WATER QUALITY IN EAST END WATERSHEDS
Water quality on the East End is critically important – for drinking water, farming and for the preservation of our waterways and marine habitats. There is a need to explore the range of cost-effective water management solutions that can be applied as a community and as individual households. PGG is conducting a survey to begin to measure the scope of the problem, particularly in regard to existing wastewater treatment, with the goal to evaluate alternative solutions if the need and desire is there.
The North Fork is surrounded by estuaries of national importance. For our fresh water needs, we rely on groundwater aquifers, which are replenished by rain and wastewater that filters through the ground. Over 70% of Suffolk County wastewater is handled through individual residential wastewater treatment systems and often carries contaminants, pathogens (shallow locations), and excess nutrients with it. After it joins with groundwater, the effluent migrates toward either the Sound or Peconic Estuary, surprisingly quickly.
Excess nitrogen is a significant problem. Nitrogen levels in exiting septic systems are typically four to six times higher than allowed in drinking water. As this filters into groundwater, it can drive the levels in drinking water over the limit, posing a health concern. The marine environment is 20 times more vulnerable to levels of nitrogen, than humans. Along the shores of the East End, nitrogen mostly exceeds safe limits.
Nitrogen entering the marine environment feeds algal blooms that create conditions that reduce oxygen levels and acidify coastal waters, affecting shellfish size and form. Some algae, such as Alexandrium fundyense, which produces the chemical toxin (saxitoxin), can be toxic to humans as well as marine life. Eelgrass, which provides a protective environment for shellfish, is also hurt by excess nitrogen. Since shellfish filters the water, shellfish loss accelerates water quality decline.
The major contributors of excess nitrogen loading to our waters are almost equally agriculture practices and wastewater.
Traditional Treatment of Human Wastewater
Decentralized human wastewater treatment systems include both on-site and community (local neighborhood) systems. In denser communities, such as Greenport and Riverhead, central sewers are used, Before 1973, most on-site systems used cesspools, whose open joints allow dissolved solids to enter the ground and hinder natural waste dissipation.
Priorities for Action
Wastewater handling can be improved. By focusing on those systems most likely to contribute to environmental failure (i.e. excess nitrogen loading), we can explore options that will give maximum effect at a reasonable cost. . Priority locations include areas that meet any of the following criteria.
- Pre-1973 installations, likely to be cesspools
- Shallow depth to groundwater – effluent is not properly treated
- Small lots (< 1 acre) – less ground area to dilute excess nutrients and contaminants
- Flood or SLOSH zones – even temporary failure can cause significant environmental damage
- Zones where groundwater travels to surface water quickly (less than 25 years)
- Soils that drain too quickly or too slowly
What can we do?
A customized range of solutions are needed, to meet the diverse needs of the communities, families and businesses affected. Combinations of the following options can significantly improve overall water quality:
- Preserve low lying coastal areas, which uptake nitrogen before groundwater reaches the sea.
- Provide advanced treatment for onsite systems
- Introduce localized, community systems with enhanced treatment.
- Consider extending central sewer districts