Water Quality

Seneca Lake Issues

The water quality of Seneca Lake is impacted by several major input sources:

  • nutrients from agricultural, residential and wastewater treatment sources that input effluents into the lake;
  • hazardous chemicals that enter the lake from groundwater streams that drain contaminated soils.
  • aging public wastewater treatment facilities and private septic systems.

Limited analytical studies over the past several decades have noted that the productivity of Seneca Lake, that is, its capability to produce plant and algae growth, is increasing as a result of increasing phosphorus and nitrogen content of the lake.

Hazardous chemical studies of the lake have been more limited and are more difficult to carry out on lake waters because of the huge dilution factor that the volume of the lake provides due to its size.  The dilution helps to reduce hazardous chemical input to below Maximum Contaminant Levels (MCL) established in groundwater.

By analyzing the streams feeding the lake, areas can be identified for corrective action by federal, state and municipal governments before the lake is impacted.

Stream Monitoring Program

In 2014, SLPWA volunteers began sampling three streams: Catharine Creek, Big Stream and Reeder Creek. Each stream is sampled in 4 locations along its course, with 4 sampling events occurring throughout the year, with a goal of one or two high water events, when feasible. In 2015, the program was expanded to include Keuka Outlet. These streams represent 75-80% of the total inflow from streams into Seneca Lake.  In 2016 Kashong Creek will be added to the program, as a result of past data indicating high nutrient levels and the presence of two algae blooms near the mouth of this stream.

SLWPA collaborates with  Community Science Institute in Ithaca for this program.  The mission of the Community Science Institute (CSI) is to foster and support environmental monitoring by volunteers in order to educate the public about water resources, and to collect scientifically credible data for use in protecting the environment and the sustainable management of such resources. The Community Science Institute is certified by the New York State Department of Health-Environmental Laboratory Approval Program (NYSDOH-ELAP) under National Environmental Laboratory Accreditation Conference (NELAC) guidelines. In addition to the laboratory testing, CSI provides training for the volunteers, logistical support for scheduling sampling dates and community education programs for each stream in the program.

The program continues to be funded by grants from the Tripp Foundation, Freshwater Future, and SLPWA member support.

The results point to the serious problems affecting the quality of water in Seneca Lake. Bacteria levels higher than recommended for public bathing beaches, 235 colonies/100 ml, have been consistently found in all streams monitored. The highest results were found, after storm events, on Keuka Outlet (73,500 colonies/100 ml; Reeder (44,000 colonies/100ml) and Big Stream (35,500 colonies/100 ml).

Phosphorus levels range from high, above DEC guidance levels (20 mg/L), to “crazy high.”  Reeder Creek results were measured once at 1390 mg/L, or ~70 times the guidance level.  Keuka Outlet, which contributes 39% of the flow into Seneca Lake, showed very high phosporus (400ug/L) and nitrogen levels in the one high flow event that was sampled in 2015.  This adds up to a tremendous amount of nutrients flowing into the lake from this one source.

The levels of E.coli and Coliform bacteria represent direct health concerns, while the phosphorus nutrient levels directly link to the problems of algae and weed growth in Seneca lake.

Our 2016 plans include continued monitoring of the four current streams, plus the addition of Kashong Creek, for nutrients, bacteria, and other key indicators of water quality and stream health. Linkage between nutrient inputs to the lake and algae blooms will be a focus of our efforts in 2016. Also, Keuka Outlet will be monitored for potential metal contaminants from the leachate of the Lockwood Ash Storage Landfill, adjacent to the Greenidge power plant in Dresden.

Outreach in the form of public meetings were held in 2015, covering some history and key results for Catharine Creek, Big Stream, and Reeder Creek. Press releases and our Lakewatch newsletter publications are also being used to disseminate findings to the public. Data has been shared with both the New York Department of Environmental Conservation (DEC) and the Federal Environmental Protection Agency (EPA).

Based on two years of study, SLPWA filed a request to have Reeder Creek added to the Clean Water Act “Impaired Water Body” list. That was approved by the DEC in January of 2016, and is pending approval of the EPA.

Linkage to the newly formed Seneca Watershed Inter-Municipal Organization is ongoing, and will be vital to future coordinated controls of contaminants that enter Seneca Lake.

A complete explanation of the monitoring program is available on the CSI website: CSI Database with the Seneca Lake monitoring data available here: SLPWA – CSI Seneca Lake Data.