Every year, water retailers are mandated to provide a water quality report. You received yours during the month of June or July. It included a table of compounds and numbers that may or may not have made sense to you. Bottom line, your drinking water has gotten another clean bill of health. There was a lot of behind-the-scenes testing, preparation and collaboration that went into this valuable document. I'd like to help you better understand Orange County Water District's (OCWD; the District) role in the process.

Groundwater quality is typically high within the large basin managed by OCWD. Recharge basins (surface facilities like lakes and ponds that are used to increase the infiltration of surface water into a groundwater basin) and the Santa Ana River improve groundwater quality through natural percolation. OCWD's celebrated Groundwater Replenishment System (GWRS) purifies wastewater to near-distilled water condition and not only increases the water supply quantity, it enhances the quality of the water in the groundwater basin further. But there can be additional influences of mankind and nature.

Orange County's booming citrus industry is just a memory now, but at its peak in 1948, the county devoted more than 67,000 acres to Valencia oranges alone. Orange County has also been home to vineyards and field crops such as strawberry, lima bean, celery, sugar beet, tomato, chili pepper, and many more.

Oil was another thriving industry. Within the last 50 years, you could still see tall stationary oil derrick towers and oil pumps that looked like grasshoppers bobbing up and down along Pacific Coast Highway in Huntington Beach. Most crops and oil derricks have given way to a growing population and various types of industries that include manufacturing.

Industry is a very good thing, but aftereffects like oil seepage and fertilizer and pesticide residue can find their way into our groundwater supply.

Pollutants can move over time. In addition, other substances of concern can enter the groundwater. They can be naturally occurring such as selenium, aluminum and salt and/or man-made such as industrial degreasers. Public health and safety require an accurate ongoing assessment of the basin.

OCWD's commitment to exceptional water quality requires that it has comprehensive knowledge of the groundwater. The District implements a very proactive, diverse and comprehensive groundwater and surface water monitoring program to continually generate real-time data of current conditions. Testing identifies water quality issues and allows OCWD to act quickly to address them.

OCWD tests for more than 500 compounds, many more than the 106 regulated constituents that are required by state and federal laws and regulations. It tests water from approximately 1,500 locations throughout the basin, analyzes more than 20,000 samples each year and reports more than 400,000 results. OCWD also provides regional testing of more than 200 drinking water wells for 29 local drinking water providers to help them meet monitoring and reporting requirements mandated by the federal Safe Drinking Water Act.

OCWD's Advanced Water Quality Laboratory is certified and audited by the State Water Resources Control Board through the Environmental Laboratory Accreditation Program and the United States Environmental Protection Agency (USEPA). It is also one of only three public agency labs in the nation to provide a full Unregulated Contaminants Monitoring Rule 3 (UCMR3) program, which is certified by the USEPA for 7 EPA methods, which include 28 trace contaminants and constituents of emerging concern (CECs).

The District's testing capabilities are quite an accomplishment. OCWD can monitor contaminants in its groundwater basin down to a part-per-trillion. That is like looking for one drop of contaminant in a volume of water large enough to fill 26 Olympic-size pools.

Besides extensive monitoring, OCWD has also taken measures to ensure high-quality and safe drinking water by participating in studies, forming work groups, and collaborating with agencies around the world to address and study water quality issues further.

If you would like to tour the Advanced Water Quality Laboratory at OCWD, or to request more information, please contact Becky Mudd at (714) 378-3362 or bmudd@ocwd.com.