Water quality: How do you know your water is safe?

Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk.

Under the Safe Drinking Water Act (SDWA), the United States Environmental Protection Agency (EPA) sets national limits on contaminant levels to ensure the safety of your drinking water. These limits are known as Maximum Contaminant Levels (MCLs). For some contaminants the monitoring techniques may be unreliable, too expensive or too difficult to perform. In these cases, the EPA establishes treatment technique requirements instead of an MCL: if it can not be determined that a contaminant is not there, systems operate as if it is and provide the treatment necessary to produce safe drinking water. The EPA regulations also specify testing and reporting requirements for each contaminant. Something every regulation has in common is a requirement to notify the public if there is a regulation violation. If a regulation is violated the supplier is required to inform the consumers being served by the system. The EPA also requires water suppliers to monitor for unregulated contaminants to provide occurrence data for future regulations.

Currently the EPA has established regulations for 140 individual contaminants. This includes six microbiological contaminants, 4 radionuclides, 26 inorganic chemicals, and 106 organic chemicals. The SDWA requires the EPA to review and revise each regulation on a regular basis. For example, the MCL for trihalomethanes was lowered from 100 to 80 ug/L (parts per billion) as part of a review completed in 1997. The 1996 reauthorization of the SDWA also requires the EPA to consider at least 5 new contaminants for regulation every 5 years.

In New York, the State Health Department is responsible for enforcing EPA's regulations. The State has the option to implement alternative regulations when the alternative is equivalent to or more stringent than the EPA's regulation. In Onondaga County, due to the strength of the local unit, the State Health Department has delegated its primary enforcement and surveillance activities to the Onondaga County Health Department. The County Health Department reviews and approves all treatment plant and distribution system modifications as well as new construction. They also review all our operating and monitoring data for compliance on a monthly basis. The Authority takes a similar, cooperative approach with the Health Departments in Oswego, Oneida, and Madison Counties.

OCWA's monitoring program exceeds both EPA and State Health Department requirements. The Authority's New York State certified water quality laboratory collects over 4,000-distribution system and 2,000-treatment plant samples each year and performs over 12,000 analyses. We also have about 600 specialized analyses performed by independent laboratories. As part of their surveillance program, the Onondaga County Health Department independently runs additional monthly surveillance monitoring on samples from our distribution system. In 2007, for water delivered to Authority customers, OCWA and MWB had no treatment plant, distribution system bacteriological, or chemical Maximum Contaminant Level violations. Accordingly, the water provided to consumers consistently meets or exceeds all New York State Health Department and EPA drinking water standards. With respect to the City of Syracuse, on January 6, 2007, due to heavy rains and runoff, the City experienced a treatment technique violation when turbidity exceeded 5 NTUs. Other than that exception, the City of Syracuse water supply also met all New York State Health Department and EPA drinking water standards.

OCWA's and MWB's raw water monitoring programs are specifically designed to address concerns about Otisco Lake and Lake Ontario as main sources of supply. In both instances raw water intakes extend from a mile to a mile and a half out into their respective lakes. This was done by design to minimize the effects of near shore currents and run-off. Lab results consistently confirm that levels of organic compounds and heavy metals do not exceed the MCL. General raw water quality remains high for both Otisco Lake and Lake Ontario. Both sources are monitored more frequently, and for a wider range of compounds than required.

A water quality summary is provided for each of the three supplies in tables (click here). More detailed information can be obtained by calling OCWA's Water Quality Manager, Bob Rusyn, at 315-673-4304 x11.

Additional information on contaminants and potential health effects can be obtained by calling EPA's "Safe Drinking Water Hotline" at 1-800-426-4791.

More information: or 315-455-7061
After hours & weekend emergency answering service 315-475-7601