Update for OCWA Customers re: Harmful Algal Blooms

With the recent news that algal blooms have been found on the surface of Skaneateles Lake, OCWA has received a number of inquiries from our customers as to the source of their water supply.  Only about 2% of OCWA retail customers receive their water from Skaneateles Lake (mainly the Nedrow, northern LaFayette and southern DeWitt areas).  The other 98% receive their water either from Otisco Lake or Lake Ontario (the accompanying Water Source Map shows where all OCWA customers receive their water). Water Source Map

As for the water that does come from Skaneateles Lake, it is treated with chlorine and ultra violet (UV) disinfection by the City of Syracuse.  The City also routinely tests the water at its lake intake for the presence of toxins that, in some cases, can be released from harmful algal blooms (in particular, microcystin).  As an extra precaution for OCWA customers receiving this water, we are testing the supply for microcystin as the supply enters our system at the City line.

For the other 98% of OCWA customers, OCWA conducts weekly tests of our Otisco Lake and Lake Ontario supplies at the entry to our water treatment facilities to confirm the absence of microcystin.  In addition, we have multiple barriers in place to remove toxins caused by HABs should they be detected in the water.  First, we have two water treatment plants, each with 6 large granular activated carbon (GAC) filters which consist of 30 to 36 inches of carbon (2,100 – 3,900 cubic feet in each filter!) over a fine sand layer. The GAC can absorb HAB toxins and help prevent them from entering the treated water. The second optional treatment barrier involves introducing powder activated carbon (PAC) to the treatment process. The PAC adsorbs the toxins, which in turn are removed by the GAC in the filters.

If you have any questions about HABs or any other water quality issue, feel free to contact the New York State Department of Health at harmfulalgae@health.ny.gov, the New York State Department of Environmental Conservation at habsinfo@dec.ny.gov, or OCWA at 315-455-7061.