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The frequency that various contaminants are tested for is regulated by the State and can vary from source to source. The State allows for some contaminants to be tested for less than once a year because the concentrations of these contaminants do not change frequently. Some of our data, though representative, is more than one year old. Some contaminants are monitored at the various sources more often than required.

Copper and lead in distribution system

The method of corrosion control used on waters originating from Otisco and Skaneateles lakes is the addition of orthophosphate. The adjustment of pH is the method used for Ontario water. OCWA's latest sampling period was in June of 2005 when OCWA sampled and tested the customers' taps to make sure the corrosion controls were effective.

90th percentile values for lead and copper: The values reported for lead and copper represent the 90th percentile. The 90th percentile value is the concentration that 90% of the taps sampled were at or below. Since the Action Level for Lead is 15 µg/L, 90% of the taps tested had to be at or below this value. As you can see from the above chart, 90% of the taps tested were at or below 4.3 µg/L in June of 2005. The Action Level for Copper is 1.3 mg/L. The observed 90th percentile for Copper was 0.18 mg/L. Of the 117 samples that OCWA tested in June of 2005, only 2 (or 1.7%) exceeded the action level for lead. No samples exceeded the action level for copper.

The testing showed that our methods of corrosion control are working.

Turbidity

Likely source of contamination: Soil runoff

Customers OCWA get their water from one of three sources. Water may originate from Otisco Lake, which is treated by OCWA itself, Lake Ontario which is treated by the Metropolitan Water Board (MWB) and wholesaled to OCWA, or Skaneateles Lake which is treated by the Syracuse Water Department and also sold to OCWA. Customers may also get a mixture of these waters.

Water purveyors are required to measure turbidity as water leaves their plants. Turbidity is a measure of the cloudiness of water. We monitor it because it is a good indicator of water quality. High turbidity can hinder the effectiveness of disinfectants. Treatment plants that filter also measure it because it is a good indicator of filter efficiency. Otisco Lake and Lake Ontario waters are filtered. Skaneateles Lake water is not.

On Jun 18-19, 2006 because of heavy rainfall and high winds, the turbidity levels entering the City of Syracuse's intake exceeded the maximum allowable standard of 5 turbidity units. OCWA customers were not affected by this high turbidity water. This is because OCWA maintains equipment that continuously monitors the turbidity of Skaneateles Lake water purchased at our connection in the Westhill Water District. This connection is shut down when turbidity approaches 5 NTU. Other OCWA customers who receive Skaneateles Water would not have been affected by this event.

Turbidity has no health effects. However, turbidity can interfere with disinfection and provide a medium for microbial growth. Turbidity may indicate the presence of disease-causing organisms. These organisms include bacteria, viruses, and parasites, which can cause symptoms such as nausea, cramps, diarrhea, and associated headaches. Please pay special attention to the additional statements in this report regarding Cryptosporidium.

Bacteria in distribution system

Likely source of contamination: Naturally present in the environment

Whenever a positive sample for total coliform is found, the sample is further tested for the presence of E. coli, and four check samples are taken.

No samples were found to be E. coli positive in 2006. OCWA regularly samples about 73 sites per week located throughout our distribution system. We test these sites for both bacteria and disinfectant residual to ensure that our water is of a safe and sanitary quality.

Disinfectant & disinfection by-products in distribution system

Disinfection by-products: During disinfection, certain by-products form as a result of chlorine reacting with naturally occurring organic matter. The disinfection process is carefully monitored so that disinfection is effective, while levels of disinfection by-products are kept low. Trihalomethanes (THMs) and haloacetic acids (HAAs) are classes of chemicals that OCWA is required to monitor in its distribution system.

Total trihalomethanes are the combined concentration of the following four contaminants: bromodichloromethane, bromoform, chloroform, and dibromochloromethane.

Haloacetic acids are the combined concentration of the following five contaminants: dibromo-, dichloro-, monobromo-, monochloro-, and trichloro-, acetic acids.

Inorganic contaminants found at entry point

Chlorine dioxide residual:
Likely source of contamination: By-product of drinking water disinfection at plants using chlorine dioxide

Organic contaminants found at entry point

Radionuclides

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