Total Trihalomethanes - System Running Annual Average (µg/L):

22

We are currently operating Water Treatment Plant No. 2, the Newark Desal Facility, and the Blending Facility to meet system demand.  Mission San Jose Water Treatment Plant was shutdown for maintenance on November 12, 2008.

About the Table

The table above shows specific water parameters and their corresponding levels at each production source.

• Flow - The amount of water produced at that facility in millions of gallons per day (mgd).
• Hardness - The amount of dissolved calcium and magnesium ions in water determines its "hardness." When excessive amounts of these minerals are present in water, certain nuisance problems occur, including decreased life of water-using appliances and increased difficulty in cleaning and laundering tasks. Hardness is measured in milligrams per liter (mg/L) as calcium carbonate (CaCO₃) and is regulated as a secondary drinking water standard.
• Specific Conductance - Specific conductance is a measure of the ability of water to conduct an electrical current. It is highly dependent on the amount of dissolved solids in the water and can therefore be used as an indicator of saline intrusion into groundwater or mineral pick-up in watershed runoff. Conductance is measured in micromhos (µmhos) and is not regulated.
• Total Dissolved Solids - A measure of the amount of dissolved substances in the water. Dissolved solids can come from organic sources such as leaves, silt, and plankton, or from inorganic materials such as rocks and soil that may contain various types of minerals. Total dissolved solids is measured in milligrams per liter of water (mg/L) and is regulated as a secondary drinking water standard.
• Total Trihalomethanes - During the water treatment process, chlorine may react with very small concentrations of naturally occurring organic material to form disinfection by-products known as trihalomethanes. Total trihalomethanes (the sum of four disinfection by-products) are measured in micrograms per liter of water (µg/L, equivalent to one part per billion) and are regulated as a primary drinking water standard. Compliance is based on a running annual average of distribution system samples collected in four quarters. The value listed on the table for each production facility is based on the running annual average for that particular facility and, when combined, are used to calculate the system-wide running annual average.
• Total Organic Carbon - Organic contaminants in water can include natural organic substances, insecticides, and herbicides, among others. A high organic (or carbon) content increases the possibility that disinfection by-products will be produced during the disinfection process. By using total organic carbon measurements, the number of carbon-containing compounds in the water can be determined. Organic carbon is measured in milligrams per liter of water (mg/L) and is not regulated.

Please note that the data contained here is provided by ACWD to give a general understanding of the water quality distribution as of the date shown. Actual water quality may vary significantly at specific locations. If you have questions about the quality of the water in the Tri-Cities area, you may contact the ACWD Water Quality Laboratory. If you have questions or comments about this web page, you may direct them to the ACWD Water Quality Laboratory Supervisor.