2014-2015 – Great Sacandaga Lake Coliform Monitoring Program

GREAT SACANDAGA LAKE COLIFORM MONITORING PROGRAM – 2014-2015

REPORTS prepared for The Great Sacandaga Lake Association
By Lawrence W. Eichler, Research Scientist & Charles W. Boylen, Associate Director Darrin Fresh Water Institute
5060 Lakeshore Drive Bolton Landing, NY 12814

2014/2015

Great Sacandaga Lake Coliform Monitoring Program

The Great Sacandaga Lake Coliform Monitoring Program (GSLCMP) for 2014-2015 is designed to quantify the bacterial water quality at selected locations in Great Sacandaga Lake for contact recreation purposes.  Public bathing facilities, recreational areas and runoff locations will be a primary focus.  Approximately 12 shoreline locations will be sampled during July and an additional 12 locations sampled in August.  The time interval coincides with the period of maximum population density and intensity of recreational use. Two primary measurements will be made for each sample:
Total Coliform (TC) and Fecal Coliform (FC) Bacteria.  These bacteria serve as indicators of the presence of animal or human waste. The presence of elevated levels of these bacteria indicate potentially disease-causing protozoa, bacteria and other microorganisms may be present in the water.  Follow-up sampling will be conducted within 48 hours for any public beach samples exceeding contact recreation standards (Table 1) at the discretion of the lake association. Sampling sites will be chosen in consultation with the Great Sacandaga Lake Association (GSLA). DFWI personnel will attempt to assist the local regulatory authorities with location of bacterial sources, working closely with the county and local authorities to locate and correct sources of contamination.

Follow-up investigations by the NYS Department of Health, NYS Department of Environmental Conservation and county and local government personnel are encouraged at sites with elevated fecal
coliform levels.

Action Levels of the Great Sacandaga Lake Coliform Monitoring Program

In order to respond effectively to contamination problems detected during the Great Sacandaga Lake
Coliform Monitoring Program, the following actions will occur for bathing beach samples:

1. If 200 or more fecal coliform bacteria per 100 milliliters are reported, the site will be resampled during the next sampling cycle.
2. If 400 or more fecal coliform bacteria per 100 milliliters are reported, the site will be resampled within 24 to 48 hours. The data for both samples will be reported to the GSLAC.  They will accept responsibility for contacting the appropriate regulatory agencies.Follow-up samples to locate specific shoreline problems are not within the guidelines of this program and will be the responsibility of the appropriate regulatory agencies. The Darrin Fresh Water Institute will provide technical assistance upon request, however the cost of additional sampling and analysis must be covered by the local, county or state agency responsible for water quality complaints.

SUGGESTIONS FOR INTERPRETATION OF COLIFORM DATA

New York State Department of Health has determined maximum allowable bacterial levels for contact recreation (swimming, wading, etc.).  A table of these bacterial concentrations is included.  When these maximum bacterial levels are exceeded, the New York State Department of Health is empowered to close the location to bathing until the problem or problems are corrected.  These levels are used by the Darrin Fresh Water Institute to determine appropriate responses to various bacterial concentrations found during sampling. A table of these responses is included.
Interpretation of data to determine and locate sources of contamination (human or other warm-blooded animal) requires more than just current bacterial levels. A knowledge of past history of the site, weather, geology of the area, drainage patterns, and some information on human activities in the area are also useful. To differentiate between human waste and that produced by other warm-blooded animals, it is sometimes helpful to refer to the ratio of fecal coliform to Enterococcus bacteria (FC/EC).  An FC/EC ratio of 4 or greater is generally considered indicative of contamination of human origin.  Enterococcus (EC) Bacteria abundance will be determined for any resample locations.

Table 1.  New York State coliform bacteria standards for bathing beaches.

Maximum Allowable Levels of Coliform Bacteria in Waters Used for Contact Recreation (NYS Dept. of Health)

Definitions
TC – Total Coliform Bacteria
FC – Fecal Coliform Bacteria
EC – Enterococcus Bacteria
FC/EC – Ratio of Fecal Coliform to Enterococcus Bacteria
TNTC – Too Numerous to Count
CONF – Confluent growth of target bacteria
MAT – Confluent growth of non-target bacteria
? – High background, referring to non-target growth of bacteria interfering with counts of target
bacteria
lt – Less than
LA – Laboratory accident preventing enumeration of bacteria