of municipal wells that will require remediation. Other states across the country, such as Michigan, Texas, Florida and New England states also have numerous wells containing arsenic greater than 10 ppb.
Many municipalities are not prepared to be in compliance by January 2006. They have the option of applying for a several-year extension with the EPA. According to local regulations, the municipal utilities that are granted extensions may have to send letters of noncompliance to their customer base. This letter basically states that the utility is currently out of compliance but is conducting research and pilot studies and reviewing funding options to remedy the situation by their new deadline date.
This creates a major opportunity for the water treatment dealer. The municipal waters that are not in compliance are easily identifiable, and the customer base is subsequently well defined. In addition, elevated arsenic levels in groundwater is a regional problem caused by geological conditions, meaning it is probable that private wells and smaller community systems located in the same region are also affected.
It is expected that there will be quite a demand for point-of-entry and point- of-use devices in the near future.
WQP: What can water treatmentprofessionals offer to their customers?
DeSilva: There are a number of point-of-use devices that can be used to provide arsenic-free water.
Cartridges containing hybrid anion exchange media, activated alumina and titanium or iron oxide media are available. They can be installed under the sink or at other various locations, i.e., water fountains, ice machines and coffee makers. It is suggested that cartridges be installed in series with the second cartridge in line acting as a polisher, preventing arsenic leakage into the treated water. Reverse osmosis is a good under-the-sink option and also has the added benefit of removing other contaminants and lowering the total dissolved solids (TDS).
Point-of-entry systems can be designed using the same media described above. For the time being, these systems are being designed and utilized as once-through units in which the exhausted media is disposed of and replaced with new media. In the future, it is probable there will be options for regeneration of the spent media.
WQP: How do water treatment professionals size equipment for arsenic removal?
DeSilva: Water treatment professionals should work closely with the media supplier to establish the best treatment scheme for the application. An accurate water analysis is indispensable in order to design a safe and reliable system. The media supplier needs to know the pH and conductivity or TDS of the water being treated, as well as the following inorganic levels: hardness, alkalinity, sulfate, iron, chloride, nitrate, silica and arsenic. In some cases, it may also be necessary to report selenium and vanadium levels.
Most importantly, a high degree of safety must be built into the system to prevent arsenic leakage or dumping. This includes using lead-lag units and applying engineering safety factors to the predicted throughput volumes.
WQP: Where can our readers learn more about the upcoming arsenic regulation?
DeSilva: Readers can visit the EPA website at www.epa.gov/ogwdw000/arsenic.html and the appropriate state regulatory agency, such as the California Division of Health Services. Other websites include:
- Water Quality Assn. â€“ www.wqa.org;
- National Rural Water Assn. â€“ www.nrwa.org; and
- American Water Works Assn. â€“ www.awwa.org.