Under the federal Safe Drinking Water Act (SDWA), the United States Environmental Protection Agency (USEPA) sets national limits on water contaminant levels to ensure the safety of public drinking water.  These limits are known as Maximum Contaminant Levels (MCLs).  Currently, the USEPA has established MCLs for 88 individual contaminants (called National Primary Drinking Water Standards) and requires certain testing and reporting requirements for each contaminant.  These contaminants are broken down into the following six categories:

Disinfectants (3 – Chloramines, Chlorine and Chlorine dioxide)

Disinfection Byproducts (4 – Bromate, Chlorite, Haloacetic Acids and Total Trihalomethanes)

Inorganic Chemicals (16 – including Copper, Fluoride, Lead, Mercury and Nitrate)

Microorganisms (8 – including Cryptosporidium, E. coli, Giardia, Turbidity and Viruses)

Organic Chemicals (53 – including both synthetic and naturally occurring chemicals)

Radionuclides (4 – Alpha emitters, Beta emitters, Radium and Uranium)

In addition, USEPA has adopted an Unregulated Contaminant Monitoring Rule every five years which is designed to collect data on up to 30 additional contaminants that are suspected to be present in drinking water but do not yet have health-based standards set under the SDWA.

In New York, the State Health Department as a primacy agency is responsible for enforcing USEPA regulations, as well as administering any additional drinking water regulations adopted by the State.  The State currently regulates 17 contaminants in addition to the 88 regulated by USEPA, including the recent additions of three emerging contaminants: 1,4 Dioxane, PFOA and PFOS.

Pursuant to Part 5 of the New York State Sanitary Code, all public water systems are responsible for periodically monitoring all of the above-referenced contaminants in their systems (a total of 135).  The State has delegated to the county health departments in each of the five counties served by OCWA (Onondaga, Oswego, Madison, Oneida and Cayuga) the authority to enforce these regulations.

How frequently do we test for potential contamination?

The frequency of our testing is dictated by government regulation.  However, in many cases OCWA tests more frequently than is required to ensure that our drinking water remains safe and clean for our customers.  Here is a general summary of the frequency of our sampling and testing:

Continuously (via electronic sensors at our two water treatment plants): Chlorine, Turbidity (recorded every 4 hours) and pH

Daily (at our two water treatment plants): Fluoride, Chlorine Dioxide, Chlorite and Potassium Permanganate (to control zebra mussels at our Lake Ontario intake)

Weekly (at our two treatment plants and in our distribution system): Total Coliform (including E.coli), Heterotrophs (including bacteria, yeasts and mold), Chlorine, and pH are sampled and tested during a typical year a minimum of 3,600 times (or 300 per month).  Turbidity is tested a minimum of 3,300 times per year (or 275 per month).  Fluoride is sampled and tested at least 1,400 times per year.  In total, we collect and analyze over 19,000 samples for these six parameters alone.

Monthly: Cryptosporidium, Giardia (both microscopic parasites which can cause intestinal illnesses) and Chlorite

Quarterly: Disinfection Byproducts, PFOA, PFOS and 1,4 Dioxane

Biannually: Organic compounds and inorganic compounds (at water source intakes)

Annually or longer: Lead and copper in homes; unregulated contaminants (to provide occurrence data for future regulations); pharmaceuticals and personal care products

How do we test?

We use a combination of internal and external laboratories to conduct over 20,500 tests during a typical year.  OCWA operates three state certified testing laboratories: one at our Otisco Lake Water Treatment Plant, one at our Lake Ontario Water Treatment Plant and one at our headquarters building outside Syracuse.  We also use several certified outside testing laboratories, including Pace Analytical, Life Sciences Laboratories, Eurofins Eaton Analytical, Analytical Services Inc. and Upstate Freshwater Institute.

Our internal laboratories are utilized to test for items that require frequent analysis.  This includes bacteria (total coliform/E.Coli and heterotrophs), fluoride, turbidity, pH, disinfectants (chlorine and chlorine dioxide), and disinfection byproducts (chlorite).  Our outside lab is used for more specialized tests that are performed less frequently and typically require more expensive testing equipment to perform.  This includes organics, inorganics, disinfection byproducts and some microorganisms.

How do we ensure the accuracy of our testing?

All OCWA laboratory chemists are certified and accredited by New York State.  Our laboratory practices and procedures are fully audited by the State every two years.  In addition, we confirm the validity of our tests by having our results evaluated by an independent outside agency several times per year.  Finally, OCWA chemists calibrate our testing equipment before every use against known standards.

What happens if there is a failed bacteriological sample?

In the rare instance that a test indicates the elevated presence of some contaminant, our first step is to contact the applicable County health department, even if there is no violation of a regulatory standard.  If there is an exceedance of a regulatory standard, we will resample to confirm the issue and take immediate steps to eliminate the cause.

In cases where the exceedance involves a bacteria such as coliform or E.coli, we promptly notify affected customers via a “boil water advisory.”   Once the cause of the exceedance is eliminated, we typically take the added step of “flushing” the affected area to ensure that any contaminants are completely removed.

Once the system is flushed, we resample at and around the site of the exceedance and if the three successive tests come back negative, only then do we lift the boil water advisory.  Importantly, all of these steps are taken in conjunction with guidance from the applicable County or State Health Department(s).